# HG changeset patch
# User František Kučera <franta-hg@frantovo.cz>
# Date 1609771512 -3600
# Node ID 15d87fdd6e6cf2cebcaf6f1ca893109e4c7dea1f
# Parent  5b351628a37767e22605f62e454fffcb78d5b3dc
use Logger instead of messing with STDIO directly

diff -r 5b351628a377 -r 15d87fdd6e6c AlsaBridge.cpp
--- a/AlsaBridge.cpp	Mon Jan 04 13:38:08 2021 +0100
+++ b/AlsaBridge.cpp	Mon Jan 04 15:45:12 2021 +0100
@@ -15,6 +15,7 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 #include <iostream>
+#include <sstream>
 #include <stdexcept>
 #include <thread>
 #include <mutex>
@@ -24,13 +25,17 @@
 #include <alsa/asoundlib.h>
 
 #include "AlsaBridge.h"
+#include "Logger.h"
 
 namespace djmfix {
 namespace alsa {
 
+using L = djmfix::logging::Level;
+
 class AlsaBridgeImpl : public AlsaBridge, private djmfix::MidiSender {
 private:
 	djmfix::DJMFix* djmFix;
+	djmfix::logging::Logger* logger;
 	snd_rawmidi_t* input;
 	snd_rawmidi_t* output;
 	std::thread receivingThread;
@@ -41,22 +46,27 @@
 
 		std::vector<int> cardNumbers;
 
-		std::cerr << "Looking for available cards:" << std::endl; // TODO: do not mess STDIO
+		logger->log(L::INFO, "Looking for available cards:");
 
 		for (int card = -1; snd_card_next(&card) == 0 && card >= 0;) {
 			char* longName = nullptr;
 			snd_card_get_longname(card, &longName);
-			std::cerr << "card: #" << card << ": '" << longName << "'"; // TODO: do not mess STDIO
+
+			std::stringstream logMessage;
+			logMessage << " - card: #" << card << ": '" << longName << "'";
+
 			if (std::regex_match(longName, cardNamePattern)) {
 				cardNumbers.push_back(card);
-				std::cerr << " [matches]"; // TODO: do not mess STDIO
+				logMessage << " [matches]";
 			}
-			std::cerr << std::endl;
+
+			logger->log(L::INFO, logMessage.str());
+
 			free(longName);
 		}
 
 		if (cardNumbers.size() == 1) {
-			std::cerr << "Going to fix card #" << cardNumbers[0] << std::endl; // TODO: do not mess STDIO
+			logger->log(L::INFO, "Going to fix card #" + std::to_string(cardNumbers[0]));
 			return "hw:" + std::to_string(cardNumbers[0]);
 		} else if (cardNumbers.empty()) {
 			throw std::invalid_argument("No card with matching name found. Is the card connected? Maybe try to provide different name pattern.");
@@ -82,7 +92,7 @@
 	}
 public:
 
-	AlsaBridgeImpl(djmfix::DJMFix* djmFix, const std::string& cardNamePattern) : djmFix(djmFix) {
+	AlsaBridgeImpl(djmfix::DJMFix* djmFix, const std::string& cardNamePattern, djmfix::logging::Logger* logger) : djmFix(djmFix), logger(logger ? logger : djmfix::logging::blackhole()) {
 		if (djmFix == nullptr) throw std::invalid_argument("need a djmFix for AlsaBridge");
 
 		std::string deviceName = findDeviceName(std::regex(cardNamePattern));
@@ -95,10 +105,10 @@
 	}
 
 	virtual ~AlsaBridgeImpl() {
-		// TODO: do not use raw/exclusive access to the device
+		// TODO: do not use raw/exclusive access to the MIDI device
 		snd_rawmidi_close(input);
 		snd_rawmidi_close(output);
-		std::cerr << "~AlsaBridgeImpl()" << std::endl; // TODO: do not mess STDIO
+		logger->log(L::FINE, "~AlsaBridgeImpl()");
 	}
 
 	virtual void start() override {
@@ -115,13 +125,13 @@
 	virtual void send(MidiMessage midiMessage) override {
 		std::lock_guard<std::