/**
 * @file play-toggle.js
 */
import Button from '../button.js';
import Component from '../component.js';
import {silencePromise} from '../utils/promise';

/** @import Player from './player' */

/**
 * Button to toggle between play and pause.
 *
 * @extends Button
 */
class PlayToggle extends Button {

  /**
   * Creates an instance of this class.
   *
   * @param {Player} player
   *        The `Player` that this class should be attached to.
   *
   * @param {Object} [options={}]
   *        The key/value store of player options.
   */
  constructor(player, options = {}) {
    super(player, options);

    // show or hide replay icon
    options.replay = options.replay === undefined || options.replay;

    this.setIcon('play');

    this.on(player, 'play', (e) => this.handlePlay(e));
    this.on(player, 'pause', (e) => this.handlePause(e));

    if (options.replay) {
      this.on(player, 'ended', (e) => this.handleEnded(e));
    }
  }

  /**
   * Builds the default DOM `className`.
   *
   * @return {string}
   *         The DOM `className` for this object.
   */
  buildCSSClass() {
    return `vjs-play-control ${super.buildCSSClass()}`;
  }

  /**
   * This gets called when an `PlayToggle` is "clicked". See
   * {@link ClickableComponent} for more detailed information on what a click can be.
   *
   * @param {Event} [event]
   *        The `keydown`, `tap`, or `click` event that caused this function to be
   *        called.
   *
   * @listens tap
   * @listens click
   */
  handleClick(event) {
    if (this.player_.paused()) {
      silencePromise(this.player_.play());
    } else {
      this.player_.pause();
    }
  }

  /**
   * This gets called once after the video has ended and the user seeks so that
   * we can change the replay button back to a play button.
   *
   * @param {Event} [event]
   *        The event that caused this function to run.
   *
   * @listens Player#seeked
   */
  handleSeeked(event) {
    this.removeClass('vjs-ended');

    if (this.player_.paused()) {
      this.handlePause(event);
    } else {
      this.handlePlay(event);
    }
  }

  /**
   * Add the vjs-playing class to the element so it can change appearance.
   *
   * @param {Event} [event]
   *        The event that caused this function to run.
   *
   * @listens Player#play
   */
  handlePlay(event) {
    this.removeClass('vjs-ended', 'vjs-paused');
    this.addClass('vjs-playing');
    // change the button text to "Pause"
    this.setIcon('pause');
    this.controlText('Pause');
  }

  /**
   * Add the vjs-paused class to the element so it can change appearance.
   *
   * @param {Event} [event]
   *        The event that caused this function to run.
   *
   * @listens Player#pause
   */
  handlePause(event) {
    this.removeClass('vjs-playing');
    this.addClass('vjs-paused');
    // change the button text to "Play"
    this.setIcon('play');
    this.controlText('Play');
  }

  /**
   * Add the vjs-ended class to the element so it can change appearance
   *
   * @param {Event} [event]
   *        The event that caused this function to run.
   *
   * @listens Player#ended
   */
  handleEnded(event) {
    this.removeClass('vjs-playing');
    this.addClass('vjs-ended');
    // change the button text to "Replay"
    this.setIcon('replay');
    this.controlText('Replay');

    // on the next seek remove the replay button
    this.one(this.player_, 'seeked', (e) => this.handleSeeked(e));
  }
}

/**
 * The text that should display over the `PlayToggle`s controls. Added for localization.
 *
 * @type {string}
 * @protected
 */
PlayToggle.prototype.controlText_ = 'Play';

Component.registerComponent('PlayToggle', PlayToggle);
export default PlayToggle;