import { isElement } from 'underscore';
import { CommandObject } from './CommandAbstract';

export default {
  /**
   * Check if fullscreen mode is enabled
   * @return {Boolean}
   */
  isEnabled() {
    const d = document;
    // @ts-ignore
    if (d.fullscreenElement || d.webkitFullscreenElement || d.mozFullScreenElement) {
      return true;
    }
    return false;
  },

  /**
   * Enable fullscreen mode and return browser prefix
   * @param  {HTMLElement} el
   * @return {string}
   */
  enable(el: any) {
    let pfx = '';

    if (el.requestFullscreen) {
      el.requestFullscreen();
    } else if (el.webkitRequestFullscreen) {
      pfx = 'webkit';
      el.webkitRequestFullscreen();
    } else if (el.mozRequestFullScreen) {
      pfx = 'moz';
      el.mozRequestFullScreen();
    } else if (el.msRequestFullscreen) {
      el.msRequestFullscreen();
    }

    return pfx;
  },

  /**
   * Disable fullscreen mode
   */
  disable() {
    const d: any = document;

    if (this.isEnabled()) {
      if (d.exitFullscreen) d.exitFullscreen();
      else if (d.webkitExitFullscreen) d.webkitExitFullscreen();
      else if (d.mozCancelFullScreen) d.mozCancelFullScreen();
      else if (d.msExitFullscreen) d.msExitFullscreen();
    }
  },

  /**
   * Triggered when the state of the fullscreen is changed. Inside detects if
   * it's enabled
   * @param  {strinf} pfx Browser prefix
   * @param  {Event} e
   */
  fsChanged(pfx: string) {
    if (!this.isEnabled()) {
      this.stopCommand({ sender: this.sender });
      document.removeEventListener(`${pfx || ''}fullscreenchange`, this.fsChanged);
    }
  },

  run(editor, sender, opts = {}) {
    this.sender = sender;
    const { target } = opts;
    const targetEl = isElement(target) ? target : document.querySelector(target!);
    const pfx = this.enable(targetEl || editor.getContainer());
    this.fsChanged = this.fsChanged.bind(this, pfx);
    document.addEventListener(pfx + 'fullscreenchange', this.fsChanged);
    editor.trigger('change:canvasOffset');
  },

  stop(editor, sender) {
    if (sender && sender.set) sender.set('active', false);
    this.disable();
    if (editor) editor.trigger('change:canvasOffset');
  },
} as CommandObject<{ target?: HTMLElement | string }, { [k: string]: any }>;