From 6940782024676a60979e177dea10a1ff28345e11 Mon Sep 17 00:00:00 2001
From: Fritz Heiden <fritz.heiden@mailbox.org>
Date: Mon, 14 Apr 2025 13:59:59 +0200
Subject: [PATCH] feat: add data channel to webrtc connection

---
 www/src/services/webrtc-service.js         | 31 ++++++++++++++++++++--
 www/src/views/devices/integration-view.jsx |  9 ++++++-
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/www/src/services/webrtc-service.js b/www/src/services/webrtc-service.js
index ad0c82a..e347051 100644
--- a/www/src/services/webrtc-service.js
+++ b/www/src/services/webrtc-service.js
@@ -8,10 +8,12 @@ function WebRTCService() {
   const STATE_CLOSED = "closed";
   const STATE_FAILED = "failed";
   const ICE_CONNECTION_STATE_CHANGE_EVENT = "iceconnectionstatechange";
+  const DATA_CHANNEL_OPEN_EVENT = "datachannelopen";
 
   let videoElement;
   let peerConnection;
   let peerId;
+  let dataChannel;
 
   let eventEmitter = new EventEmitter();
 
@@ -57,12 +59,19 @@ function WebRTCService() {
       console.log("Negotiation needed");
       negotiate(targetId);
     };
+    dataChannel = peerConnection.createDataChannel("data");
+    dataChannel.addEventListener("open", () => {
+      eventEmitter.dispatchEvent(DATA_CHANNEL_OPEN_EVENT);
+    });
     negotiate(targetId);
   }
-  
+
   function disconnect() {
     peerConnection.close();
-    eventEmitter.dispatchEvent(ICE_CONNECTION_STATE_CHANGE_EVENT, peerConnection.iceConnectionState);
+    eventEmitter.dispatchEvent(
+      ICE_CONNECTION_STATE_CHANGE_EVENT,
+      peerConnection.iceConnectionState
+    );
   }
 
   async function negotiate(targetId) {
@@ -125,12 +134,27 @@ function WebRTCService() {
     peerConnection.addIceCandidate(iceCandidate);
   }
 
+  function sendDataString(data) {
+    if (!dataChannel) return;
+    if (dataChannel.readyState !== "open") return;
+    dataChannel.send(data);
+  }
+
+  function sendDataJson(data) {
+    let dataJson = JSON.stringify(data);
+    sendDataString(dataJson);
+  }
+
   function onStateChanged(callback) {
     eventEmitter.on(ICE_CONNECTION_STATE_CHANGE_EVENT, () => {
       callback(peerConnection.iceConnectionState);
     });
   }
 
+  function onDataChannelOpen(callback) {
+    eventEmitter.on(DATA_CHANNEL_OPEN_EVENT, callback);
+  }
+
   function getConfiguration() {
     return {
       iceServers: [{ urls: "stun:stun.l.google.com:19302" }],
@@ -155,7 +179,10 @@ function WebRTCService() {
     disconnect,
     setVideoElement,
     getVideoElement,
+    sendDataString,
+    sendDataJson,
     onStateChanged,
+    onDataChannelOpen,
   };
 }
 
diff --git a/www/src/views/devices/integration-view.jsx b/www/src/views/devices/integration-view.jsx
index 8aafcad..e10ff32 100644
--- a/www/src/views/devices/integration-view.jsx
+++ b/www/src/views/devices/integration-view.jsx
@@ -22,6 +22,7 @@ function IntegrationView(props) {
       connectionState() === WebRTCService.STATE_CLOSED
   );
   WebRTCService.onStateChanged(handleConnectionStateChanged);
+  WebRTCService.onDataChannelOpen(handleDataChannelOpen);
   let videoElement = null;
 
   createEffect(() => {
@@ -40,7 +41,7 @@ function IntegrationView(props) {
   async function setIntegrationFromUrl() {
     let integrationId = UrlUtils.getQueryParameter("id");
     if (!integrationId) return;
-    let integration = await DeviceService.getIntegration(integrationId)
+    let integration = await DeviceService.getIntegration(integrationId);
     setIntegration(integration);
   }
 
@@ -58,6 +59,12 @@ function IntegrationView(props) {
     setConnectionState(state);
   }
 
+  function handleDataChannelOpen() {
+    setInterval(() => {
+      WebRTCService.sendDataJson({ message: "ping" });
+    }, 1000);
+  }
+
   return (
     <div
       class={