victauri_plugin/mcp/

mod.rs

// This file is intentionally large (~3,400 lines). rmcp's `#[tool_router]`
// macro requires every `#[tool]` method to live in a single `impl` block, so
// splitting the handler across files would break tool registration. Parameter
// structs are already factored into sub-modules (webview_params, window_params,
// etc.) to keep this file focused on dispatch logic.

mod backend_params;
mod compound_params;
mod helpers;
mod introspection_params;
mod other_params;
mod rest;
mod server;
mod verification_params;
mod webview_params;
mod window_params;

use std::collections::{HashMap, HashSet};
use std::sync::Arc;
use std::sync::atomic::{AtomicBool, Ordering};

use rmcp::handler::server::tool::ToolCallContext;
use rmcp::handler::server::wrapper::Parameters;
use rmcp::model::{
    AnnotateAble, CallToolRequestParams, CallToolResult, Content, ListResourcesResult,
    ListToolsResult, PaginatedRequestParams, RawContent, RawResource, ReadResourceRequestParams,
    ReadResourceResult, ResourceContents, ServerCapabilities, ServerInfo, SubscribeRequestParams,
    Tool, UnsubscribeRequestParams,
};
use rmcp::service::RequestContext;
use rmcp::{ErrorData, RoleServer, ServerHandler, tool, tool_router};
use tokio::sync::Mutex;

use crate::VictauriState;
use crate::bridge::WebviewBridge;

use helpers::{
    RecoveryHint, js_string, json_result, json_truthy, missing_param, sanitize_css_color,
    sanitize_injected_css, tool_disabled, tool_error, tool_error_with_hint, validate_url,
};

pub use backend_params::*;
pub use compound_params::*;
pub use introspection_params::*;
pub use other_params::{
    AppStateParams, DiagnosticsParams, FindElementsParams, ResolveCommandParams,
    SemanticAssertParams, WaitCondition, WaitForParams,
};
pub use server::*;
pub use verification_params::*;
pub use webview_params::*;
pub use window_params::*;

// ── MCP Handler ──────────────────────────────────────────────────────────────

/// Maximum number of in-flight JavaScript eval requests. Prevents unbounded
/// growth of the `pending_evals` map if callbacks are never resolved.
pub(crate) const MAX_PENDING_EVALS: usize = 100;

fn chrono_now() -> String {
    chrono::Utc::now().to_rfc3339_opts(chrono::SecondsFormat::Secs, true)
}

/// Maximum length of JavaScript code accepted by the `eval_js` tool (1 MB).
const MAX_EVAL_CODE_LEN: usize = 1_000_000;

/// Maximum length of a JavaScript eval return value (5 MB).
/// Results exceeding this are truncated to prevent memory exhaustion.
const MAX_EVAL_RESULT_LEN: usize = 5_000_000;

/// How long the eval parse-watchdog waits for the user-code script to begin executing
/// before reporting a likely syntax error. A parse error means the script never runs (so
/// it never marks itself "started"); this caps that failure at ~0.75s instead of the full
/// eval timeout, while still leaving valid-but-slow code to run to the real timeout.
const PARSE_WATCHDOG_MS: u64 = 750;

/// Default number of entries returned by IPC/network log tools when no explicit
/// `limit` is given. Prevents busy apps (large logs) from exceeding the eval cap.
const DEFAULT_LOG_LIMIT: usize = 100;

/// Per-field byte cap applied to each IPC/network log entry before serialization.
/// Large request/response bodies are truncated with a marker so the aggregate
/// log stays well under [`MAX_EVAL_RESULT_LEN`] even on heavy-traffic apps.
const MAX_LOG_FIELD_BYTES: usize = 4096;

const RESOURCE_URI_IPC_LOG: &str = "victauri://ipc-log";
const RESOURCE_URI_WINDOWS: &str = "victauri://windows";
const RESOURCE_URI_STATE: &str = "victauri://state";

const BRIDGE_VERSION: &str = env!("CARGO_PKG_VERSION");

const SAFE_ENV_PREFIXES: &[&str] = &[
    "HOME",
    "USER",
    "LANG",
    "LC_",
    "TERM",
    "SHELL",
    "DISPLAY",
    "XDG_",
    // Only Tauri's build-env namespace, NOT all of TAURI_ — the latter is an
    // app-custom namespace that can hold secrets (audit #5).
    "TAURI_ENV_",
    "VICTAURI_",
    "NODE_ENV",
    "OS",
    "HOSTNAME",
    "PWD",
    "SHLVL",
    "LOGNAME",
];

/// Substrings that mark an env var as a secret. Even when a name matches a
/// `SAFE_ENV_PREFIXES` entry it is dropped if it contains one of these — a prefix
/// like `TAURI_`/`VICTAURI_` otherwise leaks `TAURI_SIGNING_PRIVATE_KEY`,
/// `TAURI_SIGNING_PRIVATE_KEY_PASSWORD`, or `VICTAURI_AUTH_TOKEN` (audit #5).
const SECRET_ENV_SUBSTRINGS: &[&str] = &[
    "TOKEN",
    "SECRET",
    "PASS", // PASSWORD, PASSWD, PASSPHRASE
    "PRIVATE",
    "CREDENTIAL",
    "APIKEY",
    "AUTH",
    "_KEY",
    "DSN", // connection strings with embedded creds
    "PAT", // personal access token
    "JWT",
    "BEARER",
    "SESSION",
    "COOKIE",
    "SALT",
    "CERT",
    "SIGN", // signing keys/material
    "LICENSE",
];

/// Whether an env var name is safe to surface via `app_info`: it must match a
/// known-safe prefix AND not look like a secret (audit #5).
fn is_safe_env_key(key: &str) -> bool {
    let upper = key.to_uppercase();
    SAFE_ENV_PREFIXES
        .iter()
        .any(|prefix| upper.starts_with(prefix))
        && !SECRET_ENV_SUBSTRINGS.iter().any(|s| upper.contains(s))
}

/// MCP tool handler that dispatches tool calls to the webview bridge and state.
#[derive(Clone)]
pub struct VictauriMcpHandler {
    state: Arc<VictauriState>,
    bridge: Arc<dyn WebviewBridge>,
    subscriptions: Arc<Mutex<HashSet<String>>>,
    bridge_checked: Arc<AtomicBool>,
    probed_labels: Arc<Mutex<HashSet<String>>>,
    /// Window keys whose previous eval timed out. The next eval on such a window
    /// does a fast liveness probe so a reloaded/crashed bridge fails fast with a
    /// clear error instead of blocking the full timeout again.
    timed_out_labels: Arc<Mutex<HashSet<String>>>,
}

#[tool_router]
impl VictauriMcpHandler {
    // ── Standalone Tools ────────────────────────────────────────────────────

    #[tool(
        description = "Evaluate JavaScript in the Tauri webview and return the result. Async expressions are wrapped automatically.",
        annotations(
            read_only_hint = false,
            destructive_hint = true,
            idempotent_hint = false,
            open_world_hint = false
        )
    )]
    async fn eval_js(&self, Parameters(params): Parameters<EvalJsParams>) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("eval_js") {
            return tool_disabled("eval_js");
        }
        if params.code.len() > MAX_EVAL_CODE_LEN {
            return tool_error("code exceeds maximum length (1 MB)");
        }
        match self
            .eval_with_return(&params.code, params.webview_label.as_deref())
            .await
        {
            Ok(result) => CallToolResult::success(vec![Content::text(result)]),
            Err(e) => tool_error(e),
        }
    }

    #[tool(
        description = "Get the DOM snapshot with stable ref handles. Default: compact accessible text (70-80%% fewer tokens). Set format=\"json\" for full tree. Returns tree + stale_refs (refs invalidated since last snapshot).",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn dom_snapshot(&self, Parameters(params): Parameters<SnapshotParams>) -> CallToolResult {
        let format = params.format.unwrap_or(SnapshotFormat::Compact);
        let format_str = match format {
            SnapshotFormat::Compact => "compact",
            SnapshotFormat::Json => "json",
        };
        let code = format!(
            "return window.__VICTAURI__?.snapshot({})",
            js_string(format_str)
        );
        self.eval_bridge(&code, params.webview_label.as_deref())
            .await
    }

    #[tool(
        description = "Search for elements by text, role, test_id, CSS selector (via `css` or `selector` param), or accessible name without a full snapshot. Returns lightweight matches with ref handles.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn find_elements(
        &self,
        Parameters(params): Parameters<FindElementsParams>,
    ) -> CallToolResult {
        let mut parts: Vec<String> = Vec::new();
        if let Some(t) = &params.text {
            parts.push(format!("text: {}", js_string(t)));
        }
        if let Some(r) = &params.role {
            parts.push(format!("role: {}", js_string(r)));
        }
        if let Some(tid) = &params.test_id {
            parts.push(format!("test_id: {}", js_string(tid)));
        }
        if let Some(c) = params.css.as_ref().or(params.selector.as_ref()) {
            parts.push(format!("css: {}", js_string(c)));
        }
        if let Some(n) = &params.name {
            parts.push(format!("name: {}", js_string(n)));
        }
        if let Some(max) = params.max_results {
            parts.push(format!("max_results: {max}"));
        }
        if let Some(t) = &params.tag {
            parts.push(format!("tag: {}", js_string(t)));
        }
        if let Some(p) = &params.placeholder {
            parts.push(format!("placeholder: {}", js_string(p)));
        }
        if let Some(a) = &params.alt {
            parts.push(format!("alt: {}", js_string(a)));
        }
        if let Some(ta) = &params.title_attr {
            parts.push(format!("title_attr: {}", js_string(ta)));
        }
        if let Some(l) = &params.label {
            parts.push(format!("label: {}", js_string(l)));
        }
        if let Some(true) = params.exact {
            parts.push("exact: true".to_string());
        }
        if let Some(e) = params.enabled {
            parts.push(format!("enabled: {e}"));
        }
        let code = format!(
            "return window.__VICTAURI__?.findElements({{ {} }})",
            parts.join(", ")
        );
        match self
            .eval_with_return(&code, params.webview_label.as_deref())
            .await
        {
            Ok(result) => {
                if let Ok(parsed) = serde_json::from_str::<serde_json::Value>(&result)
                    && let Some(err) = parsed.get("error").and_then(|e| e.as_str())
                {
                    return tool_error(err);
                }
                CallToolResult::success(vec![Content::text(result)])
            }
            Err(e) => tool_error(e),
        }
    }

    #[tool(
        description = "Invoke a registered Tauri command via IPC, just like the frontend would. Goes through the real IPC pipeline so calls are logged and verifiable. Returns the command's result. Subject to privacy command filtering.",
        annotations(
            read_only_hint = false,
            destructive_hint = true,
            idempotent_hint = false,
            open_world_hint = false
        )
    )]
    async fn invoke_command(
        &self,
        Parameters(params): Parameters<InvokeCommandParams>,
    ) -> CallToolResult {
        if !self.state.privacy.is_invoke_allowed(&params.command) {
            return tool_disabled("invoke_command");
        }
        if !self.state.privacy.is_command_allowed(&params.command) {
            return tool_error(format!(
                "command '{}' is blocked by privacy configuration",
                params.command
            ));
        }

        // ── Fault injection check ──
        if let Some(fault) = self.state.fault_registry.check_and_trigger(&params.command) {
            match fault {
                crate::introspection::FaultType::Delay { delay_ms } => {
                    tracing::info!(
                        command = %params.command,
                        delay_ms = delay_ms,
                        "fault injection: delaying command"
                    );
                    tokio::time::sleep(std::time::Duration::from_millis(delay_ms)).await;
                    // After delay, continue with normal execution below
                }
                crate::introspection::FaultType::Error { ref message } => {
                    tracing::info!(
                        command = %params.command,
                        "fault injection: returning error"
                    );
                    return tool_error(format!(
                        "[FAULT INJECTED] command '{}': {message}",
                        params.command
                    ));
                }
                crate::introspection::FaultType::Drop => {
                    tracing::info!(
                        command = %params.command,
                        "fault injection: dropping response"
                    );
                    return CallToolResult::success(vec![Content::text("{}")]);
                }
                crate::introspection::FaultType::Corrupt => {
                    tracing::info!(
                        command = %params.command,
                        "fault injection: corrupting response"
                    );
                    // Execute normally but mangle the response
                    let args_json = params.args.unwrap_or(serde_json::json!({}));
                    let args_str =
                        serde_json::to_string(&args_json).unwrap_or_else(|_| "{}".to_string());
                    let code = format!(
                        "return window.__TAURI_INTERNALS__.invoke({}, {args_str})",
                        js_string(&params.command)
                    );
                    if let Ok(result) = self
                        .eval_with_return(&code, params.webview_label.as_deref())
                        .await
                    {
                        let corrupted = format!(
                            "{{\"__corrupted\":true,\"original_length\":{},\"fault\":\"corrupt\"}}",
                            result.len()
                        );
                        return CallToolResult::success(vec![Content::text(corrupted)]);
                    }
                    return CallToolResult::success(vec![Content::text(
                        "{\"__corrupted\":true,\"fault\":\"corrupt\",\"note\":\"original invocation also failed\"}",
                    )]);
                }
            }
        }

        // ── Normal execution with timing ──
        let start = std::time::Instant::now();
        let args_json = params.args.unwrap_or(serde_json::json!({}));
        let args_str = serde_json::to_string(&args_json).unwrap_or_else(|_| "{}".to_string());
        let code = format!(
            "return window.__TAURI_INTERNALS__.invoke({}, {args_str})",
            js_string(&params.command)
        );
        let result = self
            .eval_with_return(&code, params.webview_label.as_deref())
            .await;
        let elapsed = start.elapsed();
        self.state.command_timings.record(&params.command, elapsed);

        match result {
            Ok(result) => {
                if let Ok(parsed) = serde_json::from_str::<serde_json::Value>(&result)
                    && let Some(err) = parsed.get("__error").and_then(|e| e.as_str())
                {
                    return tool_error(format!(
                        "command '{}' returned error: {err}",
                        params.command
                    ));
                }
                CallToolResult::success(vec![Content::text(result)])
            }
            Err(e) => tool_error(format!("invoke_command failed: {e}")),
        }
    }

    #[tool(
        description = "Capture a screenshot of a Tauri window as a base64-encoded PNG image. Works on Windows (PrintWindow), macOS (CGWindowListCreateImage), and Linux (X11/Wayland).",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn screenshot(&self, Parameters(params): Parameters<ScreenshotParams>) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("screenshot") {
            return tool_disabled("screenshot");
        }
        match self
            .bridge
            .get_native_handle(params.window_label.as_deref())
        {
            Ok(hwnd) => match crate::screenshot::capture_window(hwnd).await {
                Ok(png_bytes) => {
                    use base64::Engine;
                    let b64 = base64::engine::general_purpose::STANDARD.encode(&png_bytes);
                    CallToolResult::success(vec![Content::image(b64, "image/png")])
                }
                Err(e) => tool_error(format!("screenshot capture failed: {e}")),
            },
            Err(e) => tool_error(format!("cannot get window handle: {e}")),
        }
    }

    #[tool(
        description = "Compare frontend state (evaluated via JS expression) against backend state to detect divergences. Returns a VerificationResult with any mismatches.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn verify_state(
        &self,
        Parameters(params): Parameters<VerifyStateParams>,
    ) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("eval_js") {
            return tool_disabled("verify_state requires eval_js capability");
        }
        let code = format!("return ({})", params.frontend_expr);
        let frontend_json = match self
            .eval_with_return(&code, params.webview_label.as_deref())
            .await
        {
            Ok(result) => result,
            Err(e) => return tool_error(format!("failed to evaluate frontend expression: {e}")),
        };

        let frontend_state: serde_json::Value = match serde_json::from_str(&frontend_json) {
            Ok(v) => v,
            Err(e) => {
                return tool_error(format!(
                    "frontend expression did not return valid JSON: {e}"
                ));
            }
        };

        let backend_state = if let Some(state) = params.backend_state {
            state
        } else if let Some(ref cmd) = params.backend_command {
            // Gate on BOTH is_invoke_allowed and is_command_allowed, matching
            // invoke_command and the contract/replay paths — backend_command
            // previously checked only the blocklist (audit #30 follow-up).
            if !self.state.privacy.is_invoke_allowed(cmd)
                || !self.state.privacy.is_command_allowed(cmd)
            {
                return tool_error(format!(
                    "command '{cmd}' is blocked by privacy configuration"
                ));
            }
            let args = params.backend_args.unwrap_or(serde_json::json!({}));
            let args_str = serde_json::to_string(&args).unwrap_or_else(|_| "{}".to_string());
            let invoke_code = format!(
                "return window.__TAURI_INTERNALS__.invoke({}, {args_str})",
                js_string(cmd)
            );
            match self
                .eval_with_return(&invoke_code, params.webview_label.as_deref())
                .await
            {
                Ok(result) => match serde_json::from_str(&result) {
                    Ok(v) => v,
                    Err(e) => {
                        return tool_error(format!(
                            "backend command '{cmd}' did not return valid JSON: {e}"
                        ));
                    }
                },
                Err(e) => {
                    return tool_error(format!("failed to invoke backend command '{cmd}': {e}"));
                }
            }
        } else {
            return tool_error("either backend_state or backend_command must be provided");
        };

        let result = victauri_core::verify_state(frontend_state, backend_state);
        json_result(&result)
    }

    #[tool(
        description = "Detect ghost commands. Returns TWO separate lists: `frontend_only` = the true ghosts (commands invoked from the frontend that have NO backend handler — likely typos/bugs), and `registry_only` = informational (commands registered in the backend but never invoked from the frontend this session). Reads the JS-side IPC interception log, which ACCUMULATES every command seen this session (including earlier test/probe traffic) — so a `frontend_only` result reflects what was invoked at runtime, not necessarily a real frontend bug. For a clean signal, call `logs {action:'clear'}` first, then exercise the app, then run this.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn detect_ghost_commands(
        &self,
        Parameters(params): Parameters<GhostCommandParams>,
    ) -> CallToolResult {
        // Project only command names in JS — ghost detection never needs request
        // or response bodies, so this stays tiny even when the full IPC log is
        // huge (avoids the eval size cap on busy apps).
        let code = "return (window.__VICTAURI__?.getIpcLog() || []).map(function(c){ return (c && c.command) || null; }).filter(function(x){ return x; })";
        let ipc_json = match self
            .eval_with_return(code, params.webview_label.as_deref())
            .await
        {
            Ok(r) => r,
            Err(e) => return tool_error(format!("failed to read IPC log: {e}")),
        };

        let command_names: Vec<String> = match serde_json::from_str(&ipc_json) {
            Ok(v) => v,
            Err(e) => return tool_error(format!("failed to parse IPC log JSON: {e}")),
        };
        let frontend_commands: Vec<String> = command_names
            .into_iter()
            .collect::<std::collections::HashSet<_>>()
            .into_iter()
            .collect();

        let report = victauri_core::detect_ghost_commands(&frontend_commands, &self.state.registry);
        json_result(&report)
    }

    #[tool(
        description = "Check IPC round-trip integrity: find stale (stuck) pending calls and errored calls. Returns health status and lists of problematic IPC calls.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn check_ipc_integrity(
        &self,
        Parameters(params): Parameters<IpcIntegrityParams>,
    ) -> CallToolResult {
        let threshold = params.stale_threshold_ms.unwrap_or(5000);
        let code = format!(
            r"return (function() {{
                var log = window.__VICTAURI__?.getIpcLog() || [];
                var now = Date.now();
                var threshold = {threshold};
                var pending = log.filter(function(c) {{ return c.status === 'pending'; }});
                var stale = pending.filter(function(c) {{ return (now - c.timestamp) > threshold; }});
                var errored = log.filter(function(c) {{ return c.status === 'error'; }});
                var net = window.__VICTAURI__?.getNetworkLog() || [];
                var warning = null;
                if (log.length === 0 && net.length > 5) {{
                    warning = 'Zero IPC calls captured but ' + net.length + ' network requests observed. IPC capture may not be working — verify the app uses Tauri IPC via fetch to ipc.localhost.';
                }}
                return {{
                    healthy: stale.length === 0 && errored.length === 0,
                    total_calls: log.length,
                    pending_count: pending.length,
                    stale_count: stale.length,
                    error_count: errored.length,
                    stale_calls: stale.slice(0, 20),
                    errored_calls: errored.slice(0, 20),
                    warning: warning
                }};
            }})()"
        );
        self.eval_bridge(&code, params.webview_label.as_deref())
            .await
    }

    #[tool(
        description = "Wait for a condition to be met. Polls at regular intervals until satisfied or timeout. Conditions: text (text appears), text_gone (text disappears), selector (CSS selector matches), selector_gone, url (URL contains value), ipc_idle (no pending IPC calls), network_idle (no pending network requests), expression (poll a JS expression in `value` until truthy or until it equals `expected` — may `await`, e.g. await a fire-and-forget command's status), event (block until the Tauri event named in `value` fires, with `since_ms` look-back). Use expression/event to await async backend work to true completion instead of guessing with a fixed sleep.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn wait_for(&self, Parameters(params): Parameters<WaitForParams>) -> CallToolResult {
        let timeout_ms = params.timeout_ms.unwrap_or(10_000).min(120_000);
        let poll = params.poll_ms.unwrap_or(200).max(20);

        // The `expression` and `event` conditions are awaited server-side (they
        // poll the eval engine and the captured event bus respectively), so a
        // fire-and-forget backend command can be awaited to true completion.
        match params.condition {
            WaitCondition::Expression => {
                return self.wait_for_expression(&params, timeout_ms, poll).await;
            }
            WaitCondition::Event => {
                return self.wait_for_event(&params, timeout_ms, poll).await;
            }
            _ => {}
        }

        let value = params
            .value
            .as_ref()
            .map_or_else(|| "null".to_string(), |v| js_string(v));
        let code = format!(
            "return window.__VICTAURI__?.waitFor({{ condition: {}, value: {value}, timeout_ms: {timeout_ms}, poll_ms: {poll} }})",
            js_string(params.condition.as_str())
        );
        let eval_timeout = std::time::Duration::from_millis(timeout_ms + 5000);
        match self
            .eval_with_return_timeout(&code, params.webview_label.as_deref(), eval_timeout)
            .await
        {
            Ok(result) => CallToolResult::success(vec![Content::text(result)]),
            Err(e) => tool_error(e),
        }
    }

