// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';

import 'package:meta/meta.dart';
import 'package:process/process.dart';
import 'package:vm_service/vm_service.dart' as vm_service;

import '../application_package.dart';
import '../base/common.dart';
import '../base/file_system.dart';
import '../base/io.dart';
import '../base/logger.dart';
import '../base/os.dart';
import '../base/platform.dart';
import '../base/process.dart';
import '../base/utils.dart';
import '../base/version.dart';
import '../build_info.dart';
import '../convert.dart';
import '../device.dart';
import '../device_port_forwarder.dart';
import '../globals.dart' as globals;
import '../macos/xcdevice.dart';
import '../mdns_discovery.dart';
import '../project.dart';
import '../protocol_discovery.dart';
import '../vmservice.dart';
import 'application_package.dart';
import 'core_devices.dart';
import 'ios_deploy.dart';
import 'ios_workflow.dart';
import 'iproxy.dart';
import 'mac.dart';
import 'xcode_build_settings.dart';
import 'xcode_debug.dart';
import 'xcodeproj.dart';

class IOSDevices extends PollingDeviceDiscovery {
  IOSDevices({
    required Platform platform,
    required this.xcdevice,
    required IOSWorkflow iosWorkflow,
    required Logger logger,
  }) : _platform = platform,
       _iosWorkflow = iosWorkflow,
       _logger = logger,
       super('iOS devices');

  final Platform _platform;
  final IOSWorkflow _iosWorkflow;
  final Logger _logger;

  @visibleForTesting
  final XCDevice xcdevice;

  @override
  bool get supportsPlatform => _platform.isMacOS;

  @override
  bool get canListAnything => _iosWorkflow.canListDevices;

  @override
  bool get requiresExtendedWirelessDeviceDiscovery => true;

  StreamSubscription<XCDeviceEventNotification>? _observedDeviceEventsSubscription;

  /// Cache for all devices found by `xcdevice list`, including not connected
  /// devices. Used to minimize the need to call `xcdevice list`.
  ///
  /// Separate from `deviceNotifier` since `deviceNotifier` should only contain
  /// connected devices.
  final Map<String, IOSDevice> _cachedPolledDevices = <String, IOSDevice>{};

  /// Maps device id to a map of the device's observed connections. When the
  /// mapped connection is `true`, that means that observed events indicated
  /// the device is connected via that particular interface.
  ///
  /// The device id must be missing from the map or both interfaces must be
  /// false for the device to be considered disconnected.
  ///
  /// Example:
  /// {
  ///   device-id: {
  ///     usb: false,
  ///     wifi: false,
  ///   },
  /// }
  final Map<String, Map<XCDeviceEventInterface, bool>> _observedConnectionsByDeviceId =
      <String, Map<XCDeviceEventInterface, bool>>{};

  @override
  Future<void> startPolling() async {
    if (!_platform.isMacOS) {
      throw UnsupportedError(
        'Control of iOS devices or simulators only supported on macOS.'
      );
    }
    if (!xcdevice.isInstalled) {
      return;
    }

    deviceNotifier ??= ItemListNotifier<Device>();

    // Start by populating all currently attached devices.
    _updateCachedDevices(await pollingGetDevices());
    _updateNotifierFromCache();

    // cancel any outstanding subscriptions.
    await _observedDeviceEventsSubscription?.cancel();
    _observedDeviceEventsSubscription = xcdevice.observedDeviceEvents()?.listen(
      onDeviceEvent,
      onError: (Object error, StackTrace stack) {
        _logger.printTrace('Process exception running xcdevice observe:\n$error\n$stack');
      }, onDone: () {
        // If xcdevice is killed or otherwise dies, polling will be stopped.
        // No retry is attempted and the polling client will have to restart polling
        // (restart the IDE). Avoid hammering on a process that is
        // continuously failing.
        _logger.printTrace('xcdevice observe stopped');
      },
      cancelOnError: true,
    );
  }

  @visibleForTesting
  Future<void> onDeviceEvent(XCDeviceEventNotification event) async {
    final ItemListNotifier<Device>? notifier = deviceNotifier;
    if (notifier == null) {
      return;
    }
    Device? knownDevice;
    for (final Device device in notifier.items) {
      if (device.id == event.deviceIdentifier) {
        knownDevice = device;
      }
    }

    final Map<XCDeviceEventInterface, bool> deviceObservedConnections =
        _observedConnectionsByDeviceId[event.deviceIdentifier] ??
            <XCDeviceEventInterface, bool>{
              XCDeviceEventInterface.usb: false,
              XCDeviceEventInterface.wifi: false,
            };

    if (event.eventType == XCDeviceEvent.attach) {
      // Update device's observed connections.
      deviceObservedConnections[event.eventInterface] = true;
      _observedConnectionsByDeviceId[event.deviceIdentifier] = deviceObservedConnections;

      // If device was not already in notifier, add it.
      if (knownDevice == null) {
        if (_cachedPolledDevices[event.deviceIdentifier] == null) {
          // If device is not found in cache, there's no way to get details
          // for an individual attached device, so repopulate them all.
          _updateCachedDevices(await pollingGetDevices());
        }
        _updateNotifierFromCache();
      }
    } else {
      // Update device's observed connections.
      deviceObservedConnections[event.eventInterface] = false;
      _observedConnectionsByDeviceId[event.deviceIdentifier] = deviceObservedConnections;

      // If device is in the notifier and does not have other observed
      // connections, remove it.
      if (knownDevice != null &&
          !_deviceHasObservedConnection(deviceObservedConnections)) {
        notifier.removeItem(knownDevice);
      }
    }
  }

  /// Adds or updates devices in cache. Does not remove devices from cache.
  void _updateCachedDevices(List<Device> devices) {
    for (final Device device in devices) {
      if (device is! IOSDevice) {
        continue;
      }
      _cachedPolledDevices[device.id] = device;
    }
  }

  /// Updates notifier with devices found in the cache that are determined
  /// to be connected.
  void _updateNotifierFromCache() {
    final ItemListNotifier<Device>? notifier = deviceNotifier;
    if (notifier == null) {
      return;
    }
    // Device is connected if it has either an observed usb or wifi connection
    // or it has not been observed but was found as connected in the cache.
    final List<Device> connectedDevices = _cachedPolledDevices.values.where((Device device) {
      final Map<XCDeviceEventInterface, bool>? deviceObservedConnections =
          _observedConnectionsByDeviceId[device.id];
      return (deviceObservedConnections != null &&
              _deviceHasObservedConnection(deviceObservedConnections)) ||
          (deviceObservedConnections == null && device.isConnected);
    }).toList();

    notifier.updateWithNewList(connectedDevices);
  }

  bool _deviceHasObservedConnection(
    Map<XCDeviceEventInterface, bool> deviceObservedConnections,
  ) {
    return (deviceObservedConnections[XCDeviceEventInterface.usb] ?? false) ||
        (deviceObservedConnections[XCDeviceEventInterface.wifi] ?? false);
  }

