franta-hg@0: /**
franta-hg@0:  * DJM-Fix
franta-hg@16:  * Copyright © 2025 František Kučera (Frantovo.cz, GlobalCode.info)
franta-hg@0:  *
franta-hg@0:  * This program is free software: you can redistribute it and/or modify
franta-hg@0:  * it under the terms of the GNU General Public License as published by
franta-hg@0:  * the Free Software Foundation, version 3 of the License.
franta-hg@0:  *
franta-hg@0:  * This program is distributed in the hope that it will be useful,
franta-hg@0:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
franta-hg@0:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
franta-hg@0:  * GNU General Public License for more details.
franta-hg@0:  *
franta-hg@0:  * You should have received a copy of the GNU General Public License
franta-hg@0:  * along with this program. If not, see <http://www.gnu.org/licenses/>.
franta-hg@0:  */
franta-hg@1: #include <iostream>
franta-hg@12: #include <sstream>
franta-hg@5: #include <iomanip>
franta-hg@2: #include <thread>
franta-hg@6: #include <mutex>
franta-hg@5: #include <atomic>
franta-hg@2: #include <chrono>
franta-hg@2: #include <stdexcept>
franta-hg@6: #include <vector>
franta-hg@18: #include <regex>
franta-hg@1: 
franta-hg@1: #include "DJMFix.h"
franta-hg@18: #include "MessageCodec.h"
franta-hg@1: 
franta-hg@1: namespace djmfix {
franta-hg@1: 
franta-hg@12: using L = djmfix::logging::Level;
franta-hg@6: using Bytes = std::vector<uint8_t>;
franta-hg@16: namespace chro = std::chrono;
franta-hg@6: 
franta-hg@1: class DJMFixImpl : public DJMFix {
franta-hg@1: private:
franta-hg@2: 	MidiSender* midiSender;
franta-hg@12: 	djmfix::logging::Logger* logger;
franta-hg@18: 	MessageCodec codec;
franta-hg@13: 	const int keepAliveInterval = 200;
franta-hg@13: 	int keepAliveCounter = 0;
franta-hg@2: 	std::thread keepAliveThread;
franta-hg@6: 	std::recursive_mutex midiMutex;
franta-hg@5: 	std::atomic<bool> running{false};
franta-hg@5: 	std::atomic<bool> stopped{false};
franta-hg@8: 	std::atomic<bool> sendKeepAlive{false};
franta-hg@18: 	/**
franta-hg@18: 	 * Device (V10) may send multiple greeting messages.
franta-hg@18: 	 * It works even if we respond multiple times. But one response is enough.
franta-hg@18: 	 */
franta-hg@18: 	std::atomic<bool> greetingReceived{false};
franta-hg@18: 
franta-hg@18: 	Bytes seed0 = {0x68, 0x01, 0x31, 0xFB};
franta-hg@18: 	Bytes seed1 = {0x29, 0x00, 0x00, 0x00, 0x23, 0x48, 0x00, 0x00};
franta-hg@8: 	Bytes seed2;
franta-hg@18: 	Bytes seed3;
franta-hg@18: 
franta-hg@18: 	Bytes name1 = {0x50, 0x69, 0x6f, 0x6e, 0x65, 0x65, 0x72, 0x44, 0x4a};
franta-hg@18: 	Bytes name2 = {0x72, 0x65, 0x6b, 0x6f, 0x72, 0x64, 0x62, 0x6f, 0x78};
franta-hg@18: 
franta-hg@18: 	Bytes hash1;
franta-hg@18: 	Bytes hash2;
franta-hg@18: 
franta-hg@18: 	uint8_t version = 0x17;
franta-hg@2: 
franta-hg@2: 	void run() {
franta-hg@2: 		while (!stopped) {
