fix(multiple-subtitles): repair old ASS conversion line breaks [PKG-MULTI-SUB-11]

packages/artplayer-plugin-multiple-subtitles/src/ass-conversion.ts

@@ -0,0 +1,26 @@
+import type { Converters } from './types'
+
+export default function convertAss(text: string, converter: Converters['assToVtt']): string {
+  const converted = converter(text)
+  if (!/^WEBVTT \d+ \d+:/.test(converted))
+    return converted
+
+  // Core5.1.2 main collapsed template line breaks; compare its complete output
+  // before repairing so custom converters and valid headers remain untouched.
+  const cues = []
+  for (const line of text.split(/\r?\n/)) {
+    const match = line.match(/Dialogue:\s\d,(\d+:\d{2}:\d{2}\.\d{2}),(\d+:\d{2}:\d{2}\.\d{2}),(?:[^,]*,){6}([\s\S]*)$/i)
+    if (!match)
+      continue
+    const [, start = '', end = '', content = ''] = match
+    cues.push({
+      start: `${start.replace(/^(\d):/, '0$1:')}0`,
+      end: `${end.replace(/^(\d):/, '0$1:')}0`,
+      text: content.replace(/\{[\s\S]*?\}/g, '').replace(/\\N/g, '\n').trim().split(/\r?\n/).map(line => line.trim()).join('\n'),
+    })
+  }
+  const collapsed = `WEBVTT ${cues.map((cue, index) => `${index + 1} ${cue.start} --> ${cue.end} ${cue.text}`).join('\n\n')}`
+  if (converted !== collapsed)
+    return converted
+  return `WEBVTT\n\n${cues.map((cue, index) => `${index + 1}\n${cue.start} --> ${cue.end}\n${cue.text}`).join('\n\n')}`
+}