//! annyang
//! version : 2.0.0
//! author  : Tal Ater @TalAter
//! license : MIT
//! https://www.TalAter.com/annyang/

(function (undefined) {
  "use strict";

  /**
   * # Quick Tutorial, Intro and Demos
   *
   * The quickest way to get started is to visit the [annyang homepage](https://www.talater.com/annyang/).
   *
   * For a more in-depth look at annyang, read on.
   *
   * # API Reference
   */

  // Save a reference to the global object (window in the browser)
  var root = this;

  // Get the SpeechRecognition object, while handling browser prefixes
  var SpeechRecognition = root.SpeechRecognition ||
                          root.webkitSpeechRecognition ||
                          root.mozSpeechRecognition ||
                          root.msSpeechRecognition ||
                          root.oSpeechRecognition;

  // Check browser support
  // This is done as early as possible, to make it as fast as possible for unsupported browsers
  if (!SpeechRecognition) {
    root.annyang = null;
    return undefined;
  }

  var commandsList = [];
  var recognition;
  var callbacks = { start: [], error: [], end: [], result: [], resultMatch: [], resultNoMatch: [], errorNetwork: [], errorPermissionBlocked: [], errorPermissionDenied: [] };
  var autoRestart;
  var lastStartedAt = 0;
  var debugState = false;
  var debugStyle = 'font-weight: bold; color: #00f;';
  var pauseListening = false;

  // The command matching code is a modified version of Backbone.Router by Jeremy Ashkenas, under the MIT license.
  var optionalParam = /\s*\((.*?)\)\s*/g;
  var optionalRegex = /(\(\?:[^)]+\))\?/g;
  var namedParam    = /(\(\?)?:\w+/g;
  var splatParam    = /\*\w+/g;
  var escapeRegExp  = /[\-{}\[\]+?.,\\\^$|#]/g;
  var commandToRegExp = function(command) {
    command = command.replace(escapeRegExp, '\\$&')
                  .replace(optionalParam, '(?:$1)?')
                  .replace(namedParam, function(match, optional) {
                    return optional ? match : '([^\\s]+)';
                  })
                  .replace(splatParam, '(.*?)')
                  .replace(optionalRegex, '\\s*$1?\\s*');
    return new RegExp('^' + command + '$', 'i');
  };

  // This method receives an array of callbacks to iterate over, and invokes each of them
  var invokeCallbacks = function(callbacks) {
    var args = Array.prototype.slice.call(arguments, 1);
    callbacks.forEach(function(callback) {
      callback.callback.apply(callback.context, args);
    });
  };

  var initIfNeeded = function() {
    if (!isInitialized()) {
      root.annyang.init({}, false);
    }
  };

  var isInitialized = function() {
    return recognition !== undefined;
  };

  var registerCommand = function(command, cb, phrase) {
    commandsList.push({ command: command, callback: cb, originalPhrase: phrase });
    if (debugState) {
      root.console.log('Command successfully loaded: %c'+phrase, debugStyle);
    }
  };

  root.annyang = {

    /**
     * Initialize annyang with a list of commands to recognize.
     *
     * #### Examples:
     * ````javascript
     * var commands = {'hello :name': helloFunction};
     * var commands2 = {'hi': helloFunction};
     *
     * // initialize annyang, overwriting any previously added commands
     * annyang.init(commands, true);
     * // adds an additional command without removing the previous commands
     * annyang.init(commands2, false);
     * ````
     * As of v1.1.0 it is no longer required to call init(). Just start() listening whenever you want, and addCommands() whenever, and as often as you like.
     *
     * @param {Object} commands - Commands that annyang should listen to
     * @param {Boolean} [resetCommands=true] - Remove all commands before initializing?
     * @method init
     * @deprecated
     * @see [Commands Object](#commands-object)
     */
    init: function(commands, resetCommands) {

      // resetCommands defaults to true
      if (resetCommands === undefined) {
        resetCommands = true;
      } else {
        resetCommands = !!resetCommands;
      }

      // Abort previous instances of recognition already running
      if (recognition && recognition.abort) {
        recognition.abort();
      }

      // initiate SpeechRecognition
      recognition = new SpeechRecognition();

      // Set the max number of alternative transcripts to try and match with a command
      recognition.maxAlternatives = 5;

