import 'dart:async';
import 'dart:convert';

import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;

class LiveInfoBusinessObject extends ChangeNotifier {
  LiveInfoBusinessObject({
    this.endpoint = const String.fromEnvironment(
      'KRYZ_LIVE_INFO_URL',
      defaultValue: 'http://kryz.airtime.pro/api/live-info',
    ),
    int refreshIntervalSeconds = 20,
    this.requestTimeout = const Duration(seconds: 8),
  }) : _refreshIntervalSeconds = refreshIntervalSeconds;

  final String endpoint;
  final Duration requestTimeout;

  Timer? _pollTimer;
  LiveInfoSnapshot? _snapshot;
  bool _isLoading = false;
  String? _errorMessage;
  DateTime? _lastUpdatedAt;
  int _refreshIntervalSeconds;
  final List<RecentPlayedItem> _recentPlayed = <RecentPlayedItem>[];
  final Set<String> _recentKeys = <String>{};

  LiveInfoSnapshot? get snapshot => _snapshot;
  bool get isLoading => _isLoading;
  String? get errorMessage => _errorMessage;
  DateTime? get lastUpdatedAt => _lastUpdatedAt;
  int get refreshIntervalSeconds => _refreshIntervalSeconds;
  List<RecentPlayedItem> get recentPlayed => List.unmodifiable(_recentPlayed);

  Future<void> start() async {
    await refresh();
    _restartTimer();
  }

  void setRefreshIntervalSeconds(int seconds) {
    if (seconds <= 0 || seconds == _refreshIntervalSeconds) {
      return;
    }

    _refreshIntervalSeconds = seconds;
    _restartTimer();
    notifyListeners();
  }

  Future<void> refresh() async {
    _isLoading = true;
    notifyListeners();

    try {
      final response = await http
          .get(Uri.parse(endpoint))
          .timeout(requestTimeout);
      if (response.statusCode < 200 || response.statusCode >= 300) {
        throw StateError('HTTP ${response.statusCode} from live-info API');
      }

      final dynamic decoded = jsonDecode(response.body);
      if (decoded is! Map<String, dynamic>) {
        throw StateError('Unexpected live-info payload shape');
      }

      final LiveInfoSnapshot next = LiveInfoSnapshot.fromJson(decoded);
      _snapshot = next;
      _lastUpdatedAt = DateTime.now();
      _errorMessage = null;
      _updateRecentPlayed(next);
    } catch (error) {
      _errorMessage = error.toString();
    } finally {
      _isLoading = false;
      notifyListeners();
    }
  }

  void _restartTimer() {
    _pollTimer?.cancel();
    _pollTimer = Timer.periodic(
      Duration(seconds: _refreshIntervalSeconds),
      (_) => refresh(),
    );
  }

  void _updateRecentPlayed(LiveInfoSnapshot snapshot) {
    void addIfTrack(LiveInfoTrackInfo? track, {required String source}) {
      if (track == null || track.type != 'track') {
        return;
      }

      final String key =
          '$source:${track.metadata.id ?? 'none'}:${track.starts ?? 'unknown'}';
      if (_recentKeys.contains(key)) {
        return;
      }

      _recentKeys.add(key);
      _recentPlayed.insert(
        0,
        RecentPlayedItem(
          title: track.displayTitle,
          subtitle: track.displaySubtitle,
          starts: track.starts,
          ends: track.ends,
          source: source,
        ),
      );
    }

    addIfTrack(snapshot.current, source: 'current');
    addIfTrack(snapshot.previous, source: 'previous');

    const int maxItems = 40;
    if (_recentPlayed.length > maxItems) {
      final List<RecentPlayedItem> removed = _recentPlayed
          .sublist(maxItems)
          .toList(growable: false);
      _recentPlayed.removeRange(maxItems, _recentPlayed.length);
      for (final RecentPlayedItem item in removed) {
        _recentKeys.remove(item.key);
      }
    }
  }

  @override
  void dispose() {
    _pollTimer?.cancel();
    super.dispose();
  }
}

class LiveInfoSnapshot {
  LiveInfoSnapshot({
    required this.env,
    required this.schedulerTime,
    required this.previous,
    required this.current,
    required this.next,
    required this.currentShow,
    required this.nextShow,
    required this.timezone,
    required this.timezoneOffset,
    required this.sourceEnabled,
  });

  final String? env;
  final String? schedulerTime;
  final LiveInfoTrackInfo? previous;
  final LiveInfoTrackInfo? current;
  final LiveInfoTrackInfo? next;
  final List<LiveInfoShowInfo> currentShow;
  final List<LiveInfoShowInfo> nextShow;
  final String? timezone;
  final String? timezoneOffset;
  final String? sourceEnabled;

  factory LiveInfoSnapshot.fromJson(Map<String, dynamic> json) {
    List<LiveInfoShowInfo> parseShows(dynamic value) {
      if (value is! List) {
        return const <LiveInfoShowInfo>[];
      }