  @override
  Future<void> stopPolling() async {
    await _observedDeviceEventsSubscription?.cancel();
  }

  @override
  Future<List<Device>> pollingGetDevices({ Duration? timeout }) async {
    if (!_platform.isMacOS) {
      throw UnsupportedError(
        'Control of iOS devices or simulators only supported on macOS.'
      );
    }

    return xcdevice.getAvailableIOSDevices(timeout: timeout);
  }

  Future<Device?> waitForDeviceToConnect(
    IOSDevice device,
    Logger logger,
  ) async {
    final XCDeviceEventNotification? eventDetails =
        await xcdevice.waitForDeviceToConnect(device.id);

    if (eventDetails != null) {
      device.isConnected = true;
      device.connectionInterface = eventDetails.eventInterface.connectionInterface;
      return device;
    }
    return null;
  }

  void cancelWaitForDeviceToConnect() {
    xcdevice.cancelWaitForDeviceToConnect();
  }

  @override
  Future<List<String>> getDiagnostics() async {
    if (!_platform.isMacOS) {
      return const <String>[
        'Control of iOS devices or simulators only supported on macOS.',
      ];
    }

    return xcdevice.getDiagnostics();
  }

  @override
  List<String> get wellKnownIds => const <String>[];
}

class IOSDevice extends Device {
  IOSDevice(super.id, {
    required FileSystem fileSystem,
    required this.name,
    required this.cpuArchitecture,
    required this.connectionInterface,
    required this.isConnected,
    required this.devModeEnabled,
    required this.isCoreDevice,
    String? sdkVersion,
    required Platform platform,
    required IOSDeploy iosDeploy,
    required IMobileDevice iMobileDevice,
    required IOSCoreDeviceControl coreDeviceControl,
    required XcodeDebug xcodeDebug,
    required IProxy iProxy,
    required Logger logger,
  })
    : _sdkVersion = sdkVersion,
      _iosDeploy = iosDeploy,
      _iMobileDevice = iMobileDevice,
      _coreDeviceControl = coreDeviceControl,
      _xcodeDebug = xcodeDebug,
      _iproxy = iProxy,
      _fileSystem = fileSystem,
      _logger = logger,
      _platform = platform,
        super(
          category: Category.mobile,
          platformType: PlatformType.ios,
          ephemeral: true,
      ) {
    if (!_platform.isMacOS) {
      assert(false, 'Control of iOS devices or simulators only supported on Mac OS.');
      return;
    }
  }

  final String? _sdkVersion;
  final IOSDeploy _iosDeploy;
  final FileSystem _fileSystem;
  final Logger _logger;
  final Platform _platform;
  final IMobileDevice _iMobileDevice;
  final IOSCoreDeviceControl _coreDeviceControl;
  final XcodeDebug _xcodeDebug;
  final IProxy _iproxy;

  Version? get sdkVersion {
    return Version.parse(_sdkVersion);
  }

  /// May be 0 if version cannot be parsed.
  int get majorSdkVersion {
    return sdkVersion?.major ?? 0;
  }

  @override
  final String name;

  @override
  bool supportsRuntimeMode(BuildMode buildMode) => buildMode != BuildMode.jitRelease;

  final DarwinArch cpuArchitecture;

  @override
  /// The [connectionInterface] provided from `XCDevice.getAvailableIOSDevices`
  /// may not be accurate. Sometimes if it doesn't have a long enough time
  /// to connect, wireless devices will have an interface of `usb`/`attached`.
  /// This may change after waiting for the device to connect in
  /// `waitForDeviceToConnect`.
  DeviceConnectionInterface connectionInterface;

  @override
  bool isConnected;

  /// CoreDevice is a device connectivity stack introduced in Xcode 15. Devices
  /// with iOS 17 or greater are CoreDevices.
  final bool isCoreDevice;

  final Map<IOSApp?, DeviceLogReader> _logReaders = <IOSApp?, DeviceLogReader>{};

  DevicePortForwarder? _portForwarder;

  bool devModeEnabled = false;

  @visibleForTesting
  IOSDeployDebugger? iosDeployDebugger;

  @override
  Future<bool> get isLocalEmulator async => false;

  @override
  Future<String?> get emulatorId async => null;

  @override
  bool get supportsStartPaused => false;

  @override
  Future<bool> isAppInstalled(
    ApplicationPackage app, {
    String? userIdentifier,
  }) async {
    bool result;
    try {
      if (isCoreDevice) {
        result = await _coreDeviceControl.isAppInstalled(
          bundleId: app.id,
          deviceId: id,
        );
      } else {
        result = await _iosDeploy.isAppInstalled(
          bundleId: app.id,
          deviceId: id,
        );
      }
    } on ProcessException catch (e) {
      _logger.printError(e.message);
      return false;
    }
    return result;
  }

  @override
  Future<bool> isLatestBuildInstalled(ApplicationPackage app) async => false;

  @override
  Future<bool> installApp(
    covariant IOSApp app, {
    String? userIdentifier,
  }) async {
    final Directory bundle = _fileSystem.directory(app.deviceBundlePath);
    if (!bundle.existsSync()) {
      _logger.printError('Could not find application bundle at ${bundle.path}; have you run "flutter build ios"?');
      return false;
    }

    int installationResult;
    try {
      if (isCoreDevice) {
        installationResult = await _coreDeviceControl.installApp(
          deviceId: id,
          bundlePath: bundle.path,
        ) ? 0 : 1;
      } else {
        installationResult = await _iosDeploy.installApp(
          deviceId: id,
          bundlePath: bundle.path,
          appDeltaDirectory: app.appDeltaDirectory,
          launchArguments: <String>[],
          interfaceType: connectionInterface,
        );
      }
    } on ProcessException catch (e) {
      _logger.printError(e.message);
      return false;
    }
    if (installationResult != 0) {
      _logger.printError('Could not install ${bundle.path} on $id.');
      _logger.printError('Try launching Xcode and selecting "Product > Run" to fix the problem:');
      _logger.printError('  open ios/Runner.xcworkspace');
      _logger.printError('');
      return false;
    }
    return true;
  }

  @override
  Future<bool> uninstallApp(
    ApplicationPackage app, {
    String? userIdentifier,
  }) async {
    int uninstallationResult;
    try {
      if (isCoreDevice) {
        uninstallationResult = await _coreDeviceControl.uninstallApp(
          deviceId: id,
          bundleId: app.id,
        ) ? 0 : 1;
      } else {
        uninstallationResult = await _iosDeploy.uninstallApp(
          deviceId: id,
          bundleId: app.id,
        );
      }
    } on ProcessException catch (e) {
      _logger.printError(e.message);
      return false;
    }
    if (uninstallationResult != 0) {
      _logger.printError('Could not uninstall ${app.id} on $id.');
      return false;
    }
    return true;
  }