      // In HTTPS, turn off continuous mode for faster results.
      // In HTTP,  turn on  continuous mode for much slower results, but no repeating security notices
      recognition.continuous = root.location.protocol === 'http:';

      // Sets the language to the default 'en-US'. This can be changed with annyang.setLanguage()
      recognition.lang = 'en-US';

      recognition.onstart   = function()      { invokeCallbacks(callbacks.start); };

      recognition.onerror   = function(event) {
        invokeCallbacks(callbacks.error);
        switch (event.error) {
        case 'network':
          invokeCallbacks(callbacks.errorNetwork);
          break;
        case 'not-allowed':
        case 'service-not-allowed':
          // if permission to use the mic is denied, turn off auto-restart
          autoRestart = false;
          // determine if permission was denied by user or automatically.
          if (new Date().getTime()-lastStartedAt < 200) {
            invokeCallbacks(callbacks.errorPermissionBlocked);
          } else {
            invokeCallbacks(callbacks.errorPermissionDenied);
          }
          break;
        }
      };

      recognition.onend     = function() {
        invokeCallbacks(callbacks.end);
        // annyang will auto restart if it is closed automatically and not by user action.
        if (autoRestart) {
          // play nicely with the browser, and never restart annyang automatically more than once per second
          var timeSinceLastStart = new Date().getTime()-lastStartedAt;
          if (timeSinceLastStart < 1000) {
            setTimeout(root.annyang.start, 1000-timeSinceLastStart);
          } else {
            root.annyang.start();
          }
        }
      };

      recognition.onresult  = function(event) {
        if(pauseListening) {
          if (debugState) {
            root.console.log('Speech heard, but annyang is paused');
          }
          return false;
        }

        // Map the results to an array
        var SpeechRecognitionResult = event.results[event.resultIndex];
        var results = [];
        for (var k = 0; k<SpeechRecognitionResult.length; k++) {
          results[k] = SpeechRecognitionResult[k].transcript;
        }

        invokeCallbacks(callbacks.result, results);
        var commandText;
        // go over each of the 5 results and alternative results received (we've set maxAlternatives to 5 above)
        for (var i = 0; i<results.length; i++) {
          // the text recognized
          commandText = results[i].trim();
          if (debugState) {
            root.console.log('Speech recognized: %c'+commandText, debugStyle);
          }

          // try and match recognized text to one of the commands on the list
          for (var j = 0, l = commandsList.length; j < l; j++) {
            var result = commandsList[j].command.exec(commandText);
            if (result) {
              var parameters = result.slice(1);
              if (debugState) {
                root.console.log('command matched: %c'+commandsList[j].originalPhrase, debugStyle);
                if (parameters.length) {
                  root.console.log('with parameters', parameters);
                }
              }
              // execute the matched command
              commandsList[j].callback.apply(this, parameters);
              invokeCallbacks(callbacks.resultMatch, commandText, commandsList[j].originalPhrase, results);
              return true;
            }
          }
        }
        invokeCallbacks(callbacks.resultNoMatch, results);
        return false;
      };

      // build commands list
      if (resetCommands) {
        commandsList = [];
      }
      if (commands.length) {
        this.addCommands(commands);
      }
    },

    /**
     * Start listening.
     * It's a good idea to call this after adding some commands first, but not mandatory.
     *
     * Receives an optional options object which supports the following options:
     * - `autoRestart` (Boolean, default: true) Should annyang restart itself if it is closed indirectly, because of silence or window conflicts?
     * - `continuous`  (Boolean, default: undefined) Allow forcing continuous mode on or off. Annyang is pretty smart about this, so only set this if you know what you're doing.
     *
     * #### Examples:
     * ````javascript
     * // Start listening, don't restart automatically
     * annyang.start({ autoRestart: false });
     * // Start listening, don't restart automatically, stop recognition after first phrase recognized
     * annyang.start({ autoRestart: false, continuous: false });
     * ````
     * @param {Object} [options] - Optional options.
     * @method start
     */
    start: function(options) {
      pauseListening = false;
      initIfNeeded();
      options = options || {};
      if (options.autoRestart !== undefined) {
        autoRestart = !!options.autoRestart;
      } else {
        autoRestart = true;
      }
      if (options.continuous !== undefined) {
        recognition.continuous = !!options.continuous;
      }

      lastStartedAt = new Date().getTime();
      try {
        recognition.start();
      } catch(e) {
        if (debugState) {
          root.console.log(e.message);
        }
      }
    },

