solo-api 0.5.0

// SPDX-License-Identifier: Apache-2.0

//! MCP (Model Context Protocol) server for Solo.
//!
//! Exposes eight tools to MCP clients (Claude Desktop, Cursor, etc.):
//!
//! Episode tools (v0.1+):
//!   - `memory_remember(content, source_type?, source_id?)` — store an
//!     episode. Returns the new MemoryId.
//!   - `memory_recall(query, limit?)` — vector search. Returns the top-K
//!     matches with content + tier + status.
//!   - `memory_forget(memory_id, reason?)` — soft-delete an episode.
//!   - `memory_inspect(memory_id)` — return the full episode record.
//!
//! Derived-layer tools (v0.4.0+):
//!   - `memory_themes(window_days?, limit?)` — list cluster themes.
//!   - `memory_facts_about(subject, ...)` — query the structured-fact
//!     knowledge graph (subject-predicate-object triples).
//!   - `memory_contradictions(limit?)` — disagreements flagged during
//!     consolidation.
//!
//! Derived-layer tools (v0.5.0+):
//!   - `memory_inspect_cluster(cluster_id, full_content?)` — drill
//!     into one cluster's abstraction + source episodes (truncated).
//!
//! ## Transport
//!
//! `serve_stdio` wires the server to stdin/stdout for use as a subprocess
//! ("`claude_desktop_config.json` or `~/.cursor/mcp.json` invokes
//! `solo mcp-stdio`"). The function awaits a graceful shutdown when stdin
//! closes (parent disconnects) — same lifecycle as `solo daemon`'s
//! Ctrl+C path.
//!
//! ## What's deferred
//!
//! - SSE/HTTP transports — `rmcp` ships them, but v0.1 ships stdio only.
//! - `prompts/` and `resources/` capabilities — not needed for the
//!   four-tool surface; ServerHandler defaults return empty lists.
//! - Tool argument validation beyond JSON Schema typing — we trust rmcp
//!   to deserialize per the schema, then serde-deserialize into our
//!   typed param structs. Bad inputs surface as clear errors.

use std::sync::Arc;

use rmcp::handler::server::ServerHandler;
use rmcp::model::{
    CallToolRequestParam, CallToolResult, Content, Implementation, ListToolsResult,
    PaginatedRequestParam, ProtocolVersion, ServerCapabilities, ServerInfo, Tool,
    ToolsCapability,
};
use rmcp::service::{RequestContext, RoleServer};
use rmcp::{Error as McpError, ServiceExt};
use serde::{Deserialize, Serialize};
use solo_core::{
    Confidence, Embedder, EncodingContext, Episode, MemoryId, Tier,
    VectorIndex,
};
use solo_storage::{ReaderPool, WriteHandle};
use std::str::FromStr;

/// The MCP server. Cheap to clone — every field is `Arc`-cloneable.
#[derive(Clone)]
pub struct SoloMcpServer {
    inner: Arc<Inner>,
}

struct Inner {
    write: WriteHandle,
    pool: ReaderPool,
    embedder: Arc<dyn Embedder>,
    hnsw: Arc<dyn VectorIndex + Send + Sync>,
    /// Read-path aliases for the canonical `"user"` subject. Sourced
    /// from `solo.config.toml` `[identity] user_aliases`; threaded
    /// through to `solo_query::facts_about` so a query for `"alex"`
    /// also surfaces rows historically extracted as `"user"`. Empty
    /// vec = behave as today (no expansion).
    user_aliases: Vec<String>,
}

impl SoloMcpServer {
    /// Build a server without identity-config aliases (back-compat
    /// constructor + tests). Equivalent to `new_with_identity` with an
    /// empty alias list.
    pub fn new(
        write: WriteHandle,
        pool: ReaderPool,
        embedder: Arc<dyn Embedder>,
        hnsw: Arc<dyn VectorIndex + Send + Sync>,
    ) -> Self {
        Self::new_with_identity(write, pool, embedder, hnsw, Vec::new())
    }

    /// Build a server, threading in `user_aliases` so `memory_facts_about`
    /// resolves the canonical `"user"` subject to + from each alias.
    /// Sourced from `solo.config.toml` `[identity] user_aliases`.
    pub fn new_with_identity(
        write: WriteHandle,
        pool: ReaderPool,
        embedder: Arc<dyn Embedder>,
        hnsw: Arc<dyn VectorIndex + Send + Sync>,
        user_aliases: Vec<String>,
    ) -> Self {
        Self {
            inner: Arc::new(Inner {
                write,
                pool,
                embedder,
                hnsw,
                user_aliases,
            }),
        }
    }
}

/// Convenience: run the server over stdio and await its termination.
/// Returns when stdin closes (parent disconnect) or the runtime exits.
pub async fn serve_stdio(server: SoloMcpServer) -> anyhow::Result<()> {
    use rmcp::transport::io::stdio;
    let (stdin, stdout) = stdio();
    let running = server.serve((stdin, stdout)).await?;
    running.waiting().await?;
    Ok(())
}

// ---------------------------------------------------------------------------
// Tool argument schemas
// ---------------------------------------------------------------------------

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RememberArgs {
    pub content: String,
    #[serde(default)]
    pub source_type: Option<String>,
    #[serde(default)]
    pub source_id: Option<String>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RecallArgs {
    pub query: String,
    #[serde(default = "default_limit")]
    pub limit: usize,
}

fn default_limit() -> usize {
    5
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ForgetArgs {
    pub memory_id: String,
    #[serde(default = "default_forget_reason")]
    pub reason: String,
}

fn default_forget_reason() -> String {
    "user-initiated via MCP".into()
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct InspectArgs {
    pub memory_id: String,
}

// Path 1 derived-layer tools (v0.4.0+) — query the Steward's outputs.
// `solo_query::derived` is the single source of truth; these handlers
// just translate JSON args to function args and serialise the result
// vec to JSON for the MCP wire.

