支持本地同名 krc 格式歌词文件的读取（#2053）

src/common/utils/lyricUtils/kg.js

@@ -0,0 +1,74 @@
+import { inflate } from 'zlib'
+import { decodeName } from './util'
+
+// https://github.com/lyswhut/lx-music-desktop/issues/296#issuecomment-683285784
+const enc_key = Buffer.from([0x40, 0x47, 0x61, 0x77, 0x5e, 0x32, 0x74, 0x47, 0x51, 0x36, 0x31, 0x2d, 0xce, 0xd2, 0x6e, 0x69], 'binary')
+const decodeLyric = str => new Promise((resolve, reject) => {
+  if (!str.length) return
+  const buf_str = Buffer.from(str, 'base64').subarray(4)
+  for (let i = 0, len = buf_str.length; i < len; i++) {
+    buf_str[i] = buf_str[i] ^ enc_key[i % 16]
+  }
+  inflate(buf_str, (err, result) => {
+    if (err) return reject(err)
+    resolve(result.toString())
+  })
+})
+
+const headExp = /^.*\[id:\$\w+\]\n/
+
+const parseLyric = str => {
+  str = str.replace(/\r/g, '')
+  if (headExp.test(str)) str = str.replace(headExp, '')
+  let trans = str.match(/\[language:([\w=\\/+]+)\]/)
+  let lyric
+  let rlyric
+  let tlyric
+  if (trans) {
+    str = str.replace(/\[language:[\w=\\/+]+\]\n/, '')
+    let json = JSON.parse(Buffer.from(trans[1], 'base64').toString())
+    for (const item of json.content) {
+      switch (item.type) {
+        case 0:
+          rlyric = item.lyricContent
+          break
+        case 1:
+          tlyric = item.lyricContent
+          break
+      }
+    }
+  }
+  let i = 0
+  let lxlyric = str.replace(/\[((\d+),\d+)\].*/g, str => {
+    let result = str.match(/\[((\d+),\d+)\].*/)
+    let time = parseInt(result[2])
+    let ms = time % 1000
+    time /= 1000
+    let m = parseInt(time / 60).toString().padStart(2, '0')
+    time %= 60
+    let s = parseInt(time).toString().padStart(2, '0')
+    time = `${m}:${s}.${ms}`
+    if (rlyric) rlyric[i] = `[${time}]${rlyric[i]?.join('') ?? ''}`
+    if (tlyric) tlyric[i] = `[${time}]${tlyric[i]?.join('') ?? ''}`
+    i++
+    return str.replace(result[1], time)
+  })
+  rlyric = rlyric ? rlyric.join('\n') : ''
+  tlyric = tlyric ? tlyric.join('\n') : ''
+  lxlyric = lxlyric.replace(/<(\d+,\d+),\d+>/g, '<$1>')
+  lxlyric = decodeName(lxlyric)
+  lyric = lxlyric.replace(/<\d+,\d+>/g, '')
+  rlyric = decodeName(rlyric)
+  tlyric = decodeName(tlyric)
+  return {
+    lyric,
+    tlyric,
+    rlyric,
+    lxlyric,
+  }
+}
+
+
+export const decodeKrc = async(data) => {
+  return decodeLyric(data).then(parseLyric)
+}

src/common/utils/lyricUtils/util.ts

@@ -0,0 +1,13 @@
+const encodeNames = {
+  ' ': ' ',
+  '&': '&',
+  '&lt;': '<',
+  '&gt;': '>',
+  '&quot;': '"',
+  '&apos;': "'",
+  '&#039;': "'",
+} as const
+
+export const decodeName = (str: string | null = '') => {
+  return str?.replace(/(?:&amp;|&lt;|&gt;|&quot;|&apos;|&#039;|&nbsp;)/gm, (s: string) => encodeNames[s as keyof typeof encodeNames]) ?? ''
+}