    /// Poll a JS expression until truthy (or `== expected`), server-side.
    ///
    /// Level-triggered and race-free: each poll re-evaluates the expression via
    /// the same engine as `eval_js`, so it may `await`. Eval errors are treated
    /// as "not yet met" (the target may not exist during startup) and the last
    /// error is surfaced on timeout.
    async fn wait_for_expression(
        &self,
        params: &WaitForParams,
        timeout_ms: u64,
        poll_ms: u64,
    ) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("eval_js") {
            return tool_disabled("wait_for(expression) requires eval_js capability");
        }
        let Some(expr) = params.value.as_deref().filter(|s| !s.is_empty()) else {
            return missing_param("value", "wait_for(expression)");
        };
        let code = format!("return ({expr});");
        let start = std::time::Instant::now();
        let deadline = start + std::time::Duration::from_millis(timeout_ms);
        let poll = std::time::Duration::from_millis(poll_ms);
        let mut last_value = serde_json::Value::Null;
        let mut last_error: Option<String> = None;

        loop {
            let remaining = deadline.saturating_duration_since(std::time::Instant::now());
            let per_eval = remaining
                .min(std::time::Duration::from_secs(15))
                .max(std::time::Duration::from_secs(1));
            match self
                .eval_with_return_timeout(&code, params.webview_label.as_deref(), per_eval)
                .await
            {
                Ok(raw) => {
                    let val = serde_json::from_str(&raw).unwrap_or(serde_json::Value::Null);
                    let met = match &params.expected {
                        Some(expected) => &val == expected,
                        None => json_truthy(&val),
                    };
                    if met {
                        return json_result(&serde_json::json!({
                            "ok": true,
                            "value": val,
                            "elapsed_ms": start.elapsed().as_millis() as u64,
                        }));
                    }
                    last_value = val;
                }
                Err(e) => last_error = Some(e),
            }

            if std::time::Instant::now() >= deadline {
                return json_result(&serde_json::json!({
                    "ok": false,
                    "error": format!("timeout after {timeout_ms}ms"),
                    "last_value": last_value,
                    "last_error": last_error,
                    "elapsed_ms": start.elapsed().as_millis() as u64,
                }));
            }
            tokio::time::sleep(
                poll.min(deadline.saturating_duration_since(std::time::Instant::now())),
            )
            .await;
        }
    }

    /// Block until a named Tauri event appears on the captured event bus.
    ///
    /// Edge-triggered: matches the most recent event whose timestamp is no older
    /// than `since_ms` before this call began, so an event fired in the gap
    /// between `invoke_command` and this call is still caught. Polls the
    /// event-bus ring buffer — no webview eval involved.
    async fn wait_for_event(
        &self,
        params: &WaitForParams,
        timeout_ms: u64,
        poll_ms: u64,
    ) -> CallToolResult {
        let Some(name) = params.value.as_deref().filter(|s| !s.is_empty()) else {
            return missing_param("value", "wait_for(event)");
        };
        let since_ms = params.since_ms.unwrap_or(2000);
        let start = std::time::Instant::now();
        let baseline = chrono::Utc::now()
            - chrono::TimeDelta::try_milliseconds(since_ms as i64).unwrap_or_default();
        let deadline = start + std::time::Duration::from_millis(timeout_ms);
        let poll = std::time::Duration::from_millis(poll_ms);

        loop {
            // Search newest-first for a matching event no older than the baseline.
            let matched = self.state.event_bus.events().into_iter().rev().find(|e| {
                e.name == name
                    && chrono::DateTime::parse_from_rfc3339(&e.timestamp)
                        .map_or(true, |ts| ts.with_timezone(&chrono::Utc) >= baseline)
            });
            if let Some(ev) = matched {
                return json_result(&serde_json::json!({
                    "ok": true,
                    "event": {
                        "name": ev.name,
                        "payload": ev.payload,
                        "timestamp": ev.timestamp,
                    },
                    "elapsed_ms": start.elapsed().as_millis() as u64,
                }));
            }
            if std::time::Instant::now() >= deadline {
                return json_result(&serde_json::json!({
                    "ok": false,
                    "error": format!("timeout after {timeout_ms}ms waiting for event '{name}'"),
                    "hint": "Ensure the app emits this Tauri event and Victauri captures it: \
                             custom events need VictauriBuilder::listen_events(&[\"…\"]); \
                             window-lifecycle events are captured automatically.",
                    "elapsed_ms": start.elapsed().as_millis() as u64,
                }));
            }
            tokio::time::sleep(poll).await;
        }
    }

    #[tool(
        description = "Run a semantic assertion: evaluate a JS expression and check the result against an expected condition. Conditions: equals, not_equals, contains, greater_than, less_than, truthy, falsy, exists, type_is.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn assert_semantic(
        &self,
        Parameters(params): Parameters<SemanticAssertParams>,
    ) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("eval_js") {
            return tool_disabled("assert_semantic requires eval_js capability");
        }
        let code = format!("return ({})", params.expression);
        let actual_json = match self
            .eval_with_return(&code, params.webview_label.as_deref())
            .await
        {
            Ok(result) => result,
            Err(e) => return tool_error(format!("failed to evaluate expression: {e}")),
        };

        let actual: serde_json::Value = match serde_json::from_str(&actual_json) {
            Ok(v) => v,
            Err(e) => return tool_error(format!("expression did not return valid JSON: {e}")),
        };

        let assertion = victauri_core::SemanticAssertion {
            label: params.label,
            condition: params.condition,
            expected: params.expected,
        };

        let result = victauri_core::evaluate_assertion(actual, &assertion);
        json_result(&result)
    }

    #[tool(
        description = "Resolve a natural language query to matching Tauri commands. Returns scored results ranked by relevance, using command names, descriptions, intents, categories, and examples.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn resolve_command(
        &self,
        Parameters(params): Parameters<ResolveCommandParams>,
    ) -> CallToolResult {
        let limit = params.limit.unwrap_or(5);
        let mut results = self.state.registry.resolve(&params.query);
        results.truncate(limit);
        json_result(&results)
    }

    #[tool(
        description = "List or search all registered Tauri commands with their argument schemas. Pass query to filter by name/description substring. Commands are registered via #[inspectable] macro.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn get_registry(&self, Parameters(params): Parameters<RegistryParams>) -> CallToolResult {
        let commands = match params.query {
            Some(q) => self.state.registry.search(&q),
            None => self.state.registry.list(),
        };
        json_result(&commands)
    }

    #[tool(
        description = "Read application-defined backend state via a registered probe. With no `probe`, lists available probe names. With a `probe` name, runs it and returns its JSON snapshot. Probes give first-class, discoverable access to domain state (e.g. a scoring pipeline's version + stale-item count, a queue's depth, cache stats) that would otherwise need query_db + log-grepping. Probes run in the Rust process with no IPC round-trip. Apps register them via VictauriBuilder::probe(name, closure).",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn app_state(&self, Parameters(params): Parameters<AppStateParams>) -> CallToolResult {
        let Some(name) = params.probe else {
            return json_result(&serde_json::json!({ "probes": self.state.probes.names() }));
        };
        if let Some(value) = self.state.probes.run(&name) {
            json_result(&value)
        } else {
            let available = self.state.probes.names();
            tool_error_with_hint(
                format!(
                    "unknown probe '{name}'. Available probes: {}",
                    if available.is_empty() {
                        "(none registered — add VictauriBuilder::probe(\"name\", ...))".to_string()
                    } else {
                        available.join(", ")
                    }
                ),
                RecoveryHint::CheckInput,
            )
        }
    }

    #[tool(
        description = "Get real-time process memory statistics from the OS (working set, page file usage). On Windows returns detailed metrics; on Linux returns virtual/resident size.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn get_memory_stats(&self) -> CallToolResult {
        let stats = crate::memory::current_stats();
        json_result(&stats)
    }

    #[tool(
        description = "Inspect the Victauri plugin's own configuration: port, enabled/disabled tools, command filters, privacy settings, capacities, and version. Useful for agents to understand their capabilities before acting.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn get_plugin_info(&self) -> CallToolResult {
        let disabled: Vec<&str> = self
            .state
            .privacy
            .disabled_tools
            .iter()
            .map(std::string::String::as_str)
            .collect();
        let blocklist: Vec<&str> = self
            .state
            .privacy
            .command_blocklist
            .iter()
            .map(std::string::String::as_str)
            .collect();
        let allowlist: Option<Vec<&str>> = self
            .state
            .privacy
            .command_allowlist
            .as_ref()
            .map(|s| s.iter().map(std::string::String::as_str).collect());
        let all_tools = Self::tool_router().list_all();
        let enabled_tools: Vec<&str> = all_tools
            .iter()
            .filter(|t| self.state.privacy.is_tool_enabled(t.name.as_ref()))
            .map(|t| t.name.as_ref())
            .collect();

        // Host-app identity: lets an agent verify on its FIRST call that it reached the
        // intended app (not another Victauri instance sharing the discovery port).
        let app_cfg = self.bridge.tauri_config();
        let result = serde_json::json!({
            "version": env!("CARGO_PKG_VERSION"),
            "bridge_version": BRIDGE_VERSION,
            "port": self.state.port.load(Ordering::Relaxed),
            "app": {
                "identifier": app_cfg.get("identifier"),
                "product_name": app_cfg.get("product_name"),
            },
            "tools": {
                "total": all_tools.len(),
                "enabled": enabled_tools.len(),
                "enabled_list": enabled_tools,
                "disabled_list": disabled,
            },
            "commands": {
                "allowlist": allowlist,
                "blocklist": blocklist,
            },
            "privacy": {
                "profile": self.state.privacy.profile.to_string(),
                "redaction_enabled": self.state.privacy.redaction_enabled,
            },
            "capacities": {
                "event_log": self.state.event_log.capacity(),
                "eval_timeout_secs": self.state.eval_timeout.as_secs(),
            },
            "registered_commands": self.state.registry.count(),
            "tool_invocations": self.state.tool_invocations.load(std::sync::atomic::Ordering::Relaxed),
            "uptime_secs": self.state.started_at.elapsed().as_secs(),
        });
        json_result(&result)
    }

    #[tool(
        description = "Run environment diagnostics: detect service workers (break IPC interception), closed shadow DOM (invisible to snapshots), iframes (bridge absent), large DOM warnings, and CSP status. Call this first when connecting to an unfamiliar app.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn get_diagnostics(
        &self,
        Parameters(params): Parameters<DiagnosticsParams>,
    ) -> CallToolResult {
        self.eval_bridge(
            "return window.__VICTAURI__?.getDiagnostics()",
            params.webview_label.as_deref(),
        )
        .await
    }

    // ── Backend Access Tools ───────────────────────────────────────────────

    #[tool(
        description = "Get comprehensive app info: Tauri config (identifier, product name, version), app directory paths (data, config, log, local_data), process environment variables, and database files found in app directories. Provides direct backend context without going through the webview.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn app_info(&self) -> CallToolResult {
        let config = self.bridge.tauri_config();

        let data_dir = self.bridge.app_data_dir().ok();
        let config_dir = self.bridge.app_config_dir().ok();
        let log_dir = self.bridge.app_log_dir().ok();
        let local_data_dir = self.bridge.app_local_data_dir().ok();

        let env_vars: std::collections::BTreeMap<String, String> = std::env::vars()
            .filter(|(k, _)| is_safe_env_key(k))
            .collect();

        // Enumerate every database candidate across ALL roots (configured db_search_paths
        // + every OS app dir), each tagged with size, whether it is a WebView/engine
        // internal store, and whether it is the one `query_db` would auto-select. This lets
        // an agent see and disambiguate the real app DB instead of guessing (audit /
        // red-team "wrong DB" finding — `app_info.databases` previously only walked
        // data_dir and returned bare relative names).
        #[cfg(feature = "sqlite")]
        let databases: Vec<serde_json::Value> = {
            let mut all_dirs: Vec<std::path::PathBuf> = self.state.db_search_paths.clone();
            for d in [
                data_dir.as_ref(),
                config_dir.as_ref(),
                log_dir.as_ref(),
                local_data_dir.as_ref(),
            ]
            .into_iter()
            .flatten()
            {
                all_dirs.push(d.clone());
            }
            let select_dirs: Vec<std::path::PathBuf> = if self.state.db_search_paths.is_empty() {
                all_dirs.clone()
            } else {
                self.state.db_search_paths.clone()
            };
            let selected = crate::database::select_app_database(&select_dirs).ok();
            crate::database::classify_databases(&all_dirs)
                .into_iter()
                .map(|c| {
                    serde_json::json!({
                        "path": c.path.to_string_lossy(),
                        "size_bytes": c.size_bytes,
                        "webview_internal": c.webview_internal,
                        "selected": selected.as_ref() == Some(&c.path),
                    })
                })
                .collect()
        };

        #[cfg(not(feature = "sqlite"))]
        let databases: Vec<serde_json::Value> = Vec::new();

        let result = serde_json::json!({
            "config": config,
            "paths": {
                "data": data_dir.as_ref().map(|p| p.to_string_lossy()),
                "config": config_dir.as_ref().map(|p| p.to_string_lossy()),
                "log": log_dir.as_ref().map(|p| p.to_string_lossy()),
                "local_data": local_data_dir.as_ref().map(|p| p.to_string_lossy()),
            },
            "databases": databases,
            "env": env_vars,
            "process": {
                "pid": std::process::id(),
                "arch": std::env::consts::ARCH,
                "os": std::env::consts::OS,
                "family": std::env::consts::FAMILY,
            },
        });
        json_result(&result)
    }

    #[tool(
        description = "List files in the app's data, config, log, or local_data directories. Useful for discovering databases, config files, logs, and cached data on the backend — without going through the webview.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn list_app_dir(
        &self,
        Parameters(params): Parameters<ListAppDirParams>,
    ) -> CallToolResult {
        let base = match self.resolve_app_dir(params.directory) {
            Ok(d) => d,
            Err(e) => return tool_error(e),
        };

        let target = if let Some(ref sub) = params.path {
            // Lexical traversal guard BEFORE the existence check: `safe_within`
            // canonicalizes (which errors on non-existent paths), so a `..` or
            // absolute sub-path must be rejected as traversal up front rather
            // than falling through to a misleading "does not exist" result.
            if let Err(e) = Self::lexical_safe(std::path::Path::new(sub)) {
                return tool_error(e);
            }
            let resolved = base.join(sub);
            // A missing directory is a normal, non-error result.
            if !resolved.exists() {
                return json_result(&serde_json::json!({
                    "base": base.to_string_lossy(),
                    "path": sub,
                    "exists": false,
                    "entries": [],
                    "count": 0,
                }));
            }
            if let Err(e) = Self::safe_within(&base, &resolved) {
                return tool_error(e);
            }
            resolved
        } else {
            base.clone()
        };

        // A missing base directory is a normal, non-error result.
        if !target.exists() {
            return json_result(&serde_json::json!({
                "base": base.to_string_lossy(),
                "path": params.path.unwrap_or_default(),
                "exists": false,
                "entries": [],
                "count": 0,
            }));
        }

        let max_depth = params.max_depth.unwrap_or(1).min(5);
        let pattern = params.pattern.as_deref();
        let mut entries = Vec::new();

        Self::list_dir_recursive(&target, &base, 0, max_depth, pattern, &mut entries);

        json_result(&serde_json::json!({
            "base": base.to_string_lossy(),
            "path": params.path.unwrap_or_default(),
            "exists": true,
            "entries": entries,
            "count": entries.len(),
        }))
    }

    #[tool(
        description = "Read a file from the app's data, config, log, or local_data directory. Returns UTF-8 text by default, or base64 for binary files. Directly reads backend files without going through the webview.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn read_app_file(
        &self,
        Parameters(params): Parameters<ReadAppFileParams>,
    ) -> CallToolResult {
        let base = match self.resolve_app_dir(params.directory) {
            Ok(d) => d,
            Err(e) => return tool_error(e),
        };

        // Lexical traversal guard FIRST — before the existence check — so a
        // traversal attempt (`..` / absolute) is rejected as traversal rather
        // than leaking whether the out-of-tree target exists via "file not
        // found". `safe_within` (which canonicalizes) stays below as
        // defense-in-depth for real files.
        if let Err(e) = Self::lexical_safe(std::path::Path::new(&params.path)) {
            return tool_error(e);
        }
        let target = base.join(&params.path);
        if !target.exists() {
            return tool_error(format!("file not found: {}", params.path));
        }
        if let Err(e) = Self::safe_within(&base, &target) {
            return tool_error(e);
        }
        if !target.is_file() {
            return tool_error(format!("not a file: {}", params.path));
        }

        let max_bytes = params.max_bytes.unwrap_or(1_048_576).min(10_485_760);
        let metadata = std::fs::metadata(&target).map_err(|e| e.to_string());

        match std::fs::read(&target) {
            Ok(mut bytes) => {
                let original_size = bytes.len();
                let truncated = bytes.len() > max_bytes;
                if truncated {
                    bytes.truncate(max_bytes);
                }

                let file_info = serde_json::json!({
                    "path": params.path,
                    "size": original_size,
                    "truncated": truncated,
                    "modified": metadata.as_ref().ok()
                        .and_then(|m| m.modified().ok())
                        .map(|t| {
                            let duration = t.duration_since(std::time::SystemTime::UNIX_EPOCH).unwrap_or_default();
                            duration.as_secs()
                        }),
                });

                if params.binary == Some(true) {
                    use base64::Engine;
                    let b64 = base64::engine::general_purpose::STANDARD.encode(&bytes);
                    json_result(&serde_json::json!({
                        "file": file_info,
                        "encoding": "base64",
                        "content": b64,
                    }))
                } else {
                    match String::from_utf8(bytes) {
                        Ok(text) => json_result(&serde_json::json!({
                            "file": file_info,
                            "encoding": "utf-8",
                            "content": text,
                        })),
                        Err(e) => {
                            use base64::Engine;
                            let bytes = e.into_bytes();
                            let b64 = base64::engine::general_purpose::STANDARD.encode(&bytes);
                            json_result(&serde_json::json!({
                                "file": file_info,
                                "encoding": "base64",
                                "note": "file is not valid UTF-8, returning base64",
                                "content": b64,
                            }))
                        }
                    }
                }
            }
            Err(e) => tool_error(format!("failed to read file: {e}")),
        }
    }

    #[tool(
        description = "Execute a read-only SQL query against a SQLite database in the app's data directory. Auto-discovers database files if no path is specified. Only SELECT/PRAGMA/EXPLAIN/WITH queries are allowed. Returns rows as JSON objects with column names as keys. This provides direct backend database access without going through the webview or IPC.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn query_db(&self, Parameters(params): Parameters<QueryDbParams>) -> CallToolResult {
        // query_db is ALWAYS registered as a tool so the rmcp `#[tool_router]` macro
        // compiles with `default-features = false` (a consumer that drops the heavy
        // rusqlite C dependency). The actual SQLite implementation only exists with the
        // `sqlite` feature; without it, return a clear, actionable error.
        #[cfg(feature = "sqlite")]
        {
            self.query_db_impl(params).await
        }
        #[cfg(not(feature = "sqlite"))]
        {
            let _ = params;
            tool_error(
                "query_db is unavailable: this build was compiled without the 'sqlite' \
                 feature (default-features = false). Re-enable the 'sqlite' feature to use it.",
            )
        }
    }

    /// Real `query_db` implementation — compiled only with the `sqlite` feature.
    #[cfg(feature = "sqlite")]
    async fn query_db_impl(&self, params: QueryDbParams) -> CallToolResult {
        let data_dir = match self.bridge.app_data_dir() {
            Ok(d) => d,
            Err(e) => return tool_error(format!("cannot access app data directory: {e}")),
        };

        let app_dirs: Vec<std::path::PathBuf> = [
            self.bridge.app_data_dir(),
            self.bridge.app_config_dir(),
            self.bridge.app_local_data_dir(),
            self.bridge.app_log_dir(),
        ]
        .into_iter()
        .filter_map(Result::ok)
        .collect::<std::collections::HashSet<_>>()
        .into_iter()
        .collect();
        // Explicitly-configured roots (VictauriBuilder::db_search_paths) take
        // precedence over OS app directories for auto-discovery, so a configured
        // application DB wins over incidental ones (e.g. WebView internals).
        let mut search_dirs: Vec<std::path::PathBuf> = self.state.db_search_paths.clone();
        search_dirs.extend(app_dirs);

        let db_path = if let Some(ref rel_path) = params.path {
            let candidate = std::path::Path::new(rel_path);
            // Absolute paths are permitted only when they resolve within one of
            // the allowed roots (app directories or configured db_search_paths).
            if candidate.is_absolute() {
                if !candidate.exists() {
                    return tool_error(format!("database not found: {rel_path}"));
                }
                if !search_dirs
                    .iter()
                    .any(|d| Self::safe_within(d, candidate).is_ok())
                {
                    return tool_error(format!(
                        "absolute path '{rel_path}' is not within an allowed directory; \
                         register its parent via VictauriBuilder::db_search_paths"
                    ));
                }
            }
            let mut found = None;
            if candidate.is_absolute() {
                found = Some(candidate.to_path_buf());
            } else {
                for dir in &search_dirs {
                    let resolved = dir.join(rel_path);
                    if resolved.exists() {
                        if let Err(e) = Self::safe_within(dir, &resolved) {
                            return tool_error(e);
                        }
                        found = Some(resolved);
                        break;
                    }
                }
            }
            if let Some(p) = found {
                p
            } else {
                let dirs_str = search_dirs
                    .iter()
                    .map(|d| d.display().to_string())
                    .collect::<Vec<_>>()
                    .join(", ");
                return tool_error(format!(
                    "database not found: {rel_path} (searched: {dirs_str})"
                ));
            }
        } else {
            // Auto-select the application DB. When db_search_paths is configured it is
            // EXCLUSIVE — never fall back to OS app dirs (which hold WebView internals),
            // so a configured-but-empty root yields a clear error instead of silently
            // querying the wrong database. WebView/browser-engine internal stores are
            // excluded and the largest remaining candidate wins (audit / red-team "wrong
            // DB" finding).
            let select_dirs: Vec<std::path::PathBuf> = if self.state.db_search_paths.is_empty() {
                search_dirs.clone()
            } else {
                self.state.db_search_paths.clone()
            };
            match crate::database::select_app_database(&select_dirs) {
                Ok(p) => p,
                Err(e) => return tool_error(e),
            }
        };

        let db_display = db_path
            .strip_prefix(&data_dir)
            .unwrap_or(&db_path)
            .to_string_lossy()
            .into_owned();
        let bind_params = params.params.unwrap_or_default();

        match crate::database::query(&db_path, &params.query, &bind_params, params.max_rows) {
            Ok(mut result) => {
                if let Some(obj) = result.as_object_mut() {
                    obj.insert("database".to_string(), serde_json::json!(db_display));
                }
                json_result(&result)
            }
            Err(e) => tool_error(e),
        }
    }

