forge-sandbox 0.5.1

//! Audit logging for sandbox executions.
//!
//! Every sandbox execution emits an [`AuditEntry`] containing:
//! - Execution ID (UUID)
//! - SHA-256 hash of the code (never raw code in logs)
//! - A preview of the first 500 chars of code
//! - Tool calls made (with hashed args, not raw)
//! - Duration and outcome
//!
//! The [`AuditLogger`] trait allows pluggable backends.
//! [`JsonLinesAuditLogger`] writes newline-delimited JSON to any `AsyncWrite`.

use chrono::{DateTime, Utc};
use serde::Serialize;
use sha2::{Digest, Sha256};
use std::sync::Arc;
use std::time::Instant;
use tokio::io::{AsyncWrite, AsyncWriteExt};
use tokio::sync::Mutex;
use uuid::Uuid;

/// Maximum length of the code preview in audit entries.
const CODE_PREVIEW_MAX: usize = 500;

/// A complete audit record for a single sandbox execution.
#[derive(Debug, Clone, Serialize)]
pub struct AuditEntry {
    /// Unique execution identifier.
    pub execution_id: String,
    /// ISO-8601 timestamp of when execution started.
    pub timestamp: DateTime<Utc>,
    /// SHA-256 hash of the submitted code.
    pub code_hash: String,
    /// First N characters of the code (for human review).
    pub code_preview: String,
    /// Whether this was a search or execute call.
    pub operation: AuditOperation,
    /// Tool calls made during execution.
    pub tool_calls: Vec<ToolCallAudit>,
    /// Resource reads made during execution.
    pub resource_reads: Vec<ResourceReadAudit>,
    /// Stash operations made during execution (SR-ST9).
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub stash_operations: Vec<StashOperationAudit>,
    /// Total execution duration in milliseconds.
    pub duration_ms: u64,
    /// Size of the result in bytes.
    pub result_size_bytes: usize,
    /// Final outcome.
    pub outcome: AuditOutcome,
    /// Whether a pooled worker was reused (vs. cold start).
    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
    pub worker_reused: bool,
    /// Pool size when this execution acquired a worker. None if no pool.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub pool_size_at_acquire: Option<usize>,
}

/// The type of sandbox operation.
#[derive(Debug, Clone, Serialize)]
#[serde(rename_all = "snake_case")]
#[non_exhaustive]
pub enum AuditOperation {
    /// A manifest search operation.
    Search,
    /// A code execution operation with tool access.
    Execute,
}

/// Audit record for a single tool call within an execution.
#[derive(Debug, Clone, Serialize)]
pub struct ToolCallAudit {
    /// Target server name.
    pub server: String,
    /// Tool identifier.
    pub tool: String,
    /// SHA-256 hash of the serialized arguments (args never stored raw).
    pub args_hash: String,
    /// Duration of this tool call in milliseconds.
    pub duration_ms: u64,
    /// Whether the tool call succeeded.
    pub success: bool,
}

/// Audit record for a single resource read within an execution.
#[derive(Debug, Clone, Serialize)]
pub struct ResourceReadAudit {
    /// Target server name.
    pub server: String,
    /// SHA-256 hash of the resource URI (URIs never stored raw in audit logs).
    pub uri_hash: String,
    /// Size of the resource content in bytes.
    pub size_bytes: usize,
    /// Duration of this resource read in milliseconds.
    pub duration_ms: u64,
    /// Whether the resource read succeeded.
    pub success: bool,
}

/// Type of stash operation for audit logging.
#[derive(Debug, Clone, Serialize)]
#[serde(rename_all = "snake_case")]
#[non_exhaustive]
pub enum StashOpType {
    /// Store a value.
    Put,
    /// Retrieve a value.
    Get,
    /// Delete an entry.
    Delete,
    /// List visible keys.
    Keys,
}

/// Audit record for a single stash operation within an execution.
///
/// Per SR-ST9: key name is logged but value content is NOT — only `size_bytes`.
#[derive(Debug, Clone, Serialize)]
pub struct StashOperationAudit {
    /// Type of stash operation.
    pub op_type: StashOpType,
    /// The stash key (name only, never the value).
    pub key: String,
    /// Size of the value in bytes (for put), 0 for other operations.
    pub size_bytes: usize,
    /// Duration of this operation in milliseconds.
    pub duration_ms: u64,
    /// Whether the operation succeeded.
    pub success: bool,
}

/// The outcome of a sandbox execution.
#[derive(Debug, Clone, Serialize)]
#[serde(rename_all = "snake_case")]
#[non_exhaustive]
pub enum AuditOutcome {
    /// Execution completed successfully.
    Success,
    /// Execution failed with an error.
    Error {
        /// The error message.
        message: String,
    },
    /// Execution was terminated due to timeout.
    Timeout,
}

/// Trait for audit log backends.
#[async_trait::async_trait]
pub trait AuditLogger: Send + Sync {
    /// Write an audit entry.
    async fn log(&self, entry: &AuditEntry);
}

/// Writes audit entries as newline-delimited JSON to an `AsyncWrite` sink.
pub struct JsonLinesAuditLogger<W: AsyncWrite + Unpin + Send> {
    writer: Mutex<W>,
}

impl<W: AsyncWrite + Unpin + Send> JsonLinesAuditLogger<W> {
    /// Create a new JSON lines audit logger writing to the given sink.
    pub fn new(writer: W) -> Self {
        Self {
            writer: Mutex::new(writer),
        }
    }
}

