新增：封面嵌入、歌词下载；修复Bug

src/main/utils/flacMeta.js

@@ -0,0 +1,38 @@
+const fs = require('fs')
+const flac = require('flac-metadata')
+
+module.exports = (filenPath, meta) => {
+  const reader = fs.createReadStream(filenPath)
+  const tempPath = filenPath + '.lxmtemp'
+  const writer = fs.createWriteStream(tempPath)
+  const processor = new flac.Processor()
+  if (meta.APIC) delete meta.APIC
+
+  const comments = []
+  for (const key in meta) {
+    comments.push(`${key.toUpperCase()}=${meta[key]}`)
+  }
+  const vendor = 'lx-music-desktop'
+
+  processor.on('preprocess', function(mdb) {
+    // Remove existing VORBIS_COMMENT block, if any.
+    if (mdb.type === flac.Processor.MDB_TYPE_VORBIS_COMMENT) {
+      mdb.remove()
+    }
+    // Inject new VORBIS_COMMENT block.
+    if (mdb.removed || mdb.isLast) {
+      let mdbVorbis = flac.data.MetaDataBlockVorbisComment.create(mdb.isLast, vendor, comments)
+      this.push(mdbVorbis.publish())
+    }
+  })
+
+  reader.pipe(processor).pipe(writer).on('finish', () => {
+    fs.unlink(filenPath, err => {
+      if (err) return console.log(err.message)
+      fs.rename(tempPath, filenPath, err => {
+        if (err) console.log(err.message)
+      })
+    })
+  })
+}
+