  @override
  // 32-bit devices are not supported.
  bool isSupported() => cpuArchitecture == DarwinArch.arm64;

  @override
  Future<LaunchResult> startApp(
    IOSApp package, {
    String? mainPath,
    String? route,
    required DebuggingOptions debuggingOptions,
    Map<String, Object?> platformArgs = const <String, Object?>{},
    bool prebuiltApplication = false,
    bool ipv6 = false,
    String? userIdentifier,
    @visibleForTesting Duration? discoveryTimeout,
    @visibleForTesting ShutdownHooks? shutdownHooks,
  }) async {
    String? packageId;
    if (isWirelesslyConnected &&
        debuggingOptions.debuggingEnabled &&
        debuggingOptions.disablePortPublication) {
      throwToolExit('Cannot start app on wirelessly tethered iOS device. Try running again with the --publish-port flag');
    }

    // TODO(vashworth): Remove after Xcode 15 and iOS 17 are in CI (https://github.com/flutter/flutter/issues/132128)
    // XcodeDebug workflow is used for CoreDevices (iOS 17+ and Xcode 15+).
    // Force the use of XcodeDebug workflow in CI to test from older versions
    // since devicelab has not yet been updated to iOS 17 and Xcode 15.
    bool forceXcodeDebugWorkflow = false;
    if (debuggingOptions.usingCISystem &&
        debuggingOptions.debuggingEnabled &&
        _platform.environment['FORCE_XCODE_DEBUG']?.toLowerCase() == 'true') {
      forceXcodeDebugWorkflow = true;
    }

    if (!prebuiltApplication) {
      _logger.printTrace('Building ${package.name} for $id');

      // Step 1: Build the precompiled/DBC application if necessary.
      final XcodeBuildResult buildResult = await buildXcodeProject(
          app: package as BuildableIOSApp,
          buildInfo: debuggingOptions.buildInfo,
          targetOverride: mainPath,
          activeArch: cpuArchitecture,
          deviceID: id,
          disablePortPublication: debuggingOptions.usingCISystem && debuggingOptions.disablePortPublication,
      );
      if (!buildResult.success) {
        _logger.printError('Could not build the precompiled application for the device.');
        await diagnoseXcodeBuildFailure(buildResult, globals.flutterUsage, _logger, globals.analytics);
        _logger.printError('');
        return LaunchResult.failed();
      }
      packageId = buildResult.xcodeBuildExecution?.buildSettings[IosProject.kProductBundleIdKey];
    }

    packageId ??= package.id;

    // Step 2: Check that the application exists at the specified path.
    final Directory bundle = _fileSystem.directory(package.deviceBundlePath);
    if (!bundle.existsSync()) {
      _logger.printError('Could not find the built application bundle at ${bundle.path}.');
      return LaunchResult.failed();
    }

    // Step 3: Attempt to install the application on the device.
    final List<String> launchArguments = debuggingOptions.getIOSLaunchArguments(
      EnvironmentType.physical,
      route,
      platformArgs,
      ipv6: ipv6,
      interfaceType: connectionInterface,
      isCoreDevice: isCoreDevice,
    );
    Status startAppStatus = _logger.startProgress(
      'Installing and launching...',
    );
    try {
      ProtocolDiscovery? vmServiceDiscovery;
      int installationResult = 1;
      if (debuggingOptions.debuggingEnabled) {
        _logger.printTrace('Debugging is enabled, connecting to vmService');
        vmServiceDiscovery = _setupDebuggerAndVmServiceDiscovery(
          package: package,
          bundle: bundle,
          debuggingOptions: debuggingOptions,
          launchArguments: launchArguments,
          ipv6: ipv6,
          uninstallFirst: debuggingOptions.uninstallFirst,
        );
      }

      if (isCoreDevice || forceXcodeDebugWorkflow) {
        installationResult = await _startAppOnCoreDevice(
          debuggingOptions: debuggingOptions,
          package: package,
          launchArguments: launchArguments,
          mainPath: mainPath,
          discoveryTimeout: discoveryTimeout,
          shutdownHooks: shutdownHooks ?? globals.shutdownHooks,
        ) ? 0 : 1;
      } else if (iosDeployDebugger == null) {
        installationResult = await _iosDeploy.launchApp(
          deviceId: id,
          bundlePath: bundle.path,
          appDeltaDirectory: package.appDeltaDirectory,
          launchArguments: launchArguments,
          interfaceType: connectionInterface,
          uninstallFirst: debuggingOptions.uninstallFirst,
        );
      } else {
        installationResult = await iosDeployDebugger!.launchAndAttach() ? 0 : 1;
      }
      if (installationResult != 0) {
        _printInstallError(bundle);
        await dispose();
        return LaunchResult.failed();
      }

      if (!debuggingOptions.debuggingEnabled) {
        return LaunchResult.succeeded();
      }

      _logger.printTrace('Application launched on the device. Waiting for Dart VM Service url.');

      final int defaultTimeout;
      if ((isCoreDevice || forceXcodeDebugWorkflow) && debuggingOptions.debuggingEnabled) {
        // Core devices with debugging enabled takes longer because this
        // includes time to install and launch the app on the device.
        defaultTimeout = isWirelesslyConnected ? 75 : 60;
      } else if (isWirelesslyConnected) {
        defaultTimeout = 45;
      } else {
        defaultTimeout = 30;
      }

      final Timer timer = Timer(discoveryTimeout ?? Duration(seconds: defaultTimeout), () {
        _logger.printError('The Dart VM Service was not discovered after $defaultTimeout seconds. This is taking much longer than expected...');
        if (isCoreDevice && debuggingOptions.debuggingEnabled) {
          _logger.printError(
            'Open the Xcode window the project is opened in to ensure the app '
            'is running. If the app is not running, try selecting "Product > Run" '
            'to fix the problem.',
          );
        }
        // If debugging with a wireless device and the timeout is reached, remind the
        // user to allow local network permissions.
        if (isWirelesslyConnected) {
          _logger.printError(
            '\nClick "Allow" to the prompt asking if you would like to find and connect devices on your local network. '
            'This is required for wireless debugging. If you selected "Don\'t Allow", '
            'you can turn it on in Settings > Your App Name > Local Network. '
            "If you don't see your app in the Settings, uninstall the app and rerun to see the prompt again."
          );
        } else {
          iosDeployDebugger?.checkForSymbolsFiles(_fileSystem);
          iosDeployDebugger?.pauseDumpBacktraceResume();
        }
      });

