/**
 * @ngdoc module
 * @name material.components.checkbox
 * @description Checkbox module!
 */
angular
  .module('material.components.checkbox', ['material.core'])
  .directive('mdCheckbox', MdCheckboxDirective);

/**
 * @ngdoc directive
 * @name mdCheckbox
 * @module material.components.checkbox
 * @restrict E
 *
 * @description
 * The checkbox directive is used like the normal [angular checkbox](https://docs.angularjs.org/api/ng/input/input%5Bcheckbox%5D).
 *
 * As per the [material design spec](http://www.google.com/design/spec/style/color.html#color-ui-color-application)
 * the checkbox is in the accent color by default. The primary color palette may be used with
 * the `md-primary` class.
 *
 * @param {string} ng-model Assignable angular expression to data-bind to.
 * @param {string=} name Property name of the form under which the control is published.
 * @param {expression=} ng-true-value The value to which the expression should be set when selected.
 * @param {expression=} ng-false-value The value to which the expression should be set when not selected.
 * @param {string=} ng-change Angular expression to be executed when input changes due to user interaction with the input element.
 * @param {boolean=} md-no-ink Use of attribute indicates use of ripple ink effects
 * @param {string=} aria-label Adds label to checkbox for accessibility.
 * Defaults to checkbox's text. If no default text is found, a warning will be logged.
 *
 * @usage
 * <hljs lang="html">
 * <md-checkbox ng-model="isChecked" aria-label="Finished?">
 *   Finished ?
 * </md-checkbox>
 *
 * <md-checkbox md-no-ink ng-model="hasInk" aria-label="No Ink Effects">
 *   No Ink Effects
 * </md-checkbox>
 *
 * <md-checkbox ng-disabled="true" ng-model="isDisabled" aria-label="Disabled">
 *   Disabled
 * </md-checkbox>
 *
 * </hljs>
 *
 */
function MdCheckboxDirective(inputDirective, $mdAria, $mdConstant, $mdTheming, $mdUtil, $timeout) {
  inputDirective = inputDirective[0];
  var CHECKED_CSS = 'md-checked';

  return {
    restrict: 'E',
    transclude: true,
    require: '?ngModel',
    priority:210, // Run before ngAria
    template: 
      '<div class="md-container" md-ink-ripple md-ink-ripple-checkbox>' +
        '<div class="md-icon"></div>' +
      '</div>' +
      '<div ng-transclude class="md-label"></div>',
    compile: compile
  };

  // **********************************************************
  // Private Methods
  // **********************************************************

  function compile (tElement, tAttrs) {

    tAttrs.type = 'checkbox';
    tAttrs.tabindex = tAttrs.tabindex || '0';
    tElement.attr('role', tAttrs.type);

    return function postLink(scope, element, attr, ngModelCtrl) {
      ngModelCtrl = ngModelCtrl || $mdUtil.fakeNgModel();
      $mdTheming(element);

      if (attr.ngChecked) {
        scope.$watch(
            scope.$eval.bind(scope, attr.ngChecked),
            ngModelCtrl.$setViewValue.bind(ngModelCtrl)
        );
      }
      $$watchExpr('ngDisabled', 'tabindex', {
        true: '-1',
        false: attr.tabindex
      });
      $mdAria.expectWithText(element, 'aria-label');

      // Reuse the original input[type=checkbox] directive from Angular core.
      // This is a bit hacky as we need our own event listener and own render
      // function.
      inputDirective.link.pre(scope, {
        on: angular.noop,
        0: {}
      }, attr, [ngModelCtrl]);

      scope.mouseActive = false;
      element.on('click', listener)
        .on('keypress', keypressHandler)
        .on('mousedown', function() {
          scope.mouseActive = true;
          $timeout(function(){
            scope.mouseActive = false;
          }, 100);
        })
        .on('focus', function() {
          if(scope.mouseActive === false) { element.addClass('md-focused'); }
        })
        .on('blur', function() { element.removeClass('md-focused'); });

      ngModelCtrl.$render = render;

      function $$watchExpr(expr, htmlAttr, valueOpts) {
        if (attr[expr]) {
          scope.$watch(attr[expr], function(val) {
            if (valueOpts[val]) {
              element.attr(htmlAttr, valueOpts[val]);
            }
          });
        }
      }

      function keypressHandler(ev) {
        var keyCode = ev.which || ev.keyCode;
        if (keyCode === $mdConstant.KEY_CODE.SPACE || keyCode === $mdConstant.KEY_CODE.ENTER) {
          ev.preventDefault();
          if (!element.hasClass('md-focused')) { element.addClass('md-focused'); }
          listener(ev);
        }
      }
      function listener(ev) {
        if (element[0].hasAttribute('disabled')) return;

        scope.$apply(function() {
          // Toggle the checkbox value...
          var viewValue = attr.ngChecked ? attr.checked : !ngModelCtrl.$viewValue;

          ngModelCtrl.$setViewValue( viewValue, ev && ev.type);
          ngModelCtrl.$render();
        });
      }

      function render() {
        if(ngModelCtrl.$viewValue) {
          element.addClass(CHECKED_CSS);
        } else {
          element.removeClass(CHECKED_CSS);
        }
      }
    };
  }
}
