feat: add native Linux desktop app (Rust + GTK4)

.gitignore

@@ -14,3 +14,5 @@ DerivedData/
 **/xcuserdata/
 *.xcuserstate
 *.profraw
+*.xcodeproj
+*.xcworkspace

PPG CLI/PPG CLI/WebSocketManager.swift

@@ -0,0 +1,383 @@
+import Foundation
+
+// MARK: - Notifications
+
+extension Notification.Name {
+    static let webSocketStateDidChange = Notification.Name("PPGWebSocketStateDidChange")
+    static let webSocketDidReceiveEvent = Notification.Name("PPGWebSocketDidReceiveEvent")
+}
+
+// MARK: - Connection State
+
+nonisolated enum WebSocketConnectionState: Equatable, Sendable {
+    case disconnected
+    case connecting
+    case connected
+    case reconnecting(attempt: Int)
+
+    var isConnected: Bool { self == .connected }
+
+    var isReconnecting: Bool {
+        if case .reconnecting = self { return true }
+        return false
+    }
+}
+
+// MARK: - Server Events
+
+nonisolated enum WebSocketEvent: Sendable {
+    case manifestUpdated(ManifestModel)
+    case agentStatusChanged(agentId: String, status: AgentStatus)
+    case worktreeStatusChanged(worktreeId: String, status: String)
+    case pong
+    case unknown(type: String, payload: String)
+}
+
+// MARK: - Client Commands
+
+nonisolated enum WebSocketCommand: Sendable {
+    case subscribe(channel: String)
+    case unsubscribe(channel: String)
+    case terminalInput(agentId: String, data: String)
+
+    var jsonString: String {
+        let dict: [String: String]
+        switch self {
+        case .subscribe(let channel):
+            dict = ["type": "subscribe", "channel": channel]
+        case .unsubscribe(let channel):
+            dict = ["type": "unsubscribe", "channel": channel]
+        case .terminalInput(let agentId, let data):
+            dict = ["type": "terminal_input", "agentId": agentId, "data": data]
+        }
+        guard let data = try? JSONSerialization.data(withJSONObject: dict, options: [.sortedKeys]),
+              let str = String(data: data, encoding: .utf8) else {
+            return "{}"
+        }
+        return str
+    }
+}
+
+// MARK: - WebSocketManager
+
+nonisolated class WebSocketManager: NSObject, @unchecked Sendable, URLSessionWebSocketDelegate {
+
+    /// Notification userInfo key for connection state.
+    static let stateUserInfoKey = "PPGWebSocketState"
+    /// Notification userInfo key for received event.
+    static let eventUserInfoKey = "PPGWebSocketEvent"
+
+    // MARK: - Configuration
+
+    private let url: URL
+    private let maxReconnectDelay: TimeInterval = 30.0
+    private let baseReconnectDelay: TimeInterval = 1.0
+    private let pingInterval: TimeInterval = 30.0
+
+    // MARK: - State
+
+    private let queue = DispatchQueue(label: "ppg.websocket-manager", qos: .utility)
+
+    /// Internal state — only read/write on `queue`.
+    private var _state: WebSocketConnectionState = .disconnected
+
+    /// Thread-safe read of the current connection state.
+    var state: WebSocketConnectionState {
+        queue.sync { _state }
+    }
+
+    private var session: URLSession?
+    private var task: URLSessionWebSocketTask?
+    private var pingTimer: DispatchSourceTimer?
+    private var reconnectWorkItem: DispatchWorkItem?
+    private var reconnectAttempt = 0
+    private var intentionalDisconnect = false
+    private var isHandlingConnectionLoss = false
+
+    // MARK: - Init
+
+    init(url: URL) {
+        self.url = url
+        super.init()
+    }
+
+    convenience init?(urlString: String) {
+        guard let url = URL(string: urlString) else { return nil }
+        self.init(url: url)
+    }
+
+    deinit {
+        // Synchronous cleanup — safe because we're the last reference holder.
