feat(agents): Major refactor of agent execution system

- Refactored execute_agent function with comprehensive error handling
- Added new imports: Arc, Mutex for thread safety and tauri_plugin_shell
- Improved Claude binary detection and command building
- Enhanced argument handling for agent execution
- Added better process management and output streaming
- Implemented more robust error propagation and logging
- Expanded command construction with proper environment setup
- Added extensive documentation and error context

src-tauri/src/commands/agents.rs

@@ -6,8 +6,9 @@ use rusqlite::{params, Connection, Result as SqliteResult};
 use serde::{Deserialize, Serialize};
 use serde_json::Value as JsonValue;
 use std::process::Stdio;
-use std::sync::Mutex;
+use std::sync::{Arc, Mutex};
 use tauri::{AppHandle, Emitter, Manager, State};
+use tauri_plugin_shell::ShellExt;
 use tokio::io::{AsyncBufReadExt, BufReader};
 use tokio::process::Command;
 
@@ -691,7 +692,7 @@ pub async fn execute_agent(
         conn.last_insert_rowid()
     };
 
-    // Build the command
+    // Find Claude binary
     info!("Running agent '{}'", agent.name);
     let claude_path = match find_claude_binary(&app) {
         Ok(path) => path,
@@ -700,24 +701,293 @@ pub async fn execute_agent(
             return Err(e);
         }
     };
-    let mut cmd = create_command_with_env(&claude_path);
-    cmd.arg("-p")
-        .arg(&task)
-        .arg("--system-prompt")
-        .arg(&agent.system_prompt)
-        .arg("--model")
-        .arg(&execution_model)
-        .arg("--output-format")
-        .arg("stream-json")
-        .arg("--verbose")
-        .arg("--dangerously-skip-permissions")
-        .current_dir(&project_path)
-        .stdin(Stdio::null()) // Don't pipe stdin - we have no input to send
+
+    // Build arguments
+    let args = vec![
+        "-p".to_string(),
+        task.clone(),
+        "--system-prompt".to_string(),
+        agent.system_prompt.clone(),
+        "--model".to_string(),
+        execution_model.clone(),
+        "--output-format".to_string(),
+        "stream-json".to_string(),
+        "--verbose".to_string(),
+        "--dangerously-skip-permissions".to_string(),
+    ];
+
+    // Execute based on whether we should use sidecar or system binary
+    if should_use_sidecar(&claude_path) {
+        spawn_agent_sidecar(app, run_id, agent_id, agent.name.clone(), args, project_path, task, execution_model, db, registry).await
+    } else {
+        spawn_agent_system(app, run_id, agent_id, agent.name.clone(), claude_path, args, project_path, task, execution_model, db, registry).await
+    }
+}
+
+/// Determines whether to use sidecar or system binary execution for agents
+fn should_use_sidecar(claude_path: &str) -> bool {
+    claude_path == "claude-code"
+}
+
+/// Creates a sidecar command for agent execution
+fn create_agent_sidecar_command(
+    app: &AppHandle,
+    args: Vec<String>,
+    project_path: &str,
+) -> Result<tauri_plugin_shell::process::Command, String> {
+    let mut sidecar_cmd = app
+        .shell()
+        .sidecar("claude-code")
+        .map_err(|e| format!("Failed to create sidecar command: {}", e))?;
+    
+    // Add all arguments
+    sidecar_cmd = sidecar_cmd.args(args);
+    
+    // Set working directory
+    sidecar_cmd = sidecar_cmd.current_dir(project_path);
+    
+    Ok(sidecar_cmd)
+}
+
+/// Creates a system binary command for agent execution
+fn create_agent_system_command(
+    claude_path: &str,
+    args: Vec<String>,
+    project_path: &str,
+) -> Command {
+    let mut cmd = create_command_with_env(claude_path);
+    
+    // Add all arguments
+    for arg in args {
+        cmd.arg(arg);
+    }
+    
+    cmd.current_dir(project_path)
+        .stdin(Stdio::null())
         .stdout(Stdio::piped())
         .stderr(Stdio::piped());
     
