declare global {
  interface Document {
    msFullscreenElement: Element;
    mozFullScreenElement: Element;
    webkitFullscreenElement: Element;
    mozFullScreenEnabled: boolean;
    webkitFullscreenEnabled: boolean;
    msFullscreenEnabled: boolean;
    mozCancelFullScreen: () => Promise<void>;
    webkitExitFullscreen: () => Promise<void>;
    msExitFullscreen: () => Promise<void>;
  }
  interface HTMLElement {
    mozRequestFullScreen: () => Promise<void>;
    webkitRequestFullscreen: () => Promise<void>;
    msRequestFullscreen: () => Promise<void>;
  }
}

// 是否处于浏览器全屏.
export const isBrowserFullscreen = (): boolean => {
  return (
    !!document.fullscreenElement ||
    !!document.msFullscreenElement ||
    !!document.mozFullScreenElement ||
    !!document.webkitFullscreenElement ||
    false
  );
};

// 是否允许浏览器全屏
export const isBrowserFullscreenEnabled = (): boolean => {
  return (
    document.fullscreenEnabled ||
    document.mozFullScreenEnabled ||
    document.webkitFullscreenEnabled ||
    document.msFullscreenEnabled ||
    false
  );
};

// 进入全屏
export const enterBrowserFullScreen = (element: HTMLElement): void => {
  if (!element) {
    return;
  }
  if (isBrowserFullscreenEnabled() && !isBrowserFullscreen()) {
    // 允许浏览器全屏，并且当前不是处于浏览器全屏的状态下
    if (element.requestFullscreen) {
      element.requestFullscreen();
    } else if (element.mozRequestFullScreen) {
      element.mozRequestFullScreen();
    } else if (element.webkitRequestFullscreen) {
      element.webkitRequestFullscreen();
    } else if (element.msRequestFullscreen) {
      element.msRequestFullscreen();
    }
  }
};
// 退出全屏
export const exitBrowserFullscreen = (): void => {
  if (isBrowserFullscreenEnabled() && isBrowserFullscreen()) {
    // 允许浏览器全屏，并且当前处于浏览器全屏状态下
    if (document.exitFullscreen) {
      document.exitFullscreen();
    } else if (document.mozCancelFullScreen) {
      document.mozCancelFullScreen();
    } else if (document.webkitExitFullscreen) {
      document.webkitExitFullscreen();
    } else if (document.msExitFullscreen) {
      document.msExitFullscreen();
    }
  }
};