feat: ACP health check, diagnostics page and visual polish

apps/tauri/src-tauri/src/acp/commands.rs

@@ -1,15 +1,21 @@
 use std::collections::HashMap;
 use tokio::sync::Mutex;
-use tauri::{AppHandle, State};
+use tauri::{AppHandle, State, Emitter};
 
 use super::connection::AcpConnection;
 use super::types::*;
 
-pub struct AcpState(pub Mutex<HashMap<String, AcpConnection>>);
+pub struct AcpState {
+    pub connections: Mutex<HashMap<String, AcpConnection>>,
+    pub configs: Mutex<HashMap<String, ConnectionConfig>>,
+}
 
 impl Default for AcpState {
     fn default() -> Self {
-        Self(Mutex::new(HashMap::new()))
+        Self {
+            connections: Mutex::new(HashMap::new()),
+            configs: Mutex::new(HashMap::new()),
+        }
     }
 }
 
@@ -22,21 +28,34 @@ pub async fn acp_connect(
     app_handle: AppHandle,
     state: State<'_, AcpState>,
 ) -> Result<(), String> {
-    let mut connections = state.0.lock().await;
+    let mut connections = state.connections.lock().await;
     if connections.contains_key(&workspace_id) {
         return Ok(());
     }
 
     let binary = binary_path
         .filter(|s| !s.trim().is_empty())
         .unwrap_or_else(|| std::env::var("COPILOT_PATH").unwrap_or_else(|_| "copilot".to_string()));
+
+    let config = ConnectionConfig {
+        binary: binary.clone(),
+        cwd: cwd.clone(),
+        gh_token: gh_token.clone(),
+    };
+
+    let _ = app_handle.emit("acp:connection-status", &ConnectionStatusEvent {
+        workspace_id: workspace_id.clone(),
+        status: "connecting".to_string(),
+        attempt: None,
+    });
+
     let conn = AcpConnection::spawn(
         &binary,
         &["--acp", "--stdio"],
         &cwd,
         gh_token,
         workspace_id.clone(),
-        app_handle,
+        app_handle.clone(),
     )
     .await?;
 
@@ -52,7 +71,9 @@ pub async fn acp_connect(
     .await?;
 
     conn.send_notification("initialized", None).await?;
+    conn.emit_status("connected", None);
 
+    state.configs.lock().await.insert(workspace_id.clone(), config);
     connections.insert(workspace_id, conn);
     Ok(())
 }
@@ -62,7 +83,8 @@ pub async fn acp_disconnect(
     workspace_id: String,
     state: State<'_, AcpState>,
 ) -> Result<(), String> {
-    let mut connections = state.0.lock().await;
+    state.configs.lock().await.remove(&workspace_id);
+    let mut connections = state.connections.lock().await;
     if let Some(conn) = connections.remove(&workspace_id) {
         conn.shutdown().await;
     }
@@ -75,7 +97,7 @@ pub async fn acp_new_session(
     cwd: String,
     state: State<'_, AcpState>,
 ) -> Result<SessionInfo, String> {
-    let connections = state.0.lock().await;
+    let connections = state.connections.lock().await;
     let conn = connections
         .get(&workspace_id)
         .ok_or("Not connected")?;
@@ -103,7 +125,7 @@ pub async fn acp_list_sessions(
     cwd: String,
     state: State<'_, AcpState>,
 ) -> Result<Vec<SessionSummary>, String> {
-    let connections = state.0.lock().await;
+    let connections = state.connections.lock().await;
     let conn = connections
         .get(&workspace_id)
         .ok_or("Not connected")?;
@@ -133,7 +155,7 @@ pub async fn acp_load_session(
     cwd: String,
     state: State<'_, AcpState>,
 ) -> Result<SessionInfo, String> {
-    let connections = state.0.lock().await;
+    let connections = state.connections.lock().await;
     let conn = connections
         .get(&workspace_id)
         .ok_or("Not connected")?;
@@ -167,7 +189,7 @@ pub async fn acp_send_prompt(
     text: String,
     state: State<'_, AcpState>,
 ) -> Result<(), String> {
-    let connections = state.0.lock().await;
+    let connections = state.connections.lock().await;
     let conn = connections
         .get(&workspace_id)
         .ok_or("Not connected")?;
@@ -196,7 +218,7 @@ pub async fn acp_set_mode(
     mode: String,
     state: State<'_, AcpState>,
 ) -> Result<(), String> {
-    let connections = state.0.lock().await;
+    let connections = state.connections.lock().await;
     let conn = connections
         .get(&workspace_id)
         .ok_or("Not connected")?;
@@ -221,7 +243,7 @@ pub async fn acp_cancel(
     session_id: String,
     state: State<'_, AcpState>,
 ) -> Result<(), String> {
-    let connections = state.0.lock().await;
+    let connections = state.connections.lock().await;
     let conn = connections
         .get(&workspace_id)
         .ok_or("Not connected")?;
@@ -237,8 +259,36 @@ pub async fn acp_cancel(
     Ok(())
 }
 