+    cmd
+}
+
+/// Spawn agent using sidecar command
+async fn spawn_agent_sidecar(
+    app: AppHandle,
+    run_id: i64,
+    _agent_id: i64,
+    _agent_name: String,
+    args: Vec<String>,
+    project_path: String,
+    _task: String,
+    _execution_model: String,
+    db: State<'_, AgentDb>,
+    registry: State<'_, crate::process::ProcessRegistryState>,
+) -> Result<i64, String> {
+    use std::sync::Mutex;
+
+    // Create the sidecar command
+    let sidecar_cmd = create_agent_sidecar_command(&app, args, &project_path)?;
+    
+    // Spawn the sidecar process
+    let (mut rx, child) = sidecar_cmd
+        .spawn()
+        .map_err(|e| format!("Failed to spawn Claude sidecar: {}", e))?;
+
+    // Get the child PID for logging
+    let pid = child.pid();
+    info!("✅ Spawned Claude sidecar process with PID: {:?}", pid);
+
+    // Update the database with PID and status
+    let now = chrono::Utc::now().to_rfc3339();
+    {
+        let conn = db.0.lock().map_err(|e| e.to_string())?;
+        conn.execute(
+            "UPDATE agent_runs SET status = 'running', pid = ?1, process_started_at = ?2 WHERE id = ?3",
+            params![pid as i64, now, run_id],
+        ).map_err(|e| e.to_string())?;
+        info!("📝 Updated database with running status and PID");
+    }
+
+    // We'll extract the session ID from Claude's init message
+    let session_id_holder: Arc<Mutex<Option<String>>> = Arc::new(Mutex::new(None));
+
+    // Spawn task to read events from sidecar
+    let app_handle = app.clone();
+    let session_id_holder_clone = session_id_holder.clone();
+    let live_output = std::sync::Arc::new(Mutex::new(String::new()));
+    let live_output_clone = live_output.clone();
+    let registry_clone = registry.0.clone();
+    let first_output = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
+    let first_output_clone = first_output.clone();
+
+    let sidecar_task = tokio::spawn(async move {
+        info!("📖 Starting to read Claude sidecar events...");
+        let mut line_count = 0;
+
+        while let Some(event) = rx.recv().await {
+            match event {
+                tauri_plugin_shell::process::CommandEvent::Stdout(data) => {
+                    let line = String::from_utf8_lossy(&data).trim().to_string();
+                    if !line.is_empty() {
+                        line_count += 1;
+
+                        // Log first output
+                        if !first_output_clone.load(std::sync::atomic::Ordering::Relaxed) {
+                            info!("🎉 First output received from Claude sidecar! Line: {}", line);
+                            first_output_clone.store(true, std::sync::atomic::Ordering::Relaxed);
+                        }
+
+                        if line_count <= 5 {
+                            info!("sidecar stdout[{}]: {}", line_count, line);
+                        } else {
+                            debug!("sidecar stdout[{}]: {}", line_count, line);
+                        }
+
+                        // Store live output
+                        if let Ok(mut output) = live_output_clone.lock() {
+                            output.push_str(&line);
+                            output.push('\n');
+                        }
+
+                        // Also store in process registry for cross-session access
+                        let _ = registry_clone.append_live_output(run_id, &line);
+
+                        // Extract session ID from JSONL output
+                        if let Ok(json) = serde_json::from_str::<JsonValue>(&line) {
+                            if let Some(sid) = json.get("sessionId").and_then(|s| s.as_str()) {
+                                if let Ok(mut current_session_id) = session_id_holder_clone.lock() {
+                                    if current_session_id.is_none() {
+                                        *current_session_id = Some(sid.to_string());
+                                        info!("🔑 Extracted session ID: {}", sid);
+                                    }
+                                }
+                            }
+                        }
+
+                        // Emit the line to the frontend with run_id for isolation
+                        let _ = app_handle.emit(&format!("agent-output:{}", run_id), &line);
+                        // Also emit to the generic event for backward compatibility
+                        let _ = app_handle.emit("agent-output", &line);
+                    }
+                }
+                tauri_plugin_shell::process::CommandEvent::Stderr(data) => {
+                    let line = String::from_utf8_lossy(&data).trim().to_string();
+                    if !line.is_empty() {
+                        error!("sidecar stderr: {}", line);
+                        // Emit error lines to the frontend with run_id for isolation
+                        let _ = app_handle.emit(&format!("agent-error:{}", run_id), &line);
+                        // Also emit to the generic event for backward compatibility
+                        let _ = app_handle.emit("agent-error", &line);
+                    }
+                }
+                tauri_plugin_shell::process::CommandEvent::Terminated { .. } => {
+                    info!("📖 Claude sidecar process terminated");
+                    break;
+                }
+                tauri_plugin_shell::process::CommandEvent::Error(e) => {
+                    error!("🔥 Claude sidecar error: {}", e);