    /**
     * Stop listening, and turn off mic.
     *
     * Alternatively, to only temporarily pause annyang responding to commands without stopping the SpeechRecognition engine or closing the mic, use pause() instead.
     * @see [pause()](#pause)
     *
     * @method abort
     */
    abort: function() {
      autoRestart = false;
      if (isInitialized) {
        recognition.abort();
      }
    },

    /**
     * Pause listening. annyang will stop responding to commands (until the resume or start methods are called), without turning off the browser's SpeechRecognition engine or the mic.
     *
     * Alternatively, to stop the SpeechRecognition engine and close the mic, use abort() instead.
     * @see [abort()](#abort)
     *
     * @method pause
     */
    pause: function() {
      pauseListening = true;
    },

    /**
     * Resumes listening and restores command callback execution when a result matches.
     * If SpeechRecognition was aborted (stopped), start it.
     *
     * @method resume
     */
    resume: function() {
      root.annyang.start();
    },

    /**
     * Turn on output of debug messages to the console. Ugly, but super-handy!
     *
     * @param {Boolean} [newState=true] - Turn on/off debug messages
     * @method debug
     */
    debug: function(newState) {
      if (arguments.length > 0) {
        debugState = !!newState;
      } else {
        debugState = true;
      }
    },

    /**
     * Set the language the user will speak in. If this method is not called, defaults to 'en-US'.
     *
     * @param {String} language - The language (locale)
     * @method setLanguage
     * @see [Languages](#languages)
     */
    setLanguage: function(language) {
      initIfNeeded();
      recognition.lang = language;
    },

    /**
     * Add commands that annyang will respond to. Similar in syntax to init(), but doesn't remove existing commands.
     *
     * #### Examples:
     * ````javascript
     * var commands = {'hello :name': helloFunction, 'howdy': helloFunction};
     * var commands2 = {'hi': helloFunction};
     *
     * annyang.addCommands(commands);
     * annyang.addCommands(commands2);
     * // annyang will now listen to all three commands
     * ````
     *
     * @param {Object} commands - Commands that annyang should listen to
     * @method addCommands
     * @see [Commands Object](#commands-object)
     */
    addCommands: function(commands) {
      var cb;

      initIfNeeded();

      for (var phrase in commands) {
        if (commands.hasOwnProperty(phrase)) {
          cb = root[commands[phrase]] || commands[phrase];
          if (typeof cb === 'function') {
            // convert command to regex then register the command
            registerCommand(commandToRegExp(phrase), cb, phrase);
          } else if (typeof cb === 'object' && cb.regexp instanceof RegExp) {
            // register the command
            registerCommand(new RegExp(cb.regexp.source, 'i'), cb.callback, phrase);
          } else {
            if (debugState) {
              root.console.log('Can not register command: %c'+phrase, debugStyle);
            }
            continue;
          }
        }
      }
    },

    /**
     * Remove existing commands. Called with a single phrase, array of phrases, or methodically. Pass no params to remove all commands.
     *
     * #### Examples:
     * ````javascript
     * var commands = {'hello': helloFunction, 'howdy': helloFunction, 'hi': helloFunction};
     *
     * // Remove all existing commands
     * annyang.removeCommands();
     *
     * // Add some commands
     * annyang.addCommands(commands);
     *
     * // Don't respond to hello
     * annyang.removeCommands('hello');
     *
     * // Don't respond to howdy or hi
     * annyang.removeCommands(['howdy', 'hi']);
     * ````
     * @param {String|Array|Undefined} [commandsToRemove] - Commands to remove
     * @method removeCommands
     */
    removeCommands: function(commandsToRemove) {
      if (commandsToRemove === undefined) {
        commandsList = [];
        return;
      }
      commandsToRemove = Array.isArray(commandsToRemove) ? commandsToRemove : [commandsToRemove];
      commandsList = commandsList.filter(function(command) {
        for (var i = 0; i<commandsToRemove.length; i++) {
          if (commandsToRemove[i] === command.originalPhrase) {
            return false;
          }
        }
        return true;
      });
    },