      Uri? localUri;
      if (isWirelesslyConnected) {
        // When using a CoreDevice, device logs are unavailable and therefore
        // cannot be used to get the Dart VM url. Instead, get the Dart VM
        // Service by finding services matching the app bundle id and the
        // device name.
        //
        // If not using a CoreDevice, wait for the Dart VM url to be discovered
        // via logs and then get the Dart VM Service by finding services matching
        // the app bundle id and the Dart VM port.
        //
        // Then in both cases, get the device IP from the Dart VM Service to
        // construct the Dart VM url using the device IP as the host.
        if (isCoreDevice) {
          localUri = await MDnsVmServiceDiscovery.instance!.getVMServiceUriForLaunch(
            packageId,
            this,
            usesIpv6: ipv6,
            useDeviceIPAsHost: true,
          );
        } else {
          // Wait for Dart VM Service to start up.
          final Uri? serviceURL = await vmServiceDiscovery?.uri;
          if (serviceURL == null) {
            await iosDeployDebugger?.stopAndDumpBacktrace();
            await dispose();
            return LaunchResult.failed();
          }

          // If Dart VM Service URL with the device IP is not found within 5 seconds,
          // change the status message to prompt users to click Allow. Wait 5 seconds because it
          // should only show this message if they have not already approved the permissions.
          // MDnsVmServiceDiscovery usually takes less than 5 seconds to find it.
          final Timer mDNSLookupTimer = Timer(const Duration(seconds: 5), () {
            startAppStatus.stop();
            startAppStatus = _logger.startProgress(
              'Waiting for approval of local network permissions...',
            );
          });

          // Get Dart VM Service URL with the device IP as the host.
          localUri = await MDnsVmServiceDiscovery.instance!.getVMServiceUriForLaunch(
            packageId,
            this,
            usesIpv6: ipv6,
            deviceVmservicePort: serviceURL.port,
            useDeviceIPAsHost: true,
          );

          mDNSLookupTimer.cancel();
        }
      } else {
        if ((isCoreDevice || forceXcodeDebugWorkflow) && vmServiceDiscovery != null) {
          // When searching for the Dart VM url, search for it via ProtocolDiscovery
          // (device logs) and mDNS simultaneously, since both can be flaky at times.
          final Future<Uri?> vmUrlFromMDns = MDnsVmServiceDiscovery.instance!.getVMServiceUriForLaunch(
            packageId,
            this,
            usesIpv6: ipv6,
          );
          final Future<Uri?> vmUrlFromLogs = vmServiceDiscovery.uri;
          localUri = await Future.any(
            <Future<Uri?>>[vmUrlFromMDns, vmUrlFromLogs]
          );
        } else {
          localUri = await vmServiceDiscovery?.uri;
          // If the `ios-deploy` debugger loses connection before it finds the
          // Dart Service VM url, try starting the debugger and launching the
          // app again.
          if (localUri == null &&
              debuggingOptions.usingCISystem &&
              iosDeployDebugger != null &&
              iosDeployDebugger!.lostConnection) {
            _logger.printStatus('Lost connection to device. Trying to connect again...');
            await dispose();
            vmServiceDiscovery = _setupDebuggerAndVmServiceDiscovery(
              package: package,
              bundle: bundle,
              debuggingOptions: debuggingOptions,
              launchArguments: launchArguments,
              ipv6: ipv6,
              uninstallFirst: false,
              skipInstall: true,
            );
            installationResult = await iosDeployDebugger!.launchAndAttach() ? 0 : 1;
            if (installationResult != 0) {
              _printInstallError(bundle);
              await dispose();
              return LaunchResult.failed();
            }
            localUri = await vmServiceDiscovery.uri;
          }
        }
      }
      timer.cancel();
      if (localUri == null) {
        await iosDeployDebugger?.stopAndDumpBacktrace();
        await dispose();
        return LaunchResult.failed();
      }
      return LaunchResult.succeeded(vmServiceUri: localUri);
    } on ProcessException catch (e) {
      await iosDeployDebugger?.stopAndDumpBacktrace();
      _logger.printError(e.message);
      await dispose();
      return LaunchResult.failed();
    } finally {
      startAppStatus.stop();

      if ((isCoreDevice || forceXcodeDebugWorkflow) && debuggingOptions.debuggingEnabled && package is BuildableIOSApp) {
        // When debugging via Xcode, after the app launches, reset the Generated
        // settings to not include the custom configuration build directory.
        // This is to prevent confusion if the project is later ran via Xcode
        // rather than the Flutter CLI.
        await updateGeneratedXcodeProperties(
          project: FlutterProject.current(),
          buildInfo: debuggingOptions.buildInfo,
          targetOverride: mainPath,
        );
      }
    }
  }

  void _printInstallError(Directory bundle) {
    _logger.printError('Could not run ${bundle.path} on $id.');
    _logger.printError('Try launching Xcode and selecting "Product > Run" to fix the problem:');
    _logger.printError('  open ios/Runner.xcworkspace');
    _logger.printError('');
  }

  ProtocolDiscovery _setupDebuggerAndVmServiceDiscovery({
    required IOSApp package,
    required Directory bundle,
    required DebuggingOptions debuggingOptions,
    required List<String> launchArguments,
    required bool ipv6,
    required bool uninstallFirst,
    bool skipInstall = false,
  }) {
    final DeviceLogReader deviceLogReader = getLogReader(
      app: package,
      usingCISystem: debuggingOptions.usingCISystem,
    );

    // If the device supports syslog reading, prefer launching the app without
    // attaching the debugger to avoid the overhead of the unnecessary extra running process.
    if (majorSdkVersion >= IOSDeviceLogReader.minimumUniversalLoggingSdkVersion) {
      iosDeployDebugger = _iosDeploy.prepareDebuggerForLaunch(
        deviceId: id,
        bundlePath: bundle.path,
        appDeltaDirectory: package.appDeltaDirectory,
        launchArguments: launchArguments,
        interfaceType: connectionInterface,
        uninstallFirst: uninstallFirst,
        skipInstall: skipInstall,
      );
      if (deviceLogReader is IOSDeviceLogReader) {
        deviceLogReader.debuggerStream = iosDeployDebugger;
      }
    }
    // Don't port foward if debugging with a wireless device.
    return ProtocolDiscovery.vmService(
      deviceLogReader,
      portForwarder: isWirelesslyConnected ? null : portForwarder,
      hostPort: debuggingOptions.hostVmServicePort,
      devicePort: debuggingOptions.deviceVmServicePort,
      ipv6: ipv6,
      logger: _logger,
    );
  }

  /// Starting with Xcode 15 and iOS 17, `ios-deploy` stopped working due to
  /// the new CoreDevice connectivity stack. Previously, `ios-deploy` was used
  /// to install the app, launch the app, and start `debugserver`.
  /// Xcode 15 introduced a new command line tool called `devicectl` that
  /// includes much of the functionality supplied by `ios-deploy`. However,
  /// `devicectl` lacks the ability to start a `debugserver` and therefore `ptrace`, which are needed
  /// for debug mode due to using a JIT Dart VM.
  ///
  /// Therefore, when starting an app on a CoreDevice, use `devicectl` when
  /// debugging is not enabled. Otherwise, use Xcode automation.
  Future<bool> _startAppOnCoreDevice({
    required DebuggingOptions debuggingOptions,
    required IOSApp package,
    required List<String> launchArguments,
    required String? mainPath,
    required ShutdownHooks shutdownHooks,
    @visibleForTesting Duration? discoveryTimeout,
  }) async {
    if (!debuggingOptions.debuggingEnabled) {
      // Release mode

