import 'package:audio_service/audio_service.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../api/endpoints/radio.dart';
import '../auth/auth_provider.dart';
import '../cache/audio_cache_manager.dart';
import '../library/library_providers.dart' show dioProvider;
import '../models/track.dart';
import 'album_cover_cache.dart';
import 'audio_handler.dart';

final audioHandlerProvider = Provider<MinstrelAudioHandler>((ref) {
  throw UnimplementedError('overridden in main()');
});

final albumCoverCacheProvider = Provider<AlbumCoverCache>((ref) {
  return AlbumCoverCache(
    dioFactory: () => ref.read(dioProvider.future),
  );
});

final playbackStateProvider = StreamProvider<PlaybackState>(
  (ref) => ref.watch(audioHandlerProvider).playbackState,
);

final mediaItemProvider = StreamProvider<MediaItem?>(
  (ref) => ref.watch(audioHandlerProvider).mediaItem,
);

final queueProvider = StreamProvider<List<MediaItem>>(
  (ref) => ref.watch(audioHandlerProvider).queue,
);

/// Player volume in [0.0, 1.0]. Mirrors just_audio's player.volume;
/// modify via PlayerActions.setVolume(). Surfaced separately from
/// PlaybackState because audio_service's PlaybackState doesn't carry
/// volume — it's a player-side concern.
final volumeProvider = StreamProvider<double>(
  (ref) => ref.watch(audioHandlerProvider).volumeStream,
);

/// Live playback position. just_audio emits at ~200ms cadence so seek
/// bars driven by this provider scrub smoothly. Don't use
/// PlaybackState.updatePosition for that — it only changes on state
/// transitions (play/pause/buffer/seek) and the bar would appear
/// frozen between events.
final positionProvider = StreamProvider<Duration>(
  (ref) => ref.watch(audioHandlerProvider).positionStream,
);

class PlayerActions {
  PlayerActions(this._ref);
  final Ref _ref;

  Future<void> playTracks(List<TrackRef> tracks, {int initialIndex = 0}) async {
    final url   = await _ref.read(serverUrlProvider.future);
    final token = await _ref.read(secureStorageProvider).read(key: 'session_token');
    final cache = _ref.read(albumCoverCacheProvider);
    final audioCache = _ref.read(audioCacheManagerProvider);
    final h = _ref.read(audioHandlerProvider)
      ..configure(
        baseUrl: url ?? '',
        token: token,
        coverCache: cache,
        audioCacheManager: audioCache,
      );
    await h.setQueueFromTracks(tracks, initialIndex: initialIndex);
    await h.play();
  }

  Future<void> playNext(TrackRef track) async {
    final h = _ref.read(audioHandlerProvider);
    await h.playNext(track);
  }

  Future<void> enqueue(TrackRef track) async {
    final h = _ref.read(audioHandlerProvider);
    await h.enqueue(track);
  }

  /// Toggles shuffle on/off. Pre-existing audio_service convention.
  Future<void> toggleShuffle() async {
    final h = _ref.read(audioHandlerProvider);
    final state = await h.playbackState.first;
    final next = state.shuffleMode == AudioServiceShuffleMode.none
        ? AudioServiceShuffleMode.all
        : AudioServiceShuffleMode.none;
    await h.setShuffleMode(next);
  }

  /// Cycles repeat mode: none → all → one → none.
  Future<void> cycleRepeat() async {
    final h = _ref.read(audioHandlerProvider);
    final state = await h.playbackState.first;
    final next = switch (state.repeatMode) {
      AudioServiceRepeatMode.none => AudioServiceRepeatMode.all,
      AudioServiceRepeatMode.all => AudioServiceRepeatMode.one,
      _ => AudioServiceRepeatMode.none,
    };
    await h.setRepeatMode(next);
  }

  Future<void> setVolume(double v) async {
    await _ref.read(audioHandlerProvider).setVolume(v);
  }

  /// Fetches `/api/radio?seed_track=<id>` and starts playing the
  /// returned track list (seed at index 0 + recommended picks).
  Future<void> startRadio(String trackId) async {
    final dio = await _ref.read(dioProvider.future);
    final tracks = await RadioApi(dio).seedTrack(trackId);
    if (tracks.isEmpty) return;
    await playTracks(tracks);
  }
}

final playerActionsProvider = Provider<PlayerActions>((ref) => PlayerActions(ref));