+        intentionalDisconnect = true
+        pingTimer?.cancel()
+        pingTimer = nil
+        task?.cancel(with: .goingAway, reason: nil)
+        task = nil
+        session?.invalidateAndCancel()
+        session = nil
+    }
+
+    // MARK: - Public API
+
+    func connect() {
+        queue.async { [weak self] in
+            self?.doConnect()
+        }
+    }
+
+    func disconnect() {
+        queue.async { [weak self] in
+            self?.doDisconnect()
+        }
+    }
+
+    func send(_ command: WebSocketCommand) {
+        queue.async { [weak self] in
+            self?.doSend(command.jsonString)
+        }
+    }
+
+    // MARK: - Connection Lifecycle
+
+    private func doConnect() {
+        guard _state == .disconnected || _state.isReconnecting else { return }
+
+        intentionalDisconnect = false
+        isHandlingConnectionLoss = false
+        reconnectWorkItem?.cancel()
+        reconnectWorkItem = nil
+
+        if _state.isReconnecting {
+            // Already in reconnect flow — keep the attempt counter
+        } else {
+            reconnectAttempt = 0
+            setState(.connecting)
+        }
+
+        let config = URLSessionConfiguration.default
+        config.waitsForConnectivity = true
+        session = URLSession(configuration: config, delegate: self, delegateQueue: nil)
+
+        let wsTask = session!.webSocketTask(with: url)
+        task = wsTask
+        wsTask.resume()
+    }
+
+    private func doDisconnect() {
+        intentionalDisconnect = true
+        isHandlingConnectionLoss = false
+        reconnectWorkItem?.cancel()
+        reconnectWorkItem = nil
+        stopPingTimer()
+        task?.cancel(with: .goingAway, reason: nil)
+        task = nil
+        session?.invalidateAndCancel()
+        session = nil
+        reconnectAttempt = 0
+        setState(.disconnected)
+    }
+
+    /// Set state on the queue and post a notification on main.
+    private func setState(_ newState: WebSocketConnectionState) {
+        guard _state != newState else { return }
+        _state = newState
+        DispatchQueue.main.async {
+            NotificationCenter.default.post(
+                name: .webSocketStateDidChange,
+                object: nil,
+                userInfo: [WebSocketManager.stateUserInfoKey: newState]
+            )
+        }
+    }
+
+    // MARK: - Sending
+
+    private func doSend(_ text: String) {
+        guard _state == .connected, let task = task else { return }
+        task.send(.string(text)) { error in
+            if let error = error {
+                NSLog("[WebSocketManager] send error: \(error.localizedDescription)")
+            }
+        }
+    }
+
+    // MARK: - Receiving
+
+    private func listenForMessages(for expectedTask: URLSessionWebSocketTask) {
+        expectedTask.receive { [weak self] result in
+            guard let self = self else { return }
+            self.queue.async {
+                guard self.task === expectedTask else { return }
+                switch result {
+                case .success(let message):
+                    self.handleMessage(message)
+                    self.listenForMessages(for: expectedTask)
+                case .failure(let error):
+                    if !self.intentionalDisconnect {
+                        NSLog("[WebSocketManager] receive error: \(error.localizedDescription)")
+                        self.handleConnectionLost()
+                    }
+                }
+            }
+        }
+    }
+
+    private func handleMessage(_ message: URLSessionWebSocketTask.Message) {
+        let text: String
+        switch message {
+        case .string(let s):
+            text = s
+        case .data(let d):
+            guard let s = String(data: d, encoding: .utf8) else { return }
+            text = s
+        @unknown default:
+            return
+        }
+
+        guard let event = parseEvent(text) else { return }
+
+        DispatchQueue.main.async {
+            NotificationCenter.default.post(
+                name: .webSocketDidReceiveEvent,
+                object: nil,
+                userInfo: [WebSocketManager.eventUserInfoKey: event]
+            )
+        }
+    }
+
+    // MARK: - Event Parsing
+
+    /// Parse a JSON text message into a typed event. Internal for testability.