      // Install app to device
      final bool installSuccess = await _coreDeviceControl.installApp(
        deviceId: id,
        bundlePath: package.deviceBundlePath,
      );
      if (!installSuccess) {
        return installSuccess;
      }

      // Launch app to device
      final bool launchSuccess = await _coreDeviceControl.launchApp(
        deviceId: id,
        bundleId: package.id,
        launchArguments: launchArguments,
      );

      return launchSuccess;
    } else {
      _logger.printStatus(
        'You may be prompted to give access to control Xcode. Flutter uses Xcode '
        'to run your app. If access is not allowed, you can change this through '
        'your Settings > Privacy & Security > Automation.',
      );
      final int launchTimeout = isWirelesslyConnected ? 45 : 30;
      final Timer timer = Timer(discoveryTimeout ?? Duration(seconds: launchTimeout), () {
        _logger.printError(
          'Xcode is taking longer than expected to start debugging the app. '
          'Ensure the project is opened in Xcode.',
        );
      });

      XcodeDebugProject debugProject;
      final FlutterProject flutterProject = FlutterProject.current();

      if (package is PrebuiltIOSApp) {
        debugProject = await _xcodeDebug.createXcodeProjectWithCustomBundle(
          package.deviceBundlePath,
          templateRenderer: globals.templateRenderer,
          verboseLogging: _logger.isVerbose,
        );
      } else if (package is BuildableIOSApp) {
        // Before installing/launching/debugging with Xcode, update the build
        // settings to use a custom configuration build directory so Xcode
        // knows where to find the app bundle to launch.
        final Directory bundle = _fileSystem.directory(
          package.deviceBundlePath,
        );
        await updateGeneratedXcodeProperties(
          project: flutterProject,
          buildInfo: debuggingOptions.buildInfo,
          targetOverride: mainPath,
          configurationBuildDir: bundle.parent.absolute.path,
        );

        final IosProject project = package.project;
        final XcodeProjectInfo? projectInfo = await project.projectInfo();
        if (projectInfo == null) {
          globals.printError('Xcode project not found.');
          return false;
        }
        if (project.xcodeWorkspace == null) {
          globals.printError('Unable to get Xcode workspace.');
          return false;
        }
        final String? scheme = projectInfo.schemeFor(debuggingOptions.buildInfo);
        if (scheme == null) {
          projectInfo.reportFlavorNotFoundAndExit();
        }

        _xcodeDebug.ensureXcodeDebuggerLaunchAction(project.xcodeProjectSchemeFile(scheme: scheme));

        debugProject = XcodeDebugProject(
          scheme: scheme,
          xcodeProject: project.xcodeProject,
          xcodeWorkspace: project.xcodeWorkspace!,
          hostAppProjectName: project.hostAppProjectName,
          expectedConfigurationBuildDir: bundle.parent.absolute.path,
          verboseLogging: _logger.isVerbose,
        );
      } else {
        // This should not happen. Currently, only PrebuiltIOSApp and
        // BuildableIOSApp extend from IOSApp.
        _logger.printError('IOSApp type ${package.runtimeType} is not recognized.');
        return false;
      }

      final bool debugSuccess = await _xcodeDebug.debugApp(
        project: debugProject,
        deviceId: id,
        launchArguments:launchArguments,
      );
      timer.cancel();

      // Kill Xcode on shutdown when running from CI
      if (debuggingOptions.usingCISystem) {
        shutdownHooks.addShutdownHook(() => _xcodeDebug.exit(force: true));
      }

      return debugSuccess;
    }
  }

  @override
  Future<bool> stopApp(
    ApplicationPackage? app, {
    String? userIdentifier,
  }) async {
    // If the debugger is not attached, killing the ios-deploy process won't stop the app.
    final IOSDeployDebugger? deployDebugger = iosDeployDebugger;
    if (deployDebugger != null && deployDebugger.debuggerAttached) {
      return deployDebugger.exit();
    }
    if (_xcodeDebug.debugStarted) {
      return _xcodeDebug.exit();
    }
    return false;
  }

  @override
  Future<TargetPlatform> get targetPlatform async => TargetPlatform.ios;

  @override
  Future<String> get sdkNameAndVersion async => 'iOS ${_sdkVersion ?? 'unknown version'}';

  @override
  DeviceLogReader getLogReader({
    covariant IOSApp? app,
    bool includePastLogs = false,
    bool usingCISystem = false,
  }) {
    assert(!includePastLogs, 'Past log reading not supported on iOS devices.');
    return _logReaders.putIfAbsent(app, () => IOSDeviceLogReader.create(
      device: this,
      app: app,
      iMobileDevice: _iMobileDevice,
      usingCISystem: usingCISystem,
    ));
  }

  @visibleForTesting
  void setLogReader(IOSApp app, DeviceLogReader logReader) {
    _logReaders[app] = logReader;
  }

  @override
  DevicePortForwarder get portForwarder => _portForwarder ??= IOSDevicePortForwarder(
    logger: _logger,
    iproxy: _iproxy,
    id: id,
    operatingSystemUtils: globals.os,
  );

  @visibleForTesting
  set portForwarder(DevicePortForwarder forwarder) {
    _portForwarder = forwarder;
  }

  @override
  void clearLogs() { }

  @override
  bool get supportsScreenshot {
    if (isCoreDevice) {
      // `idevicescreenshot` stopped working with iOS 17 / Xcode 15
      // (https://github.com/flutter/flutter/issues/128598).
      return false;
    }
    return _iMobileDevice.isInstalled;
  }

  @override
  Future<void> takeScreenshot(File outputFile) async {
    await _iMobileDevice.takeScreenshot(outputFile, id, connectionInterface);
  }

  @override
  bool isSupportedForProject(FlutterProject flutterProject) {
    return flutterProject.ios.existsSync();
  }

  @override
  Future<void> dispose() async {
    for (final DeviceLogReader logReader in _logReaders.values) {
      logReader.dispose();
    }
    _logReaders.clear();
    await _portForwarder?.dispose();
  }
}

/// Decodes a vis-encoded syslog string to a UTF-8 representation.
///
/// Apple's syslog logs are encoded in 7-bit form. Input bytes are encoded as follows:
/// 1. 0x00 to 0x19: non-printing range. Some ignored, some encoded as <...>.
/// 2. 0x20 to 0x7f: as-is, with the exception of 0x5c (backslash).
/// 3. 0x5c (backslash): octal representation \134.
/// 4. 0x80 to 0x9f: \M^x (using control-character notation for range 0x00 to 0x40).
/// 5. 0xa0: octal representation \240.
/// 6. 0xa1 to 0xf7: \M-x (where x is the input byte stripped of its high-order bit).
/// 7. 0xf8 to 0xff: unused in 4-byte UTF-8.
///
/// See: [vis(3) manpage](https://www.freebsd.org/cgi/man.cgi?query=vis&sektion=3)
String decodeSyslog(String line) {
  // UTF-8 values for \, M, -, ^.
  const int kBackslash = 0x5c;
  const int kM = 0x4d;
  const int kDash = 0x2d;
  const int kCaret = 0x5e;

