refactor import by youtube url into plugin

lib/player.js

@@ -17,7 +17,6 @@ var safePath = require('./safe_path');
 var PassThrough = require('stream').PassThrough;
 var url = require('url');
 var superagent = require('superagent');
-var ytdl = require('ytdl');
 
 module.exports = Player;
 
@@ -26,16 +25,6 @@ groove.setLogging(groove.LOG_WARNING);
 var cpuCount = require('os').cpus().length;
 
 
-// sorted from worst to best
-var YTDL_AUDIO_ENCODINGS = [
-  'mp3',
-  'aac',
-  'wma',
-  'vorbis',
-  'wav',
-  'flac',
-];
-
 var PLAYER_KEY_PREFIX = "Player.";
 var LIBRARY_KEY_PREFIX = "Library.";
 var LIBRARY_DIR_PREFIX = "LibraryDir.";
@@ -268,6 +257,8 @@ function Player(db, musicDirectory, instantBufferBytes) {
   this.expectHeaders = true;
 
   this.playlistItemDeleteQueue = [];
+
+  this.importUrlFilters = [];
 }
 
 Player.prototype.initialize = function(cb) {
@@ -797,19 +788,34 @@ Player.prototype.importUrl = function(urlString, cb) {
   cb = cb || logIfError;
 
   var tmpDir = path.join(self.musicDirectory, '.tmp');
+  var filterIndex = 0;
 
   mkdirp(tmpDir, function(err) {
     if (err) return cb(err);
 
-    var parsedUrl = url.parse(urlString);
+    tryImportFilter();
+  });
 
-    // detect youtube downloads
+  function tryImportFilter() {
-    if ((parsedUrl.hostname === 'youtube.com' || parsedUrl.hostname === 'www.youtube.com') &&
+    var importPlugin = self.importUrlFilters[filterIndex];
-      parsedUrl.pathname === '/watch')
+    if (importPlugin) {
-    {
+      importPlugin.importUrl(urlString, callNextFilter);
-      var bestFormat = null;
-      ytdl.getInfo(urlString, gotYouTubeInfo);
     } else {
+      downloadRaw();
+    }
+    function callNextFilter(err, dlStream, filename) {
+      if (err || !dlStream) {
+        if (err) console.warn("import filter error, skipping:", err.stack);
+        filterIndex += 1;
+        tryImportFilter();
+        return;
+      }
+      handleDownload(dlStream, filename);
+    }
+  }
+
+  function downloadRaw() {
+    var parsedUrl = url.parse(urlString);
     var remoteFilename = path.basename(parsedUrl.pathname);
     var decodedFilename;
     try {
@@ -821,30 +827,6 @@ Player.prototype.importUrl = function(urlString, cb) {
     handleDownload(req, decodedFilename);
   }
 
-    function gotYouTubeInfo(err, info) {
-      if (err) return cb(err);
-      for (var i = 0; i < info.formats.length; i += 1) {
-        var format = info.formats[i];
-        if (bestFormat == null || format.audioBitrate > bestFormat.audioBitrate ||
-           (format.audioBitrate === bestFormat.audioBitrate &&
-            YTDL_AUDIO_ENCODINGS.indexOf(format.audioEncoding) >
-            YTDL_AUDIO_ENCODINGS.indexOf(bestFormat.audioEncoding)))
-        {
-          bestFormat = format;
-        }
-      }
-      if (YTDL_AUDIO_ENCODINGS.indexOf(bestFormat.audioEncoding) === -1) {
-        console.warn("YouTube Import: unrecognized audio format:", bestFormat.audioEncoding);
-      }
-      var req = ytdl(urlString, {filter: filter});
-      handleDownload(req, info.title + '.' + bestFormat.container);
-
-      function filter(format) {
-        return format.audioBitrate === bestFormat.audioBitrate &&
-          format.audioEncoding === bestFormat.audioEncoding;
-      }
-    }
-
   function handleDownload(req, remoteFilename) {
     var ext = path.extname(remoteFilename);
     var destPath = path.join(tmpDir, uuid() + ext);
@@ -877,7 +859,6 @@ Player.prototype.importUrl = function(urlString, cb) {
       cb(err);
     }
   }
-  });
 
   function logIfError(err) {
     if (err) {

lib/plugins/ytdl.js

@@ -0,0 +1,62 @@
+var ytdl = require('ytdl');
+var url = require('url');
+
+module.exports = YtDlPlugin;
+
+// sorted from worst to best
+var YTDL_AUDIO_ENCODINGS = [
+  'mp3',
+  'aac',
+  'wma',
+  'vorbis',
+  'wav',
+  'flac',
+];
+
+function YtDlPlugin(gb) {
+  gb.player.importUrlFilters.push(this);
+}
+
+YtDlPlugin.prototype.importUrl = function(urlString, cb) {
+  var parsedUrl = url.parse(urlString);
+
+  var isYouTube = (parsedUrl.pathname === '/watch' &&
+    (parsedUrl.hostname === 'youtube.com' ||
+     parsedUrl.hostname === 'www.youtube.com' ||
+     parsedUrl.hostname === 'm.youtube.com')) ||
+    parsedUrl.hostname === 'youtu.be' ||
+    parsedUrl.hostname === 'www.youtu.be';
+
+  if (!isYouTube) {
+    cb();
+    return;
+  }
+
+  var bestFormat = null;
+  ytdl.getInfo(urlString, gotYouTubeInfo);
+
+  function gotYouTubeInfo(err, info) {
+    if (err) return cb(err);
+    for (var i = 0; i < info.formats.length; i += 1) {
+      var format = info.formats[i];
+      if (bestFormat == null || format.audioBitrate > bestFormat.audioBitrate ||
+         (format.audioBitrate === bestFormat.audioBitrate &&
+          YTDL_AUDIO_ENCODINGS.indexOf(format.audioEncoding) >
+          YTDL_AUDIO_ENCODINGS.indexOf(bestFormat.audioEncoding)))
+      {
+        bestFormat = format;
+      }
+    }
+    if (YTDL_AUDIO_ENCODINGS.indexOf(bestFormat.audioEncoding) === -1) {
+      console.warn("YouTube Import: unrecognized audio format:", bestFormat.audioEncoding);
+    }
+    var req = ytdl(urlString, {filter: filter});
+    var filename = info.title + '.' + bestFormat.container;
+    cb(null, req, filename);
+
+    function filter(format) {
+      return format.audioBitrate === bestFormat.audioBitrate &&
+        format.audioEncoding === bestFormat.audioEncoding;
+    }
+  }
+};