--- a/src/MQTTCommand.cpp	Fri May 06 23:09:56 2022 +0200
+++ b/src/MQTTCommand.cpp	Sun May 08 21:42:14 2022 +0200
@@ -23,6 +23,7 @@
 #include <unistd.h>
 #include <sstream>
 #include <iomanip>
+#include <random>
 
 #include <mosquittopp.h>
 
@@ -37,7 +38,6 @@
 #include "MQTTCommand.h"
 #include "Hex.h"
 
-using namespace std;
 using namespace relpipe::cli;
 using namespace relpipe::writer;
 
@@ -45,31 +45,79 @@
 namespace in {
 namespace mqtt {
 
-void MQTTCommand::process(std::shared_ptr<writer::RelationalWriter> writer, Configuration& configuration) {
-	vector<AttributeMetadata> metadata;
+class MQTTClient : public mosqpp::mosquittopp {
+private:
+	std::shared_ptr<writer::RelationalWriter> writer;
+	Configuration& configuration;
+	int messageCount = 0;
+	std::string clientId;
 
-	{
-		// TODO: remove
-		int major, minor, patch;
-		mosqpp::lib_version(&major, &minor, &patch);
-		std::cerr << "mosquitto version: " << major << "." << minor << "." << patch << std::endl;
+	/**
+	 * @return unique (random) client ID for MQTT to allow multiple simultaneous connections
+	 */
+	static std::string generateClientID() {
+		std::stringstream result;
+		// result << "relpipe-in-";
+		std::string symbols("0123456789abcdef");
+
+		std::random_device dev;
+		std::mt19937 rng(dev());
+		std::uniform_int_distribution<std::mt19937::result_type> dist6(0, symbols.size());
+
+		for (int i = 0; i < 8; i++) result << symbols[dist6(rng)];
+
+		// std::cerr << "generated clien ID = " << result.str() << std::endl;
+		return result.str();
+	}
+public:
+
+	MQTTClient(std::shared_ptr<writer::RelationalWriter> writer, Configuration& configuration) : mosqpp::mosquittopp((generateClientID()).c_str()), writer(writer), configuration(configuration) {
 	}
 
+	void on_message(const mosquitto_message* message) override {
+		// std::cerr << "got MQTT message: length=" << message->payloadlen << std::endl;
+		std::string payload = std::string((const char*) message->payload, message->payloadlen);
+		writer->writeAttribute(configuration.stream);
+		writer->writeAttribute(Hex::toTxt(payload));
+		writer->writeAttribute(Hex::toHex(payload));
+		messageCount++;
+	}
+
+	int popMessageCount() {
+		int count = messageCount;
+		messageCount = 0;
+		return count;
+	}
+
+};
+
+void MQTTCommand::process(std::shared_ptr<writer::RelationalWriter> writer, Configuration& configuration) {
+	std::shared_ptr<MQTTClient> mq = std::make_shared<MQTTClient>(writer, configuration);
+
 	writer->startRelation(configuration.relation,{
-		{L"queue", TypeId::STRING},
+		{L"stream", TypeId::STRING},
 		{L"text", TypeId::STRING},
 		{L"data", TypeId::STRING}
 	}, true);
 
-	for (int i = configuration.messageCount; continueProcessing && i > 0; i--) {
-		// TODO: maybe rather call mq_timedreceive() inside and check continueProcessing (to be able to stop even when no messages are comming)
-		std::string message = "TODO"; // FIXME: receive message
+	mq->max_inflight_messages_set(1);
+	mq->connect("localhost", 1883);
+	int mid;
+	mq->subscribe(&mid, convertor.to_bytes(configuration.stream).c_str());
 
-		writer->writeAttribute(configuration.queue);
-		writer->writeAttribute(Hex::toTxt(message));
-		writer->writeAttribute(Hex::toHex(message));
+	//for (int i = configuration.messageCount; continueProcessing && i > 0; i--) {
+	for (int i = configuration.messageCount; continueProcessing && i > 0; i = i - mq->popMessageCount()) {
+		// std::cerr << "loop(): i=" << i << std::endl;
+
+		//mq->loop();
+		mq->loop(1000, 1);
+		//mq->loop(1000, -1);
+		//mq->loop_forever();
+		//mq->loop_write();
 	}
 
+	// FIXME: move do destructor
+	mq->disconnect();
 }
 
 MQTTCommand::~MQTTCommand() {