    // ── Compound Tools ──────────────────────────────────────────────────────

    #[tool(
        description = "DOM element interactions. Actions: click, double_click, hover, focus, scroll_into_view, select_option. Requires ref_id from a dom_snapshot for most actions.",
        annotations(
            read_only_hint = false,
            destructive_hint = false,
            idempotent_hint = false,
            open_world_hint = false
        )
    )]
    async fn interact(&self, Parameters(params): Parameters<InteractParams>) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("interact") {
            return tool_disabled("interact");
        }
        match params.action {
            InteractAction::Click => {
                if !self.state.privacy.is_tool_enabled("interact.click") {
                    return tool_disabled("interact.click");
                }
                let Some(ref_id) = &params.ref_id else {
                    return missing_param("ref_id", "click");
                };
                if params.trusted.unwrap_or(false) {
                    // Resolve the element's viewport-center coords, run the
                    // actionability check, then deliver a real OS click.
                    let probe = format!(
                        "var __e=window.__VICTAURI__&&window.__VICTAURI__.getRef({}); \
                         if(!__e) return null; __e.scrollIntoView({{block:'center',inline:'center',behavior:'instant'}}); \
                         var __b=__e.getBoundingClientRect(); \
                         return {{x:__b.left+__b.width/2, y:__b.top+__b.height/2}}",
                        js_string(ref_id)
                    );
                    let raw = match self
                        .eval_with_return(&probe, params.webview_label.as_deref())
                        .await
                    {
                        Ok(r) => r,
                        Err(e) => return tool_error(e),
                    };
                    let Ok(point) = serde_json::from_str::<serde_json::Value>(&raw) else {
                        return tool_error_with_hint(
                            format!("ref not found: {ref_id}"),
                            RecoveryHint::CheckInput,
                        );
                    };
                    let (Some(x), Some(y)) = (
                        point.get("x").and_then(serde_json::Value::as_f64),
                        point.get("y").and_then(serde_json::Value::as_f64),
                    ) else {
                        return tool_error_with_hint(
                            format!("ref not found: {ref_id}"),
                            RecoveryHint::CheckInput,
                        );
                    };
                    return match self
                        .bridge
                        .native_click(params.webview_label.as_deref(), x, y)
                    {
                        Ok(()) => json_result(
                            &serde_json::json!({"ok": true, "trusted": true, "x": x, "y": y}),
                        ),
                        Err(e) => tool_error(e),
                    };
                }
                let code = format!("return window.__VICTAURI__?.click({})", js_string(ref_id));
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            InteractAction::DoubleClick => {
                if !self.state.privacy.is_tool_enabled("interact.double_click") {
                    return tool_disabled("interact.double_click");
                }
                let Some(ref_id) = &params.ref_id else {
                    return missing_param("ref_id", "double_click");
                };
                let code = format!(
                    "return window.__VICTAURI__?.doubleClick({})",
                    js_string(ref_id)
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            InteractAction::Hover => {
                if !self.state.privacy.is_tool_enabled("interact.hover") {
                    return tool_disabled("interact.hover");
                }
                let Some(ref_id) = &params.ref_id else {
                    return missing_param("ref_id", "hover");
                };
                let code = format!("return window.__VICTAURI__?.hover({})", js_string(ref_id));
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            InteractAction::Focus => {
                if !self.state.privacy.is_tool_enabled("interact.focus") {
                    return tool_disabled("interact.focus");
                }
                let Some(ref_id) = &params.ref_id else {
                    return missing_param("ref_id", "focus");
                };
                let code = format!(
                    "return window.__VICTAURI__?.focusElement({})",
                    js_string(ref_id)
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            InteractAction::ScrollIntoView => {
                if !self
                    .state
                    .privacy
                    .is_tool_enabled("interact.scroll_into_view")
                {
                    return tool_disabled("interact.scroll_into_view");
                }
                let ref_arg = params
                    .ref_id
                    .as_ref()
                    .map_or_else(|| "null".to_string(), |r| js_string(r));
                let x = params.x.unwrap_or(0.0);
                let y = params.y.unwrap_or(0.0);
                let code = format!("return window.__VICTAURI__?.scrollTo({ref_arg}, {x}, {y})");
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            InteractAction::SelectOption => {
                if !self.state.privacy.is_tool_enabled("interact.select_option") {
                    return tool_disabled("interact.select_option");
                }
                let Some(ref_id) = &params.ref_id else {
                    return missing_param("ref_id", "select_option");
                };
                let values_vec;
                let values: &[String] = match (&params.values, &params.value) {
                    (Some(v), _) => v,
                    (None, Some(v)) => {
                        values_vec = vec![v.clone()];
                        &values_vec
                    }
                    (None, None) => &[],
                };
                let values_json =
                    serde_json::to_string(values).unwrap_or_else(|_| "[]".to_string());
                let code = format!(
                    "return window.__VICTAURI__?.selectOption({}, {})",
                    js_string(ref_id),
                    values_json
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
        }
    }

    #[tool(
        description = "Text and keyboard input. Actions: fill (set input value), type_text (character-by-character typing), press_key (trigger a keyboard key). Subject to privacy controls.",
        annotations(
            read_only_hint = false,
            destructive_hint = false,
            idempotent_hint = false,
            open_world_hint = false
        )
    )]
    async fn input(&self, Parameters(params): Parameters<InputParams>) -> CallToolResult {
        match params.action {
            InputAction::Fill => {
                if !self.state.privacy.is_tool_enabled("fill") {
                    return tool_disabled("fill");
                }
                let Some(ref_id) = &params.ref_id else {
                    return missing_param("ref_id", "fill");
                };
                let Some(value) = &params.value else {
                    return missing_param("value", "fill");
                };
                let code = format!(
                    "return window.__VICTAURI__?.fill({}, {})",
                    js_string(ref_id),
                    js_string(value)
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            InputAction::TypeText => {
                if !self.state.privacy.is_tool_enabled("type_text") {
                    return tool_disabled("type_text");
                }
                let Some(ref_id) = &params.ref_id else {
                    return missing_param("ref_id", "type_text");
                };
                let Some(text) = &params.text else {
                    return missing_param("text", "type_text");
                };
                if params.trusted.unwrap_or(false) {
                    // Focus the element via JS, then deliver real OS keystrokes
                    // (isTrusted: true) for handlers that reject synthetic events.
                    let focus = format!(
                        "var __e=window.__VICTAURI__&&window.__VICTAURI__.getRef({}); if(__e){{__e.focus();}} return !!__e",
                        js_string(ref_id)
                    );
                    let focused = self
                        .eval_with_return(&focus, params.webview_label.as_deref())
                        .await
                        .unwrap_or_default();
                    if focused != "true" {
                        return tool_error_with_hint(
                            format!("ref not found or not focusable: {ref_id}"),
                            RecoveryHint::CheckInput,
                        );
                    }
                    return match self
                        .bridge
                        .native_type_text(params.webview_label.as_deref(), text)
                    {
                        Ok(()) => json_result(&serde_json::json!({"ok": true, "trusted": true})),
                        Err(e) => tool_error(e),
                    };
                }
                let code = format!(
                    "return window.__VICTAURI__?.type({}, {})",
                    js_string(ref_id),
                    js_string(text)
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            InputAction::PressKey => {
                if !self.state.privacy.is_tool_enabled("input.press_key") {
                    return tool_disabled("input.press_key");
                }
                let Some(key) = &params.key else {
                    return missing_param("key", "press_key");
                };
                if params.trusted.unwrap_or(false) {
                    // Optionally focus a target element, then send a real OS key.
                    if let Some(ref_id) = &params.ref_id {
                        let focus = format!(
                            "var __e=window.__VICTAURI__&&window.__VICTAURI__.getRef({}); if(__e){{__e.focus();}} return !!__e",
                            js_string(ref_id)
                        );
                        let _ = self
                            .eval_with_return(&focus, params.webview_label.as_deref())
                            .await;
                    }
                    return match self.bridge.native_key(params.webview_label.as_deref(), key) {
                        Ok(()) => json_result(&serde_json::json!({"ok": true, "trusted": true})),
                        Err(e) => tool_error(e),
                    };
                }
                let code = format!("return window.__VICTAURI__?.pressKey({})", js_string(key));
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
        }
    }

    #[tool(
        description = "Window management. Actions: get_state (window positions/sizes/visibility), list (all window labels), manage (minimize/maximize/close/focus/show/hide/fullscreen/always_on_top), resize, move_to, set_title, introspectability (probe every window and report which Victauri can actually see — a visible window that comes back introspectable:false is almost always missing the \"victauri:default\" capability; run this FIRST when eval_js/dom_snapshot/animation return nothing for a multi-window app).",
        annotations(
            read_only_hint = false,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn window(&self, Parameters(params): Parameters<WindowParams>) -> CallToolResult {
        match params.action {
            WindowAction::GetState => {
                let states = self.bridge.get_window_states(params.label.as_deref());
                // A specific label that matches no window is an error, not an
                // empty array (which reads as "success, no state").
                if states.is_empty()
                    && let Some(label) = params.label.as_deref()
                {
                    return tool_error(format!(
                        "window not found: '{label}' (use window.list to see available labels)"
                    ));
                }
                json_result(&states)
            }
            WindowAction::List => {
                let labels = self.bridge.list_window_labels();
                json_result(&labels)
            }
            WindowAction::Introspectability => self.window_introspectability().await,
            WindowAction::Manage => {
                if !self.state.privacy.is_tool_enabled("window.manage") {
                    return tool_disabled("window.manage");
                }
                let Some(manage_action) = &params.manage_action else {
                    return missing_param("manage_action", "manage");
                };
                match self
                    .bridge
                    .manage_window(params.label.as_deref(), manage_action.as_str())
                {
                    Ok(msg) => CallToolResult::success(vec![Content::text(msg)]),
                    Err(e) => tool_error(e),
                }
            }
            WindowAction::Resize => {
                if !self.state.privacy.is_tool_enabled("window.resize") {
                    return tool_disabled("window.resize");
                }
                let Some(width) = params.width else {
                    return missing_param("width", "resize");
                };
                let Some(height) = params.height else {
                    return missing_param("height", "resize");
                };
                if width == 0 || height == 0 {
                    return tool_error_with_hint(
                        format!(
                            "invalid window size {width}x{height}: width and height must be > 0"
                        ),
                        RecoveryHint::CheckInput,
                    );
                }
                match self
                    .bridge
                    .resize_window(params.label.as_deref(), width, height)
                {
                    Ok(()) => {
                        let result =
                            serde_json::json!({"ok": true, "width": width, "height": height});
                        CallToolResult::success(vec![Content::text(result.to_string())])
                    }
                    Err(e) => tool_error(e),
                }
            }
            WindowAction::MoveTo => {
                if !self.state.privacy.is_tool_enabled("window.move_to") {
                    return tool_disabled("window.move_to");
                }
                let Some(x) = params.x else {
                    return missing_param("x", "move_to");
                };
                let Some(y) = params.y else {
                    return missing_param("y", "move_to");
                };
                match self.bridge.move_window(params.label.as_deref(), x, y) {
                    Ok(()) => {
                        let result = serde_json::json!({"ok": true, "x": x, "y": y});
                        CallToolResult::success(vec![Content::text(result.to_string())])
                    }
                    Err(e) => tool_error(e),
                }
            }
            WindowAction::SetTitle => {
                if !self.state.privacy.is_tool_enabled("window.set_title") {
                    return tool_disabled("window.set_title");
                }
                let Some(title) = &params.title else {
                    return missing_param("title", "set_title");
                };
                match self.bridge.set_window_title(params.label.as_deref(), title) {
                    Ok(()) => {
                        let result = serde_json::json!({"ok": true, "title": title});
                        CallToolResult::success(vec![Content::text(result.to_string())])
                    }
                    Err(e) => tool_error(e),
                }
            }
        }
    }

    #[tool(
        description = "Browser storage operations. Actions: get (read localStorage/sessionStorage), set (write), delete (remove key), get_cookies. Subject to privacy controls for set and delete.",
        annotations(
            read_only_hint = false,
            destructive_hint = true,
            idempotent_hint = false,
            open_world_hint = false
        )
    )]
    async fn storage(&self, Parameters(params): Parameters<StorageParams>) -> CallToolResult {
        match params.action {
            StorageAction::Get => {
                let method = match params.storage_type.unwrap_or(StorageType::Local) {
                    StorageType::Session => "getSessionStorage",
                    StorageType::Local => "getLocalStorage",
                };
                let key_arg = params
                    .key
                    .as_ref()
                    .map(|k| js_string(k))
                    .unwrap_or_default();
                let code = format!("return window.__VICTAURI__?.{method}({key_arg})");
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            StorageAction::Set => {
                if !self.state.privacy.is_tool_enabled("set_storage") {
                    return tool_disabled("set_storage");
                }
                let method = match params.storage_type.unwrap_or(StorageType::Local) {
                    StorageType::Session => "setSessionStorage",
                    StorageType::Local => "setLocalStorage",
                };
                let Some(key) = &params.key else {
                    return missing_param("key", "set");
                };
                // Operator-protected keys (auth/role/tier/flags) can't be poisoned
                // via storage.set (audit #33).
                if !self.state.privacy.is_storage_key_allowed(key) {
                    return tool_error(format!(
                        "storage key '{key}' is protected by privacy configuration"
                    ));
                }
                let value = params
                    .value
                    .as_ref()
                    .cloned()
                    .unwrap_or(serde_json::Value::Null);
                let value_json =
                    serde_json::to_string(&value).unwrap_or_else(|_| "null".to_string());
                let code = format!(
                    "return window.__VICTAURI__?.{method}({}, {value_json})",
                    js_string(key)
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            StorageAction::Delete => {
                if !self.state.privacy.is_tool_enabled("delete_storage") {
                    return tool_disabled("delete_storage");
                }
                let method = match params.storage_type.unwrap_or(StorageType::Local) {
                    StorageType::Session => "deleteSessionStorage",
                    StorageType::Local => "deleteLocalStorage",
                };
                let Some(key) = &params.key else {
                    return missing_param("key", "delete");
                };
                let code = format!("return window.__VICTAURI__?.{method}({})", js_string(key));
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            StorageAction::GetCookies => {
                self.eval_bridge(
                    "return window.__VICTAURI__?.getCookies()",
                    params.webview_label.as_deref(),
                )
                .await
            }
        }
    }

    #[tool(
        description = "Navigation and dialog control. Actions: go_to (navigate to URL), go_back (browser back), get_history (navigation log), set_dialog_response (auto-respond to alert/confirm/prompt), get_dialog_log (captured dialog events). Subject to privacy controls for go_to and set_dialog_response.",
        annotations(
            read_only_hint = false,
            destructive_hint = false,
            idempotent_hint = false,
            open_world_hint = false
        )
    )]
    async fn navigate(&self, Parameters(params): Parameters<NavigateParams>) -> CallToolResult {
        match params.action {
            NavigateAction::GoTo => {
                if !self.state.privacy.is_tool_enabled("navigate") {
                    return tool_disabled("navigate");
                }
                let Some(url) = &params.url else {
                    return missing_param("url", "go_to");
                };
                if let Err(e) = validate_url(url, self.state.allow_file_navigation) {
                    return tool_error(e);
                }
                let code = format!("return window.__VICTAURI__?.navigate({})", js_string(url));
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            NavigateAction::GoBack => {
                self.eval_bridge(
                    "return window.__VICTAURI__?.navigateBack()",
                    params.webview_label.as_deref(),
                )
                .await
            }
            NavigateAction::GetHistory => {
                self.eval_bridge(
                    "return window.__VICTAURI__?.getNavigationLog()",
                    params.webview_label.as_deref(),
                )
                .await
            }
            NavigateAction::SetDialogResponse => {
                if !self.state.privacy.is_tool_enabled("set_dialog_response") {
                    return tool_disabled("set_dialog_response");
                }
                let Some(dialog_type) = params.dialog_type else {
                    return missing_param("dialog_type", "set_dialog_response");
                };
                let Some(dialog_action) = params.dialog_action else {
                    return missing_param("dialog_action", "set_dialog_response");
                };
                let text_arg = params
                    .text
                    .as_ref()
                    .map_or_else(|| "undefined".to_string(), |t| js_string(t));
                let code = format!(
                    "return window.__VICTAURI__?.setDialogAutoResponse({}, {}, {text_arg})",
                    js_string(dialog_type.as_str()),
                    js_string(dialog_action.as_str())
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            NavigateAction::GetDialogLog => {
                self.eval_bridge(
                    "return window.__VICTAURI__?.getDialogLog()",
                    params.webview_label.as_deref(),
                )
                .await
            }
        }
    }

    #[tool(
        description = "Time-travel recording. Actions: start (begin recording), stop (end and return session), checkpoint (save state snapshot), list_checkpoints, get_events (since index), events_between (two checkpoints), get_replay (IPC replay sequence), export (session as JSON), import (load session from JSON), replay (re-execute recorded IPC commands and compare responses), flush (immediately drain pending events into recording without waiting for the 1-second poll).",
        annotations(
            read_only_hint = false,
            destructive_hint = false,
            idempotent_hint = false,
            open_world_hint = false
        )
    )]
    async fn recording(&self, Parameters(params): Parameters<RecordingParams>) -> CallToolResult {
        const MAX_SESSION_JSON: usize = 10 * 1024 * 1024;
        if !self.state.privacy.is_tool_enabled("recording") {
            return tool_disabled("recording");
        }
        match params.action {
            RecordingAction::Start => {
                let session_id = params
                    .session_id
                    .unwrap_or_else(|| uuid::Uuid::new_v4().to_string());
                match self.state.recorder.start(session_id.clone()) {
                    Ok(()) => {
                        let result = serde_json::json!({
                            "started": true,
                            "session_id": session_id,
                        });
                        CallToolResult::success(vec![Content::text(result.to_string())])
                    }
                    Err(e) => tool_error(e.to_string()),
                }
            }
            RecordingAction::Stop => match self.state.recorder.stop() {
                Some(session) => json_result(&session),
                None => tool_error("no recording is active"),
            },
            RecordingAction::Checkpoint => {
                // checkpoint_id is optional — auto-generate a short id when the
                // caller just wants a positional marker. The id is echoed back in
                // the response so it can be referenced later
                // (events_between_checkpoints / replay).
                let id = params
                    .checkpoint_id
                    .unwrap_or_else(|| format!("cp-{}", uuid::Uuid::new_v4()));
                let state = params.state.unwrap_or(serde_json::Value::Null);
                match self
                    .state
                    .recorder
                    .checkpoint(id.clone(), params.checkpoint_label, state)
                {
                    Ok(()) => {
                        let result = serde_json::json!({
                            "created": true,
                            "checkpoint_id": id,
                            "event_index": self.state.recorder.event_count(),
                        });
                        CallToolResult::success(vec![Content::text(result.to_string())])
                    }
                    Err(e) => tool_error(e.to_string()),
                }
            }
            RecordingAction::ListCheckpoints => {
                let checkpoints = self.state.recorder.get_checkpoints();
                json_result(&checkpoints)
            }
            RecordingAction::GetEvents => {
                let events = self
                    .state
                    .recorder
                    .events_since(params.since_index.unwrap_or(0));
                json_result(&events)
            }
            RecordingAction::EventsBetween => {
                let Some(from) = &params.from else {
                    return missing_param("from", "events_between");
                };
                let Some(to) = &params.to else {
                    return missing_param("to", "events_between");
                };
                match self.state.recorder.events_between_checkpoints(from, to) {
                    Ok(events) => json_result(&events),
                    Err(e) => tool_error(e.to_string()),
                }
            }
            RecordingAction::GetReplay => {
                let calls = self.state.recorder.ipc_replay_sequence();
                json_result(&calls)
            }
            RecordingAction::Export => match self.state.recorder.export() {
                Some(s) => {
                    let json = serde_json::to_string_pretty(&s)
                        .unwrap_or_else(|e| format!("{{\"error\": \"{e}\"}}"));
                    CallToolResult::success(vec![Content::text(json)])
                }
                None => tool_error("no recording is active — start one first"),
            },
            RecordingAction::Import => {
                let Some(session_json) = &params.session_json else {
                    return missing_param("session_json", "import");
                };
                if session_json.len() > MAX_SESSION_JSON {
                    return tool_error("session JSON exceeds maximum size (10 MB)");
                }
                let session: victauri_core::RecordedSession =
                    match serde_json::from_str(session_json) {
                        Ok(s) => s,
                        Err(e) => return tool_error(format!("invalid session JSON: {e}")),
                    };

                let result = serde_json::json!({
                    "imported": true,
                    "session_id": session.id,
                    "event_count": session.events.len(),
                    "checkpoint_count": session.checkpoints.len(),
                    "started_at": session.started_at.to_rfc3339(),
                });
                self.state.recorder.import(session);
                CallToolResult::success(vec![Content::text(result.to_string())])
            }
            RecordingAction::Flush => {
                if !self.state.recorder.is_recording() {
                    return tool_error("no active recording — start a recording first");
                }
                let code = "return window.__VICTAURI__?.getEventStream(0)";
                match self
                    .eval_with_return(code, params.webview_label.as_deref())
                    .await
                {
                    Ok(result_str) => {
                        let events: Vec<serde_json::Value> =
                            serde_json::from_str(&result_str).unwrap_or_default();
                        let mut count = 0u64;
                        for ev in &events {
                            if let Some(app_event) = crate::mcp::server::parse_bridge_event(ev) {
                                self.state.event_log.push(app_event.clone());
                                self.state.recorder.record_event(app_event);
                                count += 1;
                            }
                        }
                        json_result(&serde_json::json!({
                            "flushed": true,
                            "events_captured": count,
                        }))
                    }
                    Err(e) => tool_error(format!("flush failed: {e}")),
                }
            }
            RecordingAction::Replay => {
                let calls = self.state.recorder.ipc_replay_sequence();
                if calls.is_empty() {
                    return tool_error("no IPC calls recorded — record a session first");
                }
                let mut replay_results = Vec::new();
                for call in &calls {
                    // Enforce the same command allow/blocklist as invoke_command
                    // (audit #30/#31): a recorded/imported session must not be able to
                    // invoke a command an operator blocked.
                    if !self.state.privacy.is_invoke_allowed(&call.command)
                        || !self.state.privacy.is_command_allowed(&call.command)
                    {
                        replay_results.push(serde_json::json!({
                            "command": call.command,
                            "status": "blocked",
                            "error": "blocked by privacy configuration",
                        }));
                        continue;
                    }
                    let code = format!(
                        "return window.__TAURI_INTERNALS__.invoke({})",
                        js_string(&call.command)
                    );
                    let outcome = match self
                        .eval_with_return(&code, params.webview_label.as_deref())
                        .await
                    {
                        Ok(result_str) => {
                            let value: serde_json::Value = serde_json::from_str(&result_str)
                                .unwrap_or(serde_json::Value::String(result_str));
                            let shape = crate::introspection::JsonShape::from_value(&value);
                            serde_json::json!({
                                "command": call.command,
                                "status": "ok",
                                "response_type": shape.type_name(),
                            })
                        }
                        Err(e) => {
                            serde_json::json!({
                                "command": call.command,
                                "status": "error",
                                "error": e,
                            })
                        }
                    };
                    replay_results.push(outcome);
                }
                let passed = replay_results
                    .iter()
                    .filter(|r| r.get("status").and_then(|s| s.as_str()) == Some("ok"))
                    .count();
                let result = serde_json::json!({
                    "replayed": replay_results.len(),
                    "passed": passed,
                    "failed": replay_results.len() - passed,
                    "results": replay_results,
                });
                json_result(&result)
            }
        }
    }