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ThemesArgs {
    /// Optional time window in days; `None` = unfiltered, return up
    /// to `limit` most-recent themes across all time. `Some(7)` =
    /// "themes from the last week".
    #[serde(default)]
    pub window_days: Option<i64>,
    #[serde(default = "default_limit")]
    pub limit: usize,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct FactsAboutArgs {
    /// Subject id to query — required (predicate-only scans
    /// intentionally not supported).
    pub subject: String,
    #[serde(default)]
    pub predicate: Option<String>,
    #[serde(default)]
    pub since_ms: Option<i64>,
    #[serde(default)]
    pub until_ms: Option<i64>,
    #[serde(default = "default_limit")]
    pub limit: usize,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ContradictionsArgs {
    #[serde(default = "default_limit")]
    pub limit: usize,
}

/// Args for `memory_inspect_cluster` (v0.5.0 Priority 3). `cluster_id`
/// is required; `full_content` is opt-in for the rare power-user case
/// where 200-char-per-episode truncation is too aggressive.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct InspectClusterArgs {
    pub cluster_id: String,
    /// If `true`, episode `content` fields are returned verbatim. If
    /// `false` or omitted (the default), each episode's content is
    /// truncated to `solo_query::EPISODE_TRUNCATE_CHARS` chars with a
    /// trailing `…`.
    #[serde(default)]
    pub full_content: bool,
}

// ---------------------------------------------------------------------------
// ServerHandler implementation
// ---------------------------------------------------------------------------

impl ServerHandler for SoloMcpServer {
    fn get_info(&self) -> ServerInfo {
        ServerInfo {
            protocol_version: ProtocolVersion::default(),
            capabilities: ServerCapabilities {
                tools: Some(ToolsCapability {
                    list_changed: Some(false),
                }),
                ..Default::default()
            },
            server_info: Implementation {
                name: "solo".into(),
                version: env!("CARGO_PKG_VERSION").into(),
            },
            instructions: Some(
                "Solo gives you persistent memory across conversations \
                 with this user — what they've told you before, the \
                 people and projects in their life, and where their \
                 stated beliefs have shifted. Reach for these tools \
                 whenever the user references something from earlier \
                 (\"like I mentioned\", \"the project I'm working \
                 on\", \"my friend Alex\") or asks a question that \
                 hinges on personal context you don't have in the \
                 current chat. \
                 \n\nTools to write or look up specific moments: \
                 memory_remember (save something worth keeping), \
                 memory_recall (search past conversations by topic), \
                 memory_inspect (show one saved item by id), \
                 memory_forget (delete one saved item). \
                 \n\nTools for the bigger picture (populated as the \
                 user uses Solo over time): memory_themes (recent \
                 topics they've been thinking about), \
                 memory_facts_about (what you know about a person, \
                 project, or place — \"what do you know about \
                 Alex?\"), memory_contradictions (places where the \
                 user has said two things that disagree — surface \
                 these before answering), memory_inspect_cluster \
                 (the raw conversations behind one summary)."
                    .into(),
            ),
        }
    }

    async fn list_tools(
        &self,
        _request: PaginatedRequestParam,
        _context: RequestContext<RoleServer>,
    ) -> std::result::Result<ListToolsResult, McpError> {
        Ok(ListToolsResult {
            tools: build_tools(),
            next_cursor: None,
        })
    }

    async fn call_tool(
        &self,
        request: CallToolRequestParam,
        _context: RequestContext<RoleServer>,
    ) -> std::result::Result<CallToolResult, McpError> {
        let CallToolRequestParam { name, arguments } = request;
        let args_value = serde_json::Value::Object(arguments.unwrap_or_default());
        self.dispatch_tool(&name, args_value).await
    }
}

impl SoloMcpServer {
    /// Direct tool-dispatch path used by both `call_tool` (the
    /// ServerHandler trait method, behind the rmcp protocol layer) and
    /// in-process tests that don't want to spin up a full transport pair.
    /// Bypasses `RequestContext` (which requires a `Peer` not constructible
    /// outside rmcp internals).
    pub async fn dispatch_tool(
        &self,
        name: &str,
        args_value: serde_json::Value,
    ) -> std::result::Result<CallToolResult, McpError> {
        match name {
            "memory_remember" => {
                let args: RememberArgs = parse_args(&args_value)?;
                self.handle_remember(args).await
            }
            "memory_recall" => {
                let args: RecallArgs = parse_args(&args_value)?;
                self.handle_recall(args).await
            }
            "memory_forget" => {
                let args: ForgetArgs = parse_args(&args_value)?;
                self.handle_forget(args).await
            }
            "memory_inspect" => {
                let args: InspectArgs = parse_args(&args_value)?;
                self.handle_inspect(args).await
            }
            "memory_themes" => {
                let args: ThemesArgs = parse_args(&args_value)?;
                self.handle_themes(args).await
            }
            "memory_facts_about" => {
                let args: FactsAboutArgs = parse_args(&args_value)?;
                self.handle_facts_about(args).await
            }
            "memory_contradictions" => {
                let args: ContradictionsArgs = parse_args(&args_value)?;
                self.handle_contradictions(args).await
            }
            "memory_inspect_cluster" => {
                let args: InspectClusterArgs = parse_args(&args_value)?;
                self.handle_inspect_cluster(args).await
            }
            other => Err(McpError::invalid_params(
                format!("unknown tool `{other}`"),
                None,
            )),
        }
    }

