import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/material.dart';
import 'package:just_audio/just_audio.dart';
import 'package:just_audio_background/just_audio_background.dart';
import 'package:ocarina/api/subsonic/song.dart';
import 'package:ocarina/main.dart';
import 'package:ocarina/util/util.dart';

/// Service used to control the audio player
class AudioPlayerService {
  /// Service used to control the audio player
  factory AudioPlayerService() {
    return _audioPlayerService;
  }

  AudioPlayerService._internal();
  static final AudioPlayerService _audioPlayerService =
      AudioPlayerService._internal();

  /// The [AudioPlayer] instance
  final _player = AudioPlayer();

  /// Check if listeners are set up
  var _setUp = false;

  /// Registers listeners on the player
  void setup() {
    if (_setUp) return;
    _player.currentIndexStream.listen((index) {
      logger.d("Done fired");
      songNotifier.value = index == null ? null : _songList[index];
      _setColorScheme();
    });
    _setUp = true;
  }

  /// True if [AudioPlayer] instance is playing
  bool get isPlaying => _player.playing;

  /// Currently playing song
  ///
  /// Null if no song is loaded
  Song? get song => _player.currentIndex == null || _player.currentIndex == -1
      ? null
      : _songList[_player.currentIndex!];

  final _queue = ConcatenatingAudioSource(
    children: [],
    shuffleOrder: DefaultShuffleOrder(),
  );

  /// Seeks to the next song
  Future<void> next() async {
    await _player.seekToNext();
  }

  /// Previous
  Future<void> previous() async {
    await _player.seekToPrevious();
  }

  /// Pauses playback
  Future<void> pause() async {
    await _player.pause();
    logger.d("Paused");
  }

  /// Resumes playback
  void resume() {
    _player.play();
    logger.d("Playing ${_player.currentIndex}");
  }

  /// Sets color scheme from image
  Future<void> _setColorScheme() async {
    if (AudioPlayerService().song == null) {
      themeNotifier.value = ColorScheme.fromSeed(seedColor: Colors.deepPurple);
    }
    themeNotifier.value = await ColorScheme.fromImageProvider(
      provider: CachedNetworkImageProvider(
        AudioPlayerService().song!.coverArtUrl,
      ),
    );
    logger.d(AudioPlayerService().song!.coverArtUrl);
  }

  final List<Song> _songList = [];

  /// Adds a selected song to the queue
  Future<void> addToQueue(Song song) async {
    final doCache = sp.getBool("doCache") ?? true;
    _songList.add(song);
    await _queue.add(
      doCache
          ? LockCachingAudioSource(
              Uri.parse(song.streamUrl),
              tag: MediaItem(
                id: song.id,
                title: song.title,
                album: song.albumName,
                artist: song.artistName,
                artUri: Uri.parse(song.coverArtUrl),
              ),
            )
          : AudioSource.uri(
              Uri.parse(song.streamUrl),
              tag: MediaItem(
                id: song.id,
                title: song.title,
                album: song.albumName,
                artist: song.artistName,
                artUri: Uri.parse(song.coverArtUrl),
              ),
            ),
    );
  }

  /// Plays the passed [Song], clearing the queue
  Future<void> playNow({
    List<Song> queueNext = const <Song>[],
    List<Song> queuePast = const <Song>[],
  }) async {
    if (queueNext.isEmpty) return;
    final doCache = sp.getBool("doCache") ?? true;
    await _queue.clear();
    _songList
      ..clear()
      ..addAll(queueNext);

    final q = List<AudioSource>.generate(
      queuePast.length,
      (i) => doCache
          ? LockCachingAudioSource(
              Uri.parse(queuePast[i].streamUrl),
              tag: MediaItem(
                id: queuePast[i].id,
                title: queuePast[i].title,
                album: queuePast[i].albumName,
                artist: queuePast[i].artistName,
                artUri: Uri.parse(queuePast[i].coverArtUrl),
              ),
            )
          : AudioSource.uri(
              Uri.parse(queuePast[i].streamUrl),
              tag: MediaItem(
                id: queuePast[i].id,
                title: queuePast[i].title,
                album: queuePast[i].albumName,
                artist: queuePast[i].artistName,
                artUri: Uri.parse(queuePast[i].coverArtUrl),
              ),
            ),
    )..addAll(
        List<AudioSource>.generate(
          queueNext.length,
          (i) => doCache
              ? LockCachingAudioSource(
                  Uri.parse(queueNext[i].streamUrl),
                  tag: MediaItem(
                    id: queueNext[i].id,
                    title: queueNext[i].title,
                    album: queueNext[i].albumName,
                    artist: queueNext[i].artistName,
                    artUri: Uri.parse(queueNext[i].coverArtUrl),
                  ),
                )
              : AudioSource.uri(
                  Uri.parse(queueNext[i].streamUrl),
                  tag: MediaItem(
                    id: queueNext[i].id,
                    title: queueNext[i].title,
                    album: queueNext[i].albumName,
                    artist: queueNext[i].artistName,
                    artUri: Uri.parse(queueNext[i].coverArtUrl),
                  ),
                ),
        ),
      );

    await _queue.addAll(
      q,
    );
    await _player.setAudioSource(
      _queue,
      initialIndex: queuePast.isEmpty ? 0 : queuePast.length - 1,
      initialPosition: Duration.zero,
    );

    playerKey.currentState?.update();
    resume();
  }
}