export type TrackAvailability = 'server' | 'downloading' | 'error' | 'missing';

/**
 * Metadata-enrichment state, distinct from file `availability`. `pending` = the
 * worker hasn't finished (or hasn't started); `enriched` = identity found;
 * `failed` = no match / a worker error (see `metadataError`); `manual` = user-
 * edited and never auto-overwritten.
 */
export type MetadataStatus = 'pending' | 'enriched' | 'failed' | 'manual';

export interface Track {
  id: string;
  title: string;
  artistId: string;
  artistName: string;
  albumId: string;
  albumTitle: string;
  albumArtUrl?: string;
  hasCover: boolean;
  durationMs: number;
  trackNumber?: number;
  discNumber?: number;
  year?: number;
  genre?: string;
  availability: TrackAvailability;
  metadataStatus: MetadataStatus;
  /** Human-readable reason the last enrichment run set `failed`; else undefined. */
  metadataError?: string;
  fileSize?: number;
  format?: string;
  bitrate?: number;
  liked: boolean;
  /** Where the track entered the library (e.g. `upload`, `local_folder`). */
  source?: string;
  /** ISO timestamp the track was added to the library. */
  createdAt?: string;
  /** ISO timestamp the last successful enrichment ran; undefined if never. */
  enrichedAt?: string;
}

export interface Album {
  id: string;
  title: string;
  artistId: string;
  artistName: string;
  artUrl?: string;
  year?: number;
  trackCount: number;
  totalDurationMs: number;
  genre?: string;
}

export interface Artist {
  id: string;
  name: string;
  artUrl?: string;
  albumCount: number;
  trackCount: number;
}

export interface Playlist {
  id: string;
  name: string;
  description?: string;
  ownerId: string;
  trackCount: number;
  totalDurationMs: number;
  artUrl?: string;
  isPublic: boolean;
  createdAt: string;
  updatedAt: string;
}

export interface PlaylistTrack extends Track {
  position: number;
  addedAt: string;
}

export interface DownloadJob {
  id: string;
  url: string;
  title?: string;
  artist?: string;
  album?: string;
  status: 'queued' | 'downloading' | 'processing' | 'done' | 'error';
  progress: number;
  errorMessage?: string;
  trackId?: string;
  createdAt: string;
  updatedAt: string;
}

export interface UploadResponse {
  track_id: string;
  title: string;
  already_exists: boolean;
}

export interface StorageFormatBreakdown {
  fileFormat: string;
  trackCount: number;
  totalSize: number;
}

export interface StorageGenreCount {
  genre: string;
  trackCount: number;
}

/** Capacity of the volume backing the media store. Absent for object-store
 * backends (S3), which have no fixed disk to report. */
export interface StorageDiskUsage {
  total: number;
  used: number;
  free: number;
}

export interface StorageStats {
  totalTracks: number;
  totalArtists: number;
  totalAlbums: number;
  /** Sum of every track's recorded file size (the library's footprint). */
  totalSize: number;
  totalDurationSeconds: number;
  largestTrackSize: number;
  earliestAdded?: string;
  latestAdded?: string;
  byFormat: StorageFormatBreakdown[];
  byMetadataStatus: Record<string, number>;
  bySource: Record<string, number>;
  topGenres: StorageGenreCount[];
  disk?: StorageDiskUsage;
}

export interface User {
  id: string;
  username: string;
  email?: string;
  role: 'admin' | 'user';
  createdAt: string;
  lastActiveAt?: string;
}

export interface AuthTokens {
  accessToken: string;
  refreshToken: string;
  // Optional: the backend's TokenResponse carries no TTL — expiry is driven by
  // 401→refresh, not a client-side clock. Present only if a backend supplies it.
  expiresIn?: number;
}

export interface LoginRequest {
  username: string;
  password: string;
}

export interface LoginResponse {
  user: User;
  tokens: AuthTokens;
}

export interface RegisterRequest {
  username: string;
  password: string;
}

export interface PaginatedResponse<T> {
  items: T[];
  total: number;
  page: number;
  pageSize: number;
  hasMore: boolean;
}

export interface LibraryFilters {
  search?: string;
  genre?: string;
  artistId?: string;
  albumId?: string;
  /** Filter by ingest origin, e.g. `upload`, `youtube`, `local`. */
  source?: string;
  liked?: boolean;
  page?: number;
  pageSize?: number;
  sortBy?: 'title' | 'artist' | 'album' | 'year' | 'dateAdded';
  sortOrder?: 'asc' | 'desc';
}

export interface ApiError {
  status: number;
  message: string;
  code?: string;
}

/** One AcoustID candidate from `GET /tracks/{id}/metadata/matches` (§A7). */
export interface MetadataMatch {
  acoustid: string;
  /** Confidence 0..1. */
  score: number;
  recordingMbid?: string;
  releaseGroupMbid?: string;
  title?: string;
  artist?: string;
  album?: string;
  year?: number;
}

/** Manual edits / an accepted match, sent to `PUT /tracks/{id}/metadata`. */
export interface MetadataEdit {
  title?: string;
  artistName?: string;
  albumTitle?: string;
  year?: number;
  genre?: string;
  trackNumber?: number;
}