    #[tool(
        description = "CSS and visual inspection. Actions: get_styles (computed CSS for element), get_bounding_boxes (layout rects), highlight (debug overlay), clear_highlights, audit_accessibility (a11y audit), get_performance (timing/heap/DOM metrics).",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn inspect(&self, Parameters(params): Parameters<InspectParams>) -> CallToolResult {
        match params.action {
            InspectAction::GetStyles => {
                let Some(ref_id) = &params.ref_id else {
                    return missing_param("ref_id", "get_styles");
                };
                let props_arg = match &params.properties {
                    Some(props) => {
                        let arr: Vec<String> = props.iter().map(|p| js_string(p)).collect();
                        format!("[{}]", arr.join(","))
                    }
                    None => "null".to_string(),
                };
                let code = format!(
                    "return window.__VICTAURI__?.getStyles({}, {})",
                    js_string(ref_id),
                    props_arg
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            InspectAction::GetBoundingBoxes => {
                let Some(ref_ids) = &params.ref_ids else {
                    return missing_param("ref_ids", "get_bounding_boxes");
                };
                let refs: Vec<String> = ref_ids.iter().map(|r| js_string(r)).collect();
                let code = format!(
                    "return window.__VICTAURI__?.getBoundingBoxes([{}])",
                    refs.join(",")
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            InspectAction::Highlight => {
                // highlight injects a debug overlay node into the page — a DOM
                // mutation — so it is gated separately and excluded from the
                // read-only Observe profile (red-team P1).
                if !self.state.privacy.is_tool_enabled("inspect.highlight") {
                    return tool_disabled("inspect.highlight");
                }
                let Some(ref_id) = &params.ref_id else {
                    return missing_param("ref_id", "highlight");
                };
                let color_arg = match &params.color {
                    Some(c) => match sanitize_css_color(c) {
                        Ok(safe) => format!("\"{safe}\""),
                        Err(e) => return tool_error(e),
                    },
                    None => "null".to_string(),
                };
                let label_arg = match &params.label {
                    Some(l) => js_string(l),
                    None => "null".to_string(),
                };
                let code = format!(
                    "return window.__VICTAURI__?.highlightElement({}, {}, {})",
                    js_string(ref_id),
                    color_arg,
                    label_arg
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            InspectAction::ClearHighlights => {
                if !self
                    .state
                    .privacy
                    .is_tool_enabled("inspect.clear_highlights")
                {
                    return tool_disabled("inspect.clear_highlights");
                }
                self.eval_bridge(
                    "return window.__VICTAURI__?.clearHighlights()",
                    params.webview_label.as_deref(),
                )
                .await
            }
            InspectAction::AuditAccessibility => {
                self.eval_bridge(
                    "return window.__VICTAURI__?.auditAccessibility()",
                    params.webview_label.as_deref(),
                )
                .await
            }
            InspectAction::GetPerformance => {
                self.eval_bridge(
                    "return window.__VICTAURI__?.getPerformanceMetrics()",
                    params.webview_label.as_deref(),
                )
                .await
            }
        }
    }

    #[tool(
        description = "CSS injection. Actions: inject (add custom CSS to page), remove (remove previously injected CSS). Subject to privacy controls.",
        annotations(
            read_only_hint = false,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn css(&self, Parameters(params): Parameters<CssParams>) -> CallToolResult {
        match params.action {
            CssAction::Inject => {
                if !self.state.privacy.is_tool_enabled("inject_css") {
                    return tool_disabled("inject_css");
                }
                let Some(css) = &params.css else {
                    return missing_param("css", "inject");
                };
                // Block remote @import / url(...) exfil vectors unless explicitly opted in.
                if let Err(e) = sanitize_injected_css(css, params.allow_remote) {
                    return tool_error(e);
                }
                let code = format!("return window.__VICTAURI__?.injectCss({})", js_string(css));
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            CssAction::Remove => {
                if !self.state.privacy.is_tool_enabled("css.remove") {
                    return tool_disabled("css.remove");
                }
                self.eval_bridge(
                    "return window.__VICTAURI__?.removeInjectedCss()",
                    params.webview_label.as_deref(),
                )
                .await
            }
        }
    }

    #[tool(
        description = "Network request interception (Playwright route() equivalent, no CDP). \
            Matches webview fetch/XHR by URL and blocks, mocks, or delays them. \
            Actions:\n\
            - `add`: add a rule. `pattern` (+ optional `match_type`: substring/glob/regex/exact, \
              and `method`) selects requests; `behavior` is `block` (abort), `fulfill` (return a \
              mock `status`/`headers`/`body`/`content_type`), or `delay` (proceed after `delay_ms`). \
              `times` limits how often it fires. Rules are page-scoped (cleared on reload).\n\
            - `list`: list active rules.\n\
            - `clear` (by `id`) / `clear_all`: remove rules.\n\
            - `matches`: log of intercepted requests.\n\
            Note: fetch supports all behaviors; XHR supports block/delay (fulfill is fetch-only). \
            Top-level navigation, sub-resource (img/css), and WebSocket traffic are not intercepted. \
            Tauri IPC (ipc.localhost) is OBSERVE-ONLY: such calls appear in `matches`, but block/\
            fulfill/delay do NOT take effect on them — Tauri serves IPC below the JS fetch layer, so \
            it cannot be controlled cross-platform without CDP. There is no IPC-control tool; the \
            `fault` tool only affects commands you drive via `invoke_command`, not real user IPC.",
        annotations(
            read_only_hint = false,
            destructive_hint = false,
            idempotent_hint = false,
            open_world_hint = false
        )
    )]
    async fn route(&self, Parameters(params): Parameters<RouteParams>) -> CallToolResult {
        match params.action {
            RouteAction::Add => {
                if !self.state.privacy.is_tool_enabled("route.add") {
                    return tool_disabled("route.add");
                }
                let Some(pattern) = &params.pattern else {
                    return missing_param("pattern", "add");
                };
                let behavior = params.behavior.unwrap_or(RouteBehavior::Fulfill);
                let match_type = params.match_type.unwrap_or(RouteMatchType::Substring);
                let mut rule = serde_json::json!({
                    "pattern": pattern,
                    "match_type": match_type.as_str(),
                    "action": behavior.as_str(),
                });
                if let Some(m) = &params.method {
                    rule["method"] = serde_json::json!(m);
                }
                if let Some(s) = params.status {
                    rule["status"] = serde_json::json!(s);
                }
                if let Some(st) = &params.status_text {
                    rule["status_text"] = serde_json::json!(st);
                }
                if let Some(h) = &params.headers {
                    rule["headers"] = h.clone();
                }
                if let Some(b) = &params.body {
                    // A JSON string body is passed through as-is; structured JSON
                    // is stringified so the bridge sends valid JSON text.
                    rule["body"] = match b {
                        serde_json::Value::String(s) => serde_json::json!(s),
                        other => serde_json::json!(other.to_string()),
                    };
                }
                if let Some(ct) = &params.content_type {
                    rule["content_type"] = serde_json::json!(ct);
                }
                if let Some(d) = params.delay_ms {
                    rule["delay_ms"] = serde_json::json!(d);
                }
                if let Some(t) = params.times {
                    rule["times"] = serde_json::json!(t);
                }
                let code = format!(
                    "return window.__VICTAURI__?.addRoute({})",
                    js_string(&rule.to_string())
                );
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            RouteAction::List => {
                self.eval_bridge(
                    "return window.__VICTAURI__?.getRouteRules()",
                    params.webview_label.as_deref(),
                )
                .await
            }
            RouteAction::Clear => {
                let Some(id) = params.id else {
                    return missing_param("id", "clear");
                };
                let code = format!("return window.__VICTAURI__?.clearRoute({id})");
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            RouteAction::ClearAll => {
                self.eval_bridge(
                    "return window.__VICTAURI__?.clearRoutes()",
                    params.webview_label.as_deref(),
                )
                .await
            }
            RouteAction::Matches => {
                let limit = params.limit.unwrap_or(100);
                let code = format!("return window.__VICTAURI__?.getRouteMatches({limit})");
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
        }
    }

    #[tool(
        description = "Screencast / visual trace (no CDP). Captures the window at a fixed interval \
            into a ring buffer, forming a visual timeline that pairs with `recording` (events) and \
            `logs` (network/console). Actions:\n\
            - `start`: begin capturing (`interval_ms` default 500, `max_frames` default 60). Set \
              `with_events=true` to also start the event recorder.\n\
            - `stop`: stop and return a summary (frame count, duration, timestamps).\n\
            - `status`: active flag + buffered frame count.\n\
            - `frames`: return captured frames as base64 PNGs (`limit` caps how many).",
        annotations(
            read_only_hint = false,
            destructive_hint = false,
            idempotent_hint = false,
            open_world_hint = false
        )
    )]
    async fn trace(&self, Parameters(params): Parameters<TraceParams>) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("trace")
            || !self.state.privacy.is_tool_enabled("screenshot")
        {
            return tool_disabled("trace");
        }
        match params.action {
            TraceAction::Start => {
                let interval = params.interval_ms.unwrap_or(500);
                let max_frames = params.max_frames.unwrap_or(60);
                let label = params.webview_label.clone();
                let generation = self
                    .state
                    .screencast
                    .start(interval, max_frames, label.clone());

                let mut events_started = false;
                if params.with_events.unwrap_or(false) {
                    let session_id = uuid::Uuid::new_v4().to_string();
                    if self.state.recorder.start(session_id).is_ok() {
                        events_started = true;
                    }
                }

                // Background capture task: snapshot the window each interval until
                // the screencast is stopped (or superseded by a newer start).
                let bridge = self.bridge.clone();
                let screencast = self.state.screencast.clone();
                tokio::spawn(async move {
                    let t0 = std::time::Instant::now();
                    while screencast.is_active() && screencast.generation() == generation {
                        if let Ok(handle) = bridge.get_native_handle(label.as_deref())
                            && let Ok(png) = crate::screenshot::capture_window(handle).await
                        {
                            use base64::Engine;
                            let b64 = base64::engine::general_purpose::STANDARD.encode(&png);
                            #[allow(clippy::cast_possible_truncation)]
                            screencast.push_frame(t0.elapsed().as_millis() as u64, b64);
                        }
                        tokio::time::sleep(std::time::Duration::from_millis(
                            screencast.interval_ms(),
                        ))
                        .await;
                    }
                });

                json_result(&serde_json::json!({
                    "started": true,
                    "interval_ms": interval.max(50),
                    "max_frames": max_frames.clamp(1, 600),
                    "with_events": events_started,
                }))
            }
            TraceAction::Stop => {
                let frame_count = self.state.screencast.stop();
                let timestamps = self.state.screencast.frame_timestamps();
                let duration_ms = timestamps.last().copied().unwrap_or(0);
                let event_count = self.state.recorder.event_count();
                json_result(&serde_json::json!({
                    "stopped": true,
                    "frame_count": frame_count,
                    "duration_ms": duration_ms,
                    "frame_timestamps_ms": timestamps,
                    "recorded_event_count": event_count,
                    "hint": "use action=frames to retrieve PNGs; pair with recording/get_events and logs for a full bundle",
                }))
            }
            TraceAction::Status => json_result(&serde_json::json!({
                "active": self.state.screencast.is_active(),
                "frame_count": self.state.screencast.frame_count(),
                "interval_ms": self.state.screencast.interval_ms(),
            })),
            TraceAction::Frames => {
                let limit = params.limit.unwrap_or(0);
                let frames = self.state.screencast.frames(limit);
                let items: Vec<Content> = frames
                    .into_iter()
                    .map(|f| Content::image(f.data_b64, "image/png"))
                    .collect();
                if items.is_empty() {
                    return json_result(&serde_json::json!({ "frames": 0 }));
                }
                CallToolResult::success(items)
            }
        }
    }

    #[tool(
        description = "Animation introspection (no CDP). Reads the Web Animations API to reveal what \
            the webview's animation engine is actually running — duration, delay, easing, iterations, \
            keyframes, current progress, and the animating element. Standard DOM, so it works \
            identically on WebView2/WKWebView/WebKitGTK. Actions:\n\
            - `list`: return all running CSS animations/transitions (optionally scoped by `selector`), \
              each with declared `timing`, `computed` progress, `keyframes`, and `target`.\n\
            - `scrub`: deterministically pause the target's animation and seek it to `points` \
              evenly-spaced steps (default 20), returning the exact geometry curve (rect + transform \
              + opacity per step). With `capture=true`, also returns a single contact-sheet filmstrip \
              PNG (one image of the whole arc) plus a `manifest` mapping each cell to its progress/time. \
              Frozen frames are jank-free, so this beats real-time capture for fast sweeps. CSS-driven \
              animations only (JS/rAF animations are not seekable — use `list`/`sample`).\n\
            - `sample`: real-time motion recorder. `record=true` arms a requestAnimationFrame watcher \
              on `selector` (or the first animating element); then trigger the animation; then call \
              with `record=false` to read the measured per-frame curve plus jank stats (dropped frames, \
              max frame gap) and declared-vs-measured duration. Works for ANY animation including \
              JS/rAF-driven ones. `clear=true` resets recorded sessions.\n\
            NOTE: an animation only appears while it is running or pending — trigger it (e.g. show the \
            notification) just before calling `list`/`scrub`, or arm `sample` before triggering.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn animation(&self, Parameters(params): Parameters<AnimationParams>) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("animation") {
            return tool_disabled("animation");
        }
        match params.action {
            AnimationAction::List => {
                let sel = params
                    .selector
                    .as_deref()
                    .map_or_else(|| "null".to_string(), js_string);
                let code = format!(
                    "return window.__VICTAURI__ && window.__VICTAURI__.listAnimations({sel})"
                );
                match self
                    .eval_with_return(&code, params.webview_label.as_deref())
                    .await
                {
                    Ok(result_str) => {
                        match serde_json::from_str::<serde_json::Value>(&result_str) {
                            Ok(v) => json_result(&v),
                            Err(_) => CallToolResult::success(vec![Content::text(result_str)]),
                        }
                    }
                    Err(e) => tool_error(format!("animation list failed: {e}")),
                }
            }
            AnimationAction::Scrub => self.animation_scrub(params).await,
            AnimationAction::Sample => {
                let label = params.webview_label.as_deref();
                let sel = params
                    .selector
                    .as_deref()
                    .map_or_else(|| "null".to_string(), js_string);
                let code = if params.record.unwrap_or(false) {
                    format!("return window.__VICTAURI__.installSweepRecorder({sel})")
                } else {
                    let clear = params.clear.unwrap_or(false);
                    format!("return window.__VICTAURI__.readSweep({clear})")
                };
                match self.eval_with_return(&code, label).await {
                    Ok(result_str) => {
                        match serde_json::from_str::<serde_json::Value>(&result_str) {
                            Ok(v) => json_result(&v),
                            Err(_) => CallToolResult::success(vec![Content::text(result_str)]),
                        }
                    }
                    Err(e) => tool_error(format!("animation sample failed: {e}")),
                }
            }
        }
    }

    /// Deterministic pause-seek-capture loop for `animation scrub`. Split out to
    /// keep the `#[tool]` method readable.
    async fn animation_scrub(&self, params: AnimationParams) -> CallToolResult {
        let label = params.webview_label.as_deref();
        let sel = params
            .selector
            .as_deref()
            .map_or_else(|| "null".to_string(), js_string);

        // 1. Prepare: pause the target's animations, learn the timeline length.
        let prep_code = format!("return await window.__VICTAURI__.scrubPrepare({sel})");
        let prep_v = match self.eval_with_return(&prep_code, label).await {
            Ok(s) => {
                serde_json::from_str::<serde_json::Value>(&s).unwrap_or(serde_json::Value::Null)
            }
            Err(e) => return tool_error(format!("scrub prepare failed: {e}")),
        };
        if prep_v.get("prepared").and_then(serde_json::Value::as_bool) != Some(true) {
            // Surface the helpful error/info object (no target, JS-driven, etc.).
            return json_result(&prep_v);
        }

        let points = params.points.unwrap_or(20).clamp(2, 120);
        let capture = params.capture.unwrap_or(false);
        let mut curve: Vec<serde_json::Value> = Vec::with_capacity(points);
        let mut frames: Vec<crate::filmstrip::Frame> = Vec::new();
        let mut manifest: Vec<serde_json::Value> = Vec::new();

        // 2. Seek to each evenly-spaced point; capture the frozen frame if asked.
        for i in 0..points {
            #[allow(clippy::cast_precision_loss)]
            let progress = i as f64 / (points - 1) as f64;
            let seek_code = format!("return await window.__VICTAURI__.scrubSeek({progress})");
            match self.eval_with_return(&seek_code, label).await {
                Ok(s) => {
                    let v = serde_json::from_str::<serde_json::Value>(&s)
                        .unwrap_or(serde_json::Value::Null);
                    if capture
                        && let Ok(handle) = self.bridge.get_native_handle(label)
                        && let Ok((rgba, w, h)) =
                            crate::screenshot::capture_window_raw(handle).await
                        && let Some(frame) = crate::filmstrip::Frame::new(rgba, w, h)
                    {
                        manifest.push(serde_json::json!({
                            "cell": frames.len(),
                            "progress": progress,
                            "t": v.get("t").cloned().unwrap_or(serde_json::Value::Null),
                        }));
                        frames.push(frame);
                    }
                    curve.push(v);
                }
                Err(e) => curve.push(serde_json::json!({ "progress": progress, "error": e })),
            }
        }

        // 3. Restore (resume) or leave paused.
        let resume = params.restore.unwrap_or(true);
        let restore_code = format!("return window.__VICTAURI__.scrubRestore({resume})");
        let _ = self.eval_with_return(&restore_code, label).await;

        let mut meta = serde_json::json!({
            "scrubbed": true,
            "points": points,
            "duration_ms": prep_v.get("duration").cloned().unwrap_or(serde_json::Value::Null),
            "anim_count": prep_v.get("anim_count").cloned().unwrap_or(serde_json::Value::Null),
            "target": prep_v.get("target").cloned().unwrap_or(serde_json::Value::Null),
            "captured": capture,
            "curve": curve,
        });

