import 'package:flutter/services.dart';

import '../models/app_entry.dart';
import '../models/media_playback.dart';
import '../models/system_status.dart';

class LauncherPlatformException implements Exception {
  LauncherPlatformException(this.message);

  final String message;

  @override
  String toString() => message;
}

/// Thin, testable boundary around Android's package manager, volume and
/// connectivity APIs.
abstract class LauncherPlatform {
  Future<List<AppEntry>> listApps();

  Future<void> launchApp({
    required String packageName,
    required String activityName,
  });

  Future<bool> isDefaultHome();

  Future<bool> requestDefaultHome();

  Future<SystemStatus> getStatus();

  Future<VolumeInfo> getVolume();

  Future<void> setVolume(int index);

  Future<bool> isMusicPlaying();

  /// Sends a standard media key to the current media session.
  Future<bool> sendMediaKey(String action);

  Future<MediaPlayback> getMediaState();

  Future<bool> openNotificationAccessSettings();

  Future<void> setKeepScreenOn(bool enabled);
}

class NativeBridge implements LauncherPlatform {
  static const _appsChannel = MethodChannel('com.wasp.cardash_launcher/apps');
  static const _systemChannel = MethodChannel(
    'com.wasp.cardash_launcher/system',
  );
  static const _mediaChannel = MethodChannel('com.wasp.cardash_launcher/media');

  @override
  Future<List<AppEntry>> listApps() async {
    try {
      final raw = await _appsChannel.invokeMethod<dynamic>('listApps');
      if (raw is Map && raw['error'] != null) {
        throw LauncherPlatformException(raw['error'].toString());
      }
      if (raw is! List) return const [];
      return raw
          .whereType<Map>()
          .map(AppEntry.fromMap)
          .where(
            (app) => app.packageName.isNotEmpty && app.activityName.isNotEmpty,
          )
          .toList(growable: false);
    } on PlatformException catch (error) {
      throw LauncherPlatformException(
        error.message ?? 'Could not load installed apps.',
      );
    } on MissingPluginException {
      throw LauncherPlatformException('The Android app bridge is unavailable.');
    }
  }

  @override
  Future<void> launchApp({
    required String packageName,
    required String activityName,
  }) async {
    try {
      await _appsChannel.invokeMethod<dynamic>('launchApp', {
        'package': packageName,
        'activity': activityName,
      });
    } on PlatformException catch (error) {
      throw LauncherPlatformException(
        error.message ?? 'Could not open the app.',
      );
    } on MissingPluginException {
      throw LauncherPlatformException('The Android app bridge is unavailable.');
    }
  }

  @override
  Future<bool> isDefaultHome() async {
    try {
      return await _appsChannel.invokeMethod<bool>('isDefaultHome') ?? false;
    } on PlatformException {
      return false;
    } on MissingPluginException {
      return false;
    }
  }

  @override
  Future<bool> requestDefaultHome() async {
    try {
      return await _appsChannel.invokeMethod<bool>('requestDefaultHome') ??
          false;
    } on PlatformException {
      return false;
    } on MissingPluginException {
      return false;
    }
  }

  @override
  Future<SystemStatus> getStatus() async {
    try {
      final raw = await _systemChannel.invokeMethod<dynamic>('getStatus');
      return raw is Map ? SystemStatus.fromMap(raw) : const SystemStatus();
    } on PlatformException {
      return const SystemStatus();
    } on MissingPluginException {
      return const SystemStatus();
    }
  }

  @override
  Future<VolumeInfo> getVolume() async {
    try {
      final raw = await _systemChannel.invokeMethod<dynamic>('getVolume');
      return raw is Map ? VolumeInfo.fromMap(raw) : const VolumeInfo();
    } on PlatformException {
      return const VolumeInfo();
    } on MissingPluginException {
      return const VolumeInfo();
    }
  }

  @override
  Future<bool> isMusicPlaying() async {
    try {
      return await _systemChannel.invokeMethod<bool>('isMusicPlaying') ?? false;
    } on PlatformException {
      return false;
    } on MissingPluginException {
      return false;
    }
  }

  @override
  Future<MediaPlayback> getMediaState() async {
    try {
      final raw = await _mediaChannel.invokeMethod<dynamic>('getMediaState');
      return raw is Map ? MediaPlayback.fromMap(raw) : const MediaPlayback();
    } on PlatformException {
      return const MediaPlayback();
    } on MissingPluginException {
      return const MediaPlayback();
    }
  }

  @override
  Future<bool> openNotificationAccessSettings() async {
    try {
      return await _mediaChannel.invokeMethod<bool>(
            'openNotificationAccessSettings',
          ) ??
          false;
    } on PlatformException {
      return false;
    } on MissingPluginException {
      return false;
    }
  }

  @override
  Future<bool> sendMediaKey(String action) async {
    try {
      return await _systemChannel.invokeMethod<bool>('mediaKey', {
            'action': action,
          }) ??
          false;
    } on PlatformException {
      return false;
    } on MissingPluginException {
      return false;
    }
  }

  @override
  Future<void> setKeepScreenOn(bool enabled) async {
    try {
      await _systemChannel.invokeMethod<dynamic>('setKeepScreenOn', {
        'enabled': enabled,
      });
    } on PlatformException {
      // Older builds simply keep the window behaviour unchanged.
    } on MissingPluginException {
      // Nothing to apply outside Android.
    }
  }

  @override
  Future<void> setVolume(int index) async {
    try {
      await _systemChannel.invokeMethod<dynamic>('setVolume', {'index': index});
    } on PlatformException {
      // Volume can be unavailable on some emulators; the UI keeps its local
      // value and will reconcile on the next poll.
    } on MissingPluginException {
      // Nothing to synchronise when running outside Android.
    }
  }
}