#[async_trait::async_trait]
impl<W: AsyncWrite + Unpin + Send + 'static> AuditLogger for JsonLinesAuditLogger<W> {
    async fn log(&self, entry: &AuditEntry) {
        let mut line = match serde_json::to_string(entry) {
            Ok(json) => json,
            Err(e) => {
                tracing::warn!(error = %e, "failed to serialize audit entry");
                return;
            }
        };
        line.push('\n');

        let mut writer = self.writer.lock().await;
        if let Err(e) = writer.write_all(line.as_bytes()).await {
            tracing::warn!(error = %e, "failed to write audit entry");
        }
        let _ = writer.flush().await;
    }
}

/// Compute the SHA-256 hash of a string, returned as a hex string.
pub fn sha256_hex(data: &str) -> String {
    let mut hasher = Sha256::new();
    hasher.update(data.as_bytes());
    let result = hasher.finalize();
    hex_encode(&result)
}

/// Encode bytes as a hex string.
fn hex_encode(bytes: &[u8]) -> String {
    let mut s = String::with_capacity(bytes.len() * 2);
    for b in bytes {
        s.push_str(&format!("{:02x}", b));
    }
    s
}

/// Create a code preview (first N bytes, with ellipsis if truncated).
///
/// Truncates at a valid UTF-8 char boundary to avoid panics on multibyte characters.
pub fn code_preview(code: &str) -> String {
    if code.len() <= CODE_PREVIEW_MAX {
        code.to_string()
    } else {
        let mut end = CODE_PREVIEW_MAX;
        while !code.is_char_boundary(end) {
            end -= 1;
        }
        let mut preview = code[..end].to_string();
        preview.push_str("...");
        preview
    }
}

/// Builder for constructing audit entries during execution.
pub struct AuditEntryBuilder {
    execution_id: String,
    timestamp: DateTime<Utc>,
    code_hash: String,
    code_preview: String,
    operation: AuditOperation,
    tool_calls: Vec<ToolCallAudit>,
    resource_reads: Vec<ResourceReadAudit>,
    stash_operations: Vec<StashOperationAudit>,
    start: Instant,
    worker_reused: bool,
    pool_size_at_acquire: Option<usize>,
}

impl AuditEntryBuilder {
    /// Start building an audit entry for an execution.
    pub fn new(code: &str, operation: AuditOperation) -> Self {
        Self {
            execution_id: Uuid::new_v4().to_string(),
            timestamp: Utc::now(),
            code_hash: sha256_hex(code),
            code_preview: crate::redact::redact_error_message(&code_preview(code)),
            operation,
            tool_calls: Vec::new(),
            resource_reads: Vec::new(),
            stash_operations: Vec::new(),
            start: Instant::now(),
            worker_reused: false,
            pool_size_at_acquire: None,
        }
    }

    /// Record a tool call.
    pub fn record_tool_call(&mut self, audit: ToolCallAudit) {
        self.tool_calls.push(audit);
    }

    /// Record a resource read.
    pub fn record_resource_read(&mut self, audit: ResourceReadAudit) {
        self.resource_reads.push(audit);
    }

    /// Record a stash operation.
    pub fn record_stash_op(&mut self, audit: StashOperationAudit) {
        self.stash_operations.push(audit);
    }

    /// Mark that a pooled worker was reused for this execution.
    pub fn worker_reused(&mut self, reused: bool) {
        self.worker_reused = reused;
    }

    /// Record the pool size when the worker was acquired.
    pub fn pool_size_at_acquire(&mut self, size: usize) {
        self.pool_size_at_acquire = Some(size);
    }

    /// Finalize the audit entry with the execution result.
    pub fn finish(self, result: &Result<serde_json::Value, crate::SandboxError>) -> AuditEntry {
        let duration_ms = self.start.elapsed().as_millis() as u64;
        let (result_size_bytes, outcome) = match result {
            Ok(value) => {
                let size = serde_json::to_string(value).map(|s| s.len()).unwrap_or(0);
                (size, AuditOutcome::Success)
            }
            Err(crate::SandboxError::Timeout { .. }) => (0, AuditOutcome::Timeout),
            Err(e) => (
                0,
                AuditOutcome::Error {
                    message: e.to_string(),
                },
            ),
        };

        AuditEntry {
            execution_id: self.execution_id,
            timestamp: self.timestamp,
            code_hash: self.code_hash,
            code_preview: self.code_preview,
            operation: self.operation,
            tool_calls: self.tool_calls,
            resource_reads: self.resource_reads,
            stash_operations: self.stash_operations,
            duration_ms,
            result_size_bytes,
            outcome,
            worker_reused: self.worker_reused,
            pool_size_at_acquire: self.pool_size_at_acquire,
        }
    }
}

/// A no-op audit logger for when auditing is not needed.
pub struct NoopAuditLogger;

#[async_trait::async_trait]
impl AuditLogger for NoopAuditLogger {
    async fn log(&self, _entry: &AuditEntry) {}
}