+#[tauri::command]
+pub async fn acp_check_health(
+    workspace_id: String,
+    app_handle: AppHandle,
+    state: State<'_, AcpState>,
+) -> Result<String, String> {
+    let connections = state.connections.lock().await;
+    let status = if let Some(conn) = connections.get(&workspace_id) {
+        if conn.is_alive().await {
+            conn.emit_status("connected", None);
+            "connected"
+        } else {
+            conn.emit_status("disconnected", None);
+            "disconnected"
+        }
+    } else {
+        let event = ConnectionStatusEvent {
+            workspace_id: workspace_id.clone(),
+            status: "disconnected".to_string(),
+            attempt: None,
+        };
+        let _ = app_handle.emit("acp:connection-status", &event);
+        "disconnected"
+    };
+    Ok(status.to_string())
+}
+
 pub async fn disconnect_all(state: &AcpState) {
-    let mut connections = state.0.lock().await;
+    state.configs.lock().await.clear();
+    let mut connections = state.connections.lock().await;
     for (id, conn) in connections.drain() {
         eprintln!("[acp] Disconnecting workspace {}", id);
         conn.shutdown().await;

apps/tauri/src-tauri/src/acp/connection.rs

@@ -9,14 +9,18 @@ use tauri::{AppHandle, Emitter};
 use super::types::*;
 
 type PendingMap = Arc<Mutex<HashMap<u64, oneshot::Sender<Result<serde_json::Value, JsonRpcError>>>>>;
+type ChildRef = Arc<Mutex<Option<Child>>>;
 
 pub struct AcpConnection {
-    child: Mutex<Option<Child>>,
+    child: ChildRef,
     writer_tx: mpsc::Sender<String>,
     pending: PendingMap,
     next_id: AtomicU64,
     reader_handle: Mutex<Option<tokio::task::JoinHandle<()>>>,
     writer_handle: Mutex<Option<tokio::task::JoinHandle<()>>>,
+    heartbeat_handle: Mutex<Option<tokio::task::JoinHandle<()>>>,
+    app_handle: AppHandle,
+    workspace_id: String,
 }
 
 impl AcpConnection {
@@ -55,17 +59,27 @@ impl AcpConnection {
             stdout,
             pending.clone(),
             writer_tx.clone(),
-            workspace_id,
-            app_handle,
+            workspace_id.clone(),
+            app_handle.clone(),
+        ));
+
+        let child_arc: ChildRef = Arc::new(Mutex::new(Some(child)));
+        let heartbeat_handle = tokio::spawn(Self::heartbeat_task(
+            child_arc.clone(),
+            workspace_id.clone(),
+            app_handle.clone(),
         ));
 