    /**
     * Add a callback function to be called in case one of the following events happens:
     *
     * * `start` - Fired as soon as the browser's Speech Recognition engine starts listening
     * * `error` - Fired when the browser's Speech Recogntion engine returns an error, this generic error callback will be followed by more accurate error callbacks (both will fire if both are defined)
     * * `errorNetwork` - Fired when Speech Recognition fails because of a network error
     * * `errorPermissionBlocked` - Fired when the browser blocks the permission request to use Speech Recognition.
     * * `errorPermissionDenied` - Fired when the user blocks the permission request to use Speech Recognition.
     * * `end` - Fired when the browser's Speech Recognition engine stops
     * * `result` - Fired as soon as some speech was identified. This generic callback will be followed by either the `resultMatch` or `resultNoMatch` callbacks.
     *     Callback functions registered to this event will include an array of possible phrases the user said as the first argument
     * * `resultMatch` - Fired when annyang was able to match between what the user said and a registered command
     *     Callback functions registered to this event will include three arguments in the following order:
     *       * The phrase the user said that matched a command
     *       * The command that was matched
     *       * An array of possible alternative phrases the user might've said
     * * `resultNoMatch` - Fired when what the user said didn't match any of the registered commands
     *     Callback functions registered to this event will include an array of possible phrases the user might've said as the first argument
     *
     * #### Examples:
     * ````javascript
     * annyang.addCallback('error', function () {
     *   $('.myErrorText').text('There was an error!');
     * });
     *
     * annyang.addCallback('resultMatch', function (userSaid, commandText, phrases) {
     *   console.log(userSaid); // sample output: 'hello'
     *   console.log(commandText); // sample output: 'hello (there)'
     *   console.log(phrases); // sample output: ['hello', 'halo', 'yellow', 'polo', 'hello kitty']
     * });
     *
     * // pass local context to a global function called notConnected
     * annyang.addCallback('errorNetwork', notConnected, this);
     * ````
     * @param {String} type - Name of event that will trigger this callback
     * @param {Function} callback - The function to call when event is triggered
     * @param {Object} [context] - Optional context for the callback function
     * @method addCallback
     */
    addCallback: function(type, callback, context) {
      if (callbacks[type]  === undefined) {
        return;
      }
      var cb = root[callback] || callback;
      if (typeof cb !== 'function') {
        return;
      }
      callbacks[type].push({callback: cb, context: context || this});
    }
  };

}).call(this);