franta-hg@12: 			logger->log(L::FINE, "DJMFixImpl::run()");
franta-hg@16: 			if (sendKeepAlive) send({
franta-hg@16: 					0xf0, 0x00, 0x40, 0x05,
franta-hg@18: 					0x00, 0x00, 0x00, version,
franta-hg@16: 					0x00, 0x50, 0x01, 0xf7
franta-hg@16: 				});
franta-hg@16: 			std::this_thread::sleep_for(chro::milliseconds(keepAliveInterval));
franta-hg@13: 			keepAliveCounter++;
franta-hg@16: 			if (keepAliveCounter % (60 * 1000 / keepAliveInterval) == 0)
franta-hg@16: 				logger->log(L::INFO,
franta-hg@16: 					"Still sending periodic keep-alive messages "
franta-hg@16: 					"(each " + std::to_string(keepAliveInterval) + " ms).");
franta-hg@2: 		}
franta-hg@2: 	}
franta-hg@2: 
franta-hg@18: 	void send(const Message& msg) {
franta-hg@18: 		logger->log(L::FINE, "<!-- Sent message: -->" + msg.toString());
franta-hg@18: 		send(codec.encode(msg));
franta-hg@18: 	}
franta-hg@18: 
franta-hg@6: 	void send(const MidiMessage& midiMessage) {
franta-hg@6: 		std::lock_guard<std::recursive_mutex> lock(midiMutex);
franta-hg@6: 		midiSender->send(midiMessage);
franta-hg@6: 	}
franta-hg@6: 
franta-hg@6: 	std::string toString(const Bytes& midiMessage) {
franta-hg@5: 		std::stringstream result;
franta-hg@16: 		for (uint8_t b : midiMessage)
franta-hg@16: 			result << std::hex << std::setw(2) << std::setfill('0') << (int) b;
franta-hg@5: 		return result.str();
franta-hg@5: 	}
franta-hg@5: 
franta-hg@6: 	Bytes normalize(const Bytes& data) {
franta-hg@16: 		if (data.size() % 2) throw std::invalid_argument(
franta-hg@16: 				"Data before normalization must have even number of bytes.");
franta-hg@6: 		Bytes result;
franta-hg@6: 		result.reserve(data.size() / 2);
franta-hg@16: 		for (size_t i = 0; i < data.size() / 2; i++) result.push_back(
franta-hg@16: 				(data[i * 2] & 0x0F) << 4 | (data[i * 2 + 1] & 0x0F));
franta-hg@6: 		return result;
franta-hg@6: 	}
franta-hg@6: 
franta-hg@8: 	Bytes denormalize(const Bytes& data) {
franta-hg@8: 		Bytes result;
franta-hg@8: 		result.reserve(data.size()*2);
franta-hg@8: 		for (size_t i = 0; i < data.size(); i++) {
franta-hg@8: 			result.push_back(data[i] >> 4);
franta-hg@8: 			result.push_back(data[i] & 0x0F);
franta-hg@8: 		}
franta-hg@8: 		return result;
franta-hg@8: 	}
franta-hg@8: 
franta-hg@6: 	uint32_t fnv32hash(const Bytes& buff) {
franta-hg@6: 		uint32_t hash = 0x811c9dc5;
franta-hg@6: 		for (uint8_t b : buff) hash = ((b^hash) * 0x1000193);
franta-hg@6: 		return hash;
franta-hg@6: 	}
franta-hg@6: 
franta-hg@6: 	Bytes toBytes(const uint32_t value) {
franta-hg@6: 		Bytes result;
franta-hg@6: 		result.reserve(4);
franta-hg@6: 		result.push_back(value >> 24);
franta-hg@6: 		result.push_back(value >> 16);
franta-hg@6: 		result.push_back(value >> 8);
franta-hg@6: 		result.push_back(value >> 0);
franta-hg@6: 		return result;
franta-hg@6: 	}
franta-hg@6: 
franta-hg@6: 	bool equals(Bytes a, Bytes b) {