    /// List the tools this server exposes. Mirrors `ServerHandler::list_tools`
    /// without requiring a RequestContext.
    pub fn dispatch_list_tools(&self) -> Vec<Tool> {
        build_tools()
    }
}

fn parse_args<T: serde::de::DeserializeOwned>(
    v: &serde_json::Value,
) -> std::result::Result<T, McpError> {
    serde_json::from_value(v.clone()).map_err(|e| {
        McpError::invalid_params(format!("invalid tool arguments: {e}"), None)
    })
}

fn solo_to_mcp(e: solo_core::Error) -> McpError {
    use solo_core::Error;
    match e {
        Error::NotFound(msg) => McpError::invalid_params(msg, None),
        Error::InvalidInput(msg) => McpError::invalid_params(msg, None),
        Error::Conflict(msg) => McpError::invalid_params(msg, None),
        other => McpError::internal_error(other.to_string(), None),
    }
}

// ---------------------------------------------------------------------------
// Tool definitions (JSON Schema)
// ---------------------------------------------------------------------------

fn build_tools() -> Vec<Tool> {
    vec![
        Tool::new(
            "memory_remember",
            "Save something the user has told you — a fact, a \
             preference, a name, a date, a context — so you can pick \
             it up next conversation. Use whenever the user mentions \
             something they'd reasonably expect you to recall later \
             (\"I just started at Quotient\", \"my partner is Maya\"). \
             Returns the saved item's id.",
            json_schema_object(serde_json::json!({
                "type": "object",
                "properties": {
                    "content": {
                        "type": "string",
                        "description": "The text to remember.",
                    },
                    "source_type": {
                        "type": "string",
                        "description": "Optional source-type tag (default: \"user_message\").",
                    },
                    "source_id": {
                        "type": "string",
                        "description": "Optional upstream id for traceability.",
                    },
                },
                "required": ["content"],
            })),
        ),
        Tool::new(
            "memory_recall",
            "Search past conversations with this user by topic or \
             phrase. Returns up to `limit` of the closest matches, \
             best match first. Use when the user references \
             something they said before (\"that book I told you \
             about\", \"the bug we were debugging last week\"). \
             Skips items the user has deleted.",
            json_schema_object(serde_json::json!({
                "type": "object",
                "properties": {
                    "query": {
                        "type": "string",
                        "description": "The query text.",
                    },
                    "limit": {
                        "type": "integer",
                        "description": "Maximum results (default 5).",
                        "minimum": 1,
                        "maximum": 100,
                    },
                },
                "required": ["query"],
            })),
        ),
        Tool::new(
            "memory_forget",
            "Delete one saved item by id. Use when the user asks you \
             to forget something specific (\"forget that I said \
             X\"). The item stops appearing in future recalls. \
             Reversible only via backups.",
            json_schema_object(serde_json::json!({
                "type": "object",
                "properties": {
                    "memory_id": {
                        "type": "string",
                        "description": "MemoryId to forget (UUID v7).",
                    },
                    "reason": {
                        "type": "string",
                        "description": "Optional free-form reason (logged, not yet persisted).",
                    },
                },
                "required": ["memory_id"],
            })),
        ),
        Tool::new(
            "memory_inspect",
            "Show the full record for one saved item — when it was \
             saved, where it came from, and the full text. Use after \
             memory_recall when you want the complete content of a \
             specific hit (recall results may be truncated).",
            json_schema_object(serde_json::json!({
                "type": "object",
                "properties": {
                    "memory_id": {
                        "type": "string",
                        "description": "MemoryId to inspect (UUID v7).",
                    },
                },
                "required": ["memory_id"],
            })),
        ),
        // Path 1 derived-layer tools (v0.4.0+) — query the Steward's
        // outputs. These four are populated by `solo consolidate` and
        // were previously unreadable except via direct SQL.
        Tool::new(
            "memory_themes",
            "Recent topics the user has been thinking about. Use to \
             orient yourself at the start of a conversation, or when \
             the user asks \"what have I been up to\" / \"what was I \
             working on last week\". Pass `window_days` to scope \
             (e.g. 7 for last week); omit for all-time.",
            json_schema_object(serde_json::json!({
                "type": "object",
                "properties": {
                    "window_days": {
                        "type": "integer",
                        "description": "Optional time window in days. Omit for unfiltered.",
                        "minimum": 1,
                    },
                    "limit": {
                        "type": "integer",
                        "description": "Maximum results (default 5).",
                        "minimum": 1,
                        "maximum": 100,
                    },
                },
            })),
        ),
        Tool::new(
            "memory_facts_about",
            "Look up what you remember about a person, project, or \
             topic — names, dates, preferences, relationships. Use \
             when the user asks \"what do you know about Alex?\", \
             \"when did I start at Quotient?\", \"who is Maya?\", or \
             whenever you need grounded facts about someone or \
             something before answering. Subject is required (the \
             person/place/thing you're asking about); narrow further \
             with `predicate` (\"works_at\", \"lives_in\") or a date \
             range. (Backed by subject-predicate-object triples \
             distilled from past conversations.)",
            json_schema_object(serde_json::json!({
                "type": "object",
                "properties": {
                    "subject": {
                        "type": "string",
                        "description": "Subject id to query (e.g. 'Sam').",
                    },
                    "predicate": {
                        "type": "string",
                        "description": "Optional predicate filter (e.g. 'works_at').",
                    },
                    "since_ms": {
                        "type": "integer",
                        "description": "Optional valid_from_ms lower bound (epoch ms).",
                    },
                    "until_ms": {
                        "type": "integer",
                        "description": "Optional valid_to_ms upper bound (epoch ms). NULL upper bounds (still-valid facts) pass through.",
                    },
                    "limit": {
                        "type": "integer",
                        "description": "Maximum results (default 5).",
                        "minimum": 1,
                        "maximum": 100,
                    },
                },
                "required": ["subject"],
            })),
        ),
        Tool::new(
            "memory_contradictions",
            "Find places where the user's stated beliefs or facts \
             disagree across conversations — flag disagreements \
             before answering. Use whenever you're about to rely on \
             a remembered fact that could have changed (jobs, \
             relationships, preferences, opinions); a disagreement \
             here means the user has told you both X and not-X over \
             time and you should ask which is current instead of \
             guessing. Each result shows both conflicting statements \
             with the topic.",
            json_schema_object(serde_json::json!({
                "type": "object",
                "properties": {
                    "limit": {
                        "type": "integer",
                        "description": "Maximum results (default 5).",
                        "minimum": 1,
                        "maximum": 100,
                    },
                },
            })),
        ),
        Tool::new(
            "memory_inspect_cluster",
            "Show the raw conversations behind one summary. Returns \
             the one-line topic (the LLM-generated summary) and the \
             source conversations the topic was built from. Use \
             after memory_themes when the user asks \"show me the \
             raw context behind this\" or \"why does Solo think \
             that about cluster Y\". Source items are truncated to \
             200 chars unless `full_content` is set.",
            json_schema_object(serde_json::json!({
                "type": "object",
                "properties": {
                    "cluster_id": {
                        "type": "string",
                        "description": "Cluster id to inspect (from memory_themes hits).",
                    },
                    "full_content": {
                        "type": "boolean",
                        "description": "If true, episode content is returned verbatim. Default false (truncate to 200 chars + ellipsis).",
                    },
                },
                "required": ["cluster_id"],
            })),
        ),
    ]
}