/// An audit logger that emits structured events via the [`tracing`] framework.
///
/// Audit entries are logged at `INFO` level with `audit = true` for easy
/// filtering. The entry's tool calls, resource reads, and stash operations
/// are summarised as counts to keep log lines concise.
///
/// Use `RUST_LOG=forge=info` to capture all audit events.
pub struct TracingAuditLogger;

#[async_trait::async_trait]
impl AuditLogger for TracingAuditLogger {
    async fn log(&self, entry: &AuditEntry) {
        let outcome = match &entry.outcome {
            AuditOutcome::Success => "success",
            AuditOutcome::Error { .. } => "error",
            AuditOutcome::Timeout => "timeout",
        };
        tracing::info!(
            audit = true,
            execution_id = %entry.execution_id,
            operation = ?entry.operation,
            code_hash = %entry.code_hash,
            duration_ms = entry.duration_ms,
            result_size_bytes = entry.result_size_bytes,
            tool_calls = entry.tool_calls.len(),
            resource_reads = entry.resource_reads.len(),
            stash_ops = entry.stash_operations.len(),
            outcome = outcome,
            "audit"
        );
    }
}

/// An audit-logging wrapper around a [`ToolDispatcher`] that records tool call metrics.
pub struct AuditingDispatcher {
    inner: Arc<dyn crate::ToolDispatcher>,
    audit_tx: tokio::sync::mpsc::UnboundedSender<ToolCallAudit>,
}

impl AuditingDispatcher {
    /// Wrap a dispatcher with audit recording.
    pub fn new(
        inner: Arc<dyn crate::ToolDispatcher>,
        audit_tx: tokio::sync::mpsc::UnboundedSender<ToolCallAudit>,
    ) -> Self {
        Self { inner, audit_tx }
    }
}

#[async_trait::async_trait]
impl crate::ToolDispatcher for AuditingDispatcher {
    async fn call_tool(
        &self,
        server: &str,
        tool: &str,
        args: serde_json::Value,
    ) -> Result<serde_json::Value, forge_error::DispatchError> {
        let args_hash = sha256_hex(&serde_json::to_string(&args).unwrap_or_default());
        let start = Instant::now();

        let result = self.inner.call_tool(server, tool, args).await;

        let audit = ToolCallAudit {
            server: server.to_string(),
            tool: tool.to_string(),
            args_hash,
            duration_ms: start.elapsed().as_millis() as u64,
            success: result.is_ok(),
        };
        let _ = self.audit_tx.send(audit);

        result
    }
}

/// An audit-logging wrapper around a [`ResourceDispatcher`] that records resource read metrics.
pub struct AuditingResourceDispatcher {
    inner: Arc<dyn crate::ResourceDispatcher>,
    audit_tx: tokio::sync::mpsc::UnboundedSender<ResourceReadAudit>,
}

impl AuditingResourceDispatcher {
    /// Wrap a resource dispatcher with audit recording.
    pub fn new(
        inner: Arc<dyn crate::ResourceDispatcher>,
        audit_tx: tokio::sync::mpsc::UnboundedSender<ResourceReadAudit>,
    ) -> Self {
        Self { inner, audit_tx }
    }
}

#[async_trait::async_trait]
impl crate::ResourceDispatcher for AuditingResourceDispatcher {
    async fn read_resource(
        &self,
        server: &str,
        uri: &str,
    ) -> Result<serde_json::Value, forge_error::DispatchError> {
        let uri_hash = sha256_hex(uri);
        let start = Instant::now();

        let result = self.inner.read_resource(server, uri).await;

        let size_bytes = result
            .as_ref()
            .ok()
            .and_then(|v| serde_json::to_string(v).ok())
            .map(|s| s.len())
            .unwrap_or(0);

        let audit = ResourceReadAudit {
            server: server.to_string(),
            uri_hash,
            size_bytes,
            duration_ms: start.elapsed().as_millis() as u64,
            success: result.is_ok(),
        };
        let _ = self.audit_tx.send(audit);

        result
    }
}

/// An audit-logging wrapper around a [`StashDispatcher`] that records stash operation metrics.
///
/// Per SR-ST9: logs key name and value size, never the value content itself.
pub struct AuditingStashDispatcher {
    inner: Arc<dyn crate::StashDispatcher>,
    audit_tx: tokio::sync::mpsc::UnboundedSender<StashOperationAudit>,
}

impl AuditingStashDispatcher {
    /// Wrap a stash dispatcher with audit recording.
    pub fn new(
        inner: Arc<dyn crate::StashDispatcher>,
        audit_tx: tokio::sync::mpsc::UnboundedSender<StashOperationAudit>,
    ) -> Self {
        Self { inner, audit_tx }
    }
}