franta-hg@6: 		if (a.size() != b.size()) return false;
franta-hg@6: 		for (size_t i = 0; i < a.size(); i++) if (a[i] != b[i]) return false;
franta-hg@6: 		return true;
franta-hg@6: 	}
franta-hg@6: 
franta-hg@16: 	template<typename T> std::vector<T> concat(
franta-hg@16: 			const std::vector<T>& a,
franta-hg@16: 			const std::vector<T>& b,
franta-hg@16: 			const std::vector<T>& c = {}) //
franta-hg@16: 	{
franta-hg@6: 		std::vector<T> result;
franta-hg@6: 		result.reserve(a.size() + b.size() + c.size());
franta-hg@6: 		for (size_t i = 0; i < a.size(); i++) result.push_back(a[i]);
franta-hg@6: 		for (size_t i = 0; i < b.size(); i++) result.push_back(b[i]);
franta-hg@6: 		for (size_t i = 0; i < c.size(); i++) result.push_back(c[i]);
franta-hg@6: 		return result;
franta-hg@6: 	}
franta-hg@6: 
franta-hg@16: 	template<typename T>
franta-hg@16: 	std::vector<T> xOR(const std::vector<T>& a, const std::vector<T>& b) {
franta-hg@16: 		if (a.size() != b.size()) throw std::invalid_argument(
franta-hg@16: 				"Both must be the same length when doing XOR.");
franta-hg@6: 		std::vector<T> result;
franta-hg@6: 		result.reserve(a.size());
franta-hg@6: 		for (size_t i = 0; i < a.size(); i++) result.push_back(a[i] ^ b[i]);
franta-hg@6: 		return result;
franta-hg@6: 	}
franta-hg@6: 
franta-hg@1: public:
franta-hg@1: 
franta-hg@16: 	DJMFixImpl(djmfix::logging::Logger* logger)
franta-hg@16: 	: logger(logger ? logger : djmfix::logging::blackhole()) {
franta-hg@12: 	}
franta-hg@12: 
franta-hg@1: 	virtual ~DJMFixImpl() override {
franta-hg@13: 		logger->log(L::FINER, "~DJMFixImpl()");
franta-hg@2: 		if (running) stop();
franta-hg@2: 	}
franta-hg@2: 
franta-hg@18: 	void setDeviceName(std::string name) override {
franta-hg@18: 		logger->log(L::FINE, "DJMFixImpl::setDeviceName(" + name + ")");
franta-hg@18: 
franta-hg@18: 		std::regex djm250pattern("Pioneer DJ Corporation DJM-250MK2.*");
franta-hg@18: 		std::regex djm450pattern(".*450.*"); // TODO: correct pattern
franta-hg@18: 
franta-hg@18: 		if (std::regex_match(name, djm250pattern)) {
franta-hg@18: 			// DJM-250MK2:
franta-hg@18: 			version = 0x17;
franta-hg@18: 			seed3 = {
franta-hg@18: 				0x59, 0xb5, 0x4b, 0xfe, 0xe4,
franta-hg@18: 				0x4a, 0x5a, 0xc8, 0xe4, 0xc5
franta-hg@18: 			};
franta-hg@18: 			logger->log(L::FINE, "Switched to DJM-250MK2 mode");
franta-hg@18: 		} else if (std::regex_match(name, djm450pattern)) {
franta-hg@18: 			// DJM-450:
franta-hg@18: 			// DJM-450 - not tested yet:
franta-hg@18: 			version = 0x13;
franta-hg@18: 			seed0 = {0x8c, 0x5b, 0x3f, 0x5d};
franta-hg@18: 			seed3 = {
franta-hg@18: 				0x08, 0xef, 0x3f, 0x2f, 0x1e,
franta-hg@18: 				0x7a, 0x90, 0x17, 0xf6, 0xaf
franta-hg@18: 			};
franta-hg@18: 			logger->log(L::FINE, "Switched to DJM-450 mode");
franta-hg@18: 		} else {
franta-hg@18: 			// DJM-V10:
franta-hg@18: 			version = 0x34;