fn json_schema_object(value: serde_json::Value) -> serde_json::Map<String, serde_json::Value> {
    match value {
        serde_json::Value::Object(map) => map,
        _ => panic!("json_schema_object: input must be an object"),
    }
}

/// Names of every tool this server exposes, in registration order.
///
/// Exposed for cross-crate consumers (notably `solo doctor
/// --check-mcp-compat`) that want the name list without paying the
/// cost of building full `rmcp::Tool` records (which allocate JSON
/// schemas). The registration order matches `build_tools()` so any
/// drift between the two would be caught by the cross-provider regex
/// test which iterates `build_tools()`.
pub fn tool_names() -> Vec<&'static str> {
    vec![
        "memory_remember",
        "memory_recall",
        "memory_forget",
        "memory_inspect",
        "memory_themes",
        "memory_facts_about",
        "memory_contradictions",
        "memory_inspect_cluster",
    ]
}

// ---------------------------------------------------------------------------
// Tool handlers
// ---------------------------------------------------------------------------

impl SoloMcpServer {
    async fn handle_remember(
        &self,
        args: RememberArgs,
    ) -> std::result::Result<CallToolResult, McpError> {
        let content = args.content.trim_end().to_string();
        if content.is_empty() {
            return Err(McpError::invalid_params(
                "memory_remember: content must not be empty".to_string(),
                None,
            ));
        }
        let embedding: solo_core::Embedding = self
            .inner
            .embedder
            .embed(&content)
            .await
            .map_err(solo_to_mcp)?;
        let episode = Episode {
            memory_id: MemoryId::new(),
            ts_ms: chrono::Utc::now().timestamp_millis(),
            source_type: args.source_type.unwrap_or_else(|| "user_message".into()),
            source_id: args.source_id,
            content,
            encoding_context: EncodingContext::default(),
            provenance: None,
            confidence: Confidence::new(0.9).unwrap(),
            strength: 0.5,
            salience: 0.5,
            tier: Tier::Hot,
        };
        let mid = self
            .inner
            .write
            .remember(episode, embedding)
            .await
            .map_err(solo_to_mcp)?;
        Ok(CallToolResult::success(vec![Content::text(format!(
            "remembered {mid}"
        ))]))
    }

    async fn handle_recall(
        &self,
        args: RecallArgs,
    ) -> std::result::Result<CallToolResult, McpError> {
        // Pipeline lives in solo-query; the transport just formats the
        // result. solo_query::run_recall validates empty queries
        // (returns InvalidInput → invalid_params via solo_to_mcp).
        let result = solo_query::run_recall(
            &self.inner.embedder,
            &self.inner.hnsw,
            &self.inner.pool,
            &args.query,
            args.limit,
        )
        .await
        .map_err(solo_to_mcp)?;

        if result.hits.is_empty() {
            return Ok(CallToolResult::success(vec![Content::text(format!(
                "no matches (index has {} vectors)",
                result.index_len
            ))]));
        }
        let body = serde_json::to_string_pretty(&result.hits).unwrap_or_else(|_| String::new());
        Ok(CallToolResult::success(vec![Content::text(body)]))
    }

    async fn handle_forget(
        &self,
        args: ForgetArgs,
    ) -> std::result::Result<CallToolResult, McpError> {
        let mid = MemoryId::from_str(&args.memory_id).map_err(|e| {
            McpError::invalid_params(format!("invalid memory_id: {e}"), None)
        })?;
        self.inner
            .write
            .forget(mid, args.reason)
            .await
            .map_err(solo_to_mcp)?;
        Ok(CallToolResult::success(vec![Content::text(format!(
            "forgotten {mid}"
        ))]))
    }

    async fn handle_inspect(
        &self,
        args: InspectArgs,
    ) -> std::result::Result<CallToolResult, McpError> {
        let mid = MemoryId::from_str(&args.memory_id).map_err(|e| {
            McpError::invalid_params(format!("invalid memory_id: {e}"), None)
        })?;
        // Pipeline lives in solo-query::inspect; transports just format.
        let row = solo_query::inspect_one(&self.inner.pool, mid)
            .await
            .map_err(solo_to_mcp)?;
        let body = serde_json::to_string_pretty(&row).unwrap_or_else(|_| String::new());
        Ok(CallToolResult::success(vec![Content::text(body)]))
    }

