/**
 * Generic Event Emitter class following a subscribe/publish paradigm.
 */
import { IMap } from "../types";

type cbFn = (...args: any[]) => any;

export interface ISubscriber {
    /**
     * Callback function that will be run when an event is emitted
     */
    cb: cbFn;

    /**
     * Name/identifier for this subscriber
     */
    id: string;
}

export class EventEmitter {
    /**
     * Map of Subscriber name -> Callback function
     */
    subscribers: IMap<cbFn> = {};

    constructor(subs?: ISubscriber[]) {
        if (Array.isArray(subs)) {
            for (const s of subs) {
                this.addSubscriber(s);
            }
        }
    }

    addSubscriber(s: ISubscriber): void {
        this.subscribers[s.id] = s.cb;
    }

    emitEvent(...args: any[]): void {
        for (const s in this.subscribers) {
            const sub = this.subscribers[s];

            sub(args);
        }
    }

    removeSubscriber(id: string): void {
        delete this.subscribers[id];
    }

}