import type { ServerWebSocket } from "bun";

export interface Track {
  filename: string;
  title: string;
  duration: number;
}

export interface StreamConfig {
  id: string;
  name: string;
  tracks: Track[];
}

export class Stream {
  id: string;
  name: string;
  playlist: Track[];
  currentIndex: number = 0;
  startedAt: number = Date.now();
  clients: Set<ServerWebSocket<{ streamId: string }>> = new Set();
  paused: boolean = false;
  pausedAt: number = 0;
  private lastPlaylistBroadcast: number = 0;
  private playlistDirty: boolean = false;

  constructor(config: StreamConfig) {
    this.id = config.id;
    this.name = config.name;
    this.playlist = config.tracks;
  }

  get currentTrack(): Track | null {
    if (this.playlist.length === 0) return null;
    return this.playlist[this.currentIndex];
  }

  get currentTimestamp(): number {
    if (this.paused) return this.pausedAt;
    return (Date.now() - this.startedAt) / 1000;
  }

  tick(): boolean {
    if (this.paused) return false;
    const track = this.currentTrack;
    if (!track) return false;
    if (this.currentTimestamp >= track.duration) {
      this.advance();
      return true;
    }
    return false;
  }

  advance() {
    if (this.playlist.length === 0) return;
    this.currentIndex = (this.currentIndex + 1) % this.playlist.length;
    this.startedAt = Date.now();
    this.broadcast();
  }

  getState(includePlaylist: boolean = false) {
    const state: Record<string, unknown> = {
      track: this.currentTrack,
      currentTimestamp: this.currentTimestamp,
      streamName: this.name,
      paused: this.paused,
      currentIndex: this.currentIndex,
    };
    if (includePlaylist) {
      state.playlist = this.playlist;
    }
    return state;
  }

  pause() {
    if (this.paused) return;
    this.pausedAt = this.currentTimestamp;
    this.paused = true;
    this.broadcast();
  }

  unpause() {
    if (!this.paused) return;
    this.paused = false;
    this.startedAt = Date.now() - this.pausedAt * 1000;
    this.broadcast();
  }

  jumpTo(index: number) {
    if (index < 0 || index >= this.playlist.length) return;
    this.currentIndex = index;
    if (this.paused) {
      this.pausedAt = 0;
    } else {
      this.startedAt = Date.now();
    }
    this.broadcast();
  }

  seek(timestamp: number) {
    const track = this.currentTrack;
    if (!track) return;
    const clamped = Math.max(0, Math.min(timestamp, track.duration));
    if (this.paused) {
      this.pausedAt = clamped;
    } else {
      this.startedAt = Date.now() - clamped * 1000;
    }
    this.broadcast();
  }

  markPlaylistDirty() {
    this.playlistDirty = true;
  }

  broadcast() {
    const now = Date.now();
    const includePlaylist = this.playlistDirty || (now - this.lastPlaylistBroadcast >= 60000);
    if (includePlaylist) {
      this.lastPlaylistBroadcast = now;
      this.playlistDirty = false;
    }
    const msg = JSON.stringify(this.getState(includePlaylist));

    for (const ws of this.clients) {
      ws.send(msg);
    }
  }

  addClient(ws: ServerWebSocket<{ streamId: string }>) {
    this.clients.add(ws);

    // Always send full state with playlist on connect
    ws.send(JSON.stringify(this.getState(true)));
    // Reset timer so next playlist broadcast is in 60s
    this.lastPlaylistBroadcast = Date.now();
  }

  removeClient(ws: ServerWebSocket<{ streamId: string }>) {
    this.clients.delete(ws);
  }
}