// ignore_for_file: invalid_annotation_target

import 'package:freezed_annotation/freezed_annotation.dart';

import '../services/settings_service.dart' show EpisodePosterMode;
import '../utils/global_key_utils.dart';
import '../utils/json_utils.dart';
import 'media_backend.dart';
import 'media_kind.dart';
import 'media_role.dart';
import 'media_version.dart';

part 'media_item.freezed.dart';
part 'media_item.g.dart';

/// Backend-neutral media item shape used by UI, providers, persistence, and
/// playback. Concrete variants retain backend-only fields without forcing the
/// rest of the app to traffic in Plex/Jellyfin DTOs.
@Freezed(unionKey: 'backend', unionValueCase: FreezedUnionCase.none, equal: false, makeCollectionsUnmodifiable: false)
sealed class MediaItem with _$MediaItem {
  const MediaItem._();

  /// Backend-dispatching compatibility factory used by existing call sites.
  factory MediaItem({
    required String id,
    required MediaBackend backend,
    required MediaKind kind,
    String? guid,
    String? title,
    String? titleSort,
    String? summary,
    String? tagline,
    String? originalTitle,
    String? studio,
    int? year,
    String? originallyAvailableAt,
    String? contentRating,
    String? parentId,
    String? parentTitle,
    String? parentThumbPath,
    int? parentIndex,
    int? index,
    String? grandparentId,
    String? grandparentTitle,
    String? grandparentThumbPath,
    String? grandparentArtPath,
    String? thumbPath,
    String? artPath,
    String? clearLogoPath,
    String? backgroundSquarePath,
    int? durationMs,
    int? viewOffsetMs,
    int? viewCount,
    int? lastViewedAt,
    int? leafCount,
    int? viewedLeafCount,
    int? childCount,
    int? addedAt,
    int? updatedAt,
    double? rating,
    double? userRating,
    List<String>? genres,
    List<String>? directors,
    List<String>? writers,
    List<String>? producers,
    List<String>? countries,
    List<String>? collections,
    List<String>? labels,
    List<String>? styles,
    List<String>? moods,
    List<MediaRole>? roles,
    List<MediaVersion>? mediaVersions,
    String? libraryId,
    String? libraryTitle,
    String? audioLanguage,
    String? subtitleLanguage,
    int? subtitleMode,
    String? serverId,
    String? serverName,
    Map<String, Object?>? raw,
  }) {
    return switch (backend) {
      MediaBackend.plex => PlexMediaItem(
        id: id,
        kind: kind,
        guid: guid,
        title: title,
        titleSort: titleSort,
        summary: summary,
        tagline: tagline,
        originalTitle: originalTitle,
        studio: studio,
        year: year,
        originallyAvailableAt: originallyAvailableAt,
        contentRating: contentRating,
        parentId: parentId,
        parentTitle: parentTitle,
        parentThumbPath: parentThumbPath,
        parentIndex: parentIndex,
        index: index,
        grandparentId: grandparentId,
        grandparentTitle: grandparentTitle,
        grandparentThumbPath: grandparentThumbPath,
        grandparentArtPath: grandparentArtPath,
        thumbPath: thumbPath,
        artPath: artPath,
        clearLogoPath: clearLogoPath,
        backgroundSquarePath: backgroundSquarePath,
        durationMs: durationMs,
        viewOffsetMs: viewOffsetMs,
        viewCount: viewCount,
        lastViewedAt: lastViewedAt,
        leafCount: leafCount,
        viewedLeafCount: viewedLeafCount,
        childCount: childCount,
        addedAt: addedAt,
        updatedAt: updatedAt,
        rating: rating,
        userRating: userRating,
        genres: genres,
        directors: directors,
        writers: writers,
        producers: producers,
        countries: countries,
        collections: collections,
        labels: labels,
        styles: styles,
        moods: moods,
        roles: roles,
        mediaVersions: mediaVersions,
        libraryId: libraryId,
        libraryTitle: libraryTitle,
        audioLanguage: audioLanguage,
        subtitleLanguage: subtitleLanguage,
        subtitleMode: subtitleMode,
        serverId: serverId,
        serverName: serverName,
        raw: raw,
      ),
      MediaBackend.jellyfin => JellyfinMediaItem(
        id: id,
        kind: kind,
        guid: guid,
        title: title,
        titleSort: titleSort,
        summary: summary,
        tagline: tagline,
        originalTitle: originalTitle,
        studio: studio,
        year: year,
        originallyAvailableAt: originallyAvailableAt,
        contentRating: contentRating,
        parentId: parentId,
        parentTitle: parentTitle,
        parentThumbPath: parentThumbPath,
        parentIndex: parentIndex,
        index: index,
        grandparentId: grandparentId,
        grandparentTitle: grandparentTitle,
        grandparentThumbPath: grandparentThumbPath,
        grandparentArtPath: grandparentArtPath,
        thumbPath: thumbPath,
        artPath: artPath,
        clearLogoPath: clearLogoPath,
        backgroundSquarePath: backgroundSquarePath,
        durationMs: durationMs,
        viewOffsetMs: viewOffsetMs,
        viewCount: viewCount,
        lastViewedAt: lastViewedAt,
        leafCount: leafCount,
        viewedLeafCount: viewedLeafCount,
        childCount: childCount,
        addedAt: addedAt,
        updatedAt: updatedAt,
        rating: rating,
        userRating: userRating,
        genres: genres,
        directors: directors,
        writers: writers,
        producers: producers,
        countries: countries,
        collections: collections,
        labels: labels,
        styles: styles,
        moods: moods,
        roles: roles,
        mediaVersions: mediaVersions,
        libraryId: libraryId,
        libraryTitle: libraryTitle,
        audioLanguage: audioLanguage,
        serverId: serverId,
        serverName: serverName,
        raw: raw,
      ),
    };
  }

