/**
 * @author Martin Karkowski
 * @email m.karkowski@zema.de
 * @create date 2020-11-06 08:52:36
 * @modify date 2020-12-30 15:09:24
 * @desc [description]
 */

import { EventEmitter } from "events";
import { ILogger } from "js-logger";
import { NopeObservable } from "../observables/nopeObservable";
import {
  IAvailableInstanceGeneratorsMsg,
  IAvailableInstancesMsg,
  IAvailableServicesMsg,
  IAvailableTopicsMsg,
  ICommunicationInterface,
  IExternalEventMsg,
  IRequestTaskMsg,
  IResponseTaskMsg,
  ITaskCancelationMsg
} from "../types/nope/nopeCommunication.interface";
import { IDispatcherInfo } from "../types/nope/nopeDispatcher.interface";
import { INopeObservable } from "../types/nope/nopeObservable.interface";

export interface IEmitter {
  on(event: string | symbol, listener: (...args: any[]) => void): this;
  off(event: string | symbol, listener: (...args: any[]) => void): this;
  emit(event: string | symbol, ...args: any[]): boolean;
  getMaxListeners?: () => number;
  setMaxListeners?: (n: number) => void;
}

/**
 * A Communication Layer for the Dispatchers.
 * Here, only a Events are used.
 *
 * @export
 * @class EventLayer
 * @implements {ICommunicationInterface}
 */
export class EventLayer implements ICommunicationInterface {
  connected: INopeObservable<boolean>;

  /**
   * Creaetes an Event Emitter-based Communication Layer:
   * @param _emitter
   * @param subscriptionMode
   * @param resultSharing
   * @param _logger
   */
  constructor(
    protected _emitter: IEmitter = new EventEmitter(),
    public readonly subscriptionMode: "individual" | "generic" = "individual",
    public readonly resultSharing: "individual" | "generic" = "individual",
    protected _logger?: ILogger
  ) {
    this.connected = new NopeObservable();
    this.connected.setContent(true);
  }

  protected _on(event: string, cb) {
    if (typeof this._emitter.getMaxListeners === "function") {
      this._emitter.setMaxListeners(this._emitter.getMaxListeners() + 1);
    }
    this._emitter.on(event, cb);
  }

  async emitStatusUpdate(status: IDispatcherInfo): Promise<void> {
    this._emitter.emit("statusUdpate", status);
  }

  async onStatusUpdate(cb: (status: IDispatcherInfo) => void): Promise<void> {
    this._on("statusUdpate", cb);
  }

  async onNewInstancesAvailable(
    cb: (instances: IAvailableInstancesMsg) => void
  ): Promise<void> {
    this._on("newInstancesAvailable", cb);
  }

  async emitNewInstancesAvailable(
    instances: IAvailableInstancesMsg
  ): Promise<void> {
    this._emitter.emit("newInstancesAvailable", instances);
  }

  async onTaskCancelation(
    cb: (msg: ITaskCancelationMsg) => void
  ): Promise<void> {
    this._on("cancel", cb);
  }

  async emitTaskCancelation(msg: ITaskCancelationMsg): Promise<void> {
    this._emitter.emit("cancel", msg);
  }

  async onAurevoir(cb: (dispatcher: string) => void): Promise<void> {
    this._on("aurevoir", cb);
  }

  async emitAurevoir(dispatcher: string): Promise<void> {
    this._emitter.emit("aurevoir", dispatcher);
  }

  async emitNewInstanceGeneratorsAvailable(
    generators: IAvailableInstanceGeneratorsMsg
  ): Promise<void> {
    this._emitter.emit("generators", generators);
  }

  async onNewInstanceGeneratorsAvailable(
    cb: (generators: IAvailableInstanceGeneratorsMsg) => void
  ): Promise<void> {
    this._on("generators", cb);
  }

  async emitRpcRequest(name: string, request: IRequestTaskMsg): Promise<void> {
    this._emitter.emit(name, request);
  }

  async emitRpcResponse(name: string, result: IResponseTaskMsg): Promise<void> {
    this._emitter.emit(name, result);
  }

  async onRpcResponse(
    name: string,
    cb: (result: IResponseTaskMsg) => void
  ): Promise<void> {
    this._on(name, cb);
  }

  async offRpcResponse(
    name: string,
    cb: (result: IResponseTaskMsg) => void
  ): Promise<void> {
    this._emitter.off(name, cb);
  }

  async onRpcRequest(
    name: string,
    cb: (data: IRequestTaskMsg) => void
  ): Promise<void> {
    this._on(name, cb);
  }

  async offRpcRequest(
    name: string,
    cb: (data: IRequestTaskMsg) => void
  ): Promise<void> {
    this._emitter.off(name, cb);
  }

  async emitNewServicesAvailable(
    services: IAvailableServicesMsg
  ): Promise<void> {
    this._emitter.emit("services", services);
  }

  async onNewServicesAvailable(
    cb: (services: IAvailableServicesMsg) => void
  ): Promise<void> {
    this._on("services", cb);
  }

  async onBonjour(cb): Promise<void> {
    this._on("bonjour", cb);
  }

  async emitBonjour(msg): Promise<void> {
    this._emitter.emit("bonjour", msg);
  }

  async emitNewObersvablesAvailable(
    topics: IAvailableTopicsMsg
  ): Promise<void> {
    this._emitter.emit("topics", topics);
  }

  async onNewObservablesAvailable(
    cb: (topics: IAvailableTopicsMsg) => void
  ): Promise<void> {
    this._on("topics", cb);
  }

  async onEvent(
    event: string,
    cb: (data: IExternalEventMsg) => void
  ): Promise<void> {
    this._on("event_" + event, cb);
  }

  async emitEvent(event: string, data: IExternalEventMsg): Promise<void> {
    this._emitter.emit("event_" + event, data);
  }

  async offEvent(
    event: string,
    cb: (data: IExternalEventMsg) => void
  ): Promise<void> {
    this._emitter.off("event_" + event, cb);
  }
}