NDI discovery

src/app/RenderCadenceApp.h

@@ -7,8 +7,10 @@
 #include "RuntimeLayerController.h"
 #include "../logging/Logger.h"
 #include "../control/RuntimeStateJson.h"
+#include "../json/JsonWriter.h"
 #include "../preview/PreviewWindowThread.h"
 #include "../telemetry/TelemetryHealthMonitor.h"
+#include "../video/ndi/NdiSourceDiscovery.h"
 #include "VideoIOEdges.h"
 #include "VideoOutputThread.h"
 
@@ -20,6 +22,7 @@
 #include <string>
 #include <thread>
 #include <type_traits>
+#include <vector>
 
 namespace RenderCadenceCompositor
 {
@@ -250,6 +253,9 @@ private:
 		callbacks.getConfigJson = [this]() {
 			return BuildConfigJson();
 		};
+		callbacks.getNdiSourcesJson = [this]() {
+			return BuildNdiSourcesJson();
+		};
 		callbacks.addLayer = [this](const std::string& body) {
 			return mRuntimeLayers.HandleAddLayer(body);
 		};
@@ -341,6 +347,31 @@ private:
 		return SerializeJson(root);
 	}
 
+	std::string BuildNdiSourcesJson() const
+	{
+		std::vector<NdiSourceInfo> sources;
+		std::string error;
+		const bool discovered = DiscoverNdiSources(sources, error);
+
+		JsonWriter writer;
+		writer.BeginObject();
+		writer.KeyBool("ok", discovered);
+		if (!error.empty())
+			writer.KeyString("error", error);
+		writer.Key("sources");
+		writer.BeginArray();
+		for (const NdiSourceInfo& source : sources)
+		{
+			writer.BeginObject();
+			writer.KeyString("name", source.name);
+			writer.KeyString("urlAddress", source.urlAddress);
+			writer.EndObject();
+		}
+		writer.EndArray();
+		writer.EndObject();
+		return writer.StringValue();
+	}
+
 	ControlActionResult HandleConfigSave(const std::string& body)
 	{
 		AppConfig nextConfig;