; {
  let
    selected1,
    selected2;

  // http://unicode.org/emoji/charts/full-emoji-list.html
  const iconAnimals = [
    '🐵',
    '🐶',
    '🐺',
    '🐱',
    '🐯',
    '🐴',
    '🐮',
    '🐷',
    '🐗',
    '🐭',
    '🐹',
    '🐰',
    '🐻',
    '🐨',
    '🐼',
    '🐔',
    '🐤',
    '🐦',
    '🐧',
    '🐸',
    //'🐢	',
    //'🐍',
    //'🐳',
    //'🐬',
    //'🐠',
    //'🐙',
  ];
  const iconFruits = [
    '🍇',
    '🍈',
    '🍉',
    '🍊',
    '🍋',
    '🍌',
    '🍍',
    '🍎',
    '🍏',
    '🍑',
    '🍒',
    '🍓',
  ];

  let icons = iconAnimals;

  const app = angular
    // Using ngTouch to remove the 300ms click delay on mobile devices
    .module('app', ['ngRoute', 'ngAnimate', 'ngTouch'])
    .controller('AppController', AppController);

  AppController.$inject = ['$scope', '$timeout', '$animate'];
  function AppController($scope, $timeout, $animate) {

    // This is a prototype, everything is in this controller.
    // For cleaner code you probably would refactor stuff out from here. 
    // I also use DOM manipulation for faster dev (prototyping)

    const vm = this;

    $timeout(() => {
      // Angular DOM has finished rendering
      $scope.appReady = true;
    });

    function showAllCards() {
      $scope.list.forEach((card) => {
        $("#card-" + card.id).flip(true);
      });
    }

    function startNewGame() {

      shuffleArray(icons); // randomize displayed icons        

      $animate.enabled(false); // disable remove animation

      $scope.list = [];

      //$animate.enabled(true); // re-enable animation

      let list = [],
        cardCount = 16;
      for (var i = 1; i <= cardCount; i++) {
        let type = (i % (cardCount / 2)) + 1;
        list.push({
          id: i,
          type: type,
          icon: icons[type - 1],
          theme: 'theme' + type,
          isKnown: false
        });
      }

      shuffleArray(list); // randomize card on the board

      // Update state
      selected1 = selected2 = null;
      $scope.clickCount = 0;

      $scope.cardsLeft = list.length;
      $scope.gameCompleted = false;
      $scope.titleAction = () => {};
      $scope.changeIcons = () => {
        icons = icons === iconFruits ? iconAnimals : iconFruits;
      };

      $timeout(() => {
        // Angular DOM has finished rendering

        $animate.enabled(true); // re-enable animation

        $scope.list = list;

        $timeout(() => {
          // Angular DOM has finished rendering

          // Apply flip to the cards in the DOM
          let $card = $(".app__cards-container__card");
          $card.flip({
            axis: 'y',
            trigger: 'manual',
            reverse: true
          }, () => {
            //callback
          });

          //showAllCards(); // debug
        });
      });
    }

    $scope.clickCount = 0;
    $scope.cardsLeft = 0;
    $scope.gameCompleted = false;
    $scope.restart = () => {
      startNewGame();
    };

    $scope.click = function(card, index) {

      if (card.flipped) return; // dont allow to flip already flipped cards

      $scope.clickCount++;

      // Update state
      card.flipped = true;
      selected2 = selected1;
      selected1 = card;

      // Update UI
      $("#card-" + card.id).flip(true); // use flip api

      if (selected1 && selected2 && selected1.type === selected2.type) {
        // We found a match

        $scope.list.splice($scope.list.indexOf(selected1), 1);
        $scope.list.splice($scope.list.indexOf(selected2), 1);
        selected1 = selected2 = null;

        $scope.cardsLeft = $scope.list.length;

        if ($scope.list.length === 0) {
          // We have finished the game
          $scope.gameCompleted = true;
        }

        return;
      }

      if (selected2) {

        // Flip back the 2nd shown card

        let id = selected2.id;
        ((id) => {
          $timeout(() => {
            $scope.list.forEach((card) => {
              if (card.id === id) {
                // Update state
                card.flipped = false;
                card.isKnown = true;
              }
            });

            $("#card-" + id).flip(false); // use flip api

          }, 800);
        })(id);
      }
    }

    startNewGame();
  }

  /**
   * Randomize array element order in-place.
   * Durstenfeld shuffle algorithm.   
   */
  function shuffleArray(array) {
    for (var i = array.length - 1; i > 0; i--) {
      var j = Math.floor(Math.random() * (i + 1));
      var temp = array[i];
      array[i] = array[j];
      array[j] = temp;
    }
    return array;
  }

};