#[async_trait::async_trait]
impl crate::StashDispatcher for AuditingStashDispatcher {
    async fn put(
        &self,
        key: &str,
        value: serde_json::Value,
        ttl_secs: Option<u32>,
        current_group: Option<String>,
    ) -> Result<serde_json::Value, forge_error::DispatchError> {
        let size_bytes = serde_json::to_string(&value).map(|s| s.len()).unwrap_or(0);
        let start = Instant::now();

        let result = self.inner.put(key, value, ttl_secs, current_group).await;

        let audit = StashOperationAudit {
            op_type: StashOpType::Put,
            key: key.to_string(),
            size_bytes,
            duration_ms: start.elapsed().as_millis() as u64,
            success: result.is_ok(),
        };
        let _ = self.audit_tx.send(audit);

        result
    }

    async fn get(
        &self,
        key: &str,
        current_group: Option<String>,
    ) -> Result<serde_json::Value, forge_error::DispatchError> {
        let start = Instant::now();

        let result = self.inner.get(key, current_group).await;

        let audit = StashOperationAudit {
            op_type: StashOpType::Get,
            key: key.to_string(),
            size_bytes: 0,
            duration_ms: start.elapsed().as_millis() as u64,
            success: result.is_ok(),
        };
        let _ = self.audit_tx.send(audit);

        result
    }

    async fn delete(
        &self,
        key: &str,
        current_group: Option<String>,
    ) -> Result<serde_json::Value, forge_error::DispatchError> {
        let start = Instant::now();

        let result = self.inner.delete(key, current_group).await;

        let audit = StashOperationAudit {
            op_type: StashOpType::Delete,
            key: key.to_string(),
            size_bytes: 0,
            duration_ms: start.elapsed().as_millis() as u64,
            success: result.is_ok(),
        };
        let _ = self.audit_tx.send(audit);

        result
    }

    async fn keys(
        &self,
        current_group: Option<String>,
    ) -> Result<serde_json::Value, forge_error::DispatchError> {
        let start = Instant::now();

        let result = self.inner.keys(current_group).await;

        let audit = StashOperationAudit {
            op_type: StashOpType::Keys,
            key: String::new(),
            size_bytes: 0,
            duration_ms: start.elapsed().as_millis() as u64,
            success: result.is_ok(),
        };
        let _ = self.audit_tx.send(audit);

        result
    }
}

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

    #[test]
    fn sha256_hex_produces_correct_hash() {
        // Known SHA-256 of "hello"
        let hash = sha256_hex("hello");
        assert_eq!(
            hash,
            "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824"
        );
    }

    #[test]
    fn code_preview_short_code_unchanged() {
        let code = "async () => { return 42; }";
        assert_eq!(code_preview(code), code);
    }

    #[test]
    fn code_preview_long_code_truncated() {
        let code = "x".repeat(1000);
        let preview = code_preview(&code);
        assert_eq!(preview.len(), 503); // 500 + "..."
        assert!(preview.ends_with("..."));
    }

    #[test]
    fn code_preview_multibyte_emoji_boundary() {
        // 499 ASCII bytes + U+1F600 (4 bytes) = 503 total, crosses the 500 boundary
        let mut code = "a".repeat(499);
        code.push('\u{1F600}'); // 😀 — 4 bytes
        code.push_str(&"b".repeat(100));
        let preview = code_preview(&code);
        assert!(preview.ends_with("..."));
        // Should truncate before the emoji since byte 500 is mid-char
        assert!(preview.starts_with(&"a".repeat(499)));
    }

    #[test]
    fn code_preview_all_emoji() {
        // 200 × U+1F600 (4 bytes each) = 800 bytes
        let code: String = "\u{1F600}".repeat(200);
        let preview = code_preview(&code);
        assert!(preview.ends_with("..."));
        // Verify valid UTF-8 (would panic on invalid)
        let _ = preview.chars().count();
    }

    #[test]
    fn code_preview_exact_500_ascii() {
        let code = "a".repeat(500);
        let preview = code_preview(&code);
        assert_eq!(preview, code); // no truncation, no "..."
    }

    #[test]
    fn code_preview_cjk_boundary() {
        // CJK chars are 3 bytes each: 167 × 3 = 501 bytes, crosses 500
        let code: String = "\u{4E00}".repeat(200); // 600 bytes
        let preview = code_preview(&code);
        assert!(preview.ends_with("..."));
        // Verify valid UTF-8
        let _ = preview.chars().count();
    }

    #[test]
    fn audit_entry_builder_success() {
        let code = "async () => { return 1; }";
        let builder = AuditEntryBuilder::new(code, AuditOperation::Execute);
        let result: Result<serde_json::Value, crate::SandboxError> = Ok(serde_json::json!(1));
        let entry = builder.finish(&result);

        assert!(!entry.execution_id.is_empty());
        assert_eq!(entry.code_preview, code);
        assert!(matches!(entry.outcome, AuditOutcome::Success));
        assert_eq!(entry.result_size_bytes, 1); // "1" = 1 byte
    }

    #[test]
    fn audit_entry_builder_error() {
        let code = "async () => { throw new Error('test'); }";
        let builder = AuditEntryBuilder::new(code, AuditOperation::Search);
        let result: Result<serde_json::Value, crate::SandboxError> =
            Err(crate::SandboxError::JsError {
                message: "test error".into(),
            });
        let entry = builder.finish(&result);

        assert!(matches!(entry.outcome, AuditOutcome::Error { .. }));
        if let AuditOutcome::Error { message } = &entry.outcome {
            assert!(message.contains("test error"));
        }
    }

