angular.module("app").run(["$rootScope", "$ionicPlatform",
 "$location", "$ionicHistory",
 function ($rootScope, $ionicPlatform, $location, $ionicHistory) {
  "use strict";
  
  // 當(dāng)用戶在主頁面， 按返回鍵時(shí)，給予提示，如果在2s內(nèi)再次出發(fā)返回鍵，就退出app
  function showTipMsg() {
   window.plugins.toast.showShortCenter("在按一次退出app"); // toast是cordova的一個(gè)插件cordova-plugin-x-toast，也可以用ionic的彈窗來代替
   $rootScope.exitApp = true;
   const delay = 2000;
   setTimeout(() => {
    $rootScope.exitApp = false;
   }, delay);
  }
  
  // 判斷當(dāng)前路由，是否是project， mission，mine， message這幾個(gè)主頁面
  function isExitPage() {
   let path = $location.path(),
    state = _.last(path.split("/")),
    ary = ["project", "mission", "mine", "", "message"];
   return _.includes(ary, state);
  }
  
  // 注冊(cè)返回事件
  function registerBackButton(event) {
   event.preventDefault();
   $cordovaKeyboard.isVisible() && $cordovaKeyboard.close();
   if (isExitPage()) {
    $rootScope.exitApp && ionic.Platform.exitApp();
    !$rootScope.exitApp && showTipMsg();
   } else {
    $ionicHistory.goBack();
   }
   return false;
  }
  
  // ionic 環(huán)境已經(jīng)準(zhǔn)備完畢
  ionic.Platform.ready(() => {
   try {
    const priority = 101;
    $ionicPlatform.is("Android") && $ionicPlatform.registerBackButtonAction(registerBackButton, priority);
   } catch (e) {
    console.warn("Application is running in browser causes inspection failed.");
   }
  });
 }]);