+                    break;
+                }
+                _ => {
+                    // Handle any other event types we might not know about
+                    debug!("Received unknown sidecar event type");
+                }
+            }
+        }
+
+        info!("📖 Finished reading Claude sidecar events. Total lines: {}", line_count);
+    });
+
+    // Create variables we need for the spawned task
+    let app_dir = app
+        .path()
+        .app_data_dir()
+        .expect("Failed to get app data dir");
+    let db_path = app_dir.join("agents.db");
+
+    // Monitor process status and wait for completion
+    tokio::spawn(async move {
+        info!("🕐 Starting sidecar process monitoring...");
+
+        // Wait for first output with timeout
+        for i in 0..300 {
+            // 30 seconds (300 * 100ms)
+            if first_output.load(std::sync::atomic::Ordering::Relaxed) {
+                info!("✅ Output detected after {}ms, continuing normal execution", i * 100);
+                break;
+            }
+
+            if i == 299 {
+                warn!("⏰ TIMEOUT: No output from Claude sidecar after 30 seconds");
+                warn!("💡 This usually means:");
+                warn!("   1. Claude sidecar is waiting for user input");
+                warn!("   2. Authentication issues (API key not found/invalid)");
+                warn!("   3. Network connectivity issues");
+                warn!("   4. Claude failed to initialize but didn't report an error");
+
+                // Update database with failed status
+                if let Ok(conn) = Connection::open(&db_path) {
+                    let _ = conn.execute(
+                        "UPDATE agent_runs SET status = 'failed', completed_at = CURRENT_TIMESTAMP WHERE id = ?1",
+                        params![run_id],
+                    );
+                }
+
+                let _ = app.emit("agent-complete", false);
+                let _ = app.emit(&format!("agent-complete:{}", run_id), false);
+                return;
+            }
+
+            tokio::time::sleep(tokio::time::Duration::from_millis(100)).await;
+        }
+
+        // Wait for sidecar task to complete
+        info!("⏳ Waiting for sidecar reading to complete...");
+        let _ = sidecar_task.await;
+
+        // Get the session ID that was extracted
+        let extracted_session_id = if let Ok(Some(sid)) = session_id_holder.lock().map(|s| s.clone()) {
+            sid
+        } else {
+            String::new()
+        };
+
+        // Update the run record with session ID and mark as completed
+        if let Ok(conn) = Connection::open(&db_path) {
+            let _ = conn.execute(
+                "UPDATE agent_runs SET session_id = ?1, status = 'completed', completed_at = CURRENT_TIMESTAMP WHERE id = ?2",
+                params![extracted_session_id, run_id],
+            );
+        }
+
+        info!("✅ Claude sidecar execution monitoring complete");
+
+        let _ = app.emit("agent-complete", true);
+        let _ = app.emit(&format!("agent-complete:{}", run_id), true);
+    });
+
+    Ok(run_id)
+}
+
+/// Spawn agent using system binary command
+async fn spawn_agent_system(
+    app: AppHandle,
+    run_id: i64,
+    agent_id: i64,
+    agent_name: String,
+    claude_path: String,
+    args: Vec<String>,
+    project_path: String,
+    task: String,
+    execution_model: String,
+    db: State<'_, AgentDb>,
+    registry: State<'_, crate::process::ProcessRegistryState>,
+) -> Result<i64, String> {
+    // Build the command
+    let mut cmd = create_agent_system_command(&claude_path, args, &project_path);
+
     // Spawn the process
-    info!("🚀 Spawning Claude process...");
+    info!("🚀 Spawning Claude system process...");
     let mut child = cmd.spawn().map_err(|e| {
         error!("❌ Failed to spawn Claude process: {}", e);
         format!("Failed to spawn Claude: {}", e)
@@ -859,7 +1129,7 @@ pub async fn execute_agent(
         .register_process(
             run_id,
             agent_id,
-            agent.name.clone(),
+            agent_name,
             pid,
             project_path.clone(),
             task.clone(),
@@ -891,23 +1161,10 @@ pub async fn execute_agent(
                 break;
             }
 
-            tokio::time::sleep(std::time::Duration::from_millis(100)).await;
-
-            // Log progress every 5 seconds
-            if i > 0 && i % 50 == 0 {
-                info!(
-                    "⏳ Still waiting for Claude output... ({}s elapsed)",
-                    i / 10
-                );
-            }
-        }
-
-        // Check if we timed out
-        if !first_output.load(std::sync::atomic::Ordering::Relaxed) {
+            if i == 299 {
                 warn!("⏰ TIMEOUT: No output from Claude process after 30 seconds");
                 warn!("💡 This usually means:");
                 warn!("   1. Claude process is waiting for user input");
-
                 warn!("   3. Claude failed to initialize but didn't report an error");
                 warn!("   4. Network connectivity issues");
                 warn!("   5. Authentication issues (API key not found/invalid)");
@@ -951,6 +1208,9 @@ pub async fn execute_agent(
                 return;
             }
 
+            tokio::time::sleep(tokio::time::Duration::from_millis(100)).await;
+        }
+
         // Wait for reading tasks to complete
         info!("⏳ Waiting for stdout/stderr reading to complete...");
         let _ = stdout_task.await;