import "dart:async";

import "package:flutter/foundation.dart";
import "package:shared_preferences/shared_preferences.dart";

const String _kWindowShadeKey = "winamp.window_shade";
const String _kAlwaysOnTopKey = "winamp.always_on_top";
const String _kEqOpenKey = "winamp.eq_open";
const String _kEqShadeKey = "winamp.eq_shade";
const String _kPlOpenKey = "winamp.pl_open";
const String _kPlShadeKey = "winamp.pl_shade";
const String _kUiScaleKey = "winamp.ui_scale";
const String _kActiveSkinKey = "winamp.active_skin";

/// Simulated playback/UI state for the player, mirroring the flags tracked by
/// the original Winamp main window. No audio yet; the transport simply drives
/// the display, sliders, and windowshade.
class PlayerState extends ChangeNotifier {
  PlayerState({
    this.windowShade = false,
    this.alwaysOnTop = false,
    this.eqOpen = false,
    this.eqShade = false,
    this.plOpen = false,
    this.plShade = false,
    double uiScale = 1.0,
  }) : _uiScale = uiScale.clamp(1.0, 3.0);

  bool playing = false;
  bool paused = false;
  bool shuffle = false;
  bool repeat = false;
  bool eqOpen = false;
  bool eqShade = false;
  bool plOpen = false;
  bool plShade = false;
  bool windowShade = false;
  bool alwaysOnTop = false;
  bool active = true;

  double _uiScale = 1.0;

  /// The window scaling factor (1.0, 2.0, or 3.0) from the Window menu.
  double get uiScale => _uiScale;

  /// 0..255, volume.bmp row index maps `volume * 27 / 255`.
  int volume = 200;

  /// -127..127; balance.bmp row maps `abs(balance) * 27 / 127`.
  int balance = 0;

  /// 0..256 seek position, posbar thumb maps directly.
  int position = 0;

  int durationSec = 205;
  int bitrate = 128;
  int mixrate = 44;
  String title = "Winamp 5.9";
  String fileName = "dartamp";
  int playIcon = 2;

  /// 0..64 per band, 32 = 0 dB (mirrors the original EQ slider state).
  int preamp = 32;

  /// The 10 band gains, index 0 = 60 Hz through 9 = 16 kHz.
  final List<int> eqBands = List.filled(10, 32);

  /// Whether the Equalizer is enabled (the ON button).
  bool eqEnabled = true;

  /// Whether the Equalizer presets auto-load per song (the AUTO button).
  bool eqAuto = false;

  Timer? _ticker;

  void togglePlay() {
    if (paused) {
      paused = false;
      playing = true;
      _startTicker();
    } else {
      playing = !playing;
      paused = false;
      playIcon = playing ? 0 : 2;
      if (playing) {
        _startTicker();
      } else {
        _stopTicker();
      }
    }
    notifyListeners();
  }

  void pause() {
    paused = true;
    playing = false;
    playIcon = 1;
    notifyListeners();
  }

  void stop() {
    playing = false;
    paused = false;
    position = 0;
    playIcon = 2;
    _stopTicker();
    notifyListeners();
  }

  void next() {}

  void prev() {}

  void toggleShuffle() {
    shuffle = !shuffle;
    notifyListeners();
  }

  void toggleRepeat() {
    repeat = !repeat;
    notifyListeners();
  }

  void setVolume(int value) {
    volume = value.clamp(0, 255);
    notifyListeners();
  }

  void setBalance(int value) {
    balance = value.clamp(-127, 127);
    notifyListeners();
  }

  void setSeek(int value) {
    position = value.clamp(0, 256);
    notifyListeners();
  }

  void setPreamp(int value) {
    final clamped = value.clamp(0, 64);
    if (clamped == preamp) return;
    preamp = clamped;
    notifyListeners();
  }

  void setEqBand(int index, int value) {
    if (index < 0 || index >= eqBands.length) return;
    final clamped = value.clamp(0, 64);
    if (clamped == eqBands[index]) return;
    eqBands[index] = clamped;
    notifyListeners();
  }

  void setEqEnabled(bool value) {
    if (eqEnabled == value) return;
    eqEnabled = value;
    notifyListeners();
  }