franta-hg@18: 			seed3 = {
franta-hg@18: 				0x70, 0x01, 0x4d, 0x05, 0xbe,
franta-hg@18: 				0xf2, 0xe4, 0xde, 0x60, 0xd6
franta-hg@18: 			};
franta-hg@18: 			logger->log(L::FINE, "Switched to DJM-V10 mode");
franta-hg@18: 		}
franta-hg@18: 	}
franta-hg@18: 
franta-hg@18: 	void setMidiSender(MidiSender* midiSender) override {
franta-hg@13: 		logger->log(L::FINER, "DJMFixImpl::setMidiSender()");
franta-hg@2: 		this->midiSender = midiSender;
franta-hg@1: 	}
franta-hg@1: 
franta-hg@16: 	virtual void receive(const MidiMessage& msg) override {
franta-hg@18: 		// TODO: remove try/catch - there should be no unknown messages
franta-hg@18: 		try {
franta-hg@18: 			receive0(msg);
franta-hg@18: 		} catch (const std::exception& e) {
franta-hg@18: 			logger->log(L::SEVERE,
franta-hg@18: 					std::string("Message receiving failed: ") + e.what());
franta-hg@18: 		}
franta-hg@18: 	}
franta-hg@18: 
franta-hg@18: 	virtual void receive0(const MidiMessage& msg) {
franta-hg@16: 		logger->log(L::FINE, "Received a message: "
franta-hg@16: 				"size = " + std::to_string(msg.size()) + " "
franta-hg@16: 				"data = " + toString(msg));
franta-hg@6: 		std::lock_guard<std::recursive_mutex> lock(midiMutex);
franta-hg@18: 		Message msgIn = codec.decode(msg);
franta-hg@5: 
franta-hg@18: 		logger->log(L::FINE, "<!-- Received message: -->" + msgIn.toString());
franta-hg@7: 
franta-hg@18: 		if (msgIn.type == MessageType::D11_GREETING && !greetingReceived) {
franta-hg@13: 			logger->log(L::INFO, "Received greeting message.");
franta-hg@18: 			Message msgOut(MessageType::H12_SEED1, version,{
franta-hg@18: 				{FieldType::F01, name1},
franta-hg@18: 				{FieldType::F02, name2},
franta-hg@18: 				{FieldType::F03, denormalize(seed1)}
franta-hg@16: 			});
franta-hg@18: 			send(msgOut);
franta-hg@18: 			greetingReceived = true;
franta-hg@13: 			logger->log(L::INFO, "Sent message with seed1.");
franta-hg@18: 		} else if (msgIn.type == MessageType::D13_HASH1_SEED2) {
franta-hg@18: 			std::vector<Field> hash1F = msgIn.findFields(FieldType::F04);
franta-hg@18: 			std::vector<Field> seed2F = msgIn.findFields(FieldType::F03);
franta-hg@18: 
franta-hg@18: 			if (hash1F.empty()) throw std::logic_error("hash1 not found");
franta-hg@18: 			if (seed2F.empty()) throw std::logic_error("seed2 not found");
franta-hg@18: 
franta-hg@18: 			hash1 = normalize(hash1F[0].data);
franta-hg@18: 			seed2 = normalize(seed2F[0].data);
franta-hg@18: 
franta-hg@16: 			logger->log(L::INFO, "Received message with "
franta-hg@16: 					"hash1 = " + toString(hash1) + " and "
franta-hg@16: 					"seed2 = " + toString(seed2));
franta-hg@6: 
franta-hg@16: 			Bytes hash1check =
franta-hg@16: 					toBytes(fnv32hash(concat(seed1, xOR(seed0, seed2))));
franta-hg@6: 
franta-hg@6: 			if (equals(hash1, hash1check)) {
franta-hg@13: 				logger->log(L::INFO, "Verification of hash1 was successful.");