         Ok(Self {
-            child: Mutex::new(Some(child)),
+            child: child_arc,
             writer_tx,
             pending,
             next_id: AtomicU64::new(1),
             reader_handle: Mutex::new(Some(reader_handle)),
             writer_handle: Mutex::new(Some(writer_handle)),
+            heartbeat_handle: Mutex::new(Some(heartbeat_handle)),
+            app_handle,
+            workspace_id,
         })
     }
 
@@ -155,6 +169,43 @@ impl AcpConnection {
             }
         }
         eprintln!("[acp] Reader task ended for workspace {}", workspace_id);
+        let event = ConnectionStatusEvent {
+            workspace_id: workspace_id.clone(),
+            status: "disconnected".to_string(),
+            attempt: None,
+        };
+        let _ = app_handle.emit("acp:connection-status", &event);
+    }
+
+    async fn heartbeat_task(child: ChildRef, workspace_id: String, app_handle: AppHandle) {
+        let interval = std::time::Duration::from_secs(15);
+        loop {
+            tokio::time::sleep(interval).await;
+            let mut guard = child.lock().await;
+            if let Some(ref mut c) = *guard {
+                match c.try_wait() {
+                    Ok(Some(status)) => {
+                        eprintln!("[acp] Heartbeat: process exited (status: {:?}) for workspace {}", status, workspace_id);
+                        *guard = None;
+                        drop(guard);
+                        let event = ConnectionStatusEvent {
+                            workspace_id,
+                            status: "disconnected".to_string(),
+                            attempt: None,
+                        };
+                        let _ = app_handle.emit("acp:connection-status", &event);
+                        return;
+                    }
+                    Ok(None) => {} // still running
+                    Err(e) => {
+                        eprintln!("[acp] Heartbeat: try_wait error for workspace {}: {}", workspace_id, e);
+                    }
+                }
+            } else {
+                // child was already taken (shutdown called)
+                return;
+            }
+        }
     }
 
     fn handle_session_update(
@@ -241,6 +292,11 @@ impl AcpConnection {
         }
         drop(child_guard);
 
+        let mut heartbeat = self.heartbeat_handle.lock().await;
+        if let Some(handle) = heartbeat.take() {
+            handle.abort();
+        }
+
         let mut reader = self.reader_handle.lock().await;
         if let Some(handle) = reader.take() {
             handle.abort();
@@ -253,4 +309,24 @@ impl AcpConnection {
 
         self.pending.lock().await.clear();
     }
+
+    /// Returns true if the child process is still running.
+    pub async fn is_alive(&self) -> bool {
+        let mut guard = self.child.lock().await;
+        if let Some(ref mut c) = *guard {
+            matches!(c.try_wait(), Ok(None))
+        } else {
+            false
+        }
+    }
+
+    /// Emits a connection-status event to the frontend.
+    pub fn emit_status(&self, status: &str, attempt: Option<u32>) {
+        let event = ConnectionStatusEvent {
+            workspace_id: self.workspace_id.clone(),
+            status: status.to_string(),
+            attempt,
+        };
+        let _ = self.app_handle.emit("acp:connection-status", &event);
+    }
 }

apps/tauri/src-tauri/src/acp/types.rs

@@ -137,3 +137,20 @@ pub struct SessionUpdateEvent {
     pub update_type: String,
     pub payload: serde_json::Value,
 }
+
+#[derive(Debug, Serialize, Clone)]
+#[serde(rename_all = "camelCase")]
+pub struct ConnectionStatusEvent {
+    pub workspace_id: String,
+    pub status: String, // "connecting" | "connected" | "disconnected" | "reconnecting"
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub attempt: Option<u32>,
+}
+
+#[derive(Debug, Clone)]
+#[allow(dead_code)] // stored for future reconnect support
+pub struct ConnectionConfig {
+    pub binary: String,
+    pub cwd: String,
+    pub gh_token: Option<String>,
+}