    #[test]
    fn audit_entry_builder_timeout() {
        let code = "async () => { while(true) {} }";
        let builder = AuditEntryBuilder::new(code, AuditOperation::Execute);
        let result: Result<serde_json::Value, crate::SandboxError> =
            Err(crate::SandboxError::Timeout { timeout_ms: 5000 });
        let entry = builder.finish(&result);

        assert!(matches!(entry.outcome, AuditOutcome::Timeout));
    }

    #[tokio::test]
    async fn json_lines_logger_writes_valid_json() {
        let buf: Vec<u8> = Vec::new();
        let logger = JsonLinesAuditLogger::new(buf);

        let entry = AuditEntry {
            execution_id: "test-id".into(),
            timestamp: Utc::now(),
            code_hash: "abc123".into(),
            code_preview: "async () => {}".into(),
            operation: AuditOperation::Execute,
            tool_calls: vec![],
            resource_reads: vec![],
            stash_operations: vec![],
            duration_ms: 42,
            result_size_bytes: 10,
            outcome: AuditOutcome::Success,
            worker_reused: false,
            pool_size_at_acquire: None,
        };

        logger.log(&entry).await;

        let writer = logger.writer.lock().await;
        let output = String::from_utf8(writer.clone()).unwrap();
        assert!(output.ends_with('\n'));

        let parsed: serde_json::Value = serde_json::from_str(output.trim()).unwrap();
        assert_eq!(parsed["execution_id"], "test-id");
        assert_eq!(parsed["duration_ms"], 42);
        assert_eq!(parsed["outcome"], "success");
    }

    #[tokio::test]
    async fn json_lines_logger_with_tool_calls() {
        let buf: Vec<u8> = Vec::new();
        let logger = JsonLinesAuditLogger::new(buf);

        let entry = AuditEntry {
            execution_id: "test-id-2".into(),
            timestamp: Utc::now(),
            code_hash: "def456".into(),
            code_preview: "async () => { await forge.callTool(...); }".into(),
            operation: AuditOperation::Execute,
            tool_calls: vec![
                ToolCallAudit {
                    server: "narsil".into(),
                    tool: "ast.parse".into(),
                    args_hash: "hash1".into(),
                    duration_ms: 10,
                    success: true,
                },
                ToolCallAudit {
                    server: "github".into(),
                    tool: "issues.list".into(),
                    args_hash: "hash2".into(),
                    duration_ms: 25,
                    success: false,
                },
            ],
            resource_reads: vec![],
            stash_operations: vec![],
            duration_ms: 100,
            result_size_bytes: 500,
            outcome: AuditOutcome::Success,
            worker_reused: false,
            pool_size_at_acquire: None,
        };

        logger.log(&entry).await;

        let writer = logger.writer.lock().await;
        let output = String::from_utf8(writer.clone()).unwrap();
        let parsed: serde_json::Value = serde_json::from_str(output.trim()).unwrap();
        let calls = parsed["tool_calls"].as_array().unwrap();
        assert_eq!(calls.len(), 2);
        assert_eq!(calls[0]["server"], "narsil");
        assert_eq!(calls[1]["success"], false);
    }

    #[test]
    fn audit_entry_serializes_no_raw_credentials() {
        let entry = AuditEntry {
            execution_id: "id".into(),
            timestamp: Utc::now(),
            code_hash: "hash".into(),
            code_preview: "preview".into(),
            operation: AuditOperation::Execute,
            tool_calls: vec![ToolCallAudit {
                server: "s".into(),
                tool: "t".into(),
                args_hash: "args_are_hashed".into(),
                duration_ms: 1,
                success: true,
            }],
            resource_reads: vec![],
            stash_operations: vec![],
            duration_ms: 1,
            result_size_bytes: 0,
            outcome: AuditOutcome::Success,
            worker_reused: false,
            pool_size_at_acquire: None,
        };

        let json = serde_json::to_string(&entry).unwrap();
        // Verify that the JSON contains "args_hash" field, not "args"
        assert!(json.contains("args_hash"));
        assert!(!json.contains("\"args\""));
    }

    #[test]
    fn stash_operations_omitted_when_empty() {
        let entry = AuditEntry {
            execution_id: "id".into(),
            timestamp: Utc::now(),
            code_hash: "hash".into(),
            code_preview: "preview".into(),
            operation: AuditOperation::Execute,
            tool_calls: vec![],
            resource_reads: vec![],
            stash_operations: vec![],
            duration_ms: 1,
            result_size_bytes: 0,
            outcome: AuditOutcome::Success,
            worker_reused: false,
            pool_size_at_acquire: None,
        };
        let json = serde_json::to_string(&entry).unwrap();
        assert!(
            !json.contains("stash_operations"),
            "stash_operations should be omitted when empty"
        );
    }

    #[test]
    fn stash_operations_included_when_present() {
        let entry = AuditEntry {
            execution_id: "id".into(),
            timestamp: Utc::now(),
            code_hash: "hash".into(),
            code_preview: "preview".into(),
            operation: AuditOperation::Execute,
            tool_calls: vec![],
            resource_reads: vec![],
            stash_operations: vec![StashOperationAudit {
                op_type: StashOpType::Put,
                key: "mykey".into(),
                size_bytes: 42,
                duration_ms: 1,
                success: true,
            }],
            duration_ms: 1,
            result_size_bytes: 0,
            outcome: AuditOutcome::Success,
            worker_reused: false,
            pool_size_at_acquire: None,
        };
        let json = serde_json::to_string(&entry).unwrap();
        assert!(json.contains("stash_operations"));
        assert!(json.contains("mykey"));
        assert!(json.contains("\"size_bytes\":42"));
        // Value content must NOT appear in audit
        assert!(!json.contains("\"value\""));
    }

