FindProviders functionality.

ipfsd.js

node.files.add([Buffer.from(contentText)], { // find the contentText hash
        onlyHash: true
    }, (err, filesAdded) => {
        if (err) {
            return console.log(err)

        }
        const hash = filesAdded[0].hash
        console.log("Searching for " + hash)
        node.dht.findprovs(hash, (err, provInfos) => { // DHT findproviders
            if (err) {
                console.log("############Error in Findprovs.")

                return //console.log(err)
            }

            console.log(provInfos)


            provInfos.forEach(element => {
           
                if (element.Type != 4 || !element.Responses["0"].ID || element.Responses["0"].ID === nodeIdB58) { //checking if it is provider using Type:4
                    return
                }
                let pingCount = 0
                element.ID = element.Responses["0"].ID

                node.ping(element.ID, {
                    // count: ,
                    // n: 2
                }, function (err, responses) {
                    if (err) {
                        return console.log("dial failed to " + element.ID)
                    }

                    if (pingCount > 0) {
                        return
                    }
                    pingCount = pingCount + 1

                    console.log("Found Provider:===========>" + element.ID + " " + element.Type)

                    var topic = element.ID

                    const receiveMsg = (msg) => {

                        if (msg.data.toString() === "send-details") {
                            return
                        }

                        var response = JSON.parse(msg.data.toString())

                        if (response.to === nodeIdB58 && response.title === "send-details-response") {

                            const receiveUnsubscribeMsg = (msg) => console.log(msg.toString())
                            node.pubsub.unsubscribe(topic, receiveUnsubscribeMsg, (err) => {
                                if (err) {
                                    return console.error(`failed to unsubscribe from ${topic}`, err)
                                }
                                console.log(`unsubscribed from ${topic}`)
                            })
                        }
                    }
                    node.pubsub.subscribe(topic, receiveMsg, (err) => {
                        if (err) {
                            return console.error(`failed to subscribe to ${topic}`, err)
                        }
                        console.log(`subscribed to ${topic}`)
                        let msg = Buffer.from("send-details")
                        node.pubsub.publish(topic, msg, (err) => {
                            if (err) {
                                return console.error(`failed to publish to ${topic}`, err)
                            }
                            // msg was broadcasted
                            console.log(`published to ${topic}`)
                        })
                    })
                })

            });
        })
    })