    // Path 1 derived-layer handlers (v0.4.0+). Each one delegates to a
    // single solo-query::derived pipeline and serialises the result Vec
    // to pretty JSON for the MCP wire. Empty result → JSON empty array
    // `[]` (not a special-case "no matches" string) so MCP clients can
    // parse uniformly.

    async fn handle_themes(
        &self,
        args: ThemesArgs,
    ) -> std::result::Result<CallToolResult, McpError> {
        let hits = solo_query::themes(
            &self.inner.pool,
            args.window_days,
            args.limit,
        )
        .await
        .map_err(solo_to_mcp)?;
        let body = serde_json::to_string_pretty(&hits).unwrap_or_else(|_| String::new());
        Ok(CallToolResult::success(vec![Content::text(body)]))
    }

    async fn handle_facts_about(
        &self,
        args: FactsAboutArgs,
    ) -> std::result::Result<CallToolResult, McpError> {
        if args.subject.trim().is_empty() {
            return Err(McpError::invalid_params(
                "memory_facts_about: subject must not be empty".to_string(),
                None,
            ));
        }
        let hits = solo_query::facts_about(
            &self.inner.pool,
            &args.subject,
            &self.inner.user_aliases,
            args.predicate.as_deref(),
            args.since_ms,
            args.until_ms,
            args.limit,
        )
        .await
        .map_err(solo_to_mcp)?;
        let body = serde_json::to_string_pretty(&hits).unwrap_or_else(|_| String::new());
        Ok(CallToolResult::success(vec![Content::text(body)]))
    }

    async fn handle_contradictions(
        &self,
        args: ContradictionsArgs,
    ) -> std::result::Result<CallToolResult, McpError> {
        let hits = solo_query::contradictions(&self.inner.pool, args.limit)
            .await
            .map_err(solo_to_mcp)?;
        let body = serde_json::to_string_pretty(&hits).unwrap_or_else(|_| String::new());
        Ok(CallToolResult::success(vec![Content::text(body)]))
    }

    async fn handle_inspect_cluster(
        &self,
        args: InspectClusterArgs,
    ) -> std::result::Result<CallToolResult, McpError> {
        if args.cluster_id.trim().is_empty() {
            return Err(McpError::invalid_params(
                "memory_inspect_cluster: cluster_id must not be empty".to_string(),
                None,
            ));
        }
        // `solo_to_mcp` maps `Error::NotFound` → `invalid_params` for
        // MCP (the protocol does not have a separate "not found" error
        // shape; clients see the message verbatim, which includes the
        // cluster_id).
        let record = solo_query::inspect_cluster(
            &self.inner.pool,
            &args.cluster_id,
            args.full_content,
        )
        .await
        .map_err(solo_to_mcp)?;
        let body = serde_json::to_string_pretty(&record).unwrap_or_else(|_| String::new());
        Ok(CallToolResult::success(vec![Content::text(body)]))
    }
}

#[cfg(test)]
mod dispatch_tests {
    //! In-process integration tests for the MCP tool surface. We invoke
    //! `SoloMcpServer::dispatch_tool` directly (bypasses the rmcp
    //! protocol framing + `RequestContext`, which requires a `Peer`
    //! that's not constructible outside rmcp internals). The server is
    //! constructed against a real WriterActor + ReaderPool +
    //! StubEmbedder + StubVectorIndex from `solo_storage::test_support`.
    //!
    //! Tests live inline in this module rather than `tests/` because an
    //! external integration-test exe in `target/debug/deps/mcp_dispatch-*`
    //! tripped Windows UAC ERROR_ELEVATION_REQUIRED on the dev machine.
    //! The lib test binary doesn't have that issue.
    use super::*;
    use serde_json::json;
    use solo_core::VectorIndex;
    use solo_storage::test_support::StubVectorIndex;
    use solo_storage::{ReaderPool, StubEmbedder, WriterActor, WriterSpawn};
    use std::sync::Arc as StdArc;

    struct Harness {
        server: SoloMcpServer,
        _tmp: tempfile::TempDir,
        write_handle_extra: Option<solo_storage::WriteHandle>,
        join: Option<std::thread::JoinHandle<()>>,
    }

    impl Harness {
        fn new(runtime: &tokio::runtime::Runtime) -> Self {
            let tmp = tempfile::TempDir::new().unwrap();
            let dim = 16usize;
            let hnsw: StdArc<dyn VectorIndex + Send + Sync> = StdArc::new(StubVectorIndex::new(dim));
            let embedder: StdArc<dyn solo_core::Embedder> = StdArc::new(StubEmbedder::new("stub", "v1", dim));

            let conn = solo_storage::test_support::open_test_db_at(&tmp.path().join("test.db"));
            let WriterSpawn { handle, join } = WriterActor::spawn(conn, hnsw.clone());

            // ReaderPool's deadpool::Pool needs a live tokio runtime for
            // both build + drop; build inside block_on.
            let path = tmp.path().join("test.db");
            let pool: ReaderPool =
                runtime.block_on(async { ReaderPool::new(&path, None, hnsw.clone()).unwrap() });

            let server = SoloMcpServer::new(handle.clone(), pool, embedder, hnsw);
            Harness {
                server,
                _tmp: tmp,
                write_handle_extra: Some(handle),
                join: Some(join),
            }
        }

        fn shutdown(mut self, runtime: &tokio::runtime::Runtime) {
            // The whole shutdown runs inside block_on so deadpool-sqlite's
            // drop (which schedules cleanup on the active runtime) sees a
            // live reactor. Without this, dropping the SoloMcpServer
            // (which holds the ReaderPool through its Arc<Inner>) panics
            // with "no reactor running".
            let join = self.join.take();
            let extra = self.write_handle_extra.take();
            runtime.block_on(async move {
                drop(extra);
                drop(self.server);
                drop(self._tmp);
                if let Some(join) = join {
                    let (tx, rx) = std::sync::mpsc::channel();
                    std::thread::spawn(move || {
                        let _ = tx.send(join.join());
                    });
                    tokio::task::spawn_blocking(move || {
                        rx.recv_timeout(std::time::Duration::from_secs(5))
                    })
                    .await
                    .expect("blocking task")
                    .expect("writer thread did not exit within 5s")
                    .expect("writer thread panicked");
                }
            });
        }
    }

    fn rt() -> tokio::runtime::Runtime {
        tokio::runtime::Builder::new_multi_thread()
            .worker_threads(2)
            .enable_all()
            .build()
            .unwrap()
    }