  void setEqAuto(bool value) {
    if (eqAuto == value) return;
    eqAuto = value;
    notifyListeners();
  }

  void toggleEq() {
    setEqOpen(!eqOpen);
  }

  void setEqOpen(bool value) {
    if (eqOpen == value) return;
    eqOpen = value;
    unawaited(_saveEqOpen(value));
    notifyListeners();
  }

  void togglePlaylist() {
    setPlOpen(!plOpen);
  }

  void setPlOpen(bool value) {
    if (plOpen == value) return;
    plOpen = value;
    unawaited(_savePlOpen(value));
    notifyListeners();
  }

  void toggleWindowShade() {
    windowShade = !windowShade;
    unawaited(_saveWindowShade(windowShade));
    notifyListeners();
  }

  void toggleAlwaysOnTop() {
    setAlwaysOnTop(!alwaysOnTop);
  }

  void setAlwaysOnTop(bool value) {
    if (alwaysOnTop == value) return;
    alwaysOnTop = value;
    unawaited(_saveAlwaysOnTop(value));
    notifyListeners();
  }

  void setUiScale(double value) {
    final clamped = value.clamp(1.0, 3.0);
    if (clamped == _uiScale) return;
    _uiScale = clamped;
    unawaited(_saveUiScale(clamped));
    notifyListeners();
  }

  void toggleEqShade() {
    eqShade = !eqShade;
    unawaited(_saveEqShade(eqShade));
    notifyListeners();
  }

  void togglePlShade() {
    plShade = !plShade;
    unawaited(_savePlShade(plShade));
    notifyListeners();
  }

  Future<void> _saveWindowShade(bool value) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_kWindowShadeKey, value);
  }

  Future<void> _saveAlwaysOnTop(bool value) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_kAlwaysOnTopKey, value);
  }

  Future<void> _saveEqOpen(bool value) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_kEqOpenKey, value);
  }

  Future<void> _saveEqShade(bool value) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_kEqShadeKey, value);
  }

  Future<void> _savePlOpen(bool value) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_kPlOpenKey, value);
  }

  Future<void> _savePlShade(bool value) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_kPlShadeKey, value);
  }

  Future<void> _saveUiScale(double value) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setDouble(_kUiScaleKey, value);
  }

  static Future<bool> loadWindowShade() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getBool(_kWindowShadeKey) ?? false;
  }

  static Future<bool> loadAlwaysOnTop() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getBool(_kAlwaysOnTopKey) ?? false;
  }

  static Future<bool> loadEqOpen() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getBool(_kEqOpenKey) ?? false;
  }

  static Future<bool> loadEqShade() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getBool(_kEqShadeKey) ?? false;
  }

  static Future<bool> loadPlOpen() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getBool(_kPlOpenKey) ?? false;
  }

  static Future<bool> loadPlShade() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getBool(_kPlShadeKey) ?? false;
  }

  static Future<double> loadUiScale() async {
    final prefs = await SharedPreferences.getInstance();
    return (prefs.getDouble(_kUiScaleKey) ?? 1.0).clamp(1.0, 3.0);
  }

  /// The name of the active skin, or `null` when the default (Base) applies.
  static Future<String?> loadActiveSkin() async {
    final prefs = await SharedPreferences.getInstance();
    return prefs.getString(_kActiveSkinKey);
  }

  /// Persists the active skin name; `null` restores the default.
  static Future<void> saveActiveSkin(String? name) async {
    final prefs = await SharedPreferences.getInstance();
    if (name == null) {
      await prefs.remove(_kActiveSkinKey);
    } else {
      await prefs.setString(_kActiveSkinKey, name);
    }
  }

  void _startTicker() {
    _ticker?.cancel();
    _ticker = Timer.periodic(const Duration(seconds: 1), (_) {
      final nextSec = position * durationSec ~/ 256 + 1;
      position = nextSec >= durationSec ? 0 : nextSec * 256 ~/ durationSec;
      playIcon = 0;
      notifyListeners();
    });
  }

  void _stopTicker() {
    _ticker?.cancel();
    _ticker = null;
  }

  @override
  void dispose() {
    _stopTicker();
    super.dispose();
  }
}