#mainContainer {
  position: relative;
  width: 640px;
  height: 360px;
}

#content, #adContainer {
  position: absolute;
  top: 0px;
  left: 0px;
  width: 640px;
  height: 360px;
}

#contentElement {
  width: 640px;
  height: 360px;
  overflow: hidden;
}

#playButton {
  margin-top:-10px;
  vertical-align: top;
  width: 350px;
  height: 60px;
  padding: 0;
  font-size: 22px;
  color: white;
  text-align: center;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.25);
  background: #2c3e50;
  border: 0;
  border-bottom: 2px solid #22303f;
  cursor: pointer;
  -webkit-box-shadow: inset 0 -2px #22303f;
  box-shadow: inset 0 -2px #22303f;
  float: left;
}

// Copyright 2015 Google Inc. All Rights Reserved.
// You may study, modify, and use this example for any purpose.
// Note that this example is provided "as is", WITHOUT WARRANTY
// of any kind either expressed or implied.

var adsManager;
var adsLoader;
var adDisplayContainer;
var intervalTimer;
var playButton;
var videoContent;

function init() {
  videoContent = document.getElementById('contentElement');
  playButton = document.getElementById('playButton');
  playButton.addEventListener('click', requestAds);
}

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 requestAds() {  
  google.ima.settings.setPlayerType('google/codepen-demo-gpt');
  google.ima.settings.setPlayerVersion('1.0.0');
  // Create the ad display container.
  createAdDisplayContainer();
  // Initialize the container. Must be done via a user action on mobile devices.
  adDisplayContainer.initialize();
  videoContent.load();
  // 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);

  // Request video ads.
  var adsRequest = new google.ima.AdsRequest();
  adsRequest.adTagUrl =
    'https://pubads.g.doubleclick.net/gampad/ads?' +
    'iu=/21775744923/external/single_preroll_skippable&sz=640x480&' +
    'ciu_szs=300x250%2C728x90&gdfp_req=1&output=vast&' +
    'unviewed_position_start=1&env=vp&impl=s&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;

  adsLoader.requestAds(adsRequest);
}

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);

  try {
    // 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 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()) {
        // Position AdDisplayContainer correctly for overlay.
        // Use ad.width and ad.height.
        videoContent.play();
      }
      break;
    case google.ima.AdEvent.Type.STARTED:
      // This event indicates the ad has started - the video player
      // can adjust the UI, for example display a pause button and
      // remaining time.
      if (ad.isLinear()) {
        // For a linear ad, a timer can be started to poll for
        // the remaining time.
        intervalTimer = setInterval(
            function() {
              var remainingTime = adsManager.getRemainingTime();
            },
            300); // every 300ms
      }
      break;
    case google.ima.AdEvent.Type.COMPLETE:
      // This event indicates the ad has finished - the video player
      // can perform appropriate UI actions, such as removing the timer for
      // remaining time detection.
      if (ad.isLinear()) {
        clearInterval(intervalTimer);
      }
      break;
  }
}

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

function onContentPauseRequested() {
  videoContent.pause();
  // This function is where you should setup UI for showing ads (e.g.
  // display ad timer countdown, disable seeking etc.)
  // setupUIForAds();
}

function onContentResumeRequested() {
  videoContent.play();
  // This function is where you should ensure that your UI is ready
  // to play content. It is the responsibility of the Publisher to
  // implement this function when necessary.
  // setupUIForContent();

}

// Wire UI element references and UI event listeners.
init();