    /// Pull the first Content::text body out of a CallToolResult. Use
    /// serde_json roundtrip as a robust extractor — `Content`'s public
    /// API doesn't directly expose the inner text without going through
    /// pattern-matching on RawContent.
    fn first_text(r: &rmcp::model::CallToolResult) -> String {
        let first = r.content.first().expect("at least one content item");
        let v = serde_json::to_value(first).expect("content serialises");
        v.get("text")
            .and_then(|t| t.as_str())
            .map(|s| s.to_string())
            .unwrap_or_else(|| format!("{v}"))
    }

    #[test]
    fn tools_list_returns_eight_canonical_tools() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        let tools = h.server.dispatch_list_tools();
        let names: Vec<&str> = tools.iter().map(|t| t.name.as_ref()).collect();
        assert_eq!(
            names,
            vec![
                "memory_remember",
                "memory_recall",
                "memory_forget",
                "memory_inspect",
                // Derived-layer tools added in v0.4.0:
                "memory_themes",
                "memory_facts_about",
                "memory_contradictions",
                // Added in v0.5.0 (Priority 3):
                "memory_inspect_cluster",
            ]
        );
        for t in &tools {
            assert!(!t.description.is_empty(), "{} description empty", t.name);
            let _schema = t.schema_as_json_value();
            // `required` is intentionally absent on memory_themes +
            // memory_contradictions (all args optional with defaults).
            // memory_facts_about does have required = ["subject"].
            // We don't assert per-tool 'required' shape here; the
            // schema's `properties` field is the more important
            // signal and is always present.
        }
        h.shutdown(&runtime);
    }

    #[test]
    fn themes_returns_json_array_on_empty_db() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            let r = h
                .server
                .dispatch_tool("memory_themes", json!({}))
                .await
                .expect("themes succeeds");
            let text = first_text(&r);
            // Empty derived layer → empty array JSON. Parses cleanly.
            let v: serde_json::Value =
                serde_json::from_str(&text).expect("parses as json");
            assert!(v.is_array(), "expected array, got: {text}");
            assert_eq!(v.as_array().unwrap().len(), 0);
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn themes_passes_through_window_and_limit_args() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            // Should not crash with optional + integer args present.
            let r = h
                .server
                .dispatch_tool(
                    "memory_themes",
                    json!({ "window_days": 7, "limit": 20 }),
                )
                .await
                .expect("themes with args succeeds");
            let text = first_text(&r);
            let v: serde_json::Value =
                serde_json::from_str(&text).expect("parses as json");
            assert!(v.is_array());
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn facts_about_rejects_empty_subject() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            let err = h
                .server
                .dispatch_tool(
                    "memory_facts_about",
                    json!({ "subject": "   " }),
                )
                .await
                .expect_err("empty subject must error");
            // McpError doesn't expose a clean kind/message accessor; just
            // verify the error fires (validation path reached).
            let s = format!("{err:?}");
            assert!(
                s.to_lowercase().contains("subject")
                    || s.to_lowercase().contains("invalid"),
                "got: {s}"
            );
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn facts_about_returns_array_for_unknown_subject() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            let r = h
                .server
                .dispatch_tool(
                    "memory_facts_about",
                    json!({ "subject": "NobodyKnowsThisSubject" }),
                )
                .await
                .expect("facts_about with unknown subject succeeds");
            let text = first_text(&r);
            let v: serde_json::Value =
                serde_json::from_str(&text).expect("parses as json");
            assert_eq!(v.as_array().unwrap().len(), 0);
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn contradictions_returns_json_array_on_empty_db() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            let r = h
                .server
                .dispatch_tool("memory_contradictions", json!({}))
                .await
                .expect("contradictions succeeds");
            let text = first_text(&r);
            let v: serde_json::Value =
                serde_json::from_str(&text).expect("parses as json");
            assert!(v.is_array());
            assert_eq!(v.as_array().unwrap().len(), 0);
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn remember_then_recall_round_trip() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        // Use &h.server directly (no clone) so the only outstanding
        // reference at shutdown time is the harness's own. The clone
        // path triggered a 5-second writer-thread timeout because the
        // local clone held an Arc<Inner> with its own WriteHandle past
        // h.shutdown().
        runtime.block_on(async {
            let r = h
                .server
                .dispatch_tool("memory_remember", json!({ "content": "the cat sat on the mat" }))
                .await
                .expect("remember succeeds");
            let text = first_text(&r);
            assert!(text.starts_with("remembered "), "got: {text}");

            let r = h
                .server
                .dispatch_tool(
                    "memory_recall",
                    json!({ "query": "the cat sat on the mat", "limit": 5 }),
                )
                .await
                .expect("recall succeeds");
            let text = first_text(&r);
            assert!(text.contains("the cat sat on the mat"), "got: {text}");
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn forget_excludes_row_from_subsequent_recall() {
        let runtime = rt();
        let h = Harness::new(&runtime);

