From e1f60cd34db5c279527a9e07b5247c1e77cefe04 Mon Sep 17 00:00:00 2001
From: Paul-Louis Ageneau <paul-louis@ageneau.org>
Date: Sat, 17 Oct 2020 23:29:31 +0200
Subject: [PATCH] Added rtcGetSelectedCandidatePair() to C API

---
 include/rtc/rtc.h          |  2 ++
 src/capi.cpp               | 31 +++++++++++++++++++++++++++++++
 test/capi_connectivity.cpp | 17 +++++++++++++++++
 3 files changed, 50 insertions(+)

diff --git a/include/rtc/rtc.h b/include/rtc/rtc.h
index bcbac29..f1e43f6 100644
--- a/include/rtc/rtc.h
+++ b/include/rtc/rtc.h
@@ -127,6 +127,8 @@ RTC_EXPORT int rtcGetRemoteDescription(int pc, char *buffer, int size);
 RTC_EXPORT int rtcGetLocalAddress(int pc, char *buffer, int size);
 RTC_EXPORT int rtcGetRemoteAddress(int pc, char *buffer, int size);
 
+RTC_EXPORT int rtcGetSelectedCandidatePair(int pc, char *local, int localSize, char *remote, int remoteSize);
+
 // DataChannel
 RTC_EXPORT int rtcSetDataChannelCallback(int pc, rtcDataChannelCallbackFunc cb);
 RTC_EXPORT int rtcAddDataChannel(int pc, const char *label); // returns dc id
diff --git a/src/capi.cpp b/src/capi.cpp
index 35cc466..c2cae6f 100644
--- a/src/capi.cpp
+++ b/src/capi.cpp
@@ -619,6 +619,37 @@ int rtcGetRemoteAddress(int pc, char *buffer, int size) {
 	});
 }
 
+int rtcGetSelectedCandidatePair(int pc, char *local, int localSize, char *remote, int remoteSize) {
+	return WRAP({
+		auto peerConnection = getPeerConnection(pc);
+
+		if (!local)
+			localSize = 0;
+		if (!remote)
+			remoteSize = 0;
+
+		Candidate localCand;
+		Candidate remoteCand;
+		if (peerConnection->getSelectedCandidatePair(&localCand, &remoteCand)) {
+			if (localSize > 0) {
+				string localSdp = string(localCand);
+				localSize = std::min(localSize - 1, int(localSdp.size()));
+				std::copy(localSdp.begin(), localSdp.begin() + localSize, local);
+				local[localSize] = '\0';
+			}
+			if (remoteSize > 0) {
+				string remoteSdp = string(remoteCand);
+				remoteSize = std::min(remoteSize - 1, int(remoteSdp.size()));
+				std::copy(remoteSdp.begin(), remoteSdp.begin() + remoteSize, remote);
+				remote[remoteSize] = '\0';
+			}
+			return localSize + remoteSize;
+		}
+
+		return RTC_ERR_FAILURE;
+	});
+}
+
 int rtcGetDataChannelLabel(int dc, char *buffer, int size) {
 	return WRAP({
 		auto dataChannel = getDataChannel(dc);
diff --git a/test/capi_connectivity.cpp b/test/capi_connectivity.cpp
index 2c80f16..c438ed1 100644
--- a/test/capi_connectivity.cpp
+++ b/test/capi_connectivity.cpp
@@ -186,6 +186,7 @@ int test_capi_connectivity_main() {
 	}
 
 	char buffer[BUFFER_SIZE];
+	char buffer2[BUFFER_SIZE];
 
 	if (rtcGetLocalDescription(peer1->pc, buffer, BUFFER_SIZE) < 0) {
 		fprintf(stderr, "rtcGetLocalDescription failed\n");
@@ -235,6 +236,22 @@ int test_capi_connectivity_main() {
 	}
 	printf("Remote address 2: %s\n", buffer);
 
+
+	if (rtcGetSelectedCandidatePair(peer1->pc, buffer, BUFFER_SIZE, buffer2, BUFFER_SIZE) < 0) {
+		fprintf(stderr, "rtcGetSelectedCandidatePair failed\n");
+		goto error;
+	}
+	printf("Local candidate 1:  %s\n", buffer);
+	printf("Remote candidate 1: %s\n", buffer2);
+
+	if (rtcGetSelectedCandidatePair(peer2->pc, buffer, BUFFER_SIZE, buffer2, BUFFER_SIZE) < 0) {
+		fprintf(stderr, "rtcGetSelectedCandidatePair failed\n");
+		goto error;
+	}
+	printf("Local candidate 2:  %s\n", buffer);
+	printf("Remote candidate 2: %s\n", buffer2);
+
+
 	deletePeer(peer1);
 	sleep(1);
 	deletePeer(peer2);