  // Mask for the UTF-8 digit range.
  const int kNum = 0x30;

  // Returns true when `byte` is within the UTF-8 7-bit digit range (0x30 to 0x39).
  bool isDigit(int byte) => (byte & 0xf0) == kNum;

  // Converts a three-digit ASCII (UTF-8) representation of an octal number `xyz` to an integer.
  int decodeOctal(int x, int y, int z) => (x & 0x3) << 6 | (y & 0x7) << 3 | z & 0x7;

  try {
    final List<int> bytes = utf8.encode(line);
    final List<int> out = <int>[];
    for (int i = 0; i < bytes.length;) {
      if (bytes[i] != kBackslash || i > bytes.length - 4) {
        // Unmapped byte: copy as-is.
        out.add(bytes[i++]);
      } else {
        // Mapped byte: decode next 4 bytes.
        if (bytes[i + 1] == kM && bytes[i + 2] == kCaret) {
          // \M^x form: bytes in range 0x80 to 0x9f.
          out.add((bytes[i + 3] & 0x7f) + 0x40);
        } else if (bytes[i + 1] == kM && bytes[i + 2] == kDash) {
          // \M-x form: bytes in range 0xa0 to 0xf7.
          out.add(bytes[i + 3] | 0x80);
        } else if (bytes.getRange(i + 1, i + 3).every(isDigit)) {
          // \ddd form: octal representation (only used for \134 and \240).
          out.add(decodeOctal(bytes[i + 1], bytes[i + 2], bytes[i + 3]));
        } else {
          // Unknown form: copy as-is.
          out.addAll(bytes.getRange(0, 4));
        }
        i += 4;
      }
    }
    return utf8.decode(out);
  } on Exception {
    // Unable to decode line: return as-is.
    return line;
  }
}

class IOSDeviceLogReader extends DeviceLogReader {
  IOSDeviceLogReader._(
    this._iMobileDevice,
    this._majorSdkVersion,
    this._deviceId,
    this.name,
    this._isWirelesslyConnected,
    this._isCoreDevice,
    String appName,
    bool usingCISystem, {
    bool forceXcodeDebug = false,
  }) : // Match for lines for the runner in syslog.
      //
      // iOS 9 format:  Runner[297] <Notice>:
      // iOS 10 format: Runner(Flutter)[297] <Notice>:
      _runnerLineRegex = RegExp(appName + r'(\(Flutter\))?\[[\d]+\] <[A-Za-z]+>: '),
      _usingCISystem = usingCISystem,
      _forceXcodeDebug = forceXcodeDebug;

  /// Create a new [IOSDeviceLogReader].
  factory IOSDeviceLogReader.create({
    required IOSDevice device,
    IOSApp? app,
    required IMobileDevice iMobileDevice,
    bool usingCISystem = false,
  }) {
    final String appName = app?.name?.replaceAll('.app', '') ?? '';
    return IOSDeviceLogReader._(
      iMobileDevice,
      device.majorSdkVersion,
      device.id,
      device.name,
      device.isWirelesslyConnected,
      device.isCoreDevice,
      appName,
      usingCISystem,
      forceXcodeDebug: device._platform.environment['FORCE_XCODE_DEBUG']?.toLowerCase() == 'true',
    );
  }

  /// Create an [IOSDeviceLogReader] for testing.
  factory IOSDeviceLogReader.test({
    required IMobileDevice iMobileDevice,
    bool useSyslog = true,
    bool usingCISystem = false,
    int? majorSdkVersion,
    bool isWirelesslyConnected = false,
    bool isCoreDevice = false,
  }) {
    final int sdkVersion;
    if (majorSdkVersion != null) {
      sdkVersion = majorSdkVersion;
    } else {
      sdkVersion = useSyslog ? 12 : 13;
    }
    return IOSDeviceLogReader._(
      iMobileDevice, sdkVersion, '1234', 'test', isWirelesslyConnected, isCoreDevice, 'Runner', usingCISystem);
  }

  @override
  final String name;
  final int _majorSdkVersion;
  final String _deviceId;
  final bool _isWirelesslyConnected;
  final bool _isCoreDevice;
  final IMobileDevice _iMobileDevice;
  final bool _usingCISystem;

  // TODO(vashworth): Remove after Xcode 15 and iOS 17 are in CI (https://github.com/flutter/flutter/issues/132128)
  /// Whether XcodeDebug workflow is being forced.
  final bool _forceXcodeDebug;

  // Matches a syslog line from the runner.
  RegExp _runnerLineRegex;

  // Similar to above, but allows ~arbitrary components instead of "Runner"
  // and "Flutter". The regex tries to strike a balance between not producing
  // false positives and not producing false negatives.
  final RegExp _anyLineRegex = RegExp(r'\w+(\([^)]*\))?\[\d+\] <[A-Za-z]+>: ');

  // Logging from native code/Flutter engine is prefixed by timestamp and process metadata:
  // 2020-09-15 19:15:10.931434-0700 Runner[541:226276] Did finish launching.
  // 2020-09-15 19:15:10.931434-0700 Runner[541:226276] [Category] Did finish launching.
  //
  // Logging from the dart code has no prefixing metadata.
  final RegExp _debuggerLoggingRegex = RegExp(r'^\S* \S* \S*\[[0-9:]*] (.*)');

  @visibleForTesting
  late final StreamController<String> linesController = StreamController<String>.broadcast(
    onListen: _listenToSysLog,
    onCancel: dispose,
  );

  // Sometimes (race condition?) we try to send a log after the controller has
  // been closed. See https://github.com/flutter/flutter/issues/99021 for more
  // context.
  @visibleForTesting
  void addToLinesController(String message, IOSDeviceLogSource source) {
    if (!linesController.isClosed) {
      if (_excludeLog(message, source)) {
        return;
      }
      linesController.add(message);
    }
  }

  /// Used to track messages prefixed with "flutter:" from the fallback log source.
  final List<String> _fallbackStreamFlutterMessages = <String>[];

  /// Used to track if a message prefixed with "flutter:" has been received from the primary log.
  bool primarySourceFlutterLogReceived = false;

  /// There are three potential logging sources: `idevicesyslog`, `ios-deploy`,
  /// and Unified Logging (Dart VM). When using more than one of these logging
  /// sources at a time, prefer to use the primary source. However, if the
  /// primary source is not working, use the fallback.
  bool _excludeLog(String message, IOSDeviceLogSource source) {
    // If no fallback, don't exclude any logs.
    if (logSources.fallbackSource == null) {
      return false;
    }