  /// Backend-tagged concrete subclass for items sourced from a Plex server.
  @FreezedUnionValue('plex')
  @JsonSerializable(includeIfNull: false, explicitToJson: true)
  const factory MediaItem.plex({
    @JsonKey(readValue: readStringField, defaultValue: '') required String id,
    @JsonKey(fromJson: _mediaKindFromJson, toJson: _mediaKindToJson) required MediaKind kind,
    String? guid,
    String? title,
    String? titleSort,
    String? summary,
    String? tagline,
    String? originalTitle,

    /// Plex `editionTitle` distinguishes versions of the same movie.
    String? editionTitle,
    String? studio,
    @JsonKey(fromJson: flexibleInt) int? year,
    String? originallyAvailableAt,
    String? contentRating,
    String? parentId,
    String? parentTitle,
    String? parentThumbPath,
    @JsonKey(fromJson: flexibleInt) int? parentIndex,
    @JsonKey(fromJson: flexibleInt) int? index,
    String? grandparentId,
    String? grandparentTitle,
    String? grandparentThumbPath,
    String? grandparentArtPath,
    String? thumbPath,
    String? artPath,
    String? clearLogoPath,
    String? backgroundSquarePath,
    @JsonKey(fromJson: flexibleInt) int? durationMs,
    @JsonKey(fromJson: flexibleInt) int? viewOffsetMs,
    @JsonKey(fromJson: flexibleInt) int? viewCount,
    @JsonKey(fromJson: flexibleInt) int? lastViewedAt,
    @JsonKey(fromJson: flexibleInt) int? leafCount,
    @JsonKey(fromJson: flexibleInt) int? viewedLeafCount,
    @JsonKey(fromJson: flexibleInt) int? childCount,
    @JsonKey(fromJson: flexibleInt) int? addedAt,
    @JsonKey(fromJson: flexibleInt) int? updatedAt,
    @JsonKey(fromJson: flexibleDouble) double? rating,
    @JsonKey(fromJson: flexibleDouble) double? audienceRating,
    @JsonKey(fromJson: flexibleDouble) double? userRating,
    String? ratingImage,
    String? audienceRatingImage,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? genres,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? directors,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? writers,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? producers,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? countries,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? collections,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? labels,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? styles,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? moods,
    @JsonKey(fromJson: _mediaItemRolesFromJson) List<MediaRole>? roles,
    @JsonKey(fromJson: _mediaItemVersionsFromJson) List<MediaVersion>? mediaVersions,
    String? libraryId,
    String? libraryTitle,
    String? audioLanguage,
    String? subtitleLanguage,
    @JsonKey(fromJson: flexibleInt) int? subtitleMode,
    String? trailerKey,
    @JsonKey(fromJson: flexibleInt) int? playlistItemId,
    @JsonKey(fromJson: flexibleInt) int? playQueueItemId,
    String? subtype,
    @JsonKey(fromJson: flexibleInt) int? extraType,
    String? serverId,
    String? serverName,
    @JsonKey(fromJson: _mediaItemRawFromJson) Map<String, Object?>? raw,
  }) = PlexMediaItem;