+    func parseEvent(_ text: String) -> WebSocketEvent? {
+        guard let data = text.data(using: .utf8),
+              let json = try? JSONSerialization.jsonObject(with: data) as? [String: Any],
+              let type = json["type"] as? String else {
+            return nil
+        }
+
+        switch type {
+        case "manifest_updated":
+            if let payloadData = json["manifest"],
+               let payloadJSON = try? JSONSerialization.data(withJSONObject: payloadData),
+               let manifest = try? JSONDecoder().decode(ManifestModel.self, from: payloadJSON) {
+                return .manifestUpdated(manifest)
+            }
+            return .unknown(type: type, payload: text)
+
+        case "agent_status_changed":
+            if let agentId = json["agentId"] as? String,
+               let statusRaw = json["status"] as? String,
+               let status = AgentStatus(rawValue: statusRaw) {
+                return .agentStatusChanged(agentId: agentId, status: status)
+            }
+            return .unknown(type: type, payload: text)
+
+        case "worktree_status_changed":
+            if let worktreeId = json["worktreeId"] as? String,
+               let status = json["status"] as? String {
+                return .worktreeStatusChanged(worktreeId: worktreeId, status: status)
+            }
+            return .unknown(type: type, payload: text)
+
+        case "pong":
+            return .pong
+
+        default:
+            return .unknown(type: type, payload: text)
+        }
+    }
+
+    // MARK: - Keepalive Ping
+
+    private func startPingTimer() {
+        stopPingTimer()
+        let timer = DispatchSource.makeTimerSource(queue: queue)
+        timer.schedule(deadline: .now() + pingInterval, repeating: pingInterval)
+        timer.setEventHandler { [weak self] in
+            self?.sendPing()
+        }
+        timer.resume()
+        pingTimer = timer
+    }
+
+    private func stopPingTimer() {
+        pingTimer?.cancel()
+        pingTimer = nil
+    }
+
+    private func sendPing() {
+        task?.sendPing { [weak self] error in
+            if let error = error {
+                NSLog("[WebSocketManager] ping error: \(error.localizedDescription)")
+                self?.queue.async { self?.handleConnectionLost() }
+            }
+        }
+    }
+
+    // MARK: - Reconnect
+
+    private func handleConnectionLost() {
+        guard !intentionalDisconnect else { return }
+        guard !isHandlingConnectionLoss else { return }
+        isHandlingConnectionLoss = true
+        stopPingTimer()
+        task?.cancel(with: .abnormalClosure, reason: nil)
+        task = nil
+        session?.invalidateAndCancel()
+        session = nil
+        scheduleReconnect()
+    }
+
+    private func scheduleReconnect() {
+        reconnectAttempt += 1
+        setState(.reconnecting(attempt: reconnectAttempt))
+
+        let delay = min(baseReconnectDelay * pow(2.0, Double(reconnectAttempt - 1)), maxReconnectDelay)
+        NSLog("[WebSocketManager] reconnecting in %.1fs (attempt %d)", delay, reconnectAttempt)
+
+        let workItem = DispatchWorkItem { [weak self] in
+            guard let self = self, !self.intentionalDisconnect else { return }
+            self.reconnectWorkItem = nil
+            self.doConnect()
+        }
+        reconnectWorkItem?.cancel()
+        reconnectWorkItem = workItem
+        queue.asyncAfter(deadline: .now() + delay, execute: workItem)
+    }
+
+    // MARK: - URLSessionWebSocketDelegate
+
+    func urlSession(_ session: URLSession, webSocketTask: URLSessionWebSocketTask, didOpenWithProtocol protocol: String?) {
+        queue.async { [weak self] in
+            guard let self = self else { return }
+            guard self.task === webSocketTask else { return }
+            self.reconnectAttempt = 0
+            self.isHandlingConnectionLoss = false
+            self.setState(.connected)
+            self.startPingTimer()
+            self.listenForMessages(for: webSocketTask)
+        }
+    }
+
+    func urlSession(_ session: URLSession, webSocketTask: URLSessionWebSocketTask, didCloseWith closeCode: URLSessionWebSocketTask.CloseCode, reason: Data?) {
+        queue.async { [weak self] in
+            guard let self = self else { return }
+            guard self.task === webSocketTask else { return }
+            if self.intentionalDisconnect {
+                self.setState(.disconnected)
+            } else {
+                self.handleConnectionLost()
+            }
+        }
+    }
+
+    func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: (any Error)?) {
+        guard error != nil else { return }
+        queue.async { [weak self] in
+            guard let self = self, !self.intentionalDisconnect else { return }
+            guard let webSocketTask = task as? URLSessionWebSocketTask,
+                  self.task === webSocketTask else { return }
+            self.handleConnectionLost()
+        }
+    }
+}