/**
 * # Good to Know
 *
 * ## Commands Object
 *
 * Both the [init()]() and addCommands() methods receive a `commands` object.
 *
 * annyang understands commands with `named variables`, `splats`, and `optional words`.
 *
 * * Use `named variables` for one word arguments in your command.
 * * Use `splats` to capture multi-word text at the end of your command (greedy).
 * * Use `optional words` or phrases to define a part of the command as optional.
 *
 * #### Examples:
 * ````html
 * <script>
 * var commands = {
 *   // annyang will capture anything after a splat (*) and pass it to the function.
 *   // e.g. saying "Show me Batman and Robin" will call showFlickr('Batman and Robin');
 *   'show me *term': showFlickr,
 *
 *   // A named variable is a one word variable, that can fit anywhere in your command.
 *   // e.g. saying "calculate October stats" will call calculateStats('October');
 *   'calculate :month stats': calculateStats,
 *
 *   // By defining a part of the following command as optional, annyang will respond
 *   // to both: "say hello to my little friend" as well as "say hello friend"
 *   'say hello (to my little) friend': greeting
 * };
 *
 * var showFlickr = function(term) {
 *   var url = 'http://api.flickr.com/services/rest/?tags='+tag;
 *   $.getJSON(url);
 * }
 *
 * var calculateStats = function(month) {
 *   $('#stats').text('Statistics for '+month);
 * }
 *
 * var greeting = function() {
 *   $('#greeting').text('Hello!');
 * }
 * </script>
 * ````
 *
 * ### Using Regular Expressions in commands
 * For advanced commands, you can pass a regular expression object, instead of
 * a simple string command.
 *
 * This is done by passing an object containing two properties: `regexp`, and
 * `callback` instead of the function.
 *
 * #### Examples:
 * ````javascript
 * var calculateFunction = function(month) { console.log(month); }
 * var commands = {
 *   // This example will accept any word as the "month"
 *   'calculate :month stats': calculateFunction,
 *   // This example will only accept months which are at the start of a quarter
 *   'calculate :quarter stats': {'regexp': /^calculate (January|April|July|October) stats$/, 'callback': calculateFunction}
 * }
 ````
 *
 * ## Languages
 *
 * While there isn't an official list of supported languages (cultures? locales?), here is a list based on [anecdotal evidence](http://stackoverflow.com/a/14302134/338039).
 *
 * * Afrikaans `af`
 * * Basque `eu`
 * * Bulgarian `bg`
 * * Catalan `ca`
 * * Arabic (Egypt) `ar-EG`
 * * Arabic (Jordan) `ar-JO`
 * * Arabic (Kuwait) `ar-KW`
 * * Arabic (Lebanon) `ar-LB`
 * * Arabic (Qatar) `ar-QA`
 * * Arabic (UAE) `ar-AE`
 * * Arabic (Morocco) `ar-MA`
 * * Arabic (Iraq) `ar-IQ`
 * * Arabic (Algeria) `ar-DZ`
 * * Arabic (Bahrain) `ar-BH`
 * * Arabic (Lybia) `ar-LY`
 * * Arabic (Oman) `ar-OM`
 * * Arabic (Saudi Arabia) `ar-SA`
 * * Arabic (Tunisia) `ar-TN`
 * * Arabic (Yemen) `ar-YE`
 * * Czech `cs`
 * * Dutch `nl-NL`
 * * English (Australia) `en-AU`
 * * English (Canada) `en-CA`
 * * English (India) `en-IN`
 * * English (New Zealand) `en-NZ`
 * * English (South Africa) `en-ZA`
 * * English(UK) `en-GB`
 * * English(US) `en-US`
 * * Finnish `fi`
 * * French `fr-FR`
 * * Galician `gl`
 * * German `de-DE`
 * * Hebrew `he`
 * * Hungarian `hu`
 * * Icelandic `is`
 * * Italian `it-IT`
 * * Indonesian `id`
 * * Japanese `ja`
 * * Korean `ko`
 * * Latin `la`
 * * Mandarin Chinese `zh-CN`
 * * Traditional Taiwan `zh-TW`
 * * Simplified China zh-CN `?`
 * * Simplified Hong Kong `zh-HK`
 * * Yue Chinese (Traditional Hong Kong) `zh-yue`
 * * Malaysian `ms-MY`
 * * Norwegian `no-NO`
 * * Polish `pl`
 * * Pig Latin `xx-piglatin`
 * * Portuguese `pt-PT`
 * * Portuguese (Brasil) `pt-BR`
 * * Romanian `ro-RO`
 * * Russian `ru`
 * * Serbian `sr-SP`
 * * Slovak `sk`
 * * Spanish (Argentina) `es-AR`
 * * Spanish (Bolivia) `es-BO`
 * * Spanish (Chile) `es-CL`
 * * Spanish (Colombia) `es-CO`
 * * Spanish (Costa Rica) `es-CR`
 * * Spanish (Dominican Republic) `es-DO`
 * * Spanish (Ecuador) `es-EC`
 * * Spanish (El Salvador) `es-SV`
 * * Spanish (Guatemala) `es-GT`
 * * Spanish (Honduras) `es-HN`
 * * Spanish (Mexico) `es-MX`
 * * Spanish (Nicaragua) `es-NI`
 * * Spanish (Panama) `es-PA`
 * * Spanish (Paraguay) `es-PY`
 * * Spanish (Peru) `es-PE`
 * * Spanish (Puerto Rico) `es-PR`
 * * Spanish (Spain) `es-ES`
 * * Spanish (US) `es-US`
 * * Spanish (Uruguay) `es-UY`
 * * Spanish (Venezuela) `es-VE`
 * * Swedish `sv-SE`
 * * Turkish `tr`
 * * Zulu `zu`
 *
 * ## Developing
 *
 * Prerequisities: node.js
 *
 * First, install dependencies in your local annyang copy:
 *
 *     npm install
 *
 * Make sure to run the default grunt task after each change to annyang.js. This can also be done automatically by running:
 *
 *     grunt watch
 *
 * You can also run a local server for testing your work with:
 *
 *     grunt dev
 *
 * Point your browser to `https://localhost:8443/demo/` to see the demo page.
 * Since it's using self-signed certificate, you might need to click *"Proceed Anyway"*.
 *
 */