        // 4. Compose the filmstrip if we captured frames.
        if capture && !frames.is_empty() {
            let cols = params
                .cols
                .unwrap_or_else(|| crate::filmstrip::default_cols(frames.len()));
            if let Some((rgba, w, h)) =
                crate::filmstrip::compose(&frames, cols, 4, [20, 20, 20, 255])
            {
                match crate::screenshot::encode_png(w, h, &rgba) {
                    Ok(png) => {
                        use base64::Engine;
                        let b64 = base64::engine::general_purpose::STANDARD.encode(&png);
                        meta["filmstrip"] = serde_json::json!({
                            "cols": cols,
                            "frame_count": frames.len(),
                            "width": w,
                            "height": h,
                            "manifest": manifest,
                        });
                        return CallToolResult::success(vec![
                            Content::image(b64, "image/png"),
                            Content::text(meta.to_string()),
                        ]);
                    }
                    Err(e) => return tool_error(format!("filmstrip encode failed: {e}")),
                }
            }
        }

        json_result(&meta)
    }

    #[tool(
        description = "Application logs and monitoring. Actions: console (captured console.log/warn/error), network (intercepted fetch/XHR), ipc (IPC call log — set wait_for_capture=true to await response capture up to 500ms), navigation (URL change history), dialogs (alert/confirm/prompt events), events (combined event stream), slow_ipc (find slow IPC calls).",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn logs(&self, Parameters(params): Parameters<LogsParams>) -> CallToolResult {
        match params.action {
            LogsAction::Console => {
                let since_arg = params.since.map(|ts| format!("{ts}")).unwrap_or_default();
                let base = if since_arg.is_empty() {
                    "window.__VICTAURI__?.getConsoleLogs()".to_string()
                } else {
                    format!("window.__VICTAURI__?.getConsoleLogs({since_arg})")
                };
                let code = if let Some(limit) = params.limit {
                    format!("return ({base} || []).slice(-{limit})")
                } else {
                    format!("return {base}")
                };
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            LogsAction::Network => {
                let filter_arg = params
                    .filter
                    .as_ref()
                    .map_or_else(|| "null".to_string(), |f| js_string(f));
                let limit = params.limit.unwrap_or(DEFAULT_LOG_LIMIT);
                let source = format!("window.__VICTAURI__?.getNetworkLog({filter_arg}, {limit})");
                let code = trimmed_log_js(&source, limit);
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            LogsAction::Ipc => {
                let wait = params.wait_for_capture.unwrap_or(false);
                let limit = params.limit.unwrap_or(DEFAULT_LOG_LIMIT);
                if wait {
                    let inner = trimmed_log_js("window.__VICTAURI__.getIpcLog()", limit);
                    let code = format!(
                        r"return (async function() {{
                            await window.__VICTAURI__.waitForIpcComplete(500);
                            return (function() {{ {inner} }})();
                        }})()"
                    );
                    let timeout = std::time::Duration::from_millis(5000);
                    match self
                        .eval_with_return_timeout(&code, params.webview_label.as_deref(), timeout)
                        .await
                    {
                        Ok(result) => CallToolResult::success(vec![Content::text(result)]),
                        Err(e) => tool_error(e),
                    }
                } else {
                    let code = trimmed_log_js("window.__VICTAURI__?.getIpcLog()", limit);
                    self.eval_bridge(&code, params.webview_label.as_deref())
                        .await
                }
            }
            LogsAction::Navigation => {
                let code = if let Some(limit) = params.limit {
                    format!(
                        "return (window.__VICTAURI__?.getNavigationLog() || []).slice(-{limit})"
                    )
                } else {
                    "return window.__VICTAURI__?.getNavigationLog()".to_string()
                };
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            LogsAction::Dialogs => {
                let code = if let Some(limit) = params.limit {
                    format!("return (window.__VICTAURI__?.getDialogLog() || []).slice(-{limit})")
                } else {
                    "return window.__VICTAURI__?.getDialogLog()".to_string()
                };
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            LogsAction::Events => {
                let since_arg = params.since.map(|ts| format!("{ts}")).unwrap_or_default();
                let base = if since_arg.is_empty() {
                    "window.__VICTAURI__?.getEventStream()".to_string()
                } else {
                    format!("window.__VICTAURI__?.getEventStream({since_arg})")
                };
                let code = if let Some(limit) = params.limit {
                    format!("return ({base} || []).slice(-{limit})")
                } else {
                    format!("return {base}")
                };
                self.eval_bridge(&code, params.webview_label.as_deref())
                    .await
            }
            LogsAction::SlowIpc => {
                let Some(threshold) = params.threshold_ms else {
                    return missing_param("threshold_ms", "slow_ipc");
                };
                let limit = params.limit.unwrap_or(20);
                let mb = MAX_LOG_FIELD_BYTES;
                let code = format!(
                    r"return (function() {{
                        var MB = {mb};
                        function trimField(v) {{
                            if (typeof v === 'string') return v.length > MB ? (v.slice(0, MB) + '…[+' + (v.length - MB) + ' bytes truncated]') : v;
                            if (v && typeof v === 'object') {{ var s; try {{ s = JSON.stringify(v); }} catch (e) {{ s = ''; }} if (s.length > MB) return '[truncated ' + s.length + ' bytes]'; }}
                            return v;
                        }}
                        function trimEntry(e) {{ if (e == null || typeof e !== 'object') return e; var o = {{}}; for (var k in e) {{ if (Object.prototype.hasOwnProperty.call(e, k)) o[k] = trimField(e[k]); }} return o; }}
                        var log = window.__VICTAURI__?.getIpcLog() || [];
                        var slow = log.filter(function(c) {{ return (c.duration_ms || 0) > {threshold}; }});
                        slow.sort(function(a, b) {{ return (b.duration_ms || 0) - (a.duration_ms || 0); }});
                        return {{ threshold_ms: {threshold}, count: Math.min(slow.length, {limit}), calls: slow.slice(0, {limit}).map(trimEntry) }};
                    }})()",
                );
                self.eval_bridge(&code, None).await
            }
            LogsAction::Clear => {
                // Clearing the IPC/network logs erases captured evidence — a
                // mutation of observable state — so it is gated separately and
                // excluded from the read-only Observe profile (red-team P1).
                if !self.state.privacy.is_tool_enabled("logs.clear") {
                    return tool_disabled("logs.clear");
                }
                let code = "return (function(){ var b = window.__VICTAURI__; if (!b) return { ok:false, error:'bridge unavailable' }; if (b.clearIpcLog) b.clearIpcLog(); if (b.clearNetworkLog) b.clearNetworkLog(); return { ok:true, cleared:['ipc','network'] }; })()";
                self.eval_bridge(code, params.webview_label.as_deref())
                    .await
            }
        }
    }

    // ── Backend Introspection ────────────────────────────────────────────────

    #[tool(
        description = "Deep backend introspection — command profiling, IPC contract testing, \
            coverage, startup timing, capability auditing, database diagnostics, process \
            enumeration, and event bus monitoring. \
            These features exploit Victauri's position inside the Rust process.\n\n\
            Actions:\n\
            - `command_timings`: Per-command execution timing stats (min/max/avg/p95). Set `slow_threshold_ms` to filter.\n\
            - `coverage`: Which registered commands have been called during this session.\n\
            - `contract_record`: Record a command's response shape as a baseline (requires `command`).\n\
            - `contract_check`: Check all recorded contracts for schema drift.\n\
            - `contract_list`: List all recorded contract baselines.\n\
            - `contract_clear`: Clear all recorded contract baselines.\n\
            - `startup_timing`: Victauri plugin initialization phase-by-phase timing breakdown.\n\
            - `capabilities`: Enumerate Tauri v2 capabilities, security config (CSP, freeze_prototype), configured plugins, and window definitions.\n\
            - `db_health`: SQLite database diagnostics (journal mode, WAL, page stats).\n\
            - `plugin_state`: Snapshot of the Victauri plugin's internal state (event log, registry, faults, recording, timings, etc.).\n\
            - `processes`: Enumerate the host process and all child processes (sidecars, background workers) with PID, name, and memory usage.\n\
            - `plugin_tasks`: List Victauri's own spawned async tasks (MCP server, event drain) with status.\n\
            - `event_bus`: List all captured Tauri events (automatically intercepted via listen_any — no app opt-in needed).\n\
            - `event_bus_clear`: Clear the event bus capture buffer.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn introspect(&self, Parameters(params): Parameters<IntrospectParams>) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("introspect") {
            return tool_disabled("introspect");
        }

        match params.action {
            IntrospectAction::CommandTimings => {
                let mut stats = self.state.command_timings.all_stats();
                if let Some(threshold) = params.slow_threshold_ms {
                    stats.retain(|s| s.avg_ms >= threshold);
                }
                let result = serde_json::json!({
                    "commands": stats,
                    "total_commands_profiled": self.state.command_timings.all_stats().len(),
                    "slow_threshold_ms": params.slow_threshold_ms,
                });
                json_result(&result)
            }
            IntrospectAction::Coverage => {
                let registered: Vec<String> = self
                    .state
                    .registry
                    .list()
                    .iter()
                    .map(|c| c.name.clone())
                    .collect();

                let code = "return window.__VICTAURI__?.getIpcLog()";
                let invoked: std::collections::HashSet<String> = match self
                    .eval_with_return(code, params.webview_label.as_deref())
                    .await
                {
                    Ok(json_str) => {
                        if let Ok(entries) =
                            serde_json::from_str::<Vec<serde_json::Value>>(&json_str)
                        {
                            entries
                                .iter()
                                .filter_map(|e| e.get("command").and_then(|c| c.as_str()))
                                .map(String::from)
                                .collect()
                        } else {
                            std::collections::HashSet::new()
                        }
                    }
                    Err(_) => std::collections::HashSet::new(),
                };

                let uncovered: Vec<&String> = registered
                    .iter()
                    .filter(|cmd| !invoked.contains(cmd.as_str()))
                    .collect();

                let coverage_pct = if registered.is_empty() {
                    100.0
                } else {
                    let covered = registered.len() - uncovered.len();
                    (covered as f64 / registered.len() as f64) * 100.0
                };

                let result = serde_json::json!({
                    "registered_commands": registered.len(),
                    "invoked_commands": invoked.len(),
                    "coverage_pct": (coverage_pct * 10.0).round() / 10.0,
                    "uncovered": uncovered,
                    "invoked_not_registered": invoked.iter()
                        .filter(|cmd| !registered.contains(cmd))
                        .collect::<Vec<_>>(),
                });
                json_result(&result)
            }
            IntrospectAction::ContractRecord => {
                let Some(command) = params.command else {
                    return missing_param("command", "contract_record");
                };
                // contract_record invokes the command with caller-supplied args, so
                // it must honour the same allow/blocklist as invoke_command (audit #30).
                if !self.state.privacy.is_invoke_allowed(&command)
                    || !self.state.privacy.is_command_allowed(&command)
                {
                    return tool_error(format!(
                        "command '{command}' is blocked by privacy configuration"
                    ));
                }
                let args_json = params.args.unwrap_or(serde_json::json!({}));
                let args_str =
                    serde_json::to_string(&args_json).unwrap_or_else(|_| "{}".to_string());
                let code = format!(
                    "return window.__TAURI_INTERNALS__.invoke({}, {args_str})",
                    js_string(&command)
                );
                match self
                    .eval_with_return(&code, params.webview_label.as_deref())
                    .await
                {
                    Ok(result_str) => {
                        let value: serde_json::Value = serde_json::from_str(&result_str)
                            .unwrap_or(serde_json::Value::String(result_str.clone()));
                        let shape = crate::introspection::JsonShape::from_value(&value);
                        let sample = if result_str.len() > 4096 {
                            format!("{}...(truncated)", &result_str[..4096])
                        } else {
                            result_str
                        };
                        let baseline = crate::introspection::ContractBaseline {
                            command: command.clone(),
                            args: args_json,
                            shape: shape.clone(),
                            sample,
                            recorded_at: chrono_now(),
                        };
                        self.state.contract_store.record(baseline);
                        let result = serde_json::json!({
                            "recorded": true,
                            "command": command,
                            "shape_type": shape.type_name(),
                        });
                        json_result(&result)
                    }
                    Err(e) => tool_error(format!(
                        "failed to invoke '{command}' for contract recording: {e}"
                    )),
                }
            }
            IntrospectAction::ContractCheck => {
                let baselines = self.state.contract_store.all();
                if baselines.is_empty() {
                    return json_result(&serde_json::json!({
                        "checked": 0,
                        "message": "no contract baselines recorded — use contract_record first",
                    }));
                }
                let mut results = Vec::new();
                for baseline in &baselines {
                    // Re-checking a baseline re-invokes the command; honour the
                    // allow/blocklist in case it changed since recording (audit #30).
                    if !self.state.privacy.is_invoke_allowed(&baseline.command)
                        || !self.state.privacy.is_command_allowed(&baseline.command)
                    {
                        continue;
                    }
                    let args_str =
                        serde_json::to_string(&baseline.args).unwrap_or_else(|_| "{}".to_string());
                    let code = format!(
                        "return window.__TAURI_INTERNALS__.invoke({}, {args_str})",
                        js_string(&baseline.command)
                    );
                    match self
                        .eval_with_return(&code, params.webview_label.as_deref())
                        .await
                    {
                        Ok(result_str) => {
                            let value: serde_json::Value = serde_json::from_str(&result_str)
                                .unwrap_or(serde_json::Value::String(result_str));
                            let current_shape = crate::introspection::JsonShape::from_value(&value);
                            let drift = crate::introspection::diff_shapes(
                                &baseline.shape,
                                &current_shape,
                                &baseline.command,
                            );
                            results.push(drift);
                        }
                        Err(e) => {
                            results.push(crate::introspection::ContractDrift {
                                command: baseline.command.clone(),
                                new_fields: Vec::new(),
                                removed_fields: Vec::new(),
                                type_changes: Vec::new(),
                                shape_matches: false,
                            });
                            tracing::warn!(
                                command = %baseline.command,
                                error = %e,
                                "contract check invocation failed"
                            );
                        }
                    }
                }
                let passing = results.iter().filter(|r| r.shape_matches).count();
                let result = serde_json::json!({
                    "checked": results.len(),
                    "passing": passing,
                    "failing": results.len() - passing,
                    "contracts": results,
                });
                json_result(&result)
            }
            IntrospectAction::ContractList => {
                let baselines = self.state.contract_store.all();
                let result = serde_json::json!({
                    "count": baselines.len(),
                    "baselines": baselines.iter().map(|b| serde_json::json!({
                        "command": b.command,
                        "shape_type": b.shape.type_name(),
                        "recorded_at": b.recorded_at,
                    })).collect::<Vec<_>>(),
                });
                json_result(&result)
            }
            IntrospectAction::ContractClear => {
                let cleared = self.state.contract_store.clear();
                json_result(&serde_json::json!({
                    "cleared": cleared,
                }))
            }
            IntrospectAction::StartupTiming => {
                let phases = self.state.startup_timeline.report();
                let result = serde_json::json!({
                    "phases": phases,
                    "total_ms": self.state.startup_timeline.total_ms(),
                    "uptime_secs": self.state.started_at.elapsed().as_secs(),
                });
                json_result(&result)
            }
            IntrospectAction::Capabilities => {
                let config = self.bridge.tauri_config();
                let live_windows = self.bridge.list_window_labels();

                let result = serde_json::json!({
                    "app": {
                        "identifier": config.get("identifier"),
                        "product_name": config.get("product_name"),
                        "version": config.get("version"),
                    },
                    "security": config.get("security"),
                    "configured_windows": config.get("windows"),
                    "live_windows": live_windows,
                    "configured_plugins": config.get("plugins"),
                    "victauri": {
                        "registered_commands": self.state.registry.list().len(),
                        "redaction_enabled": self.state.privacy.redaction_enabled,
                        "privacy_profile": format!("{:?}", self.state.privacy.profile),
                        "disabled_tools": &self.state.privacy.disabled_tools,
                    },
                });
                json_result(&result)
            }
            #[allow(unused_variables)]
            IntrospectAction::DbHealth => {
                #[cfg(feature = "sqlite")]
                {
                    let db_path = params.db_path.clone();
                    match self.run_db_health(db_path.as_deref()).await {
                        Ok(health) => json_result(&health),
                        Err(e) => tool_error(format!("db_health failed: {e}")),
                    }
                }
                #[cfg(not(feature = "sqlite"))]
                {
                    tool_error("SQLite support not compiled in — enable the `sqlite` feature")
                }
            }
            IntrospectAction::PluginState => {
                let recording_active = self.state.recorder.is_recording();
                let recording_events = self.state.recorder.event_count();
                let result = serde_json::json!({
                    "event_log": {
                        "size": self.state.event_log.len(),
                        "capacity": self.state.event_log.capacity(),
                    },
                    "registry": {
                        "commands_registered": self.state.registry.list().len(),
                    },
                    "recording": {
                        "active": recording_active,
                        "events_captured": recording_events,
                    },
                    "faults": {
                        "active_rules": self.state.fault_registry.list().len(),
                    },
                    "contracts": {
                        "baselines_recorded": self.state.contract_store.all().len(),
                    },
                    "timings": {
                        "commands_profiled": self.state.command_timings.all_stats().len(),
                    },
                    "event_bus": {
                        "captured_events": self.state.event_bus.len(),
                    },
                    "tasks": {
                        "total": self.state.task_tracker.list().len(),
                        "active": self.state.task_tracker.active_count(),
                    },
                    "tool_invocations": self.state.tool_invocations.load(Ordering::Relaxed),
                    "uptime_secs": self.state.started_at.elapsed().as_secs(),
                    "port": self.state.port.load(std::sync::atomic::Ordering::Relaxed),
                });
                json_result(&result)
            }
            IntrospectAction::Processes => {
                let pid = std::process::id();
                let uptime = self.state.started_at.elapsed();
                let children = crate::introspection::enumerate_child_processes();
                let host_memory = crate::memory::current_stats();

                let result = serde_json::json!({
                    "host": {
                        "pid": pid,
                        "uptime_secs": uptime.as_secs(),
                        "platform": std::env::consts::OS,
                        "arch": std::env::consts::ARCH,
                        "memory": host_memory,
                    },
                    "children": children.iter().map(|c| serde_json::json!({
                        "pid": c.pid,
                        "name": c.name,
                        "memory_bytes": c.memory_bytes,
                    })).collect::<Vec<_>>(),
                    "child_count": children.len(),
                    "total_child_memory_bytes": children.iter().filter_map(|c| c.memory_bytes).sum::<u64>(),
                });
                json_result(&result)
            }
            IntrospectAction::PluginTasks => {
                let tasks = self.state.task_tracker.list();
                let active = self.state.task_tracker.active_count();
                let result = serde_json::json!({
                    "total": tasks.len(),
                    "active": active,
                    "finished": tasks.len() - active,
                    "tasks": tasks,
                });
                json_result(&result)
            }
            IntrospectAction::EventBus => {
                let tauri_events = self.state.event_bus.events();
                let app_events = self.state.event_log.snapshot();
                let result = serde_json::json!({
                    "tauri_events": {
                        "count": tauri_events.len(),
                        "events": tauri_events,
                    },
                    "app_events": {
                        "count": app_events.len(),
                        "capacity": self.state.event_log.capacity(),
                        "events": app_events,
                    },
                });
                json_result(&result)
            }
            IntrospectAction::EventBusClear => {
                let tauri_cleared = self.state.event_bus.clear();
                self.state.event_log.clear();
                json_result(&serde_json::json!({
                    "tauri_events_cleared": tauri_cleared,
                    "app_events_cleared": true,
                }))
            }
        }
    }

    // ── Fault Injection / Chaos Engineering ──────────────────────────────────

    #[tool(
        description = "Probe a backend command handler under failure by faulting it for chaos engineering. \
            Simulate slow commands, backend errors, dropped responses, and corrupted data. \
            SCOPE: faults apply ONLY to commands you run via this server's `invoke_command` tool — \
            they do NOT intercept the app's real user-driven IPC (window.__TAURI_INTERNALS__.invoke), \
            which runs below the layer Victauri can reach. Use this to test a handler's error path when \
            YOU drive it; it does not reproduce a failure a user clicking the UI would see.\n\n\
            Actions:\n\
            - `inject`: Add a fault rule (requires `command`, `fault_type`). Optional: `delay_ms`, `error_message`, `max_triggers`.\n\
            - `list`: List all active fault injection rules.\n\
            - `clear`: Remove a specific fault rule (requires `command`).\n\
            - `clear_all`: Remove all fault rules.",
        annotations(
            read_only_hint = false,
            destructive_hint = true,
            idempotent_hint = false,
            open_world_hint = false
        )
    )]
    async fn fault(&self, Parameters(params): Parameters<FaultParams>) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("fault") {
            return tool_disabled("fault");
        }

        match params.action {
            FaultAction::Inject => {
                let Some(command) = params.command else {
                    return missing_param("command", "inject");
                };
                let Some(fault_kind) = params.fault_type else {
                    return missing_param("fault_type", "inject");
                };
                let fault_type = match fault_kind {
                    FaultKind::Delay => {
                        let delay_ms = params.delay_ms.unwrap_or(1000);
                        crate::introspection::FaultType::Delay { delay_ms }
                    }
                    FaultKind::Error => {
                        let message = params
                            .error_message
                            .unwrap_or_else(|| "injected fault".to_string());
                        crate::introspection::FaultType::Error { message }
                    }
                    FaultKind::Drop => crate::introspection::FaultType::Drop,
                    FaultKind::Corrupt => crate::introspection::FaultType::Corrupt,
                };
                let config = crate::introspection::FaultConfig {
                    command: command.clone(),
                    fault_type: fault_type.clone(),
                    trigger_count: 0,
                    max_triggers: params.max_triggers.unwrap_or(0),
                    created_at: std::time::Instant::now(),
                };
                self.state.fault_registry.inject(config);
                let result = serde_json::json!({
                    "injected": true,
                    "command": command,
                    "fault_type": fault_type,
                    "max_triggers": params.max_triggers.unwrap_or(0),
                });
                json_result(&result)
            }
            FaultAction::List => {
                let faults = self.state.fault_registry.list();
                let result = serde_json::json!({
                    "count": faults.len(),
                    "faults": faults.iter().map(|f| serde_json::json!({
                        "command": f.command,
                        "fault_type": f.fault_type,
                        "trigger_count": f.trigger_count,
                        "max_triggers": f.max_triggers,
                    })).collect::<Vec<_>>(),
                });
                json_result(&result)
            }
            FaultAction::Clear => {
                let Some(command) = params.command else {
                    return missing_param("command", "clear");
                };
                let removed = self.state.fault_registry.clear(&command);
                json_result(&serde_json::json!({
                    "removed": removed,
                    "command": command,
                }))
            }
            FaultAction::ClearAll => {
                let removed = self.state.fault_registry.clear_all();
                json_result(&serde_json::json!({
                    "removed": removed,
                }))
            }
        }
    }