  /// Backend-tagged concrete subclass for items sourced from a Jellyfin server.
  @FreezedUnionValue('jellyfin')
  @JsonSerializable(includeIfNull: false, explicitToJson: true)
  const factory MediaItem.jellyfin({
    @JsonKey(readValue: readStringField, defaultValue: '') required String id,
    @JsonKey(fromJson: _mediaKindFromJson, toJson: _mediaKindToJson) required MediaKind kind,
    String? guid,
    String? title,
    String? titleSort,
    String? summary,
    String? tagline,
    String? originalTitle,
    String? studio,
    @JsonKey(fromJson: flexibleInt) int? year,
    String? originallyAvailableAt,
    String? contentRating,
    String? parentId,
    String? parentTitle,
    String? parentThumbPath,
    @JsonKey(fromJson: flexibleInt) int? parentIndex,
    @JsonKey(fromJson: flexibleInt) int? index,
    String? grandparentId,
    String? grandparentTitle,
    String? grandparentThumbPath,
    String? grandparentArtPath,
    String? thumbPath,
    String? artPath,
    String? clearLogoPath,
    String? backgroundSquarePath,
    @JsonKey(fromJson: flexibleInt) int? durationMs,
    @JsonKey(fromJson: flexibleInt) int? viewOffsetMs,
    @JsonKey(fromJson: flexibleInt) int? viewCount,
    @JsonKey(fromJson: flexibleInt) int? lastViewedAt,
    @JsonKey(fromJson: flexibleInt) int? leafCount,
    @JsonKey(fromJson: flexibleInt) int? viewedLeafCount,
    @JsonKey(fromJson: flexibleInt) int? childCount,
    @JsonKey(fromJson: flexibleInt) int? addedAt,
    @JsonKey(fromJson: flexibleInt) int? updatedAt,
    @JsonKey(fromJson: flexibleDouble) double? rating,
    @JsonKey(fromJson: flexibleDouble) double? userRating,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? genres,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? directors,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? writers,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? producers,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? countries,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? collections,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? labels,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? styles,
    @JsonKey(fromJson: _mediaItemStringList) List<String>? moods,
    @JsonKey(fromJson: _mediaItemRolesFromJson) List<MediaRole>? roles,
    @JsonKey(fromJson: _mediaItemVersionsFromJson) List<MediaVersion>? mediaVersions,
    String? libraryId,
    String? libraryTitle,
    String? audioLanguage,

    /// Jellyfin playlist entry id used by playlist write endpoints.
    String? playlistItemId,
    String? serverId,
    String? serverName,
    @JsonKey(fromJson: _mediaItemRawFromJson) Map<String, Object?>? raw,
  }) = JellyfinMediaItem;

  MediaBackend get backend => switch (this) {
    PlexMediaItem() => MediaBackend.plex,
    JellyfinMediaItem() => MediaBackend.jellyfin,
  };

  /// Restore a [MediaItem] from a [toJson] payload. Missing/unknown backend
  /// values use [MediaBackend.fromString] so old offline cache rows remain
  /// readable instead of throwing before union dispatch.
  factory MediaItem.fromJson(Map<String, dynamic> json) {
    return switch (MediaBackend.fromString(json['backend'] as String?)) {
      MediaBackend.plex => _$PlexMediaItemFromJson(json),
      MediaBackend.jellyfin => _$JellyfinMediaItemFromJson(json),
    };
  }

  Map<String, dynamic> toJson() {
    return switch (this) {
      final PlexMediaItem item => {'backend': MediaBackend.plex.id, ..._$PlexMediaItemToJson(item)},
      final JellyfinMediaItem item => {'backend': MediaBackend.jellyfin.id, ..._$JellyfinMediaItemToJson(item)},
    };
  }

  /// Global unique identifier across all servers (`serverId:id`). Falls back
  /// to bare [id] if [serverId] is missing.
  String get globalKey => serverId != null ? buildGlobalKey(serverId!, id) : id;

  /// Global unique identifier of this item's library section.
  String? get libraryGlobalKey => serverId != null && libraryId != null ? buildGlobalKey(serverId!, libraryId!) : null;

  /// Parent rating keys for hierarchical invalidation. For an episode:
  /// `[seasonId, showId]`. For a season: `[showId]`. For a movie: `[]`.
  List<String> get parentChain => [?parentId, ?grandparentId];

  /// Whether this item has started but not finished playback.
  bool get hasActiveProgress {
    if (durationMs == null || viewOffsetMs == null) return false;
    return viewOffsetMs! > 0 && viewOffsetMs! < durationMs!;
  }

  /// Whether this container (show/season) has some but not all leaves watched.
  bool get isPartiallyWatched =>
      viewedLeafCount != null && leafCount != null && viewedLeafCount! > 0 && viewedLeafCount! < leafCount!;

  /// Whether the item is fully watched. Series/seasons consult leaf counts;
  /// individual movies/episodes use [viewCount].
  bool get isWatched {
    if (leafCount != null && viewedLeafCount != null) {
      return viewedLeafCount! >= leafCount!;
    }
    return viewCount != null && viewCount! > 0;
  }