      return value
          .whereType<Map<String, dynamic>>()
          .map(LiveInfoShowInfo.fromJson)
          .toList(growable: false);
    }

    return LiveInfoSnapshot(
      env: json['env'] as String?,
      schedulerTime: json['schedulerTime'] as String?,
      previous: LiveInfoTrackInfo.fromUnknown(json['previous']),
      current: LiveInfoTrackInfo.fromUnknown(json['current']),
      next: LiveInfoTrackInfo.fromUnknown(json['next']),
      currentShow: parseShows(json['currentShow']),
      nextShow: parseShows(json['nextShow']),
      timezone: json['timezone'] as String?,
      timezoneOffset: json['timezoneOffset']?.toString(),
      sourceEnabled: json['source_enabled'] as String?,
    );
  }
}

class LiveInfoTrackInfo {
  LiveInfoTrackInfo({
    required this.starts,
    required this.ends,
    required this.type,
    required this.name,
    required this.metadata,
  });

  final String? starts;
  final String? ends;
  final String? type;
  final String? name;
  final LiveInfoTrackMetadata metadata;

  String get displayTitle {
    final String candidate = _decodeHtml(
      metadata.trackTitle ??
          metadata.filepath ??
          metadata.name ??
          name ??
          'Unknown Track',
    );
    return candidate.trim().isEmpty ? 'Unknown Track' : candidate;
  }

  String get displaySubtitle {
    final String artist = _decodeHtml(metadata.artistName ?? '').trim();
    final String album = _decodeHtml(metadata.albumTitle ?? '').trim();

    if (artist.isNotEmpty && album.isNotEmpty) {
      return '$artist • $album';
    }
    if (artist.isNotEmpty) {
      return artist;
    }
    if (album.isNotEmpty) {
      return album;
    }
    return _decodeHtml(name ?? '').trim();
  }

  factory LiveInfoTrackInfo.fromUnknown(dynamic value) {
    if (value is! Map<String, dynamic>) {
      return LiveInfoTrackInfo(
        starts: null,
        ends: null,
        type: null,
        name: null,
        metadata: LiveInfoTrackMetadata.empty(),
      );
    }

    final Map<String, dynamic> metadataMap =
        value['metadata'] is Map<String, dynamic>
        ? value['metadata'] as Map<String, dynamic>
        : <String, dynamic>{};

    return LiveInfoTrackInfo(
      starts: value['starts']?.toString(),
      ends: value['ends']?.toString(),
      type: value['type']?.toString(),
      name: value['name']?.toString(),
      metadata: LiveInfoTrackMetadata.fromJson(metadataMap),
    );
  }
}

class LiveInfoTrackMetadata {
  LiveInfoTrackMetadata({
    required this.id,
    required this.name,
    required this.filepath,
    required this.trackTitle,
    required this.artistName,
    required this.albumTitle,
    required this.genre,
    required this.year,
  });

  final int? id;
  final String? name;
  final String? filepath;
  final String? trackTitle;
  final String? artistName;
  final String? albumTitle;
  final String? genre;
  final String? year;

  factory LiveInfoTrackMetadata.fromJson(Map<String, dynamic> json) {
    return LiveInfoTrackMetadata(
      id: json['id'] as int?,
      name: json['name']?.toString(),
      filepath: json['filepath']?.toString(),
      trackTitle: json['track_title']?.toString(),
      artistName: json['artist_name']?.toString(),
      albumTitle: json['album_title']?.toString(),
      genre: json['genre']?.toString(),
      year: json['year']?.toString(),
    );
  }

  factory LiveInfoTrackMetadata.empty() {
    return LiveInfoTrackMetadata(
      id: null,
      name: null,
      filepath: null,
      trackTitle: null,
      artistName: null,
      albumTitle: null,
      genre: null,
      year: null,
    );
  }
}

class LiveInfoShowInfo {
  LiveInfoShowInfo({
    required this.name,
    required this.description,
    required this.starts,
    required this.ends,
  });

  final String? name;
  final String? description;
  final String? starts;
  final String? ends;

  factory LiveInfoShowInfo.fromJson(Map<String, dynamic> json) {
    return LiveInfoShowInfo(
      name: json['name']?.toString(),
      description: json['description']?.toString(),
      starts: json['starts']?.toString(),
      ends: json['ends']?.toString(),
    );
  }
}

class RecentPlayedItem {
  RecentPlayedItem({
    required this.title,
    required this.subtitle,
    required this.starts,
    required this.ends,
    required this.source,
  });

  final String title;
  final String subtitle;
  final String? starts;
  final String? ends;
  final String source;

  String get key => '$source:$starts:$title';
}

String _decodeHtml(String raw) {
  if (raw.isEmpty) {
    return raw;
  }

  return raw
      .replaceAll('&amp;', '&')
      .replaceAll('&quot;', '"')
      .replaceAll('&#039;', "'")
      .replaceAll('&lt;', '<')
      .replaceAll('&gt;', '>');
}