如何结合现有的全屏模式和视频暂停

我设法把两个选项放在一个按钮上:当点击时，视频开始播放，同时进入全屏。

这是html:

<video id="video1" class="video-small">
<source src="video/Marinela+Pinguinos-HD.mp4" type="video/mp4" class="video-file">
<source src="video/Marinela_Pinguinos-HD.webm" type="video/webm" class="video-file">
</video>
<button id="play" class="full-play-button" onclick="vidplay(); goFullscreen('video1')">Play fullscreen</button> 

JAVASCRIPT:

function vidplay() {
   var video = document.getElementById("video1");
   var button = document.getElementsByClassName("full-play-button");
   if (video.paused) {
      video.play();
      button.textContent = "||";
   } else {
      video.pause();
      button.textContent = ">";
   }
}
function goFullscreen(id) {
// Get the element that we want to take into fullscreen mode
var element = document.getElementById(id);
// These function will not exist in the browsers that don't support fullscreen mode yet, 
// so we'll have to check to see if they're available before calling them.
if (element.mozRequestFullScreen) {
  // This is how to go into fullscren mode in Firefox
  // Note the "moz" prefix, which is short for Mozilla.
  element.mozRequestFullScreen();
} else if (element.webkitRequestFullScreen) {
  // This is how to go into fullscreen mode in Chrome and Safari
  // Both of those browsers are based on the Webkit project, hence the same prefix.
  element.webkitRequestFullScreen();
}
}

到目前为止，一切都很顺利。当进入全屏时，底部有一个默认的类似播放器的东西，有一个按钮提供退出全屏的可能性。

我想要实现的是能够在点击该按钮时暂停视频，但我不知道如何。

我能想到的是某种功能，检测我们是否全屏，如果我们不是，它会暂停/停止(不确定我更喜欢哪个)视频。

这是我想到的，但我是JS的新手，它不起作用:

 function exitPause() {
      var video = document.getElementById("video1");
    if (document.exitFullscreen) {
        video.pause();
    }
    else if (document.mozCancelFullScreen) {
        video.pause();
    }
    else if (document.webkitExitFullscreen) {
        video.pause();
    }
    else if (element.msExitFullscreen) {
        video.pause();
    }
}

我做错了什么?我怎样才能实现呢?

video.addEventListener(
  'fullscreenchange',
  function(event) {
    if (!document.fullscreenElement) {
      video.pause();
    }
  },
  false
);

 function vidplay() {
   var video = document.getElementById("video1");
   var button = document.getElementsByClassName("full-play-button");

   video.addEventListener(
   'webkitfullscreenchange',
    function(event) {
  if (!document.fullscreenElement && video.paused)  {
  video.play();
} 
else {
    video.pause();
    }
},
false
);

}

function goFullscreen(id) {
// Get the element that we want to take into fullscreen mode
var element = document.getElementById(id);
// These function will not exist in the browsers that don't support fullscreen mode yet, 
// so we'll have to check to see if they're available before calling them.
if (element.mozRequestFullScreen) {
  // This is how to go into fullscren mode in Firefox
  // Note the "moz" prefix, which is short for Mozilla.
  element.mozRequestFullScreen();
} else if (element.webkitRequestFullScreen) {
  // This is how to go into fullscreen mode in Chrome and Safari
  // Both of those browsers are based on the Webkit project, hence the same prefix.
  element.webkitRequestFullScreen();
}
// Hooray, now we're in fullscreen mode!
}