    #[tokio::test]
    async fn auditing_stash_dispatcher_records_operations() {
        use tokio::sync::mpsc;

        /// Minimal stash dispatcher that records nothing.
        struct NoopStash;

        #[async_trait::async_trait]
        impl crate::StashDispatcher for NoopStash {
            async fn put(
                &self,
                _key: &str,
                _value: serde_json::Value,
                _ttl_secs: Option<u32>,
                _current_group: Option<String>,
            ) -> Result<serde_json::Value, forge_error::DispatchError> {
                Ok(serde_json::json!({"ok": true}))
            }
            async fn get(
                &self,
                _key: &str,
                _current_group: Option<String>,
            ) -> Result<serde_json::Value, forge_error::DispatchError> {
                Ok(serde_json::Value::Null)
            }
            async fn delete(
                &self,
                _key: &str,
                _current_group: Option<String>,
            ) -> Result<serde_json::Value, forge_error::DispatchError> {
                Ok(serde_json::json!({"deleted": false}))
            }
            async fn keys(
                &self,
                _current_group: Option<String>,
            ) -> Result<serde_json::Value, forge_error::DispatchError> {
                Ok(serde_json::json!([]))
            }
        }

        let (tx, mut rx) = mpsc::unbounded_channel();
        let dispatcher = AuditingStashDispatcher::new(Arc::new(NoopStash), tx);

        // Exercise all four operations
        dispatcher
            .put("k1", serde_json::json!("hello"), None, None)
            .await
            .unwrap();
        dispatcher.get("k1", None).await.unwrap();
        dispatcher.delete("k1", None).await.unwrap();
        dispatcher.keys(None).await.unwrap();

        let mut audits = Vec::new();
        while let Ok(a) = rx.try_recv() {
            audits.push(a);
        }

        assert_eq!(audits.len(), 4, "should have 4 audit entries");
        assert!(matches!(audits[0].op_type, StashOpType::Put));
        assert_eq!(audits[0].key, "k1");
        assert!(audits[0].size_bytes > 0, "put should record value size");
        assert!(matches!(audits[1].op_type, StashOpType::Get));
        assert!(matches!(audits[2].op_type, StashOpType::Delete));
        assert!(matches!(audits[3].op_type, StashOpType::Keys));
        assert_eq!(audits[3].key, "", "keys op should have empty key");
        assert!(audits.iter().all(|a| a.success));
    }

    // --- Phase 7: TracingAuditLogger tests ---

    #[tokio::test]
    async fn ob_01_tracing_audit_logger_does_not_panic() {
        // TracingAuditLogger should handle any valid AuditEntry without panic.
        // We can't easily capture tracing output in tests, but we verify no panic.
        let logger = TracingAuditLogger;
        let entry = AuditEntry {
            execution_id: "trace-test".into(),
            timestamp: Utc::now(),
            code_hash: "abc".into(),
            code_preview: "async () => {}".into(),
            operation: AuditOperation::Execute,
            tool_calls: vec![ToolCallAudit {
                server: "s".into(),
                tool: "t".into(),
                args_hash: "h".into(),
                duration_ms: 5,
                success: true,
            }],
            resource_reads: vec![],
            stash_operations: vec![],
            duration_ms: 10,
            result_size_bytes: 100,
            outcome: AuditOutcome::Success,
            worker_reused: false,
            pool_size_at_acquire: None,
        };
        logger.log(&entry).await;
    }

    #[tokio::test]
    async fn ob_02_tracing_audit_logger_handles_error_outcome() {
        let logger = TracingAuditLogger;
        let entry = AuditEntry {
            execution_id: "err-test".into(),
            timestamp: Utc::now(),
            code_hash: "def".into(),
            code_preview: "async () => { throw new Error('x'); }".into(),
            operation: AuditOperation::Execute,
            tool_calls: vec![],
            resource_reads: vec![],
            stash_operations: vec![],
            duration_ms: 3,
            result_size_bytes: 0,
            outcome: AuditOutcome::Error {
                message: "test error".into(),
            },
            worker_reused: false,
            pool_size_at_acquire: None,
        };
        logger.log(&entry).await;
    }

    #[tokio::test]
    async fn ob_03_tracing_audit_logger_handles_timeout_outcome() {
        let logger = TracingAuditLogger;
        let entry = AuditEntry {
            execution_id: "timeout-test".into(),
            timestamp: Utc::now(),
            code_hash: "ghi".into(),
            code_preview: "async () => { while(true) {} }".into(),
            operation: AuditOperation::Search,
            tool_calls: vec![],
            resource_reads: vec![],
            stash_operations: vec![],
            duration_ms: 5000,
            result_size_bytes: 0,
            outcome: AuditOutcome::Timeout,
            worker_reused: false,
            pool_size_at_acquire: None,
        };
        logger.log(&entry).await;
    }

