src-tauri/src/mcp/handler.rs

@@ -0,0 +1,333 @@
+//! `rmcp::ServerHandler` implementation — the tools-first surface (FR-MCP-2)
+//! that a connected coding agent actually calls. Every tool handler:
+//! 1. Reads the *current* scope from `Settings` (not a snapshot taken at
+//!    server start) so `set_mcp_scope` takes effect immediately.
+//! 2. Logs the read (FR-MCP-5) — even when the read is denied, so the audit
+//!    trail reflects what an agent *asked for*.
+//! 3. Independently re-checks scope + the recordings gate (FR-MCP-3) — there
+//!    is deliberately no single choke point upstream of this file.
+
+use crate::mcp::{scope, ExposeScope};
+use crate::models::MeetingId;
+use crate::storage::{MeetingFilter, Store};
+use rmcp::model::{
+    CallToolRequestParams, CallToolResult, Implementation, JsonObject, ListToolsResult,
+    PaginatedRequestParams, ServerCapabilities, ServerInfo, Tool,
+};
+use rmcp::service::{RequestContext, RoleServer};
+use rmcp::{ErrorData as McpProtoError, ServerHandler};
+use serde_json::{json, Value};
+use std::sync::Arc;
+use tauri::{AppHandle, Emitter};
+
+/// Shared handle the HTTP/stdio transports build a fresh `rmcp` service
+/// around per-connection (`ServerHandler` methods take `&self`, so this just
+/// needs to be `Clone` + cheap — it's an `Arc<Store>` and an `AppHandle`).
+#[derive(Clone)]
+pub struct WaMcpHandler {
+    store: Arc<dyn Store>,
+    app: AppHandle,
+}
+
+impl WaMcpHandler {
+    pub fn new(store: Arc<dyn Store>, app: AppHandle) -> Self {
+        Self { store, app }
+    }
+
+    /// Live scope read (not cached) so `set_mcp_scope` applies without a
+    /// server restart.
+    fn current_scope(&self) -> (ExposeScope, bool) {
+        let settings = crate::commands::load_settings();
+        (
+            ExposeScope::parse(&settings.mcp_expose),
+            settings.mcp_expose_recordings,
+        )
+    }
+
+    async fn log_access(&self, tool: &str, meeting_id: Option<&MeetingId>, client: Option<&str>) {
+        if let Err(e) = self.store.record_mcp_access(tool, meeting_id, client).await {
+            tracing::warn!("failed to record mcp access log row: {e}");
+        }
+        let _ = self.app.emit(
+            "mcp://access",
+            json!({
+                "at": now_ms(),
+                "tool": tool,
+                "meetingId": meeting_id,
+                "client": client,
+            }),
+        );
+    }
+
+    fn client_name(context: &RequestContext<RoleServer>) -> Option<String> {
+        context
+            .peer
+            .peer_info()
+            .map(|info| info.client_info.name.clone())
+    }
+
+    async fn tool_list_recent_meetings(
+        &self,
+        args: &Option<JsonObject>,
+        client: Option<&str>,
+    ) -> Result<CallToolResult, McpProtoError> {
+        self.log_access("list_recent_meetings", None, client).await;
+        let (scope_val, expose_recordings) = self.current_scope();
+        if !scope::meetings_visible(scope_val) {
+            return Ok(CallToolResult::structured(json!({ "meetings": [] })));
+        }
+        let limit = arg_u64(args, "limit").unwrap_or(20).clamp(1, 100) as usize;
+        let items = self
+            .store
+            .list_meetings(MeetingFilter::default())
+            .await
+            .map_err(store_err)?;
+        let mut out = Vec::with_capacity(limit);
+        for item in items {
+            if out.len() >= limit {
+                break;
+            }
+            let Ok(full) = self.store.get_meeting(&item.id).await else {
+                continue;
+            };
+            if !scope::recording_gate_ok(expose_recordings, full.recorded) {
+                continue;
+            }
+            out.push(json!({
+                "id": item.id,
+                "title": item.title,
+                "startedAt": item.started_at,
+                "durationSecs": item.duration_secs,
+                "status": item.status.as_str(),
+                "tags": item.tags,
+            }));
+        }
+        Ok(CallToolResult::structured(json!({ "meetings": out })))
+    }
+
+    async fn tool_get_transcript(
+        &self,
+        args: &Option<JsonObject>,
+        client: Option<&str>,
+    ) -> Result<CallToolResult, McpProtoError> {
+        let meeting_id = arg_str(args, "meetingId")
+            .ok_or_else(|| McpProtoError::invalid_params("meetingId is required", None))?;
+        self.log_access("get_transcript", Some(&meeting_id), client)
