//service to toggle fullscreen

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: "root",
})

export class FullscreenService {
  private doc = document;

  enter() {
    const el = this.doc.documentElement;
    if (el.requestFullscreen) el.requestFullscreen();
    else if (el.msRequestFullscreen) el.msRequestFullscreen();
    else if (el.mozRequestFullScreen) el.mozRequestFullScreen();
    else if (el.webkitRequestFullscreen) el.webkitRequestFullscreen();
  }

  leave() {
    if (this.doc.exitFullscreen) this.doc.exitFullscreen();
    else if (this.doc.msExitFullscreen) this.doc.msExitFullscreen();
    else if (this.doc.mozCancelFullScreen) this.doc.mozCancelFullScreen();
    else if (this.doc.webkitExitFullscreen) this.doc.webkitExitFullscreen();
  }

  toggle() {
    if (this.enabled) this.leave();
    else this.enter();
  }

  get enabled() {
    return !!(
      this.doc.fullscreenElement ||
      this.doc.mozFullScreenElement ||
      this.doc.webkitFullscreenElement ||
      this.doc.msFullscreenElement
    );
  }
}

interface FullScreenDocument extends Document {
  documentElement: FullScreenDocumentElement;
  mozFullScreenElement?: Element;
  msFullscreenElement?: Element;
  webkitFullscreenElement?: Element;
  msExitFullscreen?: () => void;
  mozCancelFullScreen?: () => void;
  webkitExitFullscreen?: () => void;
}

interface FullScreenDocumentElement extends HTMLElement {
  msRequestFullscreen?: () => void;
  mozRequestFullScreen?: () => void;
  webkitRequestFullscreen?: () => void;
}

//usage
@Component()
export class SomeComponent {
  constructor(private fullscreenService: FullscreenService) {}

  onToggleFullscreen() {
    this.fullscreenService.toggle();
  }
}