    // ── Cross-Layer Explanation ────────────────────────────────────────────

    #[tool(
        description = "Correlate recent activity across all layers into a coherent narrative. \
            CDP shows raw events per layer; Victauri correlates IPC + DOM + console + network \
            + window events across the Rust backend and webview simultaneously.\n\n\
            Actions:\n\
            - `summary`: High-level activity summary for the last N seconds (default 30). \
              Counts IPC calls, DOM mutations, console entries, network requests, errors.\n\
            - `last_action`: Correlate the most recent burst of events into a causal timeline \
              (e.g. 'IPC call → DOM update → console.log').\n\
            - `diff`: What changed in the last N seconds — event counts, errors, new IPC commands.",
        annotations(
            read_only_hint = true,
            destructive_hint = false,
            idempotent_hint = true,
            open_world_hint = false
        )
    )]
    async fn explain(&self, Parameters(params): Parameters<ExplainParams>) -> CallToolResult {
        if !self.state.privacy.is_tool_enabled("explain") {
            return tool_disabled("explain");
        }

        match params.action {
            ExplainAction::Summary => {
                let secs = params.seconds.unwrap_or(30);
                let since = chrono::Utc::now()
                    - chrono::TimeDelta::try_seconds(secs as i64).unwrap_or_default();
                let events = self.state.event_log.since(since);

                let mut ipc_count = 0u64;
                let mut dom_mutations = 0u64;
                let mut state_changes = 0u64;
                let mut console_count = 0u64;
                let mut window_events = 0u64;
                let mut interactions = 0u64;
                let mut top_commands: HashMap<String, u64> = HashMap::new();
                let mut errors: Vec<String> = Vec::new();

                for event in &events {
                    match event {
                        victauri_core::AppEvent::Ipc(call) => {
                            ipc_count += 1;
                            *top_commands.entry(call.command.clone()).or_insert(0) += 1;
                            if let victauri_core::IpcResult::Err(e) = &call.result {
                                errors.push(format!("IPC {}: {e}", call.command));
                            }
                        }
                        victauri_core::AppEvent::DomMutation { mutation_count, .. } => {
                            dom_mutations += u64::from(*mutation_count)
                        }
                        victauri_core::AppEvent::StateChange { .. } => state_changes += 1,
                        victauri_core::AppEvent::Console { level, message, .. } => {
                            console_count += 1;
                            if level == "error" {
                                errors.push(format!("console.error: {message}"));
                            }
                        }
                        victauri_core::AppEvent::WindowEvent { .. } => window_events += 1,
                        victauri_core::AppEvent::DomInteraction { .. } => interactions += 1,
                        _ => {}
                    }
                }

                let mut sorted_cmds: Vec<_> = top_commands.into_iter().collect();
                sorted_cmds.sort_by_key(|b| std::cmp::Reverse(b.1));
                let top: Vec<_> = sorted_cmds.iter().take(5).collect();

                let narrative = format!(
                    "{ipc_count} IPC call{} in the last {secs}s{}. \
                     {dom_mutations} DOM mutation{}, {interactions} interaction{}, \
                     {console_count} console message{}, {window_events} window event{}. {}.",
                    if ipc_count == 1 { "" } else { "s" },
                    if top.is_empty() {
                        String::new()
                    } else {
                        format!(
                            ", dominated by {}",
                            top.iter()
                                .map(|(cmd, n)| format!("{cmd} ({n}x)"))
                                .collect::<Vec<_>>()
                                .join(", ")
                        )
                    },
                    if dom_mutations == 1 { "" } else { "s" },
                    if interactions == 1 { "" } else { "s" },
                    if console_count == 1 { "" } else { "s" },
                    if window_events == 1 { "" } else { "s" },
                    if errors.is_empty() {
                        "No errors".to_string()
                    } else {
                        format!(
                            "{} error{}",
                            errors.len(),
                            if errors.len() == 1 { "" } else { "s" }
                        )
                    },
                );

                let result = serde_json::json!({
                    "time_window_secs": secs,
                    "total_events": events.len(),
                    "ipc_calls": ipc_count,
                    "dom_mutations": dom_mutations,
                    "state_changes": state_changes,
                    "console_messages": console_count,
                    "window_events": window_events,
                    "interactions": interactions,
                    "top_commands": sorted_cmds.iter().take(5).map(|(cmd, n)| {
                        serde_json::json!({"command": cmd, "count": n})
                    }).collect::<Vec<_>>(),
                    "errors": errors,
                    "narrative": narrative,
                });
                json_result(&result)
            }
            ExplainAction::LastAction => {
                let secs = params.seconds.unwrap_or(5);
                let since = chrono::Utc::now()
                    - chrono::TimeDelta::try_seconds(secs as i64).unwrap_or_default();
                let events = self.state.event_log.since(since);

                let timeline: Vec<serde_json::Value> = events
                    .iter()
                    .filter(|e| !e.is_internal())
                    .map(|event| match event {
                        victauri_core::AppEvent::Ipc(call) => serde_json::json!({
                            "time": call.timestamp.to_rfc3339_opts(
                                chrono::SecondsFormat::Millis, true
                            ),
                            "type": "ipc",
                            "detail": format!(
                                "{} {} ({}ms)",
                                call.command,
                                call.result,
                                call.duration_ms.unwrap_or(0)
                            ),
                        }),
                        victauri_core::AppEvent::DomMutation {
                            timestamp,
                            mutation_count,
                            webview_label,
                        } => serde_json::json!({
                            "time": timestamp.to_rfc3339_opts(
                                chrono::SecondsFormat::Millis, true
                            ),
                            "type": "dom_mutation",
                            "detail": format!(
                                "{mutation_count} element{} updated in {webview_label}",
                                if *mutation_count == 1 { "" } else { "s" }
                            ),
                        }),
                        victauri_core::AppEvent::DomInteraction {
                            timestamp,
                            action,
                            selector,
                            ..
                        } => serde_json::json!({
                            "time": timestamp.to_rfc3339_opts(
                                chrono::SecondsFormat::Millis, true
                            ),
                            "type": "interaction",
                            "detail": format!("{action} on {selector}"),
                        }),
                        victauri_core::AppEvent::StateChange {
                            timestamp,
                            key,
                            caused_by,
                        } => serde_json::json!({
                            "time": timestamp.to_rfc3339_opts(
                                chrono::SecondsFormat::Millis, true
                            ),
                            "type": "state_change",
                            "detail": format!(
                                "{key} changed{}",
                                caused_by.as_ref().map_or(String::new(), |c| format!(" (by {c})"))
                            ),
                        }),
                        victauri_core::AppEvent::Console {
                            timestamp,
                            level,
                            message,
                        } => serde_json::json!({
                            "time": timestamp.to_rfc3339_opts(
                                chrono::SecondsFormat::Millis, true
                            ),
                            "type": "console",
                            "detail": format!("console.{level}: {message}"),
                        }),
                        victauri_core::AppEvent::WindowEvent {
                            timestamp,
                            label,
                            event,
                        } => serde_json::json!({
                            "time": timestamp.to_rfc3339_opts(
                                chrono::SecondsFormat::Millis, true
                            ),
                            "type": "window_event",
                            "detail": format!("{event} on window '{label}'"),
                        }),
                        _ => serde_json::json!({
                            "time": event.timestamp().to_rfc3339_opts(
                                chrono::SecondsFormat::Millis, true
                            ),
                            "type": "other",
                            "detail": "unknown event type",
                        }),
                    })
                    .collect();

                let narrative = if timeline.is_empty() {
                    format!("No activity in the last {secs}s.")
                } else {
                    let parts: Vec<String> = timeline
                        .iter()
                        .filter_map(|e| e.get("detail").and_then(|d| d.as_str()))
                        .map(String::from)
                        .collect();
                    parts.join(" → ")
                };

                let result = serde_json::json!({
                    "time_window_secs": secs,
                    "event_count": timeline.len(),
                    "timeline": timeline,
                    "narrative": narrative,
                });
                json_result(&result)
            }
            ExplainAction::Diff => {
                let secs = params.seconds.unwrap_or(10);
                let since = chrono::Utc::now()
                    - chrono::TimeDelta::try_seconds(secs as i64).unwrap_or_default();
                let events = self.state.event_log.since(since);

                let mut ipc_commands: Vec<String> = Vec::new();
                let mut dom_changes = 0u64;
                let mut error_count = 0u64;
                let mut interaction_count = 0u64;
                let mut console_messages = 0u64;

                for event in &events {
                    if event.is_internal() {
                        continue;
                    }
                    match event {
                        victauri_core::AppEvent::Ipc(call) => {
                            ipc_commands.push(call.command.clone());
                            if matches!(call.result, victauri_core::IpcResult::Err(_)) {
                                error_count += 1;
                            }
                        }
                        victauri_core::AppEvent::DomMutation { mutation_count, .. } => {
                            dom_changes += u64::from(*mutation_count)
                        }
                        victauri_core::AppEvent::DomInteraction { .. } => {
                            interaction_count += 1;
                        }
                        victauri_core::AppEvent::Console { level, .. } => {
                            console_messages += 1;
                            if level == "error" {
                                error_count += 1;
                            }
                        }
                        _ => {}
                    }
                }

                ipc_commands.dedup();

                let result = serde_json::json!({
                    "since": since.to_rfc3339_opts(chrono::SecondsFormat::Secs, true),
                    "time_window_secs": secs,
                    "total_events": events.len(),
                    "ipc_calls_made": ipc_commands.len(),
                    "unique_commands": ipc_commands,
                    "dom_elements_changed": dom_changes,
                    "interactions": interaction_count,
                    "console_messages": console_messages,
                    "errors": error_count,
                });
                json_result(&result)
            }
        }
    }
}

impl VictauriMcpHandler {
    /// Create a new handler backed by the given state and webview bridge.
    pub fn new(state: Arc<VictauriState>, bridge: Arc<dyn WebviewBridge>) -> Self {
        Self {
            state,
            bridge,
            subscriptions: Arc::new(Mutex::new(HashSet::new())),
            bridge_checked: Arc::new(AtomicBool::new(false)),
            probed_labels: Arc::new(Mutex::new(HashSet::new())),
            timed_out_labels: Arc::new(Mutex::new(HashSet::new())),
        }
    }

    pub(crate) fn is_tool_enabled(&self, name: &str) -> bool {
        self.state.privacy.is_tool_enabled(name)
    }

    pub(crate) async fn execute_tool(
        &self,
        name: &str,
        args: serde_json::Value,
    ) -> Result<CallToolResult, rest::ToolCallError> {
        if !self.state.privacy.is_tool_enabled(name) {
            return Ok(tool_disabled(name));
        }
        self.state.tool_invocations.fetch_add(1, Ordering::Relaxed);
        let start = std::time::Instant::now();
        tracing::debug!(tool = %name, "REST tool invocation started");

        let result = match name {
            "eval_js" => {
                let p: EvalJsParams = Self::parse_args(args)?;
                self.eval_js(Parameters(p)).await
            }
            "dom_snapshot" => {
                let p: SnapshotParams = Self::parse_args(args)?;
                self.dom_snapshot(Parameters(p)).await
            }
            "find_elements" => {
                let p: FindElementsParams = Self::parse_args(args)?;
                self.find_elements(Parameters(p)).await
            }
            "invoke_command" => {
                let p: InvokeCommandParams = Self::parse_args(args)?;
                self.invoke_command(Parameters(p)).await
            }
            "screenshot" => {
                let p: ScreenshotParams = Self::parse_args(args)?;
                self.screenshot(Parameters(p)).await
            }
            "verify_state" => {
                let p: VerifyStateParams = Self::parse_args(args)?;
                self.verify_state(Parameters(p)).await
            }
            "detect_ghost_commands" => {
                let p: GhostCommandParams = Self::parse_args(args)?;
                self.detect_ghost_commands(Parameters(p)).await
            }
            "check_ipc_integrity" => {
                let p: IpcIntegrityParams = Self::parse_args(args)?;
                self.check_ipc_integrity(Parameters(p)).await
            }
            "wait_for" => {
                let p: WaitForParams = Self::parse_args(args)?;
                self.wait_for(Parameters(p)).await
            }
            "assert_semantic" => {
                let p: SemanticAssertParams = Self::parse_args(args)?;
                self.assert_semantic(Parameters(p)).await
            }
            "resolve_command" => {
                let p: ResolveCommandParams = Self::parse_args(args)?;
                self.resolve_command(Parameters(p)).await
            }
            "get_registry" => {
                let p: RegistryParams = Self::parse_args(args)?;
                self.get_registry(Parameters(p)).await
            }
            "app_state" => {
                let p: AppStateParams = Self::parse_args(args)?;
                self.app_state(Parameters(p)).await
            }
            "get_memory_stats" => self.get_memory_stats().await,
            "get_plugin_info" => self.get_plugin_info().await,
            "get_diagnostics" => {
                let p: DiagnosticsParams = Self::parse_args(args)?;
                self.get_diagnostics(Parameters(p)).await
            }
            "app_info" => self.app_info().await,
            "list_app_dir" => {
                let p: ListAppDirParams = Self::parse_args(args)?;
                self.list_app_dir(Parameters(p)).await
            }
            "read_app_file" => {
                let p: ReadAppFileParams = Self::parse_args(args)?;
                self.read_app_file(Parameters(p)).await
            }
            "query_db" => {
                let p: QueryDbParams = Self::parse_args(args)?;
                self.query_db(Parameters(p)).await
            }
            "interact" => {
                let p: InteractParams = Self::parse_args(args)?;
                self.interact(Parameters(p)).await
            }
            "input" => {
                let p: InputParams = Self::parse_args(args)?;
                self.input(Parameters(p)).await
            }
            "window" => {
                let p: WindowParams = Self::parse_args(args)?;
                self.window(Parameters(p)).await
            }
            "storage" => {
                let p: StorageParams = Self::parse_args(args)?;
                self.storage(Parameters(p)).await
            }
            "navigate" => {
                let p: NavigateParams = Self::parse_args(args)?;
                self.navigate(Parameters(p)).await
            }
            "recording" => {
                let p: RecordingParams = Self::parse_args(args)?;
                self.recording(Parameters(p)).await
            }
            "inspect" => {
                let p: InspectParams = Self::parse_args(args)?;
                self.inspect(Parameters(p)).await
            }
            "css" => {
                let p: CssParams = Self::parse_args(args)?;
                self.css(Parameters(p)).await
            }
            "route" => {
                let p: RouteParams = Self::parse_args(args)?;
                self.route(Parameters(p)).await
            }
            "trace" => {
                let p: TraceParams = Self::parse_args(args)?;
                self.trace(Parameters(p)).await
            }
            "animation" => {
                let p: AnimationParams = Self::parse_args(args)?;
                self.animation(Parameters(p)).await
            }
            "logs" => {
                let p: LogsParams = Self::parse_args(args)?;
                self.logs(Parameters(p)).await
            }
            "introspect" => {
                let p: IntrospectParams = Self::parse_args(args)?;
                self.introspect(Parameters(p)).await
            }
            "fault" => {
                let p: FaultParams = Self::parse_args(args)?;
                self.fault(Parameters(p)).await
            }
            "explain" => {
                let p: ExplainParams = Self::parse_args(args)?;
                self.explain(Parameters(p)).await
            }
            _ => return Err(rest::ToolCallError::UnknownTool(name.to_string())),
        };

        let elapsed = start.elapsed();
        tracing::debug!(
            tool = %name,
            elapsed_ms = elapsed.as_millis() as u64,
            "REST tool invocation completed"
        );

        if self.state.privacy.redaction_enabled {
            Ok(Self::redact_result(result, &self.state.privacy))
        } else {
            Ok(result)
        }
    }

    fn parse_args<T: serde::de::DeserializeOwned>(
        args: serde_json::Value,
    ) -> Result<T, rest::ToolCallError> {
        serde_json::from_value(args).map_err(|e| rest::ToolCallError::InvalidParams(e.to_string()))
    }

    fn redact_result(
        mut result: CallToolResult,
        privacy: &crate::privacy::PrivacyConfig,
    ) -> CallToolResult {
        for item in &mut result.content {
            if let RawContent::Text(ref mut tc) = item.raw {
                tc.text = privacy.redact_output(&tc.text);
            }
        }
        result
    }

    fn resolve_app_dir(&self, dir: Option<AppDir>) -> Result<std::path::PathBuf, String> {
        match dir.unwrap_or(AppDir::Data) {
            AppDir::Data => self.bridge.app_data_dir(),
            AppDir::Config => self.bridge.app_config_dir(),
            AppDir::Log => self.bridge.app_log_dir(),
            AppDir::LocalData => self.bridge.app_local_data_dir(),
        }
    }

    /// Lexical (pre-existence) traversal guard for a user-supplied sub-path.
    ///
    /// Rejects absolute paths and any component that is `..` BEFORE the path is
    /// canonicalized. This is necessary because [`Self::safe_within`] relies on
    /// `canonicalize`, which errors on non-existent paths — so a traversal
    /// attempt against a missing target would otherwise be reported as
    /// "not found" (an info-leak oracle) rather than as traversal.
    fn lexical_safe(sub: &std::path::Path) -> Result<(), String> {
        use std::path::Component;
        if sub.is_absolute() {
            return Err("path traversal not allowed: absolute paths are rejected".to_string());
        }
        for component in sub.components() {
            match component {
                Component::ParentDir => {
                    return Err("path traversal not allowed: '..' is rejected".to_string());
                }
                Component::Prefix(_) | Component::RootDir => {
                    return Err(
                        "path traversal not allowed: absolute paths are rejected".to_string()
                    );
                }
                Component::CurDir | Component::Normal(_) => {}
            }
        }
        Ok(())
    }

    fn safe_within(base: &std::path::Path, target: &std::path::Path) -> Result<(), String> {
        let canon_base = std::fs::canonicalize(base)
            .map_err(|e| format!("cannot resolve base directory: {e}"))?;
        let canon_target = std::fs::canonicalize(target)
            .map_err(|e| format!("cannot resolve target path: {e}"))?;
        if !canon_target.starts_with(&canon_base) {
            return Err("path traversal not allowed".to_string());
        }
        Ok(())
    }

    fn list_dir_recursive(
        dir: &std::path::Path,
        base: &std::path::Path,
        depth: u32,
        max_depth: u32,
        pattern: Option<&str>,
        entries: &mut Vec<serde_json::Value>,
    ) {
        let Ok(read_dir) = std::fs::read_dir(dir) else {
            return;
        };
        for entry in read_dir.flatten() {
            let path = entry.path();
            if path.is_symlink() {
                continue;
            }
            let name = entry.file_name().to_string_lossy().into_owned();
            let relative = path
                .strip_prefix(base)
                .unwrap_or(&path)
                .to_string_lossy()
                .into_owned();

            if let Some(pat) = pattern
                && !Self::matches_glob(&name, pat)
                && !path.is_dir()
            {
                continue;
            }

            let is_dir = path.is_dir();
            let meta = std::fs::metadata(&path).ok();

            entries.push(serde_json::json!({
                "name": name,
                "path": relative,
                "is_dir": is_dir,
                "size": meta.as_ref().map(std::fs::Metadata::len),
                "modified": meta.as_ref()
                    .and_then(|m| m.modified().ok())
                    .map(|t| t.duration_since(std::time::SystemTime::UNIX_EPOCH)
                        .unwrap_or_default().as_secs()),
            }));

            if is_dir && depth < max_depth {
                Self::list_dir_recursive(&path, base, depth + 1, max_depth, pattern, entries);
            }
        }
    }

    fn matches_glob(name: &str, pattern: &str) -> bool {
        if pattern == "*" {
            return true;
        }
        if let Some(suffix) = pattern.strip_prefix("*.") {
            return name.ends_with(&format!(".{suffix}"));
        }
        if let Some(prefix) = pattern.strip_suffix("*") {
            return name.starts_with(prefix);
        }
        name == pattern
    }

    /// Probe every window's JS bridge and report which are introspectable. A
    /// visible window that fails to respond almost always lacks the
    /// `victauri:default` capability — Tauri's permission ACL silently blocks
    /// the bridge's callback IPC, so eval/dom/animation tools see nothing. This
    /// turns that silent dead-end into an actionable, up-front diagnosis.
    async fn window_introspectability(&self) -> CallToolResult {
        let labels = self.bridge.list_window_labels();
        let states = self.bridge.get_window_states(None);
        let mut report = Vec::with_capacity(labels.len());
        let mut blind = 0usize;
        for label in &labels {
            let visible = states.iter().find(|s| &s.label == label).map(|s| s.visible);
            let introspectable = self.probe_bridge(Some(label)).await.is_ok();
            if !introspectable {
                blind += 1;
            }
            let note = if introspectable {
                "ok — Victauri JS bridge is responding".to_string()
            } else if visible == Some(true) {
                format!(
                    "NOT introspectable although the window is visible — almost certainly missing \
                     the Victauri capability. Add \"victauri:default\" to the capability file \
                     (src-tauri/capabilities/*.json) whose \"windows\" list includes \"{label}\", \
                     then rebuild. Capabilities are baked at compile time, so a rebuild is required."
                )
            } else {
                "NOT introspectable (window is hidden and/or has no bridge) — show the window to \
                 confirm, and ensure its capability includes \"victauri:default\", then rebuild."
                    .to_string()
            };
            report.push(serde_json::json!({
                "label": label,
                "visible": visible,
                "introspectable": introspectable,
                "note": note,
            }));
        }
        let hint = if blind > 0 {
            "Windows with introspectable:false have no working Victauri JS bridge — eval_js, \
             dom_snapshot, animation, find_elements, etc. cannot see them. The usual cause is a \
             missing \"victauri:default\" capability for that window: Tauri's per-window permission \
             ACL silently blocks the bridge's callback IPC. This capability is required per window, \
             not just for the main window. (Note: probing a blind window takes ~2s each.)"
        } else {
            "All windows are introspectable."
        };
        json_result(&serde_json::json!({
            "windows": report,
            "introspectable_count": labels.len().saturating_sub(blind),
            "blind_count": blind,
            "hint": hint,
        }))
    }

    async fn eval_bridge(&self, code: &str, webview_label: Option<&str>) -> CallToolResult {
        match self.eval_with_return(code, webview_label).await {
            Ok(result) => CallToolResult::success(vec![Content::text(result)]),
            Err(e) => tool_error(e),
        }
    }

    async fn eval_with_return(
        &self,
        code: &str,
        webview_label: Option<&str>,
    ) -> Result<String, String> {
        self.eval_with_return_timeout(code, webview_label, self.state.eval_timeout)
            .await
    }

    async fn probe_bridge(&self, webview_label: Option<&str>) -> Result<(), String> {
        let id = uuid::Uuid::new_v4().to_string();
        let (tx, rx) = tokio::sync::oneshot::channel();
        {
            let mut pending = self.state.pending_evals.lock().await;
            pending.insert(id.clone(), tx);
        }
        let id_js = js_string(&id);
        let probe = format!(
            r#"(async()=>{{await window.__TAURI_INTERNALS__.invoke('plugin:victauri|victauri_eval_callback',{{id:{id_js},result:'"probe_ok"'}});}})();"#
        );
        if let Err(e) = self.bridge.eval_webview(webview_label, &probe) {
            self.state.pending_evals.lock().await.remove(&id);
            return Err(format!("eval injection failed: {e}"));
        }
        if let Ok(Ok(_)) = tokio::time::timeout(std::time::Duration::from_secs(2), rx).await {
            Ok(())
        } else {
            self.state.pending_evals.lock().await.remove(&id);
            let label = webview_label.unwrap_or("default");
            Err(format!(
                "bridge not responding on window '{label}' — the window may be hidden, \
                 missing the victauri capability, or the JS bridge is not loaded"
            ))
        }
    }

    async fn eval_with_return_timeout(
        &self,
        code: &str,
        webview_label: Option<&str>,
        timeout: std::time::Duration,
    ) -> Result<String, String> {
        // Wait for the JS bridge ready signal (sent on bridge init) before
        // attempting evals.  For explicitly targeted windows the probe
        // mechanism is still used because the ready signal only proves that
        // *some* webview's bridge loaded — not necessarily the targeted one.
        if !self
            .state
            .bridge_ready
            .load(std::sync::atomic::Ordering::Acquire)
        {
            let notified = self.state.bridge_notify.notified();
            if !self
                .state
                .bridge_ready
                .load(std::sync::atomic::Ordering::Acquire)
            {
                let _ = tokio::time::timeout(std::time::Duration::from_secs(5), notified).await;
            }
        }