+            .await;
+        let (scope_val, expose_recordings) = self.current_scope();
+        if !scope::meetings_visible(scope_val) {
+            return Ok(denied("get_transcript scope is not `all`"));
+        }
+        let meeting = self
+            .store
+            .get_meeting(&meeting_id)
+            .await
+            .map_err(store_err)?;
+        if !scope::recording_gate_ok(expose_recordings, meeting.recorded) {
+            return Ok(denied(
+                "this meeting retained its recording; expose_recordings is off",
+            ));
+        }
+        Ok(CallToolResult::structured(json!({
+            "meetingId": meeting.id,
+            "title": meeting.title,
+            "segments": meeting.segments,
+        })))
+    }
+
+    async fn tool_get_action_items(
+        &self,
+        args: &Option<JsonObject>,
+        client: Option<&str>,
+    ) -> Result<CallToolResult, McpProtoError> {
+        let meeting_id = arg_str(args, "meetingId")
+            .ok_or_else(|| McpProtoError::invalid_params("meetingId is required", None))?;
+        self.log_access("get_action_items", Some(&meeting_id), client)
+            .await;
+        let (scope_val, expose_recordings) = self.current_scope();
+        if !scope::meetings_visible(scope_val) {
+            return Ok(denied("get_action_items scope is not `all`"));
+        }
+        let meeting = self
+            .store
+            .get_meeting(&meeting_id)
+            .await
+            .map_err(store_err)?;
+        if !scope::recording_gate_ok(expose_recordings, meeting.recorded) {
+            return Ok(denied(
+                "this meeting retained its recording; expose_recordings is off",
+            ));
+        }
+        let items = self
+            .store
+            .list_action_items(&meeting_id)
+            .await
+            .map_err(store_err)?;
+        Ok(CallToolResult::structured(json!({
+            "meetingId": meeting_id,
+            "items": items,
+        })))
+    }
+
+    async fn tool_get_feature_brief(
+        &self,
+        args: &Option<JsonObject>,
+        client: Option<&str>,
+    ) -> Result<CallToolResult, McpProtoError> {
+        let id = arg_str(args, "id")
+            .ok_or_else(|| McpProtoError::invalid_params("id is required", None))?;
+        self.log_access("get_feature_brief", None, client).await;
+        let (scope_val, _expose_recordings) = self.current_scope();
+        if matches!(scope_val, ExposeScope::None) {
+            return Ok(denied("MCP scope is `none`; no briefs are exposed"));
+        }
+        // KNOWN GAP (M1 integration): `selected` scope should only serve a
+        // brief whose own `exposed` flag is true (`feature_briefs.exposed`,
+        // toggled via `set_brief_exposed`) — see `mcp::scope` docs. That
+        // check belongs here but M1 (feature-brief storage) is a stub in
+        // this worktree (`commands::get_feature_brief` always returns
+        // `not_implemented`), so there is nothing yet to check the flag
+        // against. Once M1 lands, add: fetch the brief's `exposed` bit and
+        // call `scope::brief_visible(scope_val, exposed)` before returning.
+        match crate::commands::get_feature_brief(id).await {
+            Ok(brief) => Ok(CallToolResult::structured(
+                serde_json::to_value(brief).map_err(|e| McpProtoError::internal_error(e.to_string(), None))?,
+            )),
+            Err(e) => Ok(CallToolResult::structured_error(json!({
+                "error": e.kind,
+                "message": e.message,
+            }))),
+        }
+    }
+}
+
+impl ServerHandler for WaMcpHandler {
+    fn get_info(&self) -> ServerInfo {
+        ServerInfo {
+            capabilities: ServerCapabilities::builder().enable_tools().build(),
+            server_info: Implementation {
+                name: "whispassist".into(),
+                title: Some("WhispAssist".into()),
+                version: env!("CARGO_PKG_VERSION").into(),
+                description: None,
+                icons: None,
+                website_url: None,
+            },
+            instructions: Some(
+                "WhispAssist meeting-assistant tools. Served data may be forwarded by this \
+                 agent to its own model provider outside WhispAssist's control -- WA discloses \
+                 this in its UI and logs every read (FR-MCP-5). Recordings (.wav) are never \
+                 served by any tool here."
