(function() {
'use strict';


/**
 * @ngdoc module
 * @name material.components.swipe
 * @description Swipe module!
 */
angular.module('material.components.swipe',[])
  .factory('$mdSwipe', MdSwipeFactory)
  .directive('mdSwipeLeft', MdSwipeLeftDirective)
  .directive('mdSwipeRight', MdSwipeRightDirective);

/*
 * @ngdoc service
 * @module material.components.swipe
 * @name $mdSwipe
 * @description
 * This service allows directives to easily attach swipe and pan listeners to
 * the specified element.
 */

function MdSwipeFactory() {
  // match expected API functionality
  var attachNoop = function(){ return angular.noop; };

  /**
   * SwipeService constructor pre-captures scope and customized event types
   *
   * @param scope
   * @param eventTypes
   * @returns {*}
   * @constructor
   */
  return function SwipeService(scope, eventTypes) {
    if ( !eventTypes ) eventTypes = "swipeleft swiperight";

    // publish configureFor() method for specific element instance
    return function configureFor(element, onSwipeCallback, attachLater ) {
      var hammertime = new Hammer(element[0], {
        recognizers : addRecognizers([], eventTypes )
      });

      // Attach swipe listeners now
      if ( !attachLater ) attachSwipe();

      // auto-disconnect during destroy
      scope.$on('$destroy', function() {
        hammertime.destroy();
      });

      return attachSwipe;

      // **********************
      // Internal methods
      // **********************

      /**
       * Delegate swipe event to callback function
       * and ensure $digest is triggered.
       *
       * @param ev HammerEvent
       */
      function swipeHandler(ev) {

        // Prevent triggering parent hammer listeners
        ev.srcEvent.stopPropagation();

        if ( angular.isFunction(onSwipeCallback) ) {
          scope.$apply(function() {
            onSwipeCallback(ev);
          });
        }
      }

      /**
       * Enable listeners and return detach() fn
       */
      function attachSwipe() {
        hammertime.on(eventTypes, swipeHandler );

        return function detachSwipe() {
          hammertime.off( eventTypes );
        };
      }

      /**
       * Add optional recognizers such as panleft, panright
       */
      function addRecognizers(list, events) {
        var hasPanning = (events.indexOf("pan") > -1);
        var hasSwipe   = (events.indexOf("swipe") > -1);

        if (hasPanning) {
          list.push([ Hammer.Pan, { direction: Hammer.DIRECTION_HORIZONTAL } ]);
        }
        if (hasSwipe) {
          list.push([ Hammer.Swipe, { direction: Hammer.DIRECTION_HORIZONTAL } ]);
        }

        return list;
      }

    };
  };
}

/**
 * @ngdoc directive
 * @module material.components.swipe
 * @name mdSwipeLeft
 *
 * @restrict A
 *
 * @description
 * The `<div  md-swipe-left="expression">` directive identifies an element on which
 * HammerJS horizontal swipe left and pan left support will be active. The swipe/pan action
 * can result in custom activity trigger by evaluating `expression`.
 *
 * @param {boolean=} mdNoPan Use of attribute indicates flag to disable detection of `panleft` activity
 *
 * @usage
 * <hljs lang="html">
 *
 * <div class="animate-switch-container"
 *      ng-switch on="data.selectedIndex"
 *      md-swipe-left="data.selectedIndex+=1;"
 *      md-swipe-right="data.selectedIndex-=1;" >
 *
 * </div>
 * </hljs>
 *
 */
function MdSwipeLeftDirective($parse, $mdSwipe) {
  return {
    restrict: 'A',
    link :  swipePostLink( $parse, $mdSwipe, "SwipeLeft" )
  };
}

/**
 * @ngdoc directive
 * @module material.components.swipe
 * @name mdSwipeRight
 *
 * @restrict A
 *
 * @description
 * The `<div  md-swipe-right="expression">` directive identifies functionality
 * that attaches HammerJS horizontal swipe right and pan right support to an element. The swipe/pan action
 * can result in activity trigger by evaluating `expression`
 *
 * @param {boolean=} mdNoPan Use of attribute indicates flag to disable detection of `panright` activity
 *
 * @usage
 * <hljs lang="html">
 *
 * <div class="animate-switch-container"
 *      ng-switch on="data.selectedIndex"
 *      md-swipe-left="data.selectedIndex+=1;"
 *      md-swipe-right="data.selectedIndex-=1;" >
 *
 * </div>
 * </hljs>
 *
 */
function MdSwipeRightDirective($parse, $mdSwipe) {
  return {
    restrict: 'A',
    link :  swipePostLink( $parse, $mdSwipe, "SwipeRight" )
  };
}

/**
 * Factory to build PostLink function specific to Swipe or Pan direction
 *
 * @param $parse
 * @param $mdSwipe
 * @param name
 * @returns {Function}
 */
function swipePostLink($parse, $mdSwipe, name ) {

  return function(scope, element, attrs) {
    var direction = name.toLowerCase();
    var directiveName= "md" + name;

    var parentGetter = $parse(attrs[directiveName]) || angular.noop;
    var configureSwipe = $mdSwipe(scope, direction);
    var requestSwipe = function(locals) {
      // build function to request scope-specific swipe response
      parentGetter(scope, locals);
    };

    configureSwipe( element, function onHandleSwipe(ev) {
      if ( ev.type == direction ) {
        requestSwipe();
      }
    });

  };
}

})();
