refactor(multiple-subtitles): [PKG-MULTI-SUB-04] type runtime modules and vendor boundaries

packages/artplayer-plugin-multiple-subtitles/src/request.ts

@@ -0,0 +1,36 @@
+import type { Converters, Lifetime, TrackOption } from './types'
+
+export default async function loadVtt(option: TrackOption, { getExt, srtToVtt, assToVtt }: Converters, lifetime: Lifetime): Promise<string | void> {
+  if (lifetime.closed)
+    return
+  const controller = typeof AbortController === 'function' ? new AbortController() : null
+  const release = lifetime.own(() => controller?.abort())
+  try {
+    const url = option.url
+    if (lifetime.closed)
+      return
+    // Keep native fetch coercion for historically optional URLs; do not add a default URL.
+    const response = await lifetime.wait(controller ? fetch(url!, { signal: controller.signal }) : fetch(url!))
+    if (lifetime.closed)
+      return
+    if (response!.ok === false)
+      throw new Error(`Failed to fetch multiple subtitles: HTTP ${response!.status}`)
+    const buffer = await lifetime.wait(response!.arrayBuffer())
+    if (lifetime.closed)
+      return
+    const text = new TextDecoder(option.encoding || 'utf-8').decode(buffer!)
+    switch (option.type || getExt(option.url!)) {
+      case 'srt': return srtToVtt(text)
+      case 'ass': return assToVtt(text)
+      case 'vtt': return text
+      default: return ''
+    }
+  }
+  catch (error) {
+    controller?.abort()
+    throw error
+  }
+  finally {
+    release()
+  }
+}