        // Reserved sentinel key for the default (unlabeled) window — cannot
        // collide with a real label.
        let label_key =
            webview_label.map_or_else(|| "\u{1}__default__".to_string(), str::to_string);

        // Proactively probe explicitly-targeted windows once (cached), so a
        // hidden/unready window fails fast rather than after the full timeout.
        if webview_label.is_some() {
            let already_probed = self.probed_labels.lock().await.contains(&label_key);
            if !already_probed {
                self.probe_bridge(webview_label).await?;
                self.probed_labels.lock().await.insert(label_key.clone());
            }
        }

        // Resilience: if the PREVIOUS eval on this window timed out, the bridge
        // may have gone away (the webview reloaded or the app crashed). Do a
        // fast liveness probe so this call fails in ~2s with a clear error
        // instead of blocking the full timeout again. If the bridge is alive
        // (the earlier timeout was slow code / an infinite loop), the probe
        // succeeds quickly and we proceed normally.
        if self.timed_out_labels.lock().await.remove(&label_key) {
            self.probe_bridge(webview_label).await.map_err(|e| {
                format!("{e} (previous eval on this window timed out; the webview may have reloaded or the app stopped responding)")
            })?;
        }

        let id = uuid::Uuid::new_v4().to_string();
        let (tx, rx) = tokio::sync::oneshot::channel();

        {
            let mut pending = self.state.pending_evals.lock().await;
            if pending.len() >= MAX_PENDING_EVALS {
                return Err(format!(
                    "too many concurrent eval requests (limit: {MAX_PENDING_EVALS})"
                ));
            }
            pending.insert(id.clone(), tx);
        }

        // Auto-prepend `return` so bare expressions produce a value — but ONLY
        // for single expressions. Multi-statement blocks (or code containing an
        // explicit `return`) are used as-is. Prepending `return` to a statement
        // block like `foo(); return bar()` would parse as `return foo();` and
        // silently discard everything after the first statement (issue: core
        // primitive returned wrong/undefined values for "do X, then return Y").
        let code = if should_prepend_return(code) {
            format!("return {}", code.trim())
        } else {
            code.trim().to_string()
        };

        let id_js = js_string(&id);

        // Fail fast on a SYNTAX error instead of hanging for the full timeout (audit /
        // red-team "malformed eval consumes the full 30s"). The user code is inlined into
        // the script below; if it has a parse error the WHOLE script fails to parse and the
        // try/catch never runs, so the callback never fires. We cannot wrap the code in
        // `new Function`/`AsyncFunction` to surface the SyntaxError, because dynamic code
        // generation is gated by the same `unsafe-eval` CSP that blocks `eval()` — which is
        // exactly why the bridge uses an inline async-IIFE in the first place. Instead an
        // independent watchdog (which always parses) reports a parse error quickly: the
        // user-code script sets a `started` flag at its very top, so a script that fails to
        // parse never sets it. A valid-but-slow eval (e.g. a `wait_for` poll) sets `started`
        // immediately and is left to run to the real timeout — the watchdog only fires when
        // the code never began executing.
        let watchdog = format!(
            r"
            (function () {{
                window.__VIC_EVAL__ = window.__VIC_EVAL__ || {{}};
                var s = (window.__VIC_EVAL__[{id_js}] =
                    window.__VIC_EVAL__[{id_js}] || {{ started: false, done: false }});
                setTimeout(function () {{
                    if (s.started || s.done) return;
                    s.done = true;
                    try {{
                        window.__TAURI_INTERNALS__.invoke('plugin:victauri|victauri_eval_callback', {{
                            id: {id_js},
                            result: JSON.stringify({{ __victauri_err: 'code did not begin executing within {PARSE_WATCHDOG_MS}ms — this almost always means a syntax/parse error in the submitted code (or the page main thread was blocked)' }})
                        }});
                    }} catch (e) {{}}
                    delete window.__VIC_EVAL__[{id_js}];
                }}, {PARSE_WATCHDOG_MS});
            }})();
            "
        );

        let inject = format!(
            r"
            (async () => {{
                var __s = (window.__VIC_EVAL__ && window.__VIC_EVAL__[{id_js}]) || null;
                if (__s) __s.started = true;
                try {{
                    const __result = await (async () => {{ {code} }})();
                    if (__s) {{ if (__s.done) return; __s.done = true; delete window.__VIC_EVAL__[{id_js}]; }}
                    const __type = __result === undefined ? 'undefined'
                        : __result === null ? 'null' : 'value';
                    const __val = __type === 'undefined' ? null
                        : __type === 'null' ? null : __result;
                    await window.__TAURI_INTERNALS__.invoke('plugin:victauri|victauri_eval_callback', {{
                        id: {id_js},
                        result: JSON.stringify({{ __victauri_ok: __val, __victauri_type: __type }})
                    }});
                }} catch (e) {{
                    if (__s) {{ if (__s.done) return; __s.done = true; delete window.__VIC_EVAL__[{id_js}]; }}
                    await window.__TAURI_INTERNALS__.invoke('plugin:victauri|victauri_eval_callback', {{
                        id: {id_js},
                        result: JSON.stringify({{ __victauri_err: String(e && e.message || e) }})
                    }});
                }}
            }})();
            "
        );

        // Inject the watchdog first so it is armed before the user code runs. Order is not
        // critical (the user-code script no-ops the watchdog state if it ran first), but
        // arming first minimises the window.
        if let Err(e) = self.bridge.eval_webview(webview_label, &watchdog) {
            self.state.pending_evals.lock().await.remove(&id);
            return Err(format!("eval injection failed: {e}"));
        }
        if let Err(e) = self.bridge.eval_webview(webview_label, &inject) {
            self.state.pending_evals.lock().await.remove(&id);
            return Err(format!("eval injection failed: {e}"));
        }

        match tokio::time::timeout(timeout, rx).await {
            Ok(Ok(raw)) => {
                self.check_bridge_version_once();
                if raw.len() > MAX_EVAL_RESULT_LEN {
                    return Err(format!(
                        "eval result too large ({} bytes, limit {MAX_EVAL_RESULT_LEN})",
                        raw.len()
                    ));
                }
                unwrap_eval_envelope(raw)
            }
            Ok(Err(_)) => Err("eval callback channel closed".to_string()),
            Err(_) => {
                self.state.pending_evals.lock().await.remove(&id);
                // Mark this window so the NEXT eval does a fast liveness probe —
                // if the bridge is gone (reloaded/crashed) the next call fails in
                // ~2s instead of blocking the full timeout again.
                self.timed_out_labels.lock().await.insert(label_key.clone());
                Err(format!(
                    "eval timed out after {}s — the code began executing but never resolved. \
                     (A syntax/parse error would have failed fast via the parse watchdog, so \
                     this is NOT a parse error.) Common causes: an unresolved promise, an \
                     infinite loop, an `await` on something that never settles, or the webview \
                     reloaded / the app stopped responding mid-eval. If the app may have \
                     navigated or crashed, retry (the next call fails fast if the bridge is \
                     gone).",
                    timeout.as_secs()
                ))
            }
        }
    }

    #[cfg(feature = "sqlite")]
    async fn run_db_health(&self, db_path: Option<&str>) -> Result<serde_json::Value, String> {
        // Roots: configured db_search_paths first, then app directories.
        let mut roots: Vec<std::path::PathBuf> = self.state.db_search_paths.clone();
        for d in [
            self.bridge.app_data_dir(),
            self.bridge.app_local_data_dir(),
            self.bridge.app_config_dir(),
        ]
        .into_iter()
        .flatten()
        {
            roots.push(d);
        }

        let path = if let Some(p) = db_path {
            let candidate = std::path::Path::new(p);
            if candidate.is_absolute() {
                if !roots
                    .iter()
                    .any(|r| Self::safe_within(r, candidate).is_ok())
                {
                    return Err(format!(
                        "absolute path '{p}' is not within an allowed directory; \
                         register its parent via VictauriBuilder::db_search_paths"
                    ));
                }
                candidate.to_path_buf()
            } else {
                roots
                    .iter()
                    .map(|r| r.join(p))
                    .find(|c| c.exists())
                    .ok_or_else(|| format!("database not found: {p}"))?
            }
        } else {
            // Configured db_search_paths are EXCLUSIVE when set (don't fall back to the
            // OS app dirs that hold WebView internals); WebView/engine internal stores are
            // excluded and the largest real candidate wins (audit / red-team "wrong DB").
            let select_dirs: Vec<std::path::PathBuf> = if self.state.db_search_paths.is_empty() {
                roots.clone()
            } else {
                self.state.db_search_paths.clone()
            };
            crate::database::select_app_database(&select_dirs)?
        };
        // No further containment check needed: the path is either discovered
        // within an allowed root, an existing relative file joined onto an
        // allowed root, or an absolute path already verified above. (A
        // safe_within check against app_data_dir would fail when that directory
        // does not exist — common for apps that store data elsewhere.)
        let path_str = path
            .to_str()
            .ok_or_else(|| "invalid path encoding".to_string())?
            .to_string();

        tokio::task::spawn_blocking(move || {
            let conn = rusqlite::Connection::open_with_flags(
                &path_str,
                rusqlite::OpenFlags::SQLITE_OPEN_READ_ONLY,
            )
            .map_err(|e| format!("cannot open database: {e}"))?;

            let journal_mode: String = conn
                .pragma_query_value(None, "journal_mode", |r| r.get(0))
                .unwrap_or_else(|_| "unknown".to_string());

            let page_count: i64 = conn
                .pragma_query_value(None, "page_count", |r| r.get(0))
                .unwrap_or(0);

            let page_size: i64 = conn
                .pragma_query_value(None, "page_size", |r| r.get(0))
                .unwrap_or(0);

            let freelist_count: i64 = conn
                .pragma_query_value(None, "freelist_count", |r| r.get(0))
                .unwrap_or(0);

            let wal_checkpoint: String = if journal_mode == "wal" {
                let mut info = String::from("n/a");
                let _ = conn.pragma_query(None, "wal_checkpoint", |r| {
                    let busy: i64 = r.get(0)?;
                    let checkpointed: i64 = r.get(1)?;
                    let total: i64 = r.get(2)?;
                    info = format!("busy={busy}, checkpointed={checkpointed}, total={total}");
                    Ok(())
                });
                info
            } else {
                "n/a (not WAL mode)".to_string()
            };

            let integrity: String = conn
                .pragma_query_value(None, "quick_check", |r| r.get(0))
                .unwrap_or_else(|_| "failed".to_string());

            let db_size_bytes = page_count * page_size;
            let db_size_mb = db_size_bytes as f64 / (1024.0 * 1024.0);

            let mut tables = Vec::new();
            if let Ok(mut stmt) =
                conn.prepare("SELECT name FROM sqlite_master WHERE type='table' ORDER BY name")
                && let Ok(rows) = stmt.query_map([], |r| r.get::<_, String>(0))
            {
                for name in rows.flatten() {
                    let count: i64 = conn
                        .query_row(&format!("SELECT count(*) FROM [{name}]"), [], |r| r.get(0))
                        .unwrap_or(0);
                    tables.push(serde_json::json!({
                        "name": name,
                        "row_count": count,
                    }));
                }
            }

            Ok(serde_json::json!({
                "database": path_str,
                "journal_mode": journal_mode,
                "page_count": page_count,
                "page_size": page_size,
                "db_size_mb": (db_size_mb * 100.0).round() / 100.0,
                "freelist_count": freelist_count,
                "wal_checkpoint": wal_checkpoint,
                "integrity_check": integrity,
                "tables": tables,
            }))
        })
        .await
        .map_err(|e| format!("db health task failed: {e}"))?
    }

    fn check_bridge_version_once(&self) {
        if self.bridge_checked.swap(true, Ordering::Relaxed) {
            return;
        }
        let handler = self.clone();
        tokio::spawn(async move {
            match handler
                .eval_with_return_timeout(
                    "window.__VICTAURI__?.version",
                    None,
                    std::time::Duration::from_secs(5),
                )
                .await
            {
                Ok(v) => {
                    let v = v.trim_matches('"');
                    if v == BRIDGE_VERSION {
                        tracing::debug!("Bridge version verified: {v}");
                    } else {
                        tracing::warn!(
                            "Bridge version mismatch: Rust expects {BRIDGE_VERSION}, JS reports {v}"
                        );
                    }
                }
                Err(e) => tracing::debug!("Bridge version check skipped: {e}"),
            }
        });
    }
}

const SERVER_INSTRUCTIONS: &str = "Victauri is a FULL-STACK inspection AND INTERVENTION tool for Tauri applications. \
It provides simultaneous access to three layers: (1) the WEBVIEW (DOM, interactions, JS eval), \
(2) the IPC LAYER (command registry, invoke commands, intercept traffic), and \
(3) the RUST BACKEND (app config, file system, SQLite databases, process memory). \
\n\nBACKEND tools (direct Rust access, no webview needed): \
'app_info' (app config, directory paths, discovered databases, process info), \
'list_app_dir' (browse app data/config/log directories), \
'read_app_file' (read files from app directories), \
'query_db' (read-only SQLite queries with auto-discovery). \
\n\nBACKEND INTROSPECTION (CDP cannot do this — Victauri-exclusive): \
'introspect' (command_timings, coverage, contract_record/check/list/clear, startup_timing, \
capabilities, db_health, plugin_state, processes, plugin_tasks, event_bus, event_bus_clear) — \
Rust-side performance profiling, IPC contract testing, command coverage analysis, startup timing, \
capability/security auditing, database diagnostics, plugin state, child process enumeration, \
task tracking, and automatic Tauri event bus monitoring. \
'fault' (inject, list, clear, clear_all) — chaos engineering: inject delays, errors, \
drops, and response corruption into Tauri commands at the Rust layer. \
'explain' (summary, last_action, diff) — cross-layer activity correlation: summarizes recent \
activity across IPC + DOM + console + network + window events into a coherent narrative. \
\n\nWEBVIEW tools: \
'interact' (click, hover, focus, scroll, select), 'input' (fill, type_text, press_key), \
'inspect' (get_styles, get_bounding_boxes, highlight, audit_accessibility, get_performance), \
'css' (inject, remove), eval_js, dom_snapshot, find_elements, screenshot. \
\n\nIPC tools: invoke_command, get_registry, detect_ghost_commands, check_ipc_integrity. \
\n\nCOMPOUND tools with an 'action' parameter: \
'window' (get_state, list, manage, resize, move_to, set_title), \
'storage' (get, set, delete, get_cookies), 'navigate' (go_to, go_back, get_history, \
set_dialog_response, get_dialog_log), 'recording' (start, stop, checkpoint, list_checkpoints, \
get_events, events_between, get_replay, export, import, replay), \
'logs' (console, network, ipc, navigation, dialogs, events, slow_ipc). \
\n\nOTHER: verify_state, wait_for (incl. 'expression'/'event' conditions to await \
async backend work to true completion), assert_semantic, resolve_command, \
app_state (app-defined backend state probes), \
get_memory_stats, get_plugin_info, get_diagnostics.";

impl ServerHandler for VictauriMcpHandler {
    fn get_info(&self) -> ServerInfo {
        ServerInfo::new(
            ServerCapabilities::builder()
                .enable_tools()
                .enable_resources()
                .enable_resources_subscribe()
                .build(),
        )
        .with_instructions(SERVER_INSTRUCTIONS)
    }

    async fn list_tools(
        &self,
        _request: Option<PaginatedRequestParams>,
        _context: RequestContext<RoleServer>,
    ) -> Result<ListToolsResult, ErrorData> {
        let all_tools = Self::tool_router().list_all();
        let filtered: Vec<Tool> = all_tools
            .into_iter()
            .filter(|t| self.state.privacy.is_tool_enabled(t.name.as_ref()))
            .collect();
        Ok(ListToolsResult {
            tools: filtered,
            ..Default::default()
        })
    }

    async fn call_tool(
        &self,
        request: CallToolRequestParams,
        context: RequestContext<RoleServer>,
    ) -> Result<CallToolResult, ErrorData> {
        let tool_name: String = request.name.as_ref().to_owned();
        if !self.state.privacy.is_tool_enabled(&tool_name) {
            tracing::debug!(tool = %tool_name, "tool call blocked by privacy config");
            return Ok(tool_disabled(&tool_name));
        }
        self.state
            .tool_invocations
            .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
        let start = std::time::Instant::now();
        tracing::debug!(tool = %tool_name, "tool invocation started");
        let ctx = ToolCallContext::new(self, request, context);
        let result = Self::tool_router().call(ctx).await;
        let elapsed = start.elapsed();
        tracing::debug!(
            tool = %tool_name,
            elapsed_ms = elapsed.as_millis() as u64,
            is_error = result.as_ref().map_or(true, |r| r.is_error.unwrap_or(false)),
            "tool invocation completed"
        );

        // Centralized output redaction: apply to all text content so no
        // individual tool can accidentally leak secrets.
        if self.state.privacy.redaction_enabled {
            result.map(|mut r| {
                for item in &mut r.content {
                    if let RawContent::Text(ref mut tc) = item.raw {
                        tc.text = self.state.privacy.redact_output(&tc.text);
                    }
                }
                r
            })
        } else {
            result
        }
    }

    fn get_tool(&self, name: &str) -> Option<Tool> {
        if !self.state.privacy.is_tool_enabled(name) {
            return None;
        }
        Self::tool_router().get(name).cloned()
    }

    async fn list_resources(
        &self,
        _request: Option<PaginatedRequestParams>,
        _context: RequestContext<RoleServer>,
    ) -> Result<ListResourcesResult, ErrorData> {
        Ok(ListResourcesResult {
            resources: vec![
                RawResource::new(RESOURCE_URI_IPC_LOG, "ipc-log")
                    .with_description(
                        "Live IPC call log — all commands invoked between frontend and backend",
                    )
                    .with_mime_type("application/json")
                    .no_annotation(),
                RawResource::new(RESOURCE_URI_WINDOWS, "windows")
                    .with_description(
                        "Current state of all Tauri windows — position, size, visibility, focus",
                    )
                    .with_mime_type("application/json")
                    .no_annotation(),
                RawResource::new(RESOURCE_URI_STATE, "state")
                    .with_description(
                        "Victauri plugin state — event count, registered commands, memory stats",
                    )
                    .with_mime_type("application/json")
                    .no_annotation(),
            ],
            ..Default::default()
        })
    }

    async fn read_resource(
        &self,
        request: ReadResourceRequestParams,
        _context: RequestContext<RoleServer>,
    ) -> Result<ReadResourceResult, ErrorData> {
        let uri = &request.uri;
        let json = match uri.as_str() {
            RESOURCE_URI_IPC_LOG => {
                if let Ok(json) = self
                    .eval_with_return("return window.__VICTAURI__?.getIpcLog()", None)
                    .await
                {
                    json
                } else {
                    let calls = self.state.event_log.ipc_calls();
                    serde_json::to_string_pretty(&calls)
                        .map_err(|e| ErrorData::internal_error(e.to_string(), None))?
                }
            }
            RESOURCE_URI_WINDOWS => {
                let states = self.bridge.get_window_states(None);
                serde_json::to_string_pretty(&states)
                    .map_err(|e| ErrorData::internal_error(e.to_string(), None))?
            }
            RESOURCE_URI_STATE => {
                let state_json = serde_json::json!({
                    "events_captured": self.state.event_log.len(),
                    "commands_registered": self.state.registry.count(),
                    "memory": crate::memory::current_stats(),
                    "port": self.state.port.load(Ordering::Relaxed),
                });
                serde_json::to_string_pretty(&state_json)
                    .map_err(|e| ErrorData::internal_error(e.to_string(), None))?
            }
            _ => {
                return Err(ErrorData::resource_not_found(
                    format!("unknown resource: {uri}"),
                    None,
                ));
            }
        };

        let json = if self.state.privacy.redaction_enabled {
            self.state.privacy.redact_output(&json)
        } else {
            json
        };

        Ok(ReadResourceResult::new(vec![ResourceContents::text(
            json, uri,
        )]))
    }

    async fn subscribe(
        &self,
        request: SubscribeRequestParams,
        _context: RequestContext<RoleServer>,
    ) -> Result<(), ErrorData> {
        let uri = &request.uri;
        match uri.as_str() {
            RESOURCE_URI_IPC_LOG | RESOURCE_URI_WINDOWS | RESOURCE_URI_STATE => {
                self.subscriptions.lock().await.insert(uri.clone());
                tracing::info!("Client subscribed to resource: {uri}");
                Ok(())
            }
            _ => Err(ErrorData::resource_not_found(
                format!("unknown resource: {uri}"),
                None,
            )),
        }
    }

    async fn unsubscribe(
        &self,
        request: UnsubscribeRequestParams,
        _context: RequestContext<RoleServer>,
    ) -> Result<(), ErrorData> {
        self.subscriptions.lock().await.remove(&request.uri);
        tracing::info!("Client unsubscribed from resource: {}", request.uri);
        Ok(())
    }
}

