Angularjs checkbox filter, how to do reset button?

(function () {'use strict';

angular.
  module('myApp', []).
  controller('WineCtrl', WineCtrl);

// Functions - Definitions
function WineCtrl() {
  // Variables - Private
  var self = this;
  
  // Variables - Public
  self.filter = {};
  self.wines = [
    {name: 'Wine A', category: 'red'},
    {name: 'Wine B', category: 'red'},
    {name: 'Wine C', category: 'white'},
    {name: 'Wine D', category: 'red'},
    {name: 'Wine E', category: 'red'},
    {name: 'Wine F', category: 'white'},
    {name: 'Wine G', category: 'champagne'},
    {name: 'Wine H', category: 'champagne'}    
  ];
  
  // Functions - Public
  self.filterByCategory = filterByCategory;
  self.getCategories = getCategories;
  self.reset = function(){self.filter = {};}
  // Functions - Definitions
  function filterByCategory(wine) {
    return self.filter[wine.category] || noFilter(self.filter);
  }
    
  function getCategories() {
    return (self.wines || []).
      map(function (wine) { return wine.category; }).
      filter(function (cat, idx, arr) { return arr.indexOf(cat) === idx; });
  }

  function noFilter(filterObj) {
    return Object.
      keys(filterObj).
      every(function (key) { return !filterObj[key]; });
  }
}

}());

<script src="https://code.angularjs.org/1.5.7/angular.min.js"></script>
<div ng-app="myApp">
  <div ng-controller="WineCtrl as ctrl">
    <h3>Categories</h3>
    <button ng-click="ctrl.reset()">Reset</button>
    <div ng-repeat="category in ctrl.getCategories()">
      <label>
        <input type="checkbox" ng-model="ctrl.filter[category]" />
        {{ category }}
      </label>
    </div>
    <hr />
    <h3>Available Wines</h3>
    <div ng-repeat="wine in (ctrl.wines | filter:ctrl.filterByCategory) as filteredWines">
      {{ wine.name }} <i>({{ wine.category }})</i>
    </div>
    <hr />
    <b>Number of results: {{ filteredWines.length }}</b>
  </div>
</div>