feat: create playback service

furumi-node-player/client/src/audioPlaybackService.ts

@@ -0,0 +1,190 @@
+import { preloadStream } from './furumiApi'
+import { fmt } from './utils'
+
+const MAX_PLAYBACK_ERROR_SKIPS = 5
+
+/** Seconds from track start above which "previous" rewinds current track instead. */
+const PREV_TRACK_REWIND_THRESHOLD_SEC = 3
+
+export interface AudioPlaybackCallbacks {
+  onEnded: () => void
+  /** Called after a recoverable playback error (to advance queue). */
+  onErrorSkip: () => void
+  onToast: (msg: string) => void
+}
+
+export interface AudioPlaybackHandle {
+  loadStreamForTrack(slug: string): Promise<void>
+  pauseAndClearSource(): void
+  togglePlay(whenNoSource: () => void): void
+  seekFromProgressBarClick(e: MouseEvent): void
+  toggleMute(): void
+  setVolume(percent: number): void
+  seekToTime(seconds: number): void
+  /** If current time is past the threshold, seeks to 0 and returns true (caller should skip prev-track logic). */
+  rewindCurrentTrackIfPastThreshold(): boolean
+  dispose(): void
+}
+
+function syncVolumeFromStorage(audio: HTMLAudioElement) {
+  try {
+    const v = window.localStorage.getItem('furumi_vol')
+    const volSlider = document.getElementById('volSlider') as HTMLInputElement | null
+    if (v !== null && volSlider) {
+      audio.volume = Number(v) / 100
+      volSlider.value = v
+    }
+  } catch {
+    // ignore
+  }
+}
+
+export function attachAudioPlayback(
+  audio: HTMLAudioElement,
+  callbacks: AudioPlaybackCallbacks,
+): AudioPlaybackHandle {
+  let muted = false
+  let playbackErrorSkips = 0
+
+  syncVolumeFromStorage(audio)
+
+  function onTimeUpdate() {
+    if (!audio.duration) return
+    const fill = document.getElementById('progressFill')
+    const timeElapsed = document.getElementById('timeElapsed')
+    const timeDuration = document.getElementById('timeDuration')
+    if (fill) fill.style.width = `${(audio.currentTime / audio.duration) * 100}%`
+    if (timeElapsed) timeElapsed.textContent = fmt(audio.currentTime)
+    if (timeDuration) timeDuration.textContent = fmt(audio.duration)
+  }
+
+  function setPlayPauseButtonPlaying(playing: boolean) {
+    const btn = document.getElementById('btnPlayPause')
+    if (btn) btn.innerHTML = playing ? '&#9208;' : '&#9654;'
+  }
+
+  function onPlaying() {
+    playbackErrorSkips = 0
+  }
+
+  function onPlay() {
+    setPlayPauseButtonPlaying(true)
+  }
+
+  function onPause() {
+    setPlayPauseButtonPlaying(false)
+  }
+
+  function onError() {
+    callbacks.onToast('Playback error')
+    if (playbackErrorSkips >= MAX_PLAYBACK_ERROR_SKIPS) return
+    playbackErrorSkips += 1
+    callbacks.onErrorSkip()
+  }
+
+  function onEnded() {
+    callbacks.onEnded()
+  }
+
+  audio.addEventListener('timeupdate', onTimeUpdate)
+  audio.addEventListener('ended', onEnded)
+  audio.addEventListener('playing', onPlaying)
+  audio.addEventListener('play', onPlay)
+  audio.addEventListener('pause', onPause)
+  audio.addEventListener('error', onError)
+
+  const progressBar = document.getElementById('progressBar')
+  const onProgressClick = (e: Event) => seekFromProgressBarClick(e as MouseEvent)
+  progressBar?.addEventListener('click', onProgressClick)
+
+  const volIcon = document.getElementById('volIcon')
+  const onVolIconClick = () => toggleMute()
+  volIcon?.addEventListener('click', onVolIconClick)
+
+  const volSlider = document.getElementById('volSlider') as HTMLInputElement | null
+  const onVolInput = (e: Event) => {
+    const v = Number((e.target as HTMLInputElement).value)
+    setVolume(v)
+  }
+  volSlider?.addEventListener('input', onVolInput)
+
+  async function loadStreamForTrack(slug: string) {
+    const response = await preloadStream(slug)
+    audio.src = URL.createObjectURL(response?.data)
+    await audio.play().catch(() => { })
+  }
+
+  function pauseAndClearSource() {
+    audio.pause()
+    audio.src = ''
+  }
+
+  function togglePlay(whenNoSource: () => void) {
+    if (!audio.src) {
+      whenNoSource()
+      return
+    }
+    if (audio.paused) void audio.play()
+    else audio.pause()
+  }
+
+  function seekFromProgressBarClick(e: MouseEvent) {
+    if (!audio.duration) return
+    const bar = document.getElementById('progressBar') as HTMLDivElement | null
+    if (!bar) return
+    const rect = bar.getBoundingClientRect()
+    const pct = (e.clientX - rect.left) / rect.width
+    audio.currentTime = pct * audio.duration
+  }
+
+  function toggleMute() {
+    muted = !muted
+    audio.muted = muted
+    const icon = document.getElementById('volIcon')
+    if (icon) icon.innerHTML = muted ? '&#128263;' : '&#128266;'
+  }
+
+  function setVolume(percent: number) {
+    audio.volume = percent / 100
+    const icon = document.getElementById('volIcon')
+    if (icon) icon.innerHTML = percent === 0 ? '&#128263;' : '&#128266;'
+    window.localStorage.setItem('furumi_vol', String(percent))
+  }
+
+  function seekToTime(seconds: number) {
+    audio.currentTime = seconds
+  }
+
+  function rewindCurrentTrackIfPastThreshold(): boolean {
+    if (audio.currentTime > PREV_TRACK_REWIND_THRESHOLD_SEC) {
+      audio.currentTime = 0
+      return true
+    }
+    return false
+  }
+
+  function dispose() {
+    audio.removeEventListener('timeupdate', onTimeUpdate)
+    audio.removeEventListener('ended', onEnded)
+    audio.removeEventListener('playing', onPlaying)
+    audio.removeEventListener('play', onPlay)
+    audio.removeEventListener('pause', onPause)
+    audio.removeEventListener('error', onError)
+    progressBar?.removeEventListener('click', onProgressClick)
+    volIcon?.removeEventListener('click', onVolIconClick)
+    volSlider?.removeEventListener('input', onVolInput)
+    audio.pause()
+  }
+
+  return {
+    loadStreamForTrack,
+    pauseAndClearSource,
+    togglePlay,
+    seekFromProgressBarClick,
+    toggleMute,
+    setVolume,
+    seekToTime,
+    rewindCurrentTrackIfPastThreshold,
+    dispose,
+  }
+}