'use strict';

/**
 * @ngdoc module
 * @name ngCookies
 * @description
 *
 * # ngCookies
 *
 * The `ngCookies` module provides a convenient wrapper for reading and writing browser cookies.
 *
 *
 * <div doc-module-components="ngCookies"></div>
 *
 * See {@link ngCookies.$cookies `$cookies`} and
 * {@link ngCookies.$cookieStore `$cookieStore`} for usage.
 */


angular.module('ngCookies', ['ng']).
  /**
   * @ngdoc service
   * @name $cookies
   *
   * @description
   * Provides read/write access to browser's cookies.
   *
   * Only a simple Object is exposed and by adding or removing properties to/from this object, new
   * cookies are created/deleted at the end of current $eval.
   * The object's properties can only be strings.
   *
   * Requires the {@link ngCookies `ngCookies`} module to be installed.
   *
   * @example
   <example>
     <file name="index.html">
       <script>
         function ExampleController($cookies) {
           // Retrieving a cookie
           var favoriteCookie = $cookies.myFavorite;
           // Setting a cookie
           $cookies.myFavorite = 'oatmeal';
         }
       </script>
     </file>
   </example>
   */
   factory('$cookies', ['$rootScope', '$browser', function ($rootScope, $browser) {
      var cookies = {},
          lastCookies = {},
          lastBrowserCookies,
          runEval = false,
          copy = angular.copy,
          isUndefined = angular.isUndefined;

      //creates a poller fn that copies all cookies from the $browser to service & inits the service
      $browser.addPollFn(function() {
        var currentCookies = $browser.cookies();
        if (lastBrowserCookies != currentCookies) { //relies on browser.cookies() impl
          lastBrowserCookies = currentCookies;
          copy(currentCookies, lastCookies);
          copy(currentCookies, cookies);
          if (runEval) $rootScope.$apply();
        }
      })();

      runEval = true;

      //at the end of each eval, push cookies
      //TODO: this should happen before the "delayed" watches fire, because if some cookies are not
      //      strings or browser refuses to store some cookies, we update the model in the push fn.
      $rootScope.$watch(push);

      return cookies;


      /**
       * Pushes all the cookies from the service to the browser and verifies if all cookies were
       * stored.
       */
      function push() {
        var name,
            value,
            browserCookies,
            updated;

        //delete any cookies deleted in $cookies
        for (name in lastCookies) {
          if (isUndefined(cookies[name])) {
            $browser.cookies(name, undefined);
          }
        }

        //update all cookies updated in $cookies
        for(name in cookies) {
          value = cookies[name];
          if (!angular.isString(value)) {
            if (angular.isDefined(lastCookies[name])) {
              cookies[name] = lastCookies[name];
            } else {
              delete cookies[name];
            }
          } else if (value !== lastCookies[name]) {
            $browser.cookies(name, value);
            updated = true;
          }
        }

        //verify what was actually stored
        if (updated){
          updated = false;
          browserCookies = $browser.cookies();

          for (name in cookies) {
            if (cookies[name] !== browserCookies[name]) {
              //delete or reset all cookies that the browser dropped from $cookies
              if (isUndefined(browserCookies[name])) {
                delete cookies[name];
              } else {
                cookies[name] = browserCookies[name];
              }
              updated = true;
            }
          }
        }
      }
    }]).


  /**
   * @ngdoc service
   * @name $cookieStore
   * @requires $cookies
   *
   * @description
   * Provides a key-value (string-object) storage, that is backed by session cookies.
   * Objects put or retrieved from this storage are automatically serialized or
   * deserialized by angular's toJson/fromJson.
   *
   * Requires the {@link ngCookies `ngCookies`} module to be installed.
   *
   * @example
   */
   factory('$cookieStore', ['$cookies', function($cookies) {

      return {
        /**
         * @ngdoc method
         * @name $cookieStore#get
         *
         * @description
         * Returns the value of given cookie key
         *
         * @param {string} key Id to use for lookup.
         * @returns {Object} Deserialized cookie value.
         */
        get: function(key) {
          var value = $cookies[key];
          return value ? angular.fromJson(value) : value;
        },

        /**
         * @ngdoc method
         * @name $cookieStore#put
         *
         * @description
         * Sets a value for given cookie key
         *
         * @param {string} key Id for the `value`.
         * @param {Object} value Value to be stored.
         */
        put: function(key, value) {
          $cookies[key] = angular.toJson(value);
        },

        /**
         * @ngdoc method
         * @name $cookieStore#remove
         *
         * @description
         * Remove given cookie
         *
         * @param {string} key Id of the key-value pair to delete.
         */
        remove: function(key) {
          delete $cookies[key];
        }
      };

    }]);