    // If log is from primary source, don't exclude it unless the fallback was
    // quicker and added the message first.
    if (source == logSources.primarySource) {
      if (!primarySourceFlutterLogReceived && message.startsWith('flutter:')) {
        primarySourceFlutterLogReceived = true;
      }

      // If the message was already added by the fallback, exclude it to
      // prevent duplicates.
      final bool foundAndRemoved = _fallbackStreamFlutterMessages.remove(message);
      if (foundAndRemoved) {
        return true;
      }
      return false;
    }

    // If a flutter log was received from the primary source, that means it's
    // working so don't use any messages from the fallback.
    if (primarySourceFlutterLogReceived) {
      return true;
    }

    // When using logs from fallbacks, skip any logs not prefixed with "flutter:".
    // This is done because different sources often have different prefixes for
    // non-flutter messages, which makes duplicate matching difficult. Also,
    // non-flutter messages are not critical for CI tests.
    if (!message.startsWith('flutter:')) {
      return true;
    }

    _fallbackStreamFlutterMessages.add(message);
    return false;
  }

  final List<StreamSubscription<void>> _loggingSubscriptions = <StreamSubscription<void>>[];

  @override
  Stream<String> get logLines => linesController.stream;

  @override
  FlutterVmService? get connectedVMService => _connectedVMService;
  FlutterVmService? _connectedVMService;

  @override
  set connectedVMService(FlutterVmService? connectedVmService) {
    if (connectedVmService != null) {
      _listenToUnifiedLoggingEvents(connectedVmService);
    }
    _connectedVMService = connectedVmService;
  }

  static const int minimumUniversalLoggingSdkVersion = 13;

  /// Determine the primary and fallback source for device logs.
  ///
  /// There are three potential logging sources: `idevicesyslog`, `ios-deploy`,
  /// and Unified Logging (Dart VM).
  @visibleForTesting
  _IOSDeviceLogSources get logSources {
    // `ios-deploy` stopped working with iOS 17 / Xcode 15, so use `idevicesyslog` instead.
    // However, `idevicesyslog` is sometimes unreliable so use Dart VM as a fallback.
    // Also, `idevicesyslog` does not work with iOS 17 wireless devices, so use the
    // Dart VM for wireless devices.
    if (_isCoreDevice || _forceXcodeDebug) {
      if (_isWirelesslyConnected) {
        return _IOSDeviceLogSources(
          primarySource: IOSDeviceLogSource.unifiedLogging,
        );
      }
      return _IOSDeviceLogSources(
        primarySource: IOSDeviceLogSource.idevicesyslog,
        fallbackSource: IOSDeviceLogSource.unifiedLogging,
      );
    }

    // Use `idevicesyslog` for iOS 12 or less.
    // Syslog stopped working on iOS 13 (https://github.com/flutter/flutter/issues/41133).
    // However, from at least iOS 16, it has began working again. It's unclear
    // why it started working again.
    if (_majorSdkVersion < minimumUniversalLoggingSdkVersion) {
      return _IOSDeviceLogSources(
        primarySource: IOSDeviceLogSource.idevicesyslog,
      );
    }

    // Use `idevicesyslog` as a fallback to `ios-deploy` when debugging from
    // CI system since sometimes `ios-deploy` does not return the device logs:
    // https://github.com/flutter/flutter/issues/121231
    if (_usingCISystem && _majorSdkVersion >= 16) {
      return _IOSDeviceLogSources(
        primarySource: IOSDeviceLogSource.iosDeploy,
        fallbackSource: IOSDeviceLogSource.idevicesyslog,
      );
    }

    // Use `ios-deploy` to stream logs from the device when the device is not a
    // CoreDevice and has iOS 13 or greater.
    // When using `ios-deploy` and the Dart VM, prefer the more complete logs
    // from the attached debugger, if available.
    if (connectedVMService != null && (_iosDeployDebugger == null || !_iosDeployDebugger!.debuggerAttached)) {
      return _IOSDeviceLogSources(
        primarySource: IOSDeviceLogSource.unifiedLogging,
        fallbackSource: IOSDeviceLogSource.iosDeploy,
      );
    }
    return _IOSDeviceLogSources(
      primarySource: IOSDeviceLogSource.iosDeploy,
      fallbackSource: IOSDeviceLogSource.unifiedLogging,
    );
  }

  /// Whether `idevicesyslog` is used as either the primary or fallback source for device logs.
  @visibleForTesting
  bool get useSyslogLogging {
    return logSources.primarySource == IOSDeviceLogSource.idevicesyslog ||
        logSources.fallbackSource == IOSDeviceLogSource.idevicesyslog;
  }

  /// Whether the Dart VM is used as either the primary or fallback source for device logs.
  ///
  /// Unified Logging only works after the Dart VM has been connected to.
  @visibleForTesting
  bool get useUnifiedLogging {
    return logSources.primarySource == IOSDeviceLogSource.unifiedLogging ||
        logSources.fallbackSource == IOSDeviceLogSource.unifiedLogging;
  }


  /// Whether `ios-deploy` is used as either the primary or fallback source for device logs.
  @visibleForTesting
  bool get useIOSDeployLogging {
    return logSources.primarySource == IOSDeviceLogSource.iosDeploy ||
        logSources.fallbackSource == IOSDeviceLogSource.iosDeploy;
  }

  /// Listen to Dart VM for logs on iOS 13 or greater.
  Future<void> _listenToUnifiedLoggingEvents(FlutterVmService connectedVmService) async {
    if (!useUnifiedLogging) {
      return;
    }
    try {
      // The VM service will not publish logging events unless the debug stream is being listened to.
      // Listen to this stream as a side effect.
      unawaited(connectedVmService.service.streamListen('Debug'));

      await Future.wait(<Future<void>>[
        connectedVmService.service.streamListen(vm_service.EventStreams.kStdout),
        connectedVmService.service.streamListen(vm_service.EventStreams.kStderr),
      ]);
    } on vm_service.RPCError {
      // Do nothing, since the tool is already subscribed.
    }

    void logMessage(vm_service.Event event) {
      final String message = processVmServiceMessage(event);
      if (message.isNotEmpty) {
        addToLinesController(message, IOSDeviceLogSource.unifiedLogging);
      }
    }

    _loggingSubscriptions.addAll(<StreamSubscription<void>>[
      connectedVmService.service.onStdoutEvent.listen(logMessage),
      connectedVmService.service.onStderrEvent.listen(logMessage),
    ]);
  }

  /// Log reader will listen to [debugger.logLines] and will detach debugger on dispose.
  IOSDeployDebugger? get debuggerStream => _iosDeployDebugger;

