From 60605e9ada68a94b19d35269b95864bae1b3f3b1 Mon Sep 17 00:00:00 2001
From: Pierre HUBERT <pierre.git@communiquons.org>
Date: Sat, 11 Apr 2020 10:30:28 +0200
Subject: [PATCH] Parse incoming signals

---
 relay.go | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 ws.go    |  8 +++++++
 2 files changed, 74 insertions(+)
 create mode 100644 relay.go

diff --git a/relay.go b/relay.go
new file mode 100644
index 0000000..f4b02f8
--- /dev/null
+++ b/relay.go
@@ -0,0 +1,66 @@
+/// 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)
+}
diff --git a/ws.go b/ws.go
index a521b4f..8bfa278 100644
--- a/ws.go
+++ b/ws.go
@@ -69,6 +69,14 @@ func openWs(conf *Config) {
 			setCallConfig(msg.Data.(map[string]interface{}))
 			break
 
+		// Remote signal
+		case "signal":
+			onSignal(msg.CallHash, msg.PeerID, msg.Data.(map[string]interface{}))
+			break
+
+		default:
+			println("Received unkown message type!")
+			break
 		}
 	}