// Copyright 2017 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

var adsManager;
var adsLoader;
var adDisplayContainer;
var playButton;
var videoContent;
var adsInitialized;
var autoplayAllowed;
var autoplayRequiresMuted;

function initDesktopAutoplayExample() {
  videoContent = document.getElementById('contentElement');
  playButton = document.getElementById('playButton');
  playButton.addEventListener('click', () => {
    // Initialize the container. Must be done via a user action where autoplay
    // is not allowed.
    adDisplayContainer.initialize();
    adsInitialized = true;
    videoContent.load();
    playAds();
  });
  // Check if autoplay is supported.
  checkAutoplaySupport();
  setUpIMA();
}

function checkAutoplaySupport() {
  // Test for autoplay support with our content player.
  videoContent.play().then(onUnmutedAutoplaySuccess, onUnmutedAutoplayFail);
}

function onUnmutedAutoplaySuccess() {
  // If we make it here, unmuted autoplay works.
  videoContent.pause();
  autoplayAllowed = true;
  autoplayRequiresMuted = false;
  autoplayChecksResolved();
}

function onUnmutedAutoplayFail() {
  // Unmuted autoplay failed. Now try muted autoplay.
  checkMutedAutoplaySupport();
}

function checkMutedAutoplaySupport() {
  videoContent.volume = 0;
  videoContent.muted = true;
  videoContent.play().then(onMutedAutoplaySuccess, onMutedAutoplayFail);
}

function onMutedAutoplaySuccess() {
  // If we make it here, muted autoplay works but unmuted autoplay does not.
  videoContent.pause();
  autoplayAllowed = true;
  autoplayRequiresMuted = true;
  autoplayChecksResolved();
}

function onMutedAutoplayFail() {
  // Both muted and unmuted autoplay failed. Fall back to click to play.
  videoContent.volume = 1;
  videoContent.muted = false;
  autoplayAllowed = false;
  autoplayRequiresMuted = false;
  autoplayChecksResolved();
}

function setUpIMA() {
  // Create the ad display container.
  createAdDisplayContainer();
  // Create ads loader.
  adsLoader = new google.ima.AdsLoader(adDisplayContainer);
  // Listen and respond to ads loaded and error events.
  adsLoader.addEventListener(
      google.ima.AdsManagerLoadedEvent.Type.ADS_MANAGER_LOADED,
      onAdsManagerLoaded,
      false);
  adsLoader.addEventListener(
      google.ima.AdErrorEvent.Type.AD_ERROR,
      onAdError,
      false);

  // An event listener to tell the SDK that our content video
  // is completed so the SDK can play any post-roll ads.
  var contentEndedListener = function() {adsLoader.contentComplete();};
  videoContent.onended = contentEndedListener;
}

function autoplayChecksResolved() {
  // Request video ads.
  var adsRequest = new google.ima.AdsRequest();
  adsRequest.adTagUrl = 'https://pubads.g.doubleclick.net/gampad/ads?' +
      'sz=640x480&iu=/124319096/external/single_ad_samples&ciu_szs=300x250&' +
      'impl=s&gdfp_req=1&env=vp&output=vast&unviewed_position_start=1&' +
      'cust_params=deployment%3Ddevsite%26sample_ct%3Dlinear&correlator=';

  // Specify the linear and nonlinear slot sizes. This helps the SDK to
  // select the correct creative if multiple are returned.
  adsRequest.linearAdSlotWidth = 640;
  adsRequest.linearAdSlotHeight = 400;

  adsRequest.nonLinearAdSlotWidth = 640;
  adsRequest.nonLinearAdSlotHeight = 150;

  adsRequest.setAdWillAutoPlay(autoplayAllowed);
  adsRequest.setAdWillPlayMuted(autoplayRequiresMuted);
  adsLoader.requestAds(adsRequest);
}

function createAdDisplayContainer() {
  // We assume the adContainer is the DOM id of the element that will house
  // the ads.
  adDisplayContainer = new google.ima.AdDisplayContainer(
      document.getElementById('adContainer'), videoContent);
}

function playAds() {
  try {
    if (!adsInitialized) {
      adDisplayContainer.initialize();
      adsInitialized = true;
    }
    // Initialize the ads manager. Ad rules playlist will start at this time.
    adsManager.init(640, 360, google.ima.ViewMode.NORMAL);
    // Call play to start showing the ad. Single video and overlay ads will
    // start at this time; the call will be ignored for ad rules.
    adsManager.start();
  } catch (adError) {
    // An error may be thrown if there was a problem with the VAST response.
    videoContent.play();
  }
}

function onAdsManagerLoaded(adsManagerLoadedEvent) {
  // Get the ads manager.
  var adsRenderingSettings = new google.ima.AdsRenderingSettings();
  adsRenderingSettings.restoreCustomPlaybackStateOnAdBreakComplete = true;
  // videoContent should be set to the content video element.
  adsManager = adsManagerLoadedEvent.getAdsManager(
      videoContent, adsRenderingSettings);

  // Add listeners to the required events.
  adsManager.addEventListener(
      google.ima.AdErrorEvent.Type.AD_ERROR,
      onAdError);
  adsManager.addEventListener(
      google.ima.AdEvent.Type.CONTENT_PAUSE_REQUESTED,
      onContentPauseRequested);
  adsManager.addEventListener(
      google.ima.AdEvent.Type.CONTENT_RESUME_REQUESTED,
      onContentResumeRequested);
  adsManager.addEventListener(
      google.ima.AdEvent.Type.ALL_ADS_COMPLETED,
      onAdEvent);

  // Listen to any additional events, if necessary.
  adsManager.addEventListener(
      google.ima.AdEvent.Type.LOADED,
      onAdEvent);
  adsManager.addEventListener(
      google.ima.AdEvent.Type.STARTED,
      onAdEvent);
  adsManager.addEventListener(
      google.ima.AdEvent.Type.COMPLETE,
      onAdEvent);


  if (autoplayAllowed) {
    playAds();
  } else {
    playButton.style.display = 'block';
  }
}

function onAdEvent(adEvent) {
  // Retrieve the ad from the event. Some events (e.g. ALL_ADS_COMPLETED)
  // don't have ad object associated.
  var ad = adEvent.getAd();
  switch (adEvent.type) {
    case google.ima.AdEvent.Type.LOADED:
      // This is the first event sent for an ad - it is possible to
      // determine whether the ad is a video ad or an overlay.
      if (!ad.isLinear()) {
        videoContent.play();
      }
      break;
  }
}

function onAdError(adErrorEvent) {
  // Handle the error logging.
  console.log(adErrorEvent.getError());
  adsManager.destroy();
}

function onContentPauseRequested() {
  videoContent.pause();
}

function onContentResumeRequested() {
  videoContent.play();

}