        runtime.block_on(async {
            let r = h
                .server
                .dispatch_tool("memory_remember", json!({ "content": "to be forgotten" }))
                .await
                .unwrap();
            let text = first_text(&r);
            let mid = text.strip_prefix("remembered ").unwrap().to_string();

            h.server
                .dispatch_tool(
                    "memory_forget",
                    json!({ "memory_id": mid, "reason": "test" }),
                )
                .await
                .expect("forget succeeds");

            let r = h
                .server
                .dispatch_tool(
                    "memory_recall",
                    json!({ "query": "to be forgotten", "limit": 5 }),
                )
                .await
                .unwrap();
            let text = first_text(&r);
            assert!(
                !text.contains(r#""content": "to be forgotten""#),
                "forgotten row should be excluded; got: {text}"
            );
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn empty_remember_returns_invalid_params() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            let err = h
                .server
                .dispatch_tool("memory_remember", json!({ "content": "" }))
                .await
                .unwrap_err();
            assert!(format!("{err:?}").contains("must not be empty"));
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn empty_recall_query_returns_invalid_params() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            let err = h
                .server
                .dispatch_tool("memory_recall", json!({ "query": "   " }))
                .await
                .unwrap_err();
            assert!(format!("{err:?}").contains("must not be empty"));
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn inspect_with_invalid_id_returns_invalid_params() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            let err = h
                .server
                .dispatch_tool("memory_inspect", json!({ "memory_id": "not-a-uuid" }))
                .await
                .unwrap_err();
            assert!(format!("{err:?}").contains("invalid memory_id"));
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn forget_unknown_id_returns_invalid_params() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            // Valid UUID format but not in episodes — handle_forget
            // surfaces NotFound, mapped to invalid_params per
            // solo_to_mcp.
            let err = h
                .server
                .dispatch_tool(
                    "memory_forget",
                    json!({ "memory_id": "00000000-0000-7000-8000-000000000000" }),
                )
                .await
                .unwrap_err();
            assert!(format!("{err:?}").contains("not found"));
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn unknown_tool_name_returns_invalid_params() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            let err = h
                .server
                .dispatch_tool("memory.summon", json!({}))
                .await
                .unwrap_err();
            assert!(format!("{err:?}").contains("unknown tool"));
        });
        h.shutdown(&runtime);
    }

    /// Regression guard for v0.4.1's MCP tool name fix, generalised
    /// in v0.5.0 Priority 4 to cover **all three** major LLM
    /// providers, not just Anthropic.
    ///
    /// Each provider enforces its own tool-name regex on the
    /// function-calling wire. A tool name has to satisfy ALL of them
    /// to be portable across clients:
    ///
    ///   - **Anthropic**: `^[a-zA-Z0-9_-]{1,64}$` (what shipped in
    ///     v0.4.1; failing this rejects the entire toolset on Claude
    ///     Desktop / Cursor / Claude Code with
    ///     `FrontendRemoteMcpToolDefinition.name: String should
    ///     match pattern ...`).
    ///   - **OpenAI** function-calling: `^[a-zA-Z_][a-zA-Z0-9_-]*$`
    ///     with length ≤ 64 (must start with letter or underscore).
    ///   - **Gemini** function-calling: documented as a-z, A-Z, 0-9,
    ///     underscores and dashes; some sources also allow dots. We
    ///     use the conservative intersection — must start with
    ///     letter or underscore, alphanumeric + underscore only (no
    ///     hyphen, no dot), length ≤ 63. This is the strictest of
    ///     the three patterns, so any tool that passes it also
    ///     passes the other two. Sources differ on whether Gemini
    ///     accepts dots or hyphens; the strictest reading guards us
    ///     against the future where one provider tightens the regex
    ///     (which is the failure mode v0.4.1 hit on Anthropic). See
    ///     <https://github.com/google-gemini/deprecated-generative-ai-python/blob/main/docs/api/google/generativeai/protos/FunctionDeclaration.md>
    ///     and <https://ai.google.dev/gemini-api/docs/function-calling>.
    ///
    /// Lesson banked v0.3 #8: rmcp framing tests pass dot-named
    /// tools fine because rmcp's own client-side validation is
    /// permissive. Only the downstream provider API enforces the
    /// regex. This test gates the names at `cargo test` time so any
    /// future tool-name change has to pass all three provider
    /// regexes before reaching real clients.
    #[test]
    fn tool_names_match_cross_provider_regex() {
        /// Anthropic API name regex: `^[a-zA-Z0-9_-]{1,64}$`.
        fn passes_anthropic(name: &str) -> bool {
            let len = name.len();
            if !(1..=64).contains(&len) {
                return false;
            }
            name.chars()
                .all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '-')
        }

        /// OpenAI function-calling name regex:
        /// `^[a-zA-Z_][a-zA-Z0-9_-]*$`, length ≤ 64.
        fn passes_openai(name: &str) -> bool {
            let len = name.len();
            if !(1..=64).contains(&len) {
                return false;
            }
            let mut chars = name.chars();
            let first = match chars.next() {
                Some(c) => c,
                None => return false,
            };
            if !(first.is_ascii_alphabetic() || first == '_') {
                return false;
            }
            chars.all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '-')
        }