  /// Display-friendly title that prefers the show name for episodes/seasons.
  String get displayTitle {
    if ((kind == MediaKind.episode || kind == MediaKind.season) && grandparentTitle != null) {
      return grandparentTitle!;
    }
    if (kind == MediaKind.season && parentTitle != null) {
      return parentTitle!;
    }
    return title ?? '';
  }

  /// Subtitle line shown below [displayTitle] for episodes/seasons.
  String? get displaySubtitle {
    if (kind == MediaKind.episode || kind == MediaKind.season) {
      if (grandparentTitle != null || (kind == MediaKind.season && parentTitle != null)) {
        return title;
      }
    }
    return null;
  }

  /// Plex-only edition label. Jellyfin returns null.
  String? get editionTitle => null;

  /// Returns the appropriate poster path based on episode poster mode.
  String? posterThumb({EpisodePosterMode mode = EpisodePosterMode.seriesPoster, bool mixedHubContext = false}) {
    if (kind == MediaKind.episode) {
      switch (mode) {
        case EpisodePosterMode.episodeThumbnail:
          return thumbPath;
        case EpisodePosterMode.seasonPoster:
          return parentThumbPath ?? grandparentThumbPath ?? thumbPath;
        case EpisodePosterMode.seriesPoster:
          return grandparentThumbPath ?? thumbPath;
      }
    } else if (kind == MediaKind.season) {
      if (mixedHubContext && mode == EpisodePosterMode.episodeThumbnail) {
        return artPath ?? thumbPath;
      }
      if (grandparentThumbPath != null) {
        return grandparentThumbPath;
      }
    }

    if (mixedHubContext &&
        mode == EpisodePosterMode.episodeThumbnail &&
        (kind == MediaKind.movie || kind == MediaKind.show)) {
      return artPath ?? thumbPath;
    }

    return thumbPath;
  }

  /// Secondary poster path to try when [posterThumb] returns an image URL that
  /// exists syntactically but the server cannot serve it.
  String? posterThumbFallback({EpisodePosterMode mode = EpisodePosterMode.seriesPoster, bool mixedHubContext = false}) {
    if (kind != MediaKind.episode || mode != EpisodePosterMode.seasonPoster) return null;
    final fallback = grandparentThumbPath ?? thumbPath;
    return fallback != null && fallback != posterThumb(mode: mode, mixedHubContext: mixedHubContext) ? fallback : null;
  }

  /// True when the item should render in 16:9.
  bool usesWideAspectRatio(EpisodePosterMode mode, {bool mixedHubContext = false}) {
    if (kind == MediaKind.clip) return true;
    if (kind == MediaKind.episode && mode == EpisodePosterMode.episodeThumbnail) {
      return true;
    }
    if (mixedHubContext &&
        mode == EpisodePosterMode.episodeThumbnail &&
        (kind == MediaKind.movie || kind == MediaKind.show || kind == MediaKind.season)) {
      return true;
    }
    return false;
  }

  /// Returns the best hero art path based on the container's aspect ratio.
  String? heroArt({required double containerAspectRatio}) {
    final candidates = heroArtCandidates(containerAspectRatio: containerAspectRatio);
    if (candidates.isEmpty) return null;
    return candidates.first;
  }

  /// Returns hero art candidates in display-preference order.
  List<String> heroArtCandidates({required double containerAspectRatio}) {
    final preferred = containerAspectRatio < 1.39 ? [backgroundSquarePath, artPath] : [artPath, backgroundSquarePath];

    final candidates = <String>[];
    for (final path in preferred) {
      if (path == null || path.isEmpty || candidates.contains(path)) continue;
      candidates.add(path);
    }
    return candidates;
  }
}

MediaKind _mediaKindFromJson(Object? raw) => MediaKind.fromString(raw as String?);

String _mediaKindToJson(MediaKind kind) => kind.id;

List<String>? _mediaItemStringList(Object? raw) => stringListFromRaw(raw, stringify: true);

List<MediaRole>? _mediaItemRolesFromJson(Object? raw) {
  return raw is List
      ? [
          for (final role in raw)
            if (role is Map<String, dynamic>) MediaRole.fromJson(role),
        ]
      : null;
}

List<MediaVersion>? _mediaItemVersionsFromJson(Object? raw) {
  return raw is List
      ? [
          for (final version in raw)
            if (version is Map<String, dynamic>) MediaVersion.fromJson(version),
        ]
      : null;
}

Map<String, Object?>? _mediaItemRawFromJson(Object? raw) => raw is Map ? Map<String, Object?>.from(raw) : null;