franta-hg@18: 				hash2 = toBytes(fnv32hash(concat(seed2, xOR(seed0, seed2))));
franta-hg@18: 
franta-hg@18: 				Message msgOut(MessageType::H14_HASH2, version,{
franta-hg@18: 					{FieldType::F01, name1},
franta-hg@18: 					{FieldType::F02, name2},
franta-hg@18: 					{FieldType::F04, denormalize(hash2)},
franta-hg@18: 					{FieldType::F05, denormalize(seed3)}
franta-hg@18: 				});
franta-hg@18: 				send(msgOut);
franta-hg@13: 				logger->log(L::INFO, "Sent message with hash2.");
franta-hg@6: 			} else {
franta-hg@12: 				std::stringstream logMessage;
franta-hg@12: 				logMessage
franta-hg@13: 						<< "Verification of hash1 failed: "
franta-hg@16: 						<< " midiMessage = " << toString(msg)
franta-hg@8: 						<< " seed0 = " << toString(seed0)
franta-hg@8: 						<< " seed1 = " << toString(seed1)
franta-hg@8: 						<< " seed2 = " << toString(seed2)
franta-hg@8: 						<< " hash1 = " << toString(hash1)
franta-hg@12: 						<< " hash1check = " << toString(hash1check);
franta-hg@12: 				logger->log(L::SEVERE, logMessage.str());
franta-hg@8: 				// TODO: graceful death
franta-hg@6: 			}
franta-hg@18: 		} else if (msgIn.type == MessageType::D15_CONFIRMATION) {
franta-hg@8: 			sendKeepAlive = true;
franta-hg@16: 			logger->log(L::INFO, "Received acknowledgment message. "
franta-hg@16: 					"Started sending keep-alive messages. "
franta-hg@16: 					"LINE/PHONO channels should work now.");
franta-hg@18: 		} else {
franta-hg@18: 			logger->log(L::SEVERE, "Received unexpected message type.");
franta-hg@5: 		}
franta-hg@5: 
franta-hg@1: 	}
franta-hg@1: 
franta-hg@1: 	void start() override {
franta-hg@12: 		logger->log(L::FINE, "DJMFixImpl::start()");
franta-hg@16: 		if (midiSender == nullptr)
franta-hg@16: 			throw std::logic_error("Need a midiSender when starting DJMFix");
franta-hg@5: 
franta-hg@16: 		send({
franta-hg@16: 			0xf0, 0x00, 0x40, 0x05,
franta-hg@18: 			0x00, 0x00, 0x00, version,
franta-hg@16: 			0x00, 0x50, 0x01, 0xf7
franta-hg@16: 		});
franta-hg@18: 
franta-hg@18: 		// TODO: check whether this second message is neccessary for V10:
franta-hg@18: 		send({
franta-hg@18: 			0xf0, 0x00, 0x40, 0x05,
franta-hg@18: 			0x00, 0x00, 0x00, version,
franta-hg@18: 			0x00, 0x03, 0x01, 0xf7
franta-hg@18: 		});
franta-hg@13: 		logger->log(L::INFO, "Sent greeting message.");
franta-hg@2: 
franta-hg@2: 		keepAliveThread = std::thread(&DJMFixImpl::run, this);
franta-hg@2: 		running = true;
franta-hg@2: 
franta-hg@1: 	}
franta-hg@1: 
franta-hg@1: 	void stop() override {
franta-hg@2: 		stopped = true;
franta-hg@2: 		keepAliveThread.join();
franta-hg@2: 		running = false;
franta-hg@12: 		logger->log(L::FINE, "DJMFixImpl::stop()");
franta-hg@1: 	}
franta-hg@1: };
franta-hg@1: 
franta-hg@12: DJMFix* create(djmfix::logging::Logger* logger) {
franta-hg@12: 	return new DJMFixImpl(logger);
franta-hg@1: }
franta-hg@1: 
franta-hg@1: }