  /// Send messages from ios-deploy debugger stream to device log reader stream.
  set debuggerStream(IOSDeployDebugger? debugger) {
    // Logging is gathered from syslog on iOS earlier than 13.
    if (!useIOSDeployLogging) {
      return;
    }
    _iosDeployDebugger = debugger;
    if (debugger == null) {
      return;
    }
    // Add the debugger logs to the controller created on initialization.
    _loggingSubscriptions.add(debugger.logLines.listen(
      (String line) => addToLinesController(
        _debuggerLineHandler(line),
        IOSDeviceLogSource.iosDeploy,
      ),
      onError: linesController.addError,
      onDone: linesController.close,
      cancelOnError: true,
    ));
  }
  IOSDeployDebugger? _iosDeployDebugger;

  // Strip off the logging metadata (leave the category), or just echo the line.
  String _debuggerLineHandler(String line) => _debuggerLoggingRegex.firstMatch(line)?.group(1) ?? line;

  /// Start and listen to idevicesyslog to get device logs for iOS versions
  /// prior to 13 or if [useBothLogDeviceReaders] is true.
  void _listenToSysLog() {
    if (!useSyslogLogging) {
      return;
    }
    _iMobileDevice.startLogger(_deviceId).then<void>((Process process) {
      process.stdout.transform<String>(utf8.decoder).transform<String>(const LineSplitter()).listen(_newSyslogLineHandler());
      process.stderr.transform<String>(utf8.decoder).transform<String>(const LineSplitter()).listen(_newSyslogLineHandler());
      process.exitCode.whenComplete(() {
        if (!linesController.hasListener) {
          return;
        }
        // When using both log readers, do not close the stream on exit.
        // This is to allow ios-deploy to be the source of authority to close
        // the stream.
        if (useSyslogLogging && useIOSDeployLogging && debuggerStream != null) {
          return;
        }
        linesController.close();
      });
      assert(idevicesyslogProcess == null);
      idevicesyslogProcess = process;
    });
  }

  @visibleForTesting
  Process? idevicesyslogProcess;

  // Returns a stateful line handler to properly capture multiline output.
  //
  // For multiline log messages, any line after the first is logged without
  // any specific prefix. To properly capture those, we enter "printing" mode
  // after matching a log line from the runner. When in printing mode, we print
  // all lines until we find the start of another log message (from any app).
  void Function(String line) _newSyslogLineHandler() {
    bool printing = false;

    return (String line) {
      if (printing) {
        if (!_anyLineRegex.hasMatch(line)) {
          addToLinesController(decodeSyslog(line), IOSDeviceLogSource.idevicesyslog);
          return;
        }

        printing = false;
      }

      final Match? match = _runnerLineRegex.firstMatch(line);

      if (match != null) {
        final String logLine = line.substring(match.end);
        // Only display the log line after the initial device and executable information.
        addToLinesController(decodeSyslog(logLine), IOSDeviceLogSource.idevicesyslog);
        printing = true;
      }
    };
  }

  @override
  void dispose() {
    for (final StreamSubscription<void> loggingSubscription in _loggingSubscriptions) {
      loggingSubscription.cancel();
    }
    idevicesyslogProcess?.kill();
    _iosDeployDebugger?.detach();
  }
}

enum IOSDeviceLogSource {
  /// Gets logs from ios-deploy debugger.
  iosDeploy,
  /// Gets logs from idevicesyslog.
  idevicesyslog,
  /// Gets logs from the Dart VM Service.
  unifiedLogging,
}

class _IOSDeviceLogSources {
  _IOSDeviceLogSources({
    required this.primarySource,
    this.fallbackSource,
  });

  final IOSDeviceLogSource primarySource;
  final IOSDeviceLogSource? fallbackSource;
}

/// A [DevicePortForwarder] specialized for iOS usage with iproxy.
class IOSDevicePortForwarder extends DevicePortForwarder {

  /// Create a new [IOSDevicePortForwarder].
  IOSDevicePortForwarder({
    required Logger logger,
    required String id,
    required IProxy iproxy,
    required OperatingSystemUtils operatingSystemUtils,
  }) : _logger = logger,
       _id = id,
       _iproxy = iproxy,
       _operatingSystemUtils = operatingSystemUtils;

  /// Create a [IOSDevicePortForwarder] for testing.
  ///
  /// This specifies the path to iproxy as 'iproxy` and the dyLdLibEntry as
  /// 'DYLD_LIBRARY_PATH: /path/to/libs'.
  ///
  /// The device id may be provided, but otherwise defaults to '1234'.
  factory IOSDevicePortForwarder.test({
    required ProcessManager processManager,
    required Logger logger,
    String? id,
    required OperatingSystemUtils operatingSystemUtils,
  }) {
    return IOSDevicePortForwarder(
      logger: logger,
      iproxy: IProxy.test(
        logger: logger,
        processManager: processManager,
      ),
      id: id ?? '1234',
      operatingSystemUtils: operatingSystemUtils,
    );
  }

  final Logger _logger;
  final String _id;
  final IProxy _iproxy;
  final OperatingSystemUtils _operatingSystemUtils;

  @override
  List<ForwardedPort> forwardedPorts = <ForwardedPort>[];

  @visibleForTesting
  void addForwardedPorts(List<ForwardedPort> ports) {
    ports.forEach(forwardedPorts.add);
  }

  static const Duration _kiProxyPortForwardTimeout = Duration(seconds: 1);

  @override
  Future<int> forward(int devicePort, { int? hostPort }) async {
    final bool autoselect = hostPort == null || hostPort == 0;
    if (autoselect) {
      final int freePort = await _operatingSystemUtils.findFreePort();
      // Dynamic port range 49152 - 65535.
      hostPort = freePort == 0 ? 49152 : freePort;
    }

    Process? process;

    bool connected = false;
    while (!connected) {
      _logger.printTrace('Attempting to forward device port $devicePort to host port $hostPort');
      process = await _iproxy.forward(devicePort, hostPort!, _id);
      // TODO(ianh): This is a flaky race condition, https://github.com/libimobiledevice/libimobiledevice/issues/674
      connected = !await process.stdout.isEmpty.timeout(_kiProxyPortForwardTimeout, onTimeout: () => false);
      if (!connected) {
        process.kill();
        if (autoselect) {
          hostPort += 1;
          if (hostPort > 65535) {
            throw Exception('Could not find open port on host.');
          }
        } else {
          throw Exception('Port $hostPort is not available.');
        }
      }
    }
    assert(connected);
    assert(process != null);

    final ForwardedPort forwardedPort = ForwardedPort.withContext(
      hostPort!, devicePort, process,
    );
    _logger.printTrace('Forwarded port $forwardedPort');
    forwardedPorts.add(forwardedPort);
    return hostPort;
  }

  @override
  Future<void> unforward(ForwardedPort forwardedPort) async {
    if (!forwardedPorts.remove(forwardedPort)) {
      // Not in list. Nothing to remove.
      return;
    }

    _logger.printTrace('Un-forwarding port $forwardedPort');
    forwardedPort.dispose();
  }

  @override
  Future<void> dispose() async {
    for (final ForwardedPort forwardedPort in forwardedPorts) {
      forwardedPort.dispose();
    }
  }
}