/// Build a JS expression that takes an array of log entries (`source_expr`),
/// keeps at most `limit` of the most recent, and truncates any per-entry field
/// larger than [`MAX_LOG_FIELD_BYTES`]. This keeps IPC/network log results under
/// the eval size cap on busy apps where individual entries carry large bodies.
///
/// The returned code is a complete `return (...)` statement.
fn trimmed_log_js(source_expr: &str, limit: usize) -> String {
    let mb = MAX_LOG_FIELD_BYTES;
    format!(
        r"return (function() {{
            var MB = {mb};
            function trimField(v) {{
                if (typeof v === 'string') {{
                    return v.length > MB ? (v.slice(0, MB) + '…[+' + (v.length - MB) + ' bytes truncated]') : v;
                }}
                if (v && typeof v === 'object') {{
                    var s; try {{ s = JSON.stringify(v); }} catch (e) {{ s = ''; }}
                    if (s.length > MB) {{ return '[truncated ' + s.length + ' bytes]'; }}
                }}
                return v;
            }}
            function trimEntry(e) {{
                if (e == null || typeof e !== 'object') return e;
                var out = Array.isArray(e) ? [] : {{}};
                for (var k in e) {{ if (Object.prototype.hasOwnProperty.call(e, k)) out[k] = trimField(e[k]); }}
                return out;
            }}
            var arr = {source_expr} || [];
            if (arr.length > {limit}) arr = arr.slice(-{limit});
            return arr.map(trimEntry);
        }})()"
    )
}

/// Unwrap the `{"__victauri_ok": <val>, "__victauri_type": <t>}` (or
/// `{"__victauri_err": <msg>}`) envelope produced by the eval bridge into the
/// value/error string returned to callers.
///
/// Parsing uses `serde_json`'s default recursion limit (it is intentionally NOT
/// disabled — an unbounded recursive parse of a pathologically deep result
/// overflows the worker thread stack and crashes the host). When the parse
/// fails because the value is too deeply nested, the envelope is stripped by
/// string slicing (no recursion) so the actual value is still returned rather
/// than leaking the raw envelope string.
fn unwrap_eval_envelope(raw: String) -> Result<String, String> {
    if let Ok(envelope) = serde_json::from_str::<serde_json::Value>(&raw) {
        if let Some(err) = envelope.get("__victauri_err") {
            return Err(format!(
                "JavaScript error: {}",
                err.as_str().unwrap_or("unknown error")
            ));
        }
        if envelope.get("__victauri_ok").is_some() {
            let js_type = envelope
                .get("__victauri_type")
                .and_then(|t| t.as_str())
                .unwrap_or("value");
            return match js_type {
                "undefined" => Ok("undefined".to_string()),
                "null" => Ok("null".to_string()),
                _ => Ok(serde_json::to_string(&envelope["__victauri_ok"])
                    .unwrap_or_else(|_| "null".to_string())),
            };
        }
    }
    // Fallback for results too deeply nested for the recursion-limited parser.
    if let Some(after) = raw.strip_prefix(r#"{"__victauri_ok":"#)
        && let Some(idx) = after.rfind(r#","__victauri_type":"#)
    {
        return Ok(after[..idx].to_string());
    }
    if let Some(after) = raw.strip_prefix(r#"{"__victauri_err":"#) {
        let msg = after.trim_end_matches('}').trim_matches('"');
        return Err(format!("JavaScript error: {msg}"));
    }
    Ok(raw)
}

/// Statement keywords where a leading `return` would be a syntax error.
const STMT_STARTS: &[&str] = &[
    "return ",
    "return;",
    "return\n",
    "return\t",
    "if ",
    "if(",
    "for ",
    "for(",
    "while ",
    "while(",
    "switch ",
    "switch(",
    "try ",
    "try{",
    "const ",
    "let ",
    "var ",
    "function ",
    "function(",
    "function*",
    "class ",
    "throw ",
    "do ",
    "do{",
    "{",
    "async function",
    "debugger",
];

/// String/template/comment scan state for [`should_prepend_return`].
#[derive(PartialEq, Clone, Copy)]
enum ScanState {
    Code,
    SingleQuote,
    DoubleQuote,
    Template,
}

/// Decide whether to wrap `code` with a leading `return`.
///
/// Only a single bare expression should get `return` prepended. Code that is a
/// multi-statement block, contains an explicit top-level `return`, or starts
/// with a statement keyword is used as-is — prepending `return` to such code
/// would execute only the first statement and silently discard the rest.
///
/// The scan is string/template/comment-aware and only treats a `;` or an
/// explicit `return` token as significant when it occurs at bracket depth 0
/// outside of any string, template literal, or comment.
fn should_prepend_return(code: &str) -> bool {
    use ScanState::{Code, DoubleQuote, SingleQuote, Template};

    let code = code.trim();
    if code.is_empty() {
        return false;
    }

    if STMT_STARTS.iter().any(|k| code.starts_with(k)) {
        return false;
    }

    let bytes = code.as_bytes();
    let mut i = 0;
    let mut depth: i32 = 0;
    let mut state = ScanState::Code;

    let is_ident = |b: u8| b.is_ascii_alphanumeric() || b == b'_' || b == b'$';
    // Is there a top-level `return` token starting at byte `i` (word-bounded)?
    let is_return_token = |i: usize| -> bool {
        let prev_ok = i == 0 || !is_ident(bytes[i - 1]);
        prev_ok
            && code[i..].starts_with("return")
            && bytes.get(i + 6).copied().is_none_or(|b| !is_ident(b))
    };

    while i < bytes.len() {
        let c = bytes[i];
        match state {
            Code => match c {
                b'\'' => state = SingleQuote,
                b'"' => state = DoubleQuote,
                b'`' => state = Template,
                b'/' if i + 1 < bytes.len() && bytes[i + 1] == b'/' => {
                    while i < bytes.len() && bytes[i] != b'\n' {
                        i += 1;
                    }
                    continue;
                }
                b'/' if i + 1 < bytes.len() && bytes[i + 1] == b'*' => {
                    i += 2;
                    while i + 1 < bytes.len() && !(bytes[i] == b'*' && bytes[i + 1] == b'/') {
                        i += 1;
                    }
                    i += 2;
                    continue;
                }
                b'(' | b'[' | b'{' => depth += 1,
                b')' | b']' | b'}' => depth -= 1,
                // A top-level `;` with more code after it == multi-statement.
                b';' if depth <= 0 && !code[i + 1..].trim().is_empty() => return false,
                // An explicit top-level `return` token means the code already returns.
                b'r' if depth <= 0 && is_return_token(i) => return false,
                _ => {}
            },
            SingleQuote => {
                if c == b'\\' {
                    i += 1;
                } else if c == b'\'' {
                    state = Code;
                }
            }
            DoubleQuote => {
                if c == b'\\' {
                    i += 1;
                } else if c == b'"' {
                    state = Code;
                }
            }
            Template => {
                if c == b'\\' {
                    i += 1;
                } else if c == b'`' {
                    state = Code;
                }
            }
        }
        i += 1;
    }

    true
}

#[cfg(test)]
mod prop_tests {
    //! Property-based tests for the eval auto-return heuristic — the code that
    //! caused the worst bug in the system (silent corruption of multi-statement
    //! eval) and has bitten twice. These generate many JS-ish snippets and
    //! assert the invariants that keep eval correct.
    use super::should_prepend_return;
    use proptest::prelude::*;

    /// A small set of non-keyword identifier-ish expressions.
    fn ident() -> impl Strategy<Value = String> {
        prop_oneof![
            Just("a".to_string()),
            Just("x".to_string()),
            Just("foo".to_string()),
            Just("window.x".to_string()),
            Just("document.title".to_string()),
            Just("obj.prop".to_string()),
            Just("arr[0]".to_string()),
            Just("localStorage".to_string()),
        ]
    }

    /// A single bare expression: never starts with a statement keyword, has no
    /// top-level `;`, and contains no `return`.
    fn bare_expr() -> impl Strategy<Value = String> {
        prop_oneof![
            ident(),
            (ident(), ident()).prop_map(|(a, b)| format!("{a} + {b}")),
            (ident(), ident()).prop_map(|(a, b)| format!("{a}({b})")),
            ident().prop_map(|a| format!("{a}.length")),
            any::<u16>().prop_map(|n| n.to_string()),
        ]
    }

    proptest! {
        /// Must never panic or hang on ANY input — including malformed code,
        /// unbalanced quotes, and arbitrary unicode (the scanner indexes bytes).
        #[test]
        fn never_panics_on_arbitrary_input(s in ".{0,256}") {
            let _ = should_prepend_return(&s);
        }

        /// A single bare expression is safe to wrap with `return` → true.
        #[test]
        fn bare_expressions_are_prepended(e in bare_expr()) {
            prop_assert!(should_prepend_return(&e), "bare expr not prepended: {e:?}");
        }

        /// THE critical bug class: `<expr>; return <expr>` must NOT be prepended
        /// (else `return <expr>;` runs and the rest is silently discarded).
        #[test]
        fn semicolon_multistatement_with_return_never_prepended(
            setup in bare_expr(), ret in bare_expr()
        ) {
            let code = format!("{setup}; return {ret}");
            prop_assert!(!should_prepend_return(&code), "would corrupt: {code:?}");
        }

        /// Newline-separated (ASI) explicit return must also be left as-is.
        #[test]
        fn newline_explicit_return_never_prepended(pre in bare_expr(), ret in bare_expr()) {
            let code = format!("{pre}\nreturn {ret}");
            prop_assert!(!should_prepend_return(&code), "explicit return prepended: {code:?}");
        }

        /// `;` or the word `return` INSIDE a string literal must not trigger a
        /// false multi-statement split — a bare string is one expression.
        #[test]
        fn semicolons_and_return_inside_strings_are_ignored(inner in "[a-z0-9;= ]{0,24}") {
            // `inner` never contains a quote, so the literal is well-formed.
            let code = format!("'do;not;split return {inner}'");
            prop_assert!(should_prepend_return(&code), "string literal mis-split: {code:?}");
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn env_filter_drops_secrets_keeps_safe() {
        // Safe, non-secret vars pass.
        assert!(is_safe_env_key("HOME"));
        assert!(is_safe_env_key("LANG"));
        assert!(is_safe_env_key("TAURI_ENV_PLATFORM"));
        assert!(is_safe_env_key("VICTAURI_PORT"));
        // Secret-looking vars are dropped even under a safe prefix (audit #5).
        assert!(!is_safe_env_key("TAURI_SIGNING_PRIVATE_KEY"));
        assert!(!is_safe_env_key("TAURI_SIGNING_PRIVATE_KEY_PASSWORD"));
        assert!(!is_safe_env_key("VICTAURI_AUTH_TOKEN"));
        assert!(!is_safe_env_key("VICTAURI_API_KEY"));
        // Unknown prefixes are dropped regardless.
        assert!(!is_safe_env_key("AWS_SECRET_ACCESS_KEY"));
        assert!(!is_safe_env_key("RANDOM_VAR"));
        // The broad TAURI_ namespace is no longer allowed — only TAURI_ENV_ — so
        // app-custom TAURI_ secrets are dropped even without a denylist hit.
        assert!(!is_safe_env_key("TAURI_CUSTOM_THING"));
        // Adversarial leaks closed (audit #5 follow-up): connection strings,
        // passphrases, PATs, JWTs, etc. under an allowed prefix.
        assert!(!is_safe_env_key("VICTAURI_DB_DSN"));
        assert!(!is_safe_env_key("VICTAURI_SIGNING_PASSPHRASE"));
        assert!(!is_safe_env_key("VICTAURI_GH_PAT"));
        assert!(!is_safe_env_key("VICTAURI_JWT"));
        assert!(!is_safe_env_key("VICTAURI_SESSION_ID"));
    }

    #[test]
    fn prepend_return_bare_expressions() {
        assert!(should_prepend_return("document.title"));
        assert!(should_prepend_return("5 + 5"));
        assert!(should_prepend_return("\"justexpr\""));
        assert!(should_prepend_return("await fetch('/x')"));
        assert!(should_prepend_return(
            "document.querySelectorAll('a').length"
        ));
        assert!(should_prepend_return("x ? a : b"));
        // Single trailing semicolon on a bare expression is still an expression.
        assert!(should_prepend_return("document.title;"));
        // Semicolons inside strings must not be treated as boundaries.
        assert!(should_prepend_return("'a;b;c'"));
        assert!(should_prepend_return("\"x;y\".length"));
        // IIFE workaround: the `;` lives inside the arrow body (depth > 0).
        assert!(should_prepend_return("(()=>{window.x=5; return 'ok'})()"));
    }

    #[test]
    fn no_prepend_for_statement_blocks() {
        // The original silent-corruption cases.
        assert!(!should_prepend_return(
            "localStorage.setItem('k','v'); return localStorage.getItem('k')"
        ));
        assert!(!should_prepend_return(
            "window.scrollTo(0,50); return window.scrollY"
        ));
        assert!(!should_prepend_return("console.log('x'); return 123"));
        assert!(!should_prepend_return("window.__z=7; return 'ok'"));
        // Explicit return without a preceding semicolon (newline-separated).
        assert!(!should_prepend_return("window.x = 5\nreturn window.x"));
    }

    #[test]
    fn no_prepend_for_statement_keywords() {
        assert!(!should_prepend_return("return 42"));
        assert!(!should_prepend_return("const x = 1; return x"));
        assert!(!should_prepend_return("let y = 2"));
        assert!(!should_prepend_return("var z = 3"));
        assert!(!should_prepend_return("if (x) { return 1 }"));
        assert!(!should_prepend_return("for (const x of y) doThing(x)"));
        assert!(!should_prepend_return("throw new Error('x')"));
        assert!(!should_prepend_return("function f(){}"));
        assert!(!should_prepend_return("{ a: 1 }")); // object-literal-as-block ambiguity → as-is
    }

    #[test]
    fn empty_code_no_prepend() {
        assert!(!should_prepend_return(""));
        assert!(!should_prepend_return("   "));
    }

    #[test]
    fn envelope_unwrap_value() {
        assert_eq!(
            unwrap_eval_envelope(r#"{"__victauri_ok":"4DA","__victauri_type":"value"}"#.into()),
            Ok("\"4DA\"".to_string())
        );
        assert_eq!(
            unwrap_eval_envelope(r#"{"__victauri_ok":42,"__victauri_type":"value"}"#.into()),
            Ok("42".to_string())
        );
    }

    #[test]
    fn envelope_unwrap_undefined_null() {
        assert_eq!(
            unwrap_eval_envelope(r#"{"__victauri_ok":null,"__victauri_type":"undefined"}"#.into()),
            Ok("undefined".to_string())
        );
        assert_eq!(
            unwrap_eval_envelope(r#"{"__victauri_ok":null,"__victauri_type":"null"}"#.into()),
            Ok("null".to_string())
        );
    }

    #[test]
    fn envelope_unwrap_error() {
        let r = unwrap_eval_envelope(r#"{"__victauri_err":"boom"}"#.into());
        assert!(r.unwrap_err().contains("boom"));
    }

    #[test]
    fn envelope_unwrap_deeply_nested_does_not_leak() {
        // Build an envelope whose value is nested far deeper than serde_json's
        // default recursion limit (128). The full parse fails, so the slice
        // fallback must return the value — NOT the raw `__victauri_ok` envelope.
        let mut value = String::from("0");
        for _ in 0..300 {
            value = format!("{{\"n\":{value}}}");
        }
        let raw = format!(r#"{{"__victauri_ok":{value},"__victauri_type":"value"}}"#);
        let out = unwrap_eval_envelope(raw).unwrap();
        assert!(
            out.starts_with(r#"{"n":"#),
            "deep value should be unwrapped, got: {}",
            &out[..out.len().min(40)]
        );
        assert!(
            !out.contains("__victauri_ok"),
            "envelope must not leak into the result"
        );
    }

    #[test]
    fn js_string_simple() {
        assert_eq!(js_string("hello"), "\"hello\"");
    }

    #[test]
    fn js_string_single_quotes() {
        let result = js_string("it's a test");
        assert!(result.contains("it's a test"));
    }

    #[test]
    fn js_string_double_quotes() {
        let result = js_string(r#"say "hello""#);
        assert!(result.contains(r#"\""#));
    }

    #[test]
    fn js_string_backslashes() {
        let result = js_string(r"path\to\file");
        assert!(result.contains(r"\\"));
    }

    #[test]
    fn js_string_newlines_and_tabs() {
        let result = js_string("line1\nline2\ttab");
        assert!(result.contains(r"\n"));
        assert!(result.contains(r"\t"));
        assert!(!result.contains('\n'));
    }

    #[test]
    fn js_string_null_bytes() {
        let input = String::from_utf8(b"before\x00after".to_vec()).unwrap();
        let result = js_string(&input);
        // serde_json escapes null bytes as
        assert!(result.contains("\\u0000"));
        assert!(!result.contains('\0'));
    }

    #[test]
    fn js_string_template_literal_injection() {
        let result = js_string("`${alert(1)}`");
        // Should not contain unescaped backticks that could break template literals
        // serde_json wraps in double quotes, so backticks are safe
        assert!(result.starts_with('"'));
        assert!(result.ends_with('"'));
    }

    #[test]
    fn js_string_unicode_separators() {
        // U+2028 (Line Separator) and U+2029 (Paragraph Separator) are valid in
        // JSON strings per RFC 8259, and serde_json passes them through literally.
        // Since js_string is used inside JS double-quoted strings (not template
        // literals), they are safe in modern JS engines (ES2019+).
        let result = js_string("a\u{2028}b\u{2029}c");
        // Verify the string is valid JSON that round-trips correctly
        let decoded: String = serde_json::from_str(&result).unwrap();
        assert_eq!(decoded, "a\u{2028}b\u{2029}c");
    }

    #[test]
    fn js_string_empty() {
        assert_eq!(js_string(""), "\"\"");
    }

    #[test]
    fn js_string_html_script_close() {
        // </script> in a JS string inside HTML could break out of script tags
        let result = js_string("</script><img onerror=alert(1)>");
        assert!(result.starts_with('"'));
        // The string is JSON-encoded; verify it round-trips safely
        let decoded: String = serde_json::from_str(&result).unwrap();
        assert_eq!(decoded, "</script><img onerror=alert(1)>");
    }

    #[test]
    fn js_string_very_long() {
        let long = "a".repeat(100_000);
        let result = js_string(&long);
        assert!(result.len() >= 100_002); // quotes + content
    }

    // ── URL validation tests ────────────────────────────────────────────────

    #[test]
    fn url_allows_http() {
        assert!(validate_url("http://example.com", false).is_ok());
    }

    #[test]
    fn url_allows_https() {
        assert!(validate_url("https://example.com/path?q=1", false).is_ok());
    }

    #[test]
    fn url_allows_http_localhost() {
        assert!(validate_url("http://localhost:3000", false).is_ok());
    }

    #[test]
    fn url_blocks_file_by_default() {
        let err = validate_url("file:///etc/passwd", false).unwrap_err();
        assert!(err.contains("file"), "error should mention the file scheme");
    }

    #[test]
    fn url_allows_file_when_opted_in() {
        assert!(validate_url("file:///tmp/test.html", true).is_ok());
    }

    #[test]
    fn url_blocks_javascript() {
        assert!(validate_url("javascript:alert(1)", false).is_err());
    }

    #[test]
    fn url_blocks_javascript_case_insensitive() {
        assert!(validate_url("JAVASCRIPT:alert(1)", false).is_err());
    }

    #[test]
    fn url_blocks_data_scheme() {
        assert!(validate_url("data:text/html,<script>alert(1)</script>", false).is_err());
    }

    #[test]
    fn url_blocks_vbscript() {
        assert!(validate_url("vbscript:MsgBox(1)", false).is_err());
    }

    #[test]
    fn url_rejects_invalid() {
        assert!(validate_url("not a url at all", false).is_err());
    }

    #[test]
    fn url_strips_control_chars() {
        // Control characters should be stripped, leaving a valid URL
        let input = format!("http://example{}com", '\0');
        assert!(validate_url(&input, false).is_ok());
    }

    // ── CSS color sanitization tests ───────────────────────────────────────

    #[test]
    fn css_color_valid_hex() {
        assert_eq!(sanitize_css_color("#ff0000").unwrap(), "#ff0000");
        assert_eq!(sanitize_css_color("#FFF").unwrap(), "#FFF");
        assert_eq!(sanitize_css_color("#12345678").unwrap(), "#12345678");
    }

    #[test]
    fn css_color_valid_rgb() {
        assert_eq!(
            sanitize_css_color("rgb(255, 0, 0)").unwrap(),
            "rgb(255, 0, 0)"
        );
        assert_eq!(
            sanitize_css_color("rgba(0, 0, 0, 0.5)").unwrap(),
            "rgba(0, 0, 0, 0.5)"
        );
    }

    #[test]
    fn css_color_valid_named() {
        assert_eq!(sanitize_css_color("red").unwrap(), "red");
        assert_eq!(sanitize_css_color("transparent").unwrap(), "transparent");
    }

    #[test]
    fn css_color_valid_hsl() {
        assert_eq!(
            sanitize_css_color("hsl(120, 50%, 50%)").unwrap(),
            "hsl(120, 50%, 50%)"
        );
    }

    #[test]
    fn css_color_rejects_too_long() {
        let long = "a".repeat(101);
        assert!(sanitize_css_color(&long).is_err());
    }

    #[test]
    fn css_color_rejects_backslash_escapes() {
        assert!(sanitize_css_color(r"red\00").is_err());
        assert!(sanitize_css_color(r"\72\65\64").is_err());
    }

    #[test]
    fn css_color_rejects_url_injection() {
        assert!(sanitize_css_color("url(http://evil.com)").is_err());
        assert!(sanitize_css_color("URL(http://evil.com)").is_err());
    }

    #[test]
    fn css_color_rejects_expression_injection() {
        assert!(sanitize_css_color("expression(alert(1))").is_err());
        assert!(sanitize_css_color("EXPRESSION(alert(1))").is_err());
    }

    #[test]
    fn css_color_rejects_import() {
        assert!(sanitize_css_color("@import url(evil.css)").is_err());
    }

    #[test]
    fn css_color_rejects_semicolons_and_braces() {
        assert!(sanitize_css_color("red; background: url(evil)").is_err());
        assert!(sanitize_css_color("red} body { color: blue").is_err());
    }

    #[test]
    fn css_color_rejects_special_chars() {
        assert!(sanitize_css_color("red<script>").is_err());
        assert!(sanitize_css_color("red\"onload=alert").is_err());
        assert!(sanitize_css_color("red'onclick=alert").is_err());
    }

    #[test]
    fn css_color_trims_whitespace() {
        assert_eq!(sanitize_css_color("  red  ").unwrap(), "red");
    }

    #[test]
    fn css_color_empty_string() {
        assert_eq!(sanitize_css_color("").unwrap(), "");
    }
}