ComunicRTCProxy/relay.go

/// RTC Relay
///
/// @author Pierre Hubert

package main

import (
	"encoding/json"
	"fmt"
	"log"

	"github.com/pion/webrtc/v2"
)

const (
	// SDP This is a SDP signal
	SDP = iota

	// CANDIDATE This is a candidate
	CANDIDATE = iota
)

type receivedSignal struct {
	sigType   uint
	offer     webrtc.SessionDescription
	candidate webrtc.ICECandidateInit
}

/// We keep for each connection its channel
var connections = make(map[string]chan receivedSignal)

/// Process incoming messages
func onSignal(callHash, peerID string, data map[string]interface{}) {

	// Decode received signal
	newSignal := receivedSignal{}

	if data["type"] == "SDP" {
		newSignal.sigType = SDP
		newSignal.offer.Type = webrtc.SDPTypeOffer
		newSignal.offer.SDP = data["data"].(map[string]interface{})["sdp"].(string)

	} else if data["type"] == "CANDIDATE" {
		newSignal.sigType = CANDIDATE

		// I have to re-encode data to initialize ICECandidate
		var enc []byte
		enc, err := json.Marshal(data["data"])
		if err != nil {
			log.Printf("Could not re-encode candidate ! %s", err)
			return
		}

		err = json.Unmarshal(enc, &newSignal.candidate)
		if err != nil {
			log.Printf("Discarding invalid candidate: %s", err)
			return
		}

	} else {
		log.Fatalf("Invalid signal type: %s !", data["type"])
	}

	println("Signal successfully processed!")
	fmt.Println("sig:", newSignal)
}