/**
 * Copyright (c) 2015, Facebook, Inc.  All rights reserved.
 *
 * Facebook, Inc. ("Facebook") owns all right, title and interest, including
 * all intellectual property and other proprietary rights, in and to the React
 * Native CustomComponents software (the "Software").  Subject to your
 * compliance with these terms, you are hereby granted a non-exclusive,
 * worldwide, royalty-free copyright license to (1) use and copy the Software;
 * and (2) reproduce and distribute the Software as part of your own software
 * ("Your Software").  Facebook reserves all rights not expressly granted to
 * you in this license agreement.
 *
 * THE SOFTWARE AND DOCUMENTATION, IF ANY, ARE PROVIDED "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES (INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE) ARE DISCLAIMED.
 * IN NO EVENT SHALL FACEBOOK OR ITS AFFILIATES, OFFICERS, DIRECTORS OR
 * EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THE SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @noflow
 */
'use strict';

const EventSubscription = require('./EventSubscription');

import type EventEmitter from './EventEmitter';
import type EventSubscriptionVendor from './EventSubscriptionVendor';

/**
 * EmitterSubscription represents a subscription with listener and context data.
 */
class EmitterSubscription extends EventSubscription {

  emitter: EventEmitter;
  listener: Function;
  context: ?Object;

  /**
   * @param {EventEmitter} emitter - The event emitter that registered this
   *   subscription
   * @param {EventSubscriptionVendor} subscriber - The subscriber that controls
   *   this subscription
   * @param {function} listener - Function to invoke when the specified event is
   *   emitted
   * @param {*} context - Optional context object to use when invoking the
   *   listener
   */
  constructor(
    emitter: EventEmitter,
    subscriber: EventSubscriptionVendor,
    listener: Function,
    context: ?Object
  ) {
    super(subscriber);
    this.emitter = emitter;
    this.listener = listener;
    this.context = context;
  }

  /**
   * Removes this subscription from the emitter that registered it.
   * Note: we're overriding the `remove()` method of EventSubscription here
   * but deliberately not calling `super.remove()` as the responsibility
   * for removing the subscription lies with the EventEmitter.
   */
  remove() {
    this.emitter.removeSubscription(this);
  }
}

module.exports = EmitterSubscription;