import Domain
import Foundation

public enum AlbumSort: String, CaseIterable, Sendable {
    case recentlyAdded, title, artist, year
}

public enum SearchHit: Identifiable, Hashable, Codable, Sendable {
    case artist(Artist)
    case album(Album)
    case track(Track)
    case playlist(Playlist)

    public var id: EntityID {
        switch self {
        case let .artist(artist): artist.id
        case let .album(album): album.id
        case let .track(track): track.id
        case let .playlist(playlist): playlist.id
        }
    }
}

public struct SearchResults: Sendable {
    public var top: [SearchHit] = []
    public var artists: [Artist] = []
    public var albums: [Album] = []
    public var tracks: [Track] = []
    public var playlists: [Playlist] = []

    public init() {}

    public var isEmpty: Bool {
        artists.isEmpty && albums.isEmpty && tracks.isEmpty && playlists.isEmpty
    }
}

public protocol Library: Sendable {
    func apply(_ changes: [Change]) async
    func cursor(for source: SourceID) async -> Cursor?
    func setCursor(_ cursor: Cursor, for source: SourceID) async
    func updates() async -> AsyncStream<Void>

    func artists() async -> [Artist]
    func artist(_ id: EntityID) async -> Artist?
    func albums(sortedBy sort: AlbumSort) async -> [Album]
    func albums(byArtist id: EntityID) async -> [Album]
    func albums(inGenre genre: String) async -> [Album]
    func album(_ id: EntityID) async -> Album?
    func tracks() async -> [Track]
    func tracks(inAlbum id: EntityID) async -> [Track]
    func tracks(byArtist id: EntityID) async -> [Track]
    func tracks(inGenre genre: String) async -> [Track]
    func tracks(inPlaylist id: EntityID) async -> [Track]
    func playlists() async -> [Playlist]
    func stations() async -> [RadioStation]
    func genres() async -> [Genre]

    func recentlyPlayed(limit: Int) async -> [Album]
    func mostPlayed(limit: Int) async -> [Album]
    func favoriteTracks() async -> [Track]
    func favorites() async -> Set<EntityID>
    func setFavorite(_ isFavorite: Bool, for id: EntityID) async
    func recordPlay(of track: Track, at date: Date) async

    func search(_ query: String) async -> SearchResults
}