From ea4bccdaf781ddd75c083ab5d07d237d64892147 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Calvi=C3=B1o=20S=C3=A1nchez?= <danxuliu@gmail.com>
Date: Thu, 5 Dec 2024 03:40:11 +0100
Subject: [PATCH] Add support for sending data channel messages to a single
 participant
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This is not possible when Janus is used, as Janus only allows
broadcasting data channel messages to all the subscribers of the
publisher connection.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>
---
 .../nextcloud/talk/call/MessageSenderMcu.java |  3 ++
 .../talk/call/MessageSenderNoMcu.java         | 13 ++++++++
 .../talk/call/MessageSenderNoMcuTest.kt       | 33 +++++++++++++++++++
 3 files changed, 49 insertions(+)

diff --git a/app/src/main/java/com/nextcloud/talk/call/MessageSenderMcu.java b/app/src/main/java/com/nextcloud/talk/call/MessageSenderMcu.java
index 803becf57..f3278fe4c 100644
--- a/app/src/main/java/com/nextcloud/talk/call/MessageSenderMcu.java
+++ b/app/src/main/java/com/nextcloud/talk/call/MessageSenderMcu.java
@@ -13,6 +13,9 @@ import java.util.List;
 
 /**
  * Helper class to send messages to participants in a call when an MCU is used.
+ * <p>
+ * Note that when Janus is used it is not possible to send a data channel message to a specific participant. Any data
+ * channel message will be broadcast to all the subscribers of the publisher peer connection (the own peer connection).
  */
 public class MessageSenderMcu extends MessageSender {
 
diff --git a/app/src/main/java/com/nextcloud/talk/call/MessageSenderNoMcu.java b/app/src/main/java/com/nextcloud/talk/call/MessageSenderNoMcu.java
index 6f4306262..b5b903503 100644
--- a/app/src/main/java/com/nextcloud/talk/call/MessageSenderNoMcu.java
+++ b/app/src/main/java/com/nextcloud/talk/call/MessageSenderNoMcu.java
@@ -20,6 +20,19 @@ public class MessageSenderNoMcu extends MessageSender {
         super(peerConnectionWrappers);
     }
 
+    /**
+     * Sends the given data channel message to the given signaling session ID.
+     *
+     * @param dataChannelMessage the message to send
+     * @param sessionId the signaling session ID of the participant to send the message to
+     */
+    public void send(DataChannelMessage dataChannelMessage, String sessionId) {
+        PeerConnectionWrapper peerConnectionWrapper = getPeerConnectionWrapper(sessionId);
+        if (peerConnectionWrapper != null) {
+            peerConnectionWrapper.send(dataChannelMessage);
+        }
+    }
+
     public void sendToAll(DataChannelMessage dataChannelMessage) {
         for (PeerConnectionWrapper peerConnectionWrapper: peerConnectionWrappers) {
             if ("video".equals(peerConnectionWrapper.getVideoStreamType())){
diff --git a/app/src/test/java/com/nextcloud/talk/call/MessageSenderNoMcuTest.kt b/app/src/test/java/com/nextcloud/talk/call/MessageSenderNoMcuTest.kt
index cfd4a850d..6784bcef3 100644
--- a/app/src/test/java/com/nextcloud/talk/call/MessageSenderNoMcuTest.kt
+++ b/app/src/test/java/com/nextcloud/talk/call/MessageSenderNoMcuTest.kt
@@ -50,6 +50,39 @@ class MessageSenderNoMcuTest {
         messageSender = MessageSenderNoMcu(peerConnectionWrappers)
     }
 
+    @Test
+    fun testSendDataChannelMessage() {
+        val message = DataChannelMessage()
+        messageSender!!.send(message, "theSessionId2")
+
+        Mockito.verify(peerConnectionWrapper2!!).send(message)
+        Mockito.verify(peerConnectionWrapper1!!, never()).send(message)
+        Mockito.verify(peerConnectionWrapper2Screen!!, never()).send(message)
+        Mockito.verify(peerConnectionWrapper4Screen!!, never()).send(message)
+    }
+
+    @Test
+    fun testSendDataChannelMessageIfScreenPeerConnection() {
+        val message = DataChannelMessage()
+        messageSender!!.send(message, "theSessionId4")
+
+        Mockito.verify(peerConnectionWrapper1!!, never()).send(message)
+        Mockito.verify(peerConnectionWrapper2!!, never()).send(message)
+        Mockito.verify(peerConnectionWrapper2Screen!!, never()).send(message)
+        Mockito.verify(peerConnectionWrapper4Screen!!, never()).send(message)
+    }
+
+    @Test
+    fun testSendDataChannelMessageIfNoPeerConnection() {
+        val message = DataChannelMessage()
+        messageSender!!.send(message, "theSessionId3")
+
+        Mockito.verify(peerConnectionWrapper1!!, never()).send(message)
+        Mockito.verify(peerConnectionWrapper2!!, never()).send(message)
+        Mockito.verify(peerConnectionWrapper2Screen!!, never()).send(message)
+        Mockito.verify(peerConnectionWrapper4Screen!!, never()).send(message)
+    }
+
     @Test
     fun testSendDataChannelMessageToAll() {
         val message = DataChannelMessage()