feat: extract watch progress persistence

static/player/progress.ts

@@ -0,0 +1,70 @@
+import { state } from './state'
+import { displayTimeFromAbsolute } from './timeline'
+
+const buildPayload = (episode: number, seconds: number) => JSON.stringify({
+  mal_id: state.malID,
+  episode,
+  time_seconds: seconds,
+})
+
+const sendBeacon = (payload: string) => {
+  if (!navigator.sendBeacon) return false
+  navigator.sendBeacon('/api/watch-progress', new Blob([payload], { type: 'application/json' }))
+  return true
+}
+
+export const saveProgress = async (): Promise<void> => {
+  if (!state.malID || state.video.currentTime < 1) return
+  const episode = Number.parseInt(state.currentEpisode, 10)
+  if (!episode) return
+
+  const safeTime = displayTimeFromAbsolute(state.video.currentTime)
+  if (state.lastSavedProgress.episode === state.currentEpisode &&
+      Math.abs(state.lastSavedProgress.seconds - safeTime) < 5) return
+
+  const payload = buildPayload(episode, safeTime)
+  try {
+    const res = await fetch('/api/watch-progress', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: payload })
+    if (!res.ok) return
+    state.lastSavedProgress = { episode: state.currentEpisode, seconds: safeTime }
+  } catch {}
+}
+
+const scheduleProgressSave = (): void => {
+  if (state.progressSaveTimer !== undefined) return
+  state.progressSaveTimer = window.setTimeout(() => {
+    state.progressSaveTimer = undefined
+    saveProgress()
+  }, 30000)
+}
+
+export const markEpisodeTransition = (episodeNumber: number): void => {
+  if (!state.malID || !episodeNumber) return
+  if (state.progressSaveTimer !== undefined) { window.clearTimeout(state.progressSaveTimer); state.progressSaveTimer = undefined }
+  state.transitionEpisode = episodeNumber
+  const payload = buildPayload(episodeNumber, 0)
+  if (!sendBeacon(payload)) {
+    fetch('/api/watch-progress', { method: 'POST', headers: { 'Content-Type': 'application/json' }, keepalive: true, body: payload }).catch(() => {})
+  }
+}
+
+export const setupProgress = (): void => {
+  state.video.addEventListener('timeupdate', () => {
+    scheduleProgressSave()
+  })
+
+  state.video.addEventListener('pause', () => {
+    window.clearTimeout(state.progressSaveTimer)
+    state.progressSaveTimer = undefined
+    saveProgress()
+  })
+
+  window.addEventListener('mouseup', () => { state.isScrubbing = false; saveProgress() })
+
+  window.addEventListener('beforeunload', () => {
+    if (state.transitionEpisode !== null || state.completionSent || !state.malID) return
+    const episode = Number.parseInt(state.currentEpisode, 10)
+    if (!episode) return
+    sendBeacon(buildPayload(episode, displayTimeFromAbsolute(state.video.currentTime)))
+  })
+}