refactor(thumbnail): [PKG-TOOL-THUMB-04] type runtime modules and retain emitter attribution

packages/artplayer-tool-thumbnail/src/source.ts

@@ -0,0 +1,115 @@
+import type ArtplayerToolThumbnail from './index'
+import type { Cleanup } from './types'
+import { cleanupAll, revoke, stateFor } from './lifecycle'
+
+export function loadSource(tool: ArtplayerToolThumbnail, file?: File | null) {
+  const state = stateFor(tool)
+  if (!file || state.closed)
+    return
+  const initialEpoch = state.epoch
+  const video = tool.video
+  const support = video.canPlayType(file.type)
+  tool.errorHandle(support === 'maybe' || support === 'probably', `Playback of this file format is not supported: ${file.type}`)
+  if (state.closed || state.epoch !== initialEpoch)
+    return
+  const url = URL.createObjectURL(file)
+  state.sourceUrls.add(url)
+  if (state.closed || state.epoch !== initialEpoch) {
+    revoke(state.sourceUrls, url)
+    return
+  }
+  const epoch = ++state.epoch
+  const initialWait = !state.sourceUrl && !tool.file && state.job?.adopt(epoch)
+  if (!initialWait)
+    state.job?.cancel('source changed')
+  state.loading = true
+  const current = () => !state.closed && state.epoch === epoch
+  const previousListeners = state.sourceListeners
+  const listeners: Cleanup[] = []
+  state.sourceListeners = listeners
+  let pendingCleanup = () => {}
+  let reported = false
+  const error = () => {
+    if (!current() || reported || (video.currentSrc && video.currentSrc !== url))
+      return
+    reported = true
+    state.loading = false
+    const failure = new Error(`Unable to load video: media error ${video.error?.code || 0}`)
+    if (state.job)
+      state.job.fail(failure)
+    else
+      tool.emit('error', failure.message)
+  }
+  const ready = () => {
+    if (current() && (!video.currentSrc || video.currentSrc === url)) {
+      state.loading = false
+      state.job?.ready()
+    }
+  }
+  try {
+    cleanupAll(previousListeners.splice(0))
+    if (!current()) {
+      revoke(state.sourceUrls, url)
+      return
+    }
+    for (const [name, callback] of [['error', error], ['loadedmetadata', ready]] as const) {
+      pendingCleanup = () => video.removeEventListener(name, callback)
+      listeners.push(pendingCleanup)
+      video.addEventListener(name, callback)
+      if (!current()) {
+        cleanupAll([pendingCleanup, ...listeners.splice(0)])
+        revoke(state.sourceUrls, url)
+        return
+      }
+    }
+    tool.videoUrl = url
+    tool.file = file
+    tool.emit('file', file)
+    if (!current()) {
+      revoke(state.sourceUrls, url)
+      return
+    }
+    video.src = url
+    if (!current()) {
+      revoke(state.sourceUrls, url)
+      return
+    }
+    state.sourceUrl = url
+    for (const previous of [...state.sourceUrls]) {
+      if (previous !== url)
+        revoke(state.sourceUrls, previous)
+    }
+    if (current())
+      tool.emit('video', video)
+  }
+  catch (error) {
+    if (current()) {
+      state.loading = false
+      state.job?.cancel('source setup failed')
+    }
+    try {
+      cleanupAll([pendingCleanup, ...listeners.splice(0)])
+    }
+    catch {}
+    revoke(state.sourceUrls, url)
+    throw error
+  }
+}
+
+export function replaceThumbnail(tool: ArtplayerToolThumbnail, blob: Blob, live: () => boolean) {
+  const state = stateFor(tool)
+  const url = URL.createObjectURL(blob)
+  state.thumbnailUrls.add(url)
+  if (!live()) {
+    revoke(state.thumbnailUrls, url)
+    return null
+  }
+  const previous = new Set([...state.thumbnailUrls, tool.thumbnailUrl])
+  state.thumbnailUrl = url
+  tool.thumbnailUrl = url
+  for (const old of previous) {
+    if (old && old !== url)
+      revoke(state.thumbnailUrls, old)
+  }
+  return live() ? url : null
+}