publishsuscribe.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(`MessageReciever. 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({
            channel:CHANNELS.BLOCKCHAIN,
            message:JSON.stringify(this.blockchain.chain)
        })
    }
}

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

module.exports = PubSub;