Use Media Library for finding mp3s

Closes #4

bin/tag-reader-dummy

@@ -1,5 +1,5 @@
 #!/bin/bash
 
-while date +%s ; do
-    sleep 5
+while echo 1234567890 ; do
+    sleep 0.2
 done

jukebox/library/file-backend.js

@@ -0,0 +1,23 @@
+"use strict";
+
+const glob = require('glob');
+
+class FileBackend {
+  constructor(config) {
+    this.config = config;
+  }
+
+  find(tag, callback) {
+    glob('media/' + tag + ' - *.mp3', (err, files) => {
+      if (files.length > 0) {
+        callback(files[0]);
+      }
+    });
+  }
+}
+
+module.exports = function(config) {
+  return new FileBackend(config);
+};
+
+// vim:ts=2 sw=2 et:

jukebox/library/index.js

@@ -0,0 +1,72 @@
+"use strict";
+
+const EventEmitter = require('events').EventEmitter;
+
+class Library extends EventEmitter {
+  constructor(config, backend) {
+    super();
+
+    this.log_size = 10;
+    this.config = config;
+    this.backend = backend;
+    this.log = [];
+  }
+
+  find(tag) {
+    this.backend.find(tag, path => {
+      if (!path) {
+        this.updateLog(new NotFoundLogEntry(tag));
+        return;
+      }
+
+      this.updateLog(new FileLogEntry(tag, path));
+    });
+  }
+
+  updateLog(entry) {
+    this.log.unshift(entry);
+    if (this.log.length > this.log_size) {
+      this.log.pop();
+    }
+    this.emit('play', entry);
+  }
+
+  getLastTag() {
+    if (this.log.length == 0) {
+      return;
+    }
+
+    return this.log[0].tag;
+  }
+
+  getLog() {
+    return this.log;
+  }
+}
+
+class LogEntry {
+  constructor(tag) {
+    this.tag = tag;
+  }
+
+  toString() {
+    return this.tag;
+  }
+}
+
+class NotFoundLogEntry extends LogEntry {
+  toString() {
+    return `Unknown media: ${this.tag}`
+  }
+}
+
+class FileLogEntry extends LogEntry {
+  constructor(tag, path) {
+    super(tag);
+    this.path = path;
+  }
+}
+
+module.exports.Library = Library;
+
+// vim:set ts=2 sw=2 et:

jukebox/media-player.js

@@ -1,18 +1,53 @@
 "use strict";
 
+const throttle = require('throttle-debounce/throttle');
+
 const ChildProcessEmitter = require('./child-process').ChildProcessEmitter;
 
+const DEFAULT_PAUSE_THROTTLE = 2000;
+const DEFAULT_PLAY_THROTTLE = 5000;
+
 class MediaPlayer extends ChildProcessEmitter {
-    constructor(config, logger) {
-      super(config.mpg321, logger);
-      this.stderrFilters.push(line => {
-        return line.substr(0, 3) == '@F '
-      });
-    }
+  constructor(config, logger) {
+    super(config.mpg321, logger);
+
+    this.stderrFilters.push(line => {
+      return line.substr(0, 3) == '@F '
+    });
+
+    this.pauseThrottled = throttle(config.pause_throttle || DEFAULT_PAUSE_THROTTLE, () => {
+      this._pause();
+    });
+
+    this.playFileThrottled = throttle(config.play_throttle || DEFAULT_PLAY_THROTTLE, (path) => {
+      this._playFile(path);
+    });
+
+    // default to unthrottled
+    this.pause = this._pauseFile;
+    this.playFile = this._playFile;
+  }
+
+  throttle() {
+    this.pause = this.pauseThrottled;
+    this.playFile = this.playFileThrottled;
+  }
+
+  stop() {
+    this.send('STOP');
+  }
+
+  _pause() {
+    this.send('PAUSE');
+  }
+
+  _playFile(path) {
+    this.send("LOAD " + path);
+  }
 }
 
 module.exports = function(config, logger) {
-    return new MediaPlayer(config, logger);
+  return new MediaPlayer(config, logger);
 };
 
