/**
 * @ngdoc directive
 * @name patternfly.validation:pfValidation
 * @restrict E
 * @element INPUT
 * @scope
 *
 * @description
 * Directive used for input validation based on custom function.
 *
 * @param {expression=} pfValidationDisabled If true, the validation is disabled, it is enabled otherwise.
 *
 * @example
 <example module="patternfly.validation">

   <file name="index.html">
     <div ng-controller="ValidationDemoCtrl">
     <form class="form-horizontal">

       <div class="form-group">
         <label class="col-sm-2 control-label" for="message">Initially valid:</label>
         <div class="col-sm-10">
           <input class="form-control" type="text" ng-model="myValueValid" pf-validation="isNumber(input)"/>
           <span class="help-block">The value you typed is not a number.</span>
         </div>
       </div>

       <div class="form-group">
         <label class="col-sm-2 control-label" for="message">Fixed Number:</label>
         <div class="col-sm-10">
           <input class="form-control" type="text" ng-model="myValue" pf-validation="isNumber(input)"/>
           <span class="help-block">The value you typed is not a number.</span>
         </div>
       </div>

       <div class="form-group">
         <label class="col-sm-2 control-label" for="message">Number:</label>
         <div class="col-sm-10">
           <input class="form-control" type="text" ng-model="myValue" pf-validation="isNumber(input)" pf-validation-disabled="isValidationDisabled"/>
           <span class="help-block">The value you typed is not a number.</span>
         </div>
       </div>

       <div class="form-group">
         <label class="col-sm-2 control-label" for="message">Validation disabled:</label>
         <div class="col-sm-10">
           <input class="form-control" type="checkbox" ng-model="isValidationDisabled"/>
         </div>
       </div>
     </form>
     </div>
   </file>

   <file name="script.js">
     angular.module( 'patternfly.validation' ).controller( 'ValidationDemoCtrl', function( $scope ) {
       $scope.myValue = "Change this value to be a number";
       $scope.myValueValid = 42;
       $scope.isValidationDisabled = false;

       $scope.isNumber = function (value) {
         if (isNaN(value)) {
           return false;
         }

         return true;
       }
     });
   </file>

 </example>
 */
angular.module('patternfly.validation', []).directive('pfValidation', function ($timeout) {
  'use strict';

  return {
    restrict: 'A',
    require: 'ngModel',
    scope: {
      pfValidation: '&',
      pfValidationDisabled: '='
    },
    link: function (scope, element, attrs, ctrl) {

      scope.inputCtrl = ctrl;
      scope.valEnabled = !attrs.pfValidationDisabled;

      scope.$watch('pfValidationDisabled', function (newVal) {
        scope.valEnabled = !newVal;
        if (newVal) {
          scope.inputCtrl.$setValidity('pfValidation', true);
          toggleErrorClass(false);
        } else {
          validate();
        }
      });

      // If validation function is set
      if (attrs.pfValidation) {
        // using $timeout(0) to get the actual $modelValue
        $timeout(function () {
          validate();
        }, 0);
      } else if (!scope.inputCtrl.$valid && scope.inputCtrl.$dirty) {
        toggleErrorClass(true);
      }

      scope.$watch('inputCtrl.$valid', function (isValid) {
        if (isValid) {
          toggleErrorClass(false);
        } else {
          toggleErrorClass(true);
        }
      });

      scope.$watch('inputCtrl.$modelValue', function () {
        validate();
      });

      function validate () {
        var valid;

        var val = scope.inputCtrl.$modelValue;

        var valFunc = scope.pfValidation({'input': val});

        if (!attrs.pfValidation) {
          valFunc = true;
        }

        valid = !val || valFunc  || val === '';

        if (scope.valEnabled && !valid) {
          toggleErrorClass(true);
        } else {
          toggleErrorClass(false);
        }
      }

      function toggleErrorClass (add) {
        var messageElement = element.next();
        var parentElement = element.parent();
        var hasErrorM = parentElement.hasClass('has-error');
        var wasHidden = messageElement.hasClass('ng-hide');

        scope.inputCtrl.$setValidity('pf-validation', !add);

        if (add) {
          if (!hasErrorM) {
            parentElement.addClass('has-error');
          }
          if (wasHidden) {
            messageElement.removeClass('ng-hide');
          }
        }

        if (!add) {
          if (hasErrorM) {
            parentElement.removeClass('has-error');
          }
          if (!wasHidden) {
            messageElement.addClass('ng-hide');
          }
        }
      }
    }
  };
});