TTMusic/entry/src/main/ets/controller/PlaybackCoordinator.ets

import { PlaybackStateBridge } from './PlaybackStateBridge'
import { VideoItem } from '../viewmodel/VideoItem'

export interface PlaybackRuntime {
  playQueue: (queue: VideoItem[], startIndex: number, source: string) => Promise<void>
  playOrPause: () => Promise<void>
  playNext: () => Promise<void>
  playPrevious: () => Promise<void>
  seekTo: (value: string, source?: string) => Promise<void>
}

export class PlaybackCoordinator {
  private static instance?: PlaybackCoordinator
  private runtime?: PlaybackRuntime
  private stateBridge: PlaybackStateBridge = PlaybackStateBridge.getInstance()

  public static getInstance(): PlaybackCoordinator {
    if (!PlaybackCoordinator.instance) {
      PlaybackCoordinator.instance = new PlaybackCoordinator()
    }
    return PlaybackCoordinator.instance
  }

  public setRuntime(runtime: PlaybackRuntime): void {
    this.runtime = runtime
  }

  public clearRuntime(runtime?: PlaybackRuntime): void {
    if (!runtime || this.runtime === runtime) {
      this.runtime = undefined
    }
  }

  public async playQueue(queue: VideoItem[], startIndex: number, source: string): Promise<void> {
    if (!this.runtime || queue.length <= 0) {
      return
    }
    this.stateBridge.replaceQueue(queue, startIndex)
    await this.runtime.playQueue(queue, this.stateBridge.getSnapshot().currentIndex, source)
  }

  public async playSong(song: VideoItem, source: string): Promise<void> {
    await this.playQueue([song], 0, source)
  }

  public async playOrPause(): Promise<void> {
    await this.runtime?.playOrPause()
  }

  public async playNext(): Promise<void> {
    await this.runtime?.playNext()
  }

  public async playPrevious(): Promise<void> {
    await this.runtime?.playPrevious()
  }

  public async seekTo(value: string, source?: string): Promise<void> {
    await this.runtime?.seekTo(value, source)
  }
}