    #[tokio::test]
    async fn ob_04_audit_entry_never_contains_raw_code() {
        // Security: the audit entry must never contain the raw submitted code.
        // It should only store a SHA-256 hash and a truncated preview.
        let secret_code = "async () => { const API_KEY = 'sk-secret-12345'; return API_KEY; }";
        let builder = AuditEntryBuilder::new(secret_code, AuditOperation::Execute);
        let entry = builder.finish(&Ok(serde_json::json!("ok")));

        // The serialized entry should not have a raw "code" field — only code_hash and code_preview.
        let json = serde_json::to_string(&entry).expect("serialize");
        let parsed: serde_json::Value = serde_json::from_str(&json).expect("parse");
        assert!(
            parsed.get("code").is_none(),
            "serialized entry must not have a raw 'code' field"
        );
        assert!(
            parsed.get("code_hash").is_some(),
            "serialized entry must include code_hash"
        );
        // code_preview IS included (it's the first 500 chars) — that's by design
        // But the full code should not appear as a separate field
        assert_eq!(entry.code_hash, sha256_hex(secret_code));
        assert!(!entry.code_hash.contains("sk-secret"));
        // Verify the hash is a valid 64-char hex string (SHA-256)
        assert_eq!(entry.code_hash.len(), 64);
        assert!(entry.code_hash.chars().all(|c| c.is_ascii_hexdigit()));
    }

    #[tokio::test]
    async fn ob_05_audit_entry_code_preview_truncated() {
        let long_code = "x".repeat(1000);
        let builder = AuditEntryBuilder::new(&long_code, AuditOperation::Execute);
        let entry = builder.finish(&Ok(serde_json::json!(null)));

        // Preview should be truncated + "..."
        assert!(entry.code_preview.len() <= CODE_PREVIEW_MAX + 3); // +3 for "..."
        assert!(entry.code_preview.ends_with("..."));
    }

    #[tokio::test]
    async fn ob_06_audit_entry_serializes_all_fields() {
        // Verify the full audit entry serializes correctly with all field types populated.
        let entry = AuditEntry {
            execution_id: "test-id".into(),
            timestamp: Utc::now(),
            code_hash: sha256_hex("code"),
            code_preview: "code".into(),
            operation: AuditOperation::Execute,
            tool_calls: vec![ToolCallAudit {
                server: "srv".into(),
                tool: "t".into(),
                args_hash: "h".into(),
                duration_ms: 1,
                success: true,
            }],
            resource_reads: vec![ResourceReadAudit {
                server: "srv".into(),
                uri_hash: "uri_h".into(),
                size_bytes: 1024,
                duration_ms: 2,
                success: true,
            }],
            stash_operations: vec![StashOperationAudit {
                op_type: StashOpType::Put,
                key: "k".into(),
                size_bytes: 100,
                duration_ms: 1,
                success: true,
            }],
            duration_ms: 50,
            result_size_bytes: 200,
            outcome: AuditOutcome::Success,
            worker_reused: false,
            pool_size_at_acquire: None,
        };

        let json = serde_json::to_string(&entry).expect("serialize");
        let parsed: serde_json::Value = serde_json::from_str(&json).expect("parse");

        assert_eq!(parsed["execution_id"], "test-id");
        assert_eq!(parsed["tool_calls"][0]["server"], "srv");
        assert_eq!(parsed["resource_reads"][0]["size_bytes"], 1024);
        assert_eq!(parsed["stash_operations"][0]["op_type"], "put");
        assert_eq!(parsed["outcome"], "success");
    }

    #[tokio::test]
    async fn ob_07_tracing_audit_logger_with_all_fields() {
        // TracingAuditLogger should handle entries with tool_calls, resource_reads,
        // and stash_operations without panic, summarised as counts.
        let logger = TracingAuditLogger;
        let entry = AuditEntry {
            execution_id: "full-test".into(),
            timestamp: Utc::now(),
            code_hash: sha256_hex("test"),
            code_preview: "test".into(),
            operation: AuditOperation::Execute,
            tool_calls: vec![
                ToolCallAudit {
                    server: "s1".into(),
                    tool: "t1".into(),
                    args_hash: "h1".into(),
                    duration_ms: 5,
                    success: true,
                },
                ToolCallAudit {
                    server: "s2".into(),
                    tool: "t2".into(),
                    args_hash: "h2".into(),
                    duration_ms: 10,
                    success: false,
                },
            ],
            resource_reads: vec![ResourceReadAudit {
                server: "s1".into(),
                uri_hash: "uh".into(),
                size_bytes: 512,
                duration_ms: 3,
                success: true,
            }],
            stash_operations: vec![
                StashOperationAudit {
                    op_type: StashOpType::Put,
                    key: "k1".into(),
                    size_bytes: 50,
                    duration_ms: 1,
                    success: true,
                },
                StashOperationAudit {
                    op_type: StashOpType::Get,
                    key: "k1".into(),
                    size_bytes: 0,
                    duration_ms: 1,
                    success: true,
                },
            ],
            duration_ms: 100,
            result_size_bytes: 500,
            outcome: AuditOutcome::Success,
            worker_reused: false,
            pool_size_at_acquire: None,
        };
        // Should not panic with multiple tool_calls, resource_reads, stash_ops
        logger.log(&entry).await;
    }

