/**
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

import EventEmitter from './EventEmitter';
import {clientEventTopics} from './defaultTopics';

import InitListener from './listeners/Init';
import AnnouncementsListener from './listeners/Announcements';
import BeginChatListener from './listeners/BeginChat';
import ChatListener from './listeners/Chat';
import CharacterListener from './listeners/Character';
import EnemyTargetListener from './listeners/EnemyTarget';
import FriendlyTargetListener from './listeners/FriendlyTarget';
import ControlGameListener from './listeners/ControlGame';
import ControlGameScoreListener from './listeners/ControlGameScore';
import InventoryListener from './listeners/Inventory';
import EquippedGearListener from './listeners/EquippedGear';
import ConsoleListener from './listeners/Console';
import LoggingListener from './listeners/Logging';
import PlotListener from './listeners/Plot';

// Listeners
const listeners: any = {
  [clientEventTopics.initialize]: new InitListener(),
  [clientEventTopics.handlesAnnouncements]: new AnnouncementsListener(),
  [clientEventTopics.handlesBeginChat]: new BeginChatListener(),
  [clientEventTopics.handlesChat]: new ChatListener(),
  [clientEventTopics.handlesCharacter]: new CharacterListener(),
  [clientEventTopics.handlesEnemyTarget]: new EnemyTargetListener(),
  [clientEventTopics.handlesFriendlyTarget]: new FriendlyTargetListener(),
  [clientEventTopics.handlesControlGame]: new ControlGameListener(),
  [clientEventTopics.handlesControlGameScore]: new ControlGameScoreListener(),
  [clientEventTopics.handlesInventory]: new InventoryListener(),
  [clientEventTopics.handlesEquippedGear]: new EquippedGearListener(),
  [clientEventTopics.handlesConsole]: new ConsoleListener(),
  [clientEventTopics.handlesLogging]: new LoggingListener(),
  [clientEventTopics.handlesPlot]: new PlotListener()
};

// Event Emitter.  A single instance of event emitter handles all cu-events events
const emitter: EventEmitter = new EventEmitter();

/**
 * Register a callback for specified topic.
 * @method on
 * @param topic {string}      The topic name of the event
 * @param callback {function} The handler to be called when the event is triggered.
 *                            Passed the event data as the first argumnt
 * @return {any} an event handler id (can be used to stop listening for the event)
 */

export function on(topic: string, callback: (info: any) => void): any {
  const listener = listeners[topic];
  if (listener) {
    const handle = emitter.addListener(topic, listener.once, callback);
    listener.start(emitter);
    return handle;
  }
  return emitter.addListener(topic, false, callback);
}

/**
 * Register a callback for specified topic, once only.  Automatically unregisters
 * from the event one triggered.
 * @method once
 * @param topic {string}      The topic name of the event
 * @param callback {function} The handler to be called when the event is triggered.
 *                            Passed the event data as the first argument
 * @return {any} an event handler id (can be used to stop listening for the event)
 */

export function once(topic: string, callback: (info: any) => void): any {
  const listener = listeners[topic];
  if (listener) {
    const handle = emitter.addListener(topic, true, callback);
    listener.start(emitter);
    return handle;
  }
  return emitter.addListener(topic, true, callback);
}

// Unregister from events

/**
 * Register a callback for specified topic, once only.  Automatically unregisters
 * from the event one triggered.
 * @method off
 * @param listener {any}      ID returned from a call to on() once() or addEventListener()
 */

export function off(listener: any): void {
  emitter.removeListener(listener);
}

// Fire events

/**
 * Trigger an event for a topic, passing the event data (by reference) to any registered
 * handlers.  If passing by reference is an issue, the caller is responsible for cloning.
 * @method fire
 * @param topic {string}  The topic name of the event
 * @param data {any}      Data to be passed to registered handlers
 */

export function fire(topic: string, data: any) : void {
  emitter.emit(topic, data);
}

function diagnostics() : void {
  emitter.diagnostics();
}

export function addListener(topic: string, callback: (info: any) => void): void {
  on(topic, callback);
}

export function removeListener(listener: any): void {
  off(listener);
}

export default {
  clientEventTopics,
  on,
  once,
  off,
  fire,
  diagnostics,
  addListener,
  removeListener
}