        /// Gemini function-calling name regex (conservative
        /// reading): `^[a-zA-Z_][a-zA-Z0-9_]*$`, length ≤ 63. No
        /// hyphen, no dot — strictest of the three so any name that
        /// passes this passes the other two.
        fn passes_gemini(name: &str) -> bool {
            let len = name.len();
            if !(1..=63).contains(&len) {
                return false;
            }
            let mut chars = name.chars();
            let first = match chars.next() {
                Some(c) => c,
                None => return false,
            };
            if !(first.is_ascii_alphabetic() || first == '_') {
                return false;
            }
            chars.all(|c| c.is_ascii_alphanumeric() || c == '_')
        }

        let tools = build_tools();
        assert_eq!(
            tools.len(),
            8,
            "expected 8 tools in v0.5.0 (7 v0.4.x + memory_inspect_cluster)"
        );
        // Sanity-check that tool_names() agrees with build_tools().
        let tool_name_strings: Vec<String> =
            tools.iter().map(|t| t.name.to_string()).collect();
        let public_names: Vec<String> =
            super::tool_names().iter().map(|s| s.to_string()).collect();
        assert_eq!(
            tool_name_strings, public_names,
            "tool_names() drifted from build_tools() — keep them in sync"
        );

        for t in tools {
            assert!(
                passes_anthropic(&t.name),
                "tool name {:?} fails Anthropic regex \
                 ^[a-zA-Z0-9_-]{{1,64}}$ — see v0.3 lesson #8",
                t.name
            );
            assert!(
                passes_openai(&t.name),
                "tool name {:?} fails OpenAI function-calling regex \
                 ^[a-zA-Z_][a-zA-Z0-9_-]*$ (len ≤ 64)",
                t.name
            );
            assert!(
                passes_gemini(&t.name),
                "tool name {:?} fails Gemini function-calling regex \
                 ^[a-zA-Z_][a-zA-Z0-9_]*$ (len ≤ 63, strict)",
                t.name
            );
        }
    }

    /// Regression guard for the v0.5.0 Priority 4 jargon pass.
    ///
    /// Tool descriptions and `get_info().instructions` are the first
    /// (and often only) thing a calling LLM reads when its
    /// tool-search mechanism decides whether Solo's tools are
    /// relevant. Earlier descriptions leaned on Solo-internal
    /// vocabulary (`SPO`, `Steward`, `LEFT JOIN`, `candidate pair`,
    /// `tagged_with`) which doesn't pattern-match natural-language
    /// agent queries like "what do you know about Alex?" — that's
    /// the load-bearing v0.5.0 finding from the 2026-05-14
    /// thesis-test in Claude Desktop.
    ///
    /// This test pins the de-jargoning by forbidding the old
    /// vocabulary from appearing in any user-facing text. Future
    /// contributors who reach for jargon trip the test and have to
    /// pick plain-English phrasing instead.
    #[test]
    fn tool_descriptions_avoid_internal_jargon() {
        // Case-insensitive substring match. Drawn from the
        // pre-Priority-4 descriptions; expand only if a new term
        // creeps in.
        const FORBIDDEN: &[&str] = &[
            "SPO",
            "Steward",
            "Steward-flagged",
            "LEFT JOIN",
            "candidate pair",
            "candidate_pair",
            "tagged_with",
        ];

        fn contains_case_insensitive(haystack: &str, needle: &str) -> bool {
            haystack.to_lowercase().contains(&needle.to_lowercase())
        }

        // 1. Each tool description.
        for t in build_tools() {
            for term in FORBIDDEN {
                assert!(
                    !contains_case_insensitive(&t.description, term),
                    "tool {:?} description contains forbidden jargon \
                     {:?} — rewrite in plain English (see v0.5.0 \
                     Priority 4)",
                    t.name,
                    term,
                );
            }
        }

        // 2. The server-level instructions (what tool-search sees
        // first).
        let server_info = harness_server_info();
        let instructions = server_info
            .instructions
            .as_deref()
            .expect("get_info() must set instructions");
        for term in FORBIDDEN {
            assert!(
                !contains_case_insensitive(instructions, term),
                "get_info().instructions contains forbidden jargon \
                 {:?} — rewrite in plain English",
                term,
            );
        }
    }

    /// Build a `ServerInfo` for the jargon test without spinning up
    /// the full harness (which needs tokio + tempdir). The
    /// `ServerHandler::get_info()` method doesn't take `&self` state
    /// in any meaningful way for our impl — it returns a static
    /// `ServerInfo` literal — so we construct a minimal-input server
    /// just to call it.
    fn harness_server_info() -> rmcp::model::ServerInfo {
        let runtime = rt();
        let h = Harness::new(&runtime);
        let info = ServerHandler::get_info(&h.server);
        h.shutdown(&runtime);
        info
    }

    // ---- memory_inspect_cluster (v0.5.0 Priority 3) ----

    #[test]
    fn inspect_cluster_unknown_id_returns_invalid_params() {
        // NotFound from solo_query::inspect_cluster is mapped through
        // `solo_to_mcp` to `invalid_params` (MCP has no separate
        // not-found error shape). Error message should name the id.
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            let err = h
                .server
                .dispatch_tool(
                    "memory_inspect_cluster",
                    json!({ "cluster_id": "no-such-cluster" }),
                )
                .await
                .expect_err("unknown cluster must error");
            let s = format!("{err:?}");
            assert!(
                s.contains("no-such-cluster") || s.to_lowercase().contains("not found"),
                "expected error to mention the missing cluster id; got: {s}"
            );
        });
        h.shutdown(&runtime);
    }

    #[test]
    fn inspect_cluster_rejects_empty_id() {
        let runtime = rt();
        let h = Harness::new(&runtime);
        runtime.block_on(async {
            let err = h
                .server
                .dispatch_tool(
                    "memory_inspect_cluster",
                    json!({ "cluster_id": "   " }),
                )
                .await
                .expect_err("blank cluster_id must error");
            let s = format!("{err:?}");
            assert!(
                s.to_lowercase().contains("cluster_id")
                    || s.to_lowercase().contains("must not be empty"),
                "got: {s}"
            );
        });
        h.shutdown(&runtime);
    }
}

// fetch_recall_rows + RecallHit + RecallRow used to live here. Recall
// pipeline moved to solo_query::recall in commit (consolidate-recall);
// transports just call solo_query::run_recall and format the result.