    #[tokio::test]
    async fn ob_08_audit_entry_builder_execution_id_is_uuid() {
        let builder = AuditEntryBuilder::new("code", AuditOperation::Execute);
        let entry = builder.finish(&Ok(serde_json::json!(null)));
        // Execution ID should be a valid UUID v4
        assert!(
            uuid::Uuid::parse_str(&entry.execution_id).is_ok(),
            "execution_id should be a valid UUID: {}",
            entry.execution_id
        );
    }

    #[tokio::test]
    async fn ob_09_audit_outcome_error_redaction() {
        // Error messages in audit should not contain raw internal paths or stack traces
        // beyond what the error itself provides. Verify the mapping works correctly.
        let err = crate::SandboxError::Timeout { timeout_ms: 5000 };
        let builder = AuditEntryBuilder::new("code", AuditOperation::Execute);
        let entry = builder.finish(&Err(err));
        assert!(matches!(entry.outcome, AuditOutcome::Timeout));

        let err2 = crate::SandboxError::JsError {
            message: "ReferenceError: x is not defined".into(),
        };
        let builder2 = AuditEntryBuilder::new("code", AuditOperation::Execute);
        let entry2 = builder2.finish(&Err(err2));
        match &entry2.outcome {
            AuditOutcome::Error { message } => {
                assert!(message.contains("ReferenceError"));
            }
            other => panic!("expected Error outcome, got {:?}", other),
        }
    }

    // --- Phase R6: AuditEntry new fields ---

    #[tokio::test]
    async fn ae_01_audit_entry_worker_reused_defaults_false() {
        let builder = AuditEntryBuilder::new("code", AuditOperation::Execute);
        let entry = builder.finish(&Ok(serde_json::json!(null)));
        assert!(!entry.worker_reused);
    }

    #[tokio::test]
    async fn ae_02_audit_entry_pool_size_defaults_none() {
        let builder = AuditEntryBuilder::new("code", AuditOperation::Execute);
        let entry = builder.finish(&Ok(serde_json::json!(null)));
        assert!(entry.pool_size_at_acquire.is_none());
    }

    #[tokio::test]
    async fn ae_03_builder_sets_worker_reused() {
        let mut builder = AuditEntryBuilder::new("code", AuditOperation::Execute);
        builder.worker_reused(true);
        let entry = builder.finish(&Ok(serde_json::json!(null)));
        assert!(entry.worker_reused);
    }

    #[tokio::test]
    async fn ae_04_builder_sets_pool_size() {
        let mut builder = AuditEntryBuilder::new("code", AuditOperation::Execute);
        builder.pool_size_at_acquire(4);
        let entry = builder.finish(&Ok(serde_json::json!(null)));
        assert_eq!(entry.pool_size_at_acquire, Some(4));
    }

    #[tokio::test]
    async fn ae_05_new_fields_serialize_correctly() {
        let mut builder = AuditEntryBuilder::new("code", AuditOperation::Execute);
        builder.worker_reused(true);
        builder.pool_size_at_acquire(3);
        let entry = builder.finish(&Ok(serde_json::json!(null)));

        let json = serde_json::to_string(&entry).expect("serialize");
        let parsed: serde_json::Value = serde_json::from_str(&json).expect("parse");
        assert_eq!(parsed["worker_reused"], true);
        assert_eq!(parsed["pool_size_at_acquire"], 3);

        // When defaults: worker_reused should be skipped, pool_size_at_acquire should be skipped
        let builder2 = AuditEntryBuilder::new("code", AuditOperation::Execute);
        let entry2 = builder2.finish(&Ok(serde_json::json!(null)));
        let json2 = serde_json::to_string(&entry2).expect("serialize");
        let parsed2: serde_json::Value = serde_json::from_str(&json2).expect("parse");
        assert!(
            parsed2.get("worker_reused").is_none(),
            "worker_reused=false should be skipped"
        );
        assert!(
            parsed2.get("pool_size_at_acquire").is_none(),
            "pool_size_at_acquire=None should be skipped"
        );
    }

    // --- Phase 7 Gap #16: Audit code_preview redaction ---

    #[test]
    fn audit_l2_01_code_preview_redacts_api_keys() {
        // API keys in code_preview must be redacted before storage
        let code = "async () => { const key = 'Bearer sk-1234567890abcdef'; return key; }";
        let builder = AuditEntryBuilder::new(code, AuditOperation::Execute);
        let entry = builder.finish(&Ok(serde_json::json!("ok")));

        // The code_preview should have been redacted
        assert!(
            !entry.code_preview.contains("sk-1234567890abcdef"),
            "code_preview should not contain raw API key: {}",
            entry.code_preview
        );
        assert!(
            entry.code_preview.contains("[REDACTED]"),
            "code_preview should contain redaction marker: {}",
            entry.code_preview
        );
    }

    #[test]
    fn audit_l2_02_code_preview_preserves_safe_code() {
        // Safe code without credentials should pass through unchanged
        let code = "async () => { return 42; }";
        let builder = AuditEntryBuilder::new(code, AuditOperation::Execute);
        let entry = builder.finish(&Ok(serde_json::json!(42)));

        assert_eq!(
            entry.code_preview, code,
            "safe code_preview should be unchanged"
        );
    }
}