/**
 * @function 开启全屏方法
 * @param el { Element } 全屏的dom，默认是document.documentElement
 */
function fullScreen(el = document.documentElement) {
  let rfs = el.requestFullscreen
    || el.webkitRequestFullScreen
    || el.mozRequestFullScreen
    || el.msRequestFullscreen
  try {
    if (typeof rfs !== 'undefined' && rfs) rfs.call(el)
  } catch (e) {
    console.error('fullScreen: %o', e);
  }
}

/**
 * @function 监测是否全屏
 * @return {boolean}
 */
function isFullscreen() {
  return !!(
    document.webkitIsFullScreen ||
    document.mozFullScreen ||
    document.mozFullScreenElement ||
    document.webkitFullscreenElement ||
    document.msFullscreenElement ||
    document.fullscreenElement ||
    window.fullScreen
  )
}

/**
 * @function 退出全屏
 */
function exitScreen() {
  const exitFn = document.exitFullscreen || document.mozCancelFullScreen || document.webkitCancelFullScreen || document.msExitFullscreen
  try {
    if (typeof exitFn !== 'undefined' && exitFn) exitFn.call(document)
  } catch (e) {
    console.error('exitScreen: %o', e)
  }
}

export {
  fullScreen,
  exitScreen,
  isFullscreen
}