 // vim:set ts=2 sw=2 et:

jukebox/views.js

@@ -36,7 +36,6 @@ class IndexView extends View {
     }
 
     partials() {
-        console.log(views.log);
         return {
             log: views.log.template
         }

package.json

@@ -18,6 +18,7 @@
     "glob": "^7.1.1",
     "morgan": "^1.7.0",
     "mustache": "^2.3.0",
+    "throttle-debounce": "^1.0.1",
     "winston": "^2.3.1",
     "ws": "^2.2.2"
   },

player.js

@@ -2,9 +2,11 @@
 
 const config = require('./config.json')
 
-const glob = require('glob');
-
 const views = require('./jukebox/views')(__dirname + '/templates/');
+const library = require('./jukebox/library');
+
+const MediaLibraryFileBackend = require('./jukebox/library/file-backend')(config);
+const MediaLibrary = new library.Library(config, MediaLibraryFileBackend);
 
 const express = require('express');
 const morgan = require('morgan')
@@ -21,6 +23,8 @@ logger.level = config.debug ? 'debug' : 'info';
 const MediaPlayer = require('./jukebox/media-player')(config, logger);
 const TagReader = require('./jukebox/tag-reader')(config, logger);
 
+MediaPlayer.throttle();
+
 var app = express();
 var server = require('http').createServer();
 
@@ -28,8 +32,6 @@ const WebSocket = require('ws');
 const WebSocketServer = WebSocket.Server;
 var wss = new WebSocketServer({server: server});
 
-var play_log = [];
-
 function exitHandler(options, err) {
   logger.debug('closing child tasks');
   if (err) logger.debug(err.stack);
@@ -45,8 +47,8 @@ function exitHandler(options, err) {
 process.on('exit', exitHandler.bind(null));
 process.on('SIGINT', exitHandler.bind(null, {exit:true}));
 
-TagReader.on('message', data => {
-  processLine(data);
+TagReader.on('message', tag => {
+  MediaLibrary.find(tag);
 });
 
 if (config.debug) {
@@ -55,61 +57,28 @@ if (config.debug) {
   });
 }
 
-var last_tag = null;
-var debounce_until = 0;
-
-function lookup(tag, cb) {
-  if (tag === config.stop_id) {
-    return cb('STOP');
-  }
-  if (tag === config.pause_id) {
-    return cb('PAUSE', 2);
-  }
-
-  glob('media/' + tag + ' - *.mp3', (er, files) => {
-    if (files.length > 0) {
-      appendLog(files[0]);
-      return cb("LOAD " + files[0], 5);
-    }
-    appendLog(tag);
-  });
-}
-
-function appendLog(message) {
-  if (play_log.length > 10) {
-    play_log.pop();
-  }
-
-  play_log.unshift(message);
-
+MediaLibrary.on('play', event => {
   var data = {
-    html: views.log.render({ play_log: play_log }),
-    tag: last_tag
+    html: views.log.render({ play_log: MediaLibrary.getLog() }),
+    tag: MediaLibrary.getLastTag()
   };
 
   wss.broadcast(JSON.stringify(data));
-}
+});
 
-function processLine(data) {
-  if (Date.now() / 1000 < debounce_until) {
-    return;
+MediaLibrary.on('play', event => {
+  if (event.tag === config.stop_id) {
+    MediaPlayer.stop();
   }
 
-  last_tag = String(data).trim();
-  logger.debug("got tag from tag reader", { tag: last_tag });
+  if (event.tag === config.pause_id) {
+    MediaPlayer.pause();
+  }
 
-  // min 1 sec debounce
-  debounce_until = Date.now() / 1000 + 1;
-
-  lookup(last_tag, function(action, wait_sec) {
-    wait_sec = wait_sec || 1;
-    debounce_until = Date.now() / 1000 + wait_sec;
-    if (action) {
-      logger.info("sending action to media player", { action: action, tag: last_tag });
-      MediaPlayer.send(action + "\n");
-    }
-  });
-}
+  if (event.path) {
+    MediaPlayer.playFile(event.path);
+  }
+});
 
 app.use(morgan('dev'))
 app.use(express.static(__dirname + '/static'))
@@ -117,9 +86,9 @@ app.use(express.static(__dirname + '/static'))
 app.get('/', function (req, res, next) {
   try {
     var index = views.index.render({
-      last_tag: last_tag
+      last_tag: MediaLibrary.getLastTag()
       , config: config
-      , play_log: play_log
+      , play_log: MediaLibrary.getLog()
     });
 
     var html = views.base.render({