+                    .into(),
+            ),
+            ..Default::default()
+        }
+    }
+
+    async fn list_tools(
+        &self,
+        _request: Option<PaginatedRequestParams>,
+        _context: RequestContext<RoleServer>,
+    ) -> Result<ListToolsResult, McpProtoError> {
+        let tools = vec![
+            Tool::new(
+                "list_recent_meetings",
+                "Recent meetings, most recent first (scoped by the user's MCP settings).",
+                obj_schema(json!({
+                    "type": "object",
+                    "properties": { "limit": { "type": "integer", "minimum": 1, "maximum": 100 } },
+                    "additionalProperties": false,
+                })),
+            ),
+            Tool::new(
+                "get_transcript",
+                "Full transcript (speaker-labeled segments) for one meeting.",
+                obj_schema(json!({
+                    "type": "object",
+                    "properties": { "meetingId": { "type": "string" } },
+                    "required": ["meetingId"],
+                    "additionalProperties": false,
+                })),
+            ),
+            Tool::new(
+                "get_action_items",
+                "Confirmed action items for one meeting.",
+                obj_schema(json!({
+                    "type": "object",
+                    "properties": { "meetingId": { "type": "string" } },
+                    "required": ["meetingId"],
+                    "additionalProperties": false,
+                })),
+            ),
+            Tool::new(
+                "get_feature_brief",
+                "Agent-ready spec (problem/outcome/acceptance criteria) distilled from a meeting.",
+                obj_schema(json!({
+                    "type": "object",
+                    "properties": { "id": { "type": "string" } },
+                    "required": ["id"],
+                    "additionalProperties": false,
+                })),
+            ),
+        ];
+        Ok(ListToolsResult::with_all_items(tools))
+    }
+
+    async fn call_tool(
+        &self,
+        request: CallToolRequestParams,
+        context: RequestContext<RoleServer>,
+    ) -> Result<CallToolResult, McpProtoError> {
+        let client = Self::client_name(&context);
+        match request.name.as_ref() {
+            "list_recent_meetings" => {
+                self.tool_list_recent_meetings(&request.arguments, client.as_deref())
+                    .await
+            }
+            "get_transcript" => {
+                self.tool_get_transcript(&request.arguments, client.as_deref())
+                    .await
+            }
+            "get_action_items" => {
+                self.tool_get_action_items(&request.arguments, client.as_deref())
+                    .await
+            }
+            "get_feature_brief" => {
+                self.tool_get_feature_brief(&request.arguments, client.as_deref())
+                    .await
+            }
+            other => Err(McpProtoError::invalid_params(
+                format!("unknown tool: {other}"),
+                None,
+            )),
+        }
+    }
+}
+
+fn obj_schema(value: Value) -> Arc<JsonObject> {
+    Arc::new(value.as_object().cloned().unwrap_or_default())
+}
+
+fn arg_str(args: &Option<JsonObject>, key: &str) -> Option<String> {
+    args.as_ref()?.get(key)?.as_str().map(str::to_string)
+}
+
+fn arg_u64(args: &Option<JsonObject>, key: &str) -> Option<u64> {
+    args.as_ref()?.get(key)?.as_u64()
+}
+
+fn store_err(e: crate::storage::StoreError) -> McpProtoError {
+    McpProtoError::internal_error(e.to_string(), None)
+}
+
+fn denied(reason: &str) -> CallToolResult {
+    CallToolResult::structured_error(json!({ "error": "scope_denied", "message": reason }))
+}
+
+fn now_ms() -> i64 {
+    use std::time::{SystemTime, UNIX_EPOCH};
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|d| d.as_millis() as i64)
+        .unwrap_or_default()
+}