pubsub.ats

import { Logger } from '../logger';

export class Provider {
    constructor() {
        this.msgQueue = []
        this.subscribers = {}
    }

    notify(msg:string) {
        this.msgQueue.push(msg)
    }

    subscribe(msg:string, subscriber:Subscriber) {
        if (!(msg in this.subscribers)) {
            this.subscribers[msg] = [];
        }

        this.subscribers[msg].push(subscriber);
    }

    unsubscribe(msg:string, subscriber:Subscriber) {
        var subscribers = this.subscribers[msg];
        var index = subscribers.indexOf(subscriber);
        if (index > -1) {
            subscribers.splice(index, 1);
        }
    }

    update() {
        var _that = this;
        this.msgQueue.forEach(msg=> {
            if (msg in this.subscribers) {
                _that.subscribers[msg].forEach(sub=> {
                    sub.run(msg)
                });
            }
        });

        this.msgQueue = []
    }
}

export class Publisher {
    constructor(msgCenter:Provider) {
        this.provider = msgCenter;
    }

    publish(msg:string) {
        this.provider.notify(msg)
    }
}

export class Subscriber {
    constructor(name:string, msgCenter:Provider) {
        this.name = name;
        this.provider = msgCenter;
        this.logger = new Logger();
    }

    subscribe(msg:string) {
        this.provider.subscribe(msg, this);
    }

    run(msg:string) {
        this.logger.log(this.name + " & " + msg);
    }
}