publishsubscribe.js

const redis = require('redis');

const CHANNELS = {
    TEST: 'TEST',
    BLOCKCHAIN: 'BLOCKCHAIN'
}

class PubSub {
    constructor({ blockchain }) {
        this.blockchain = blockchain;
        this.publisher = redis.createClient();
        this.subscriber = redis.createClient();

        this.subscriber.subscribe(CHANNELS.TEST);
        this.subscriber.subscribe(CHANNELS.BLOCKCHAIN);

        this.subscriber.on('message', (channel, message) => this.handleMessage(channel, message))
    }
    handleMessage(channel, message) {
        console.log(`Message recieved.Channel: ${channel} Message: ${message}`);
        const parseMessage = JSON.parse(message)
        if (channel==CHANNELS.BLOCKCHAIN) {
            this.blockchain.replaceChain(parseMessage);
        }
    }

    publish({ channel, message }) {
        this.publisher.publish(channel, message);
    }

    broadcastChain(){
        this.publish({
            channnel:CHANNELS.BLOCKCHAIN,
            message:JSON.stringify(this.blockchain.chain),
        });
    }
}

//const checkPubSub = new PubSub();
//setTimeout(() => checkPubSub.publisher.publish(CHANNELS.TEST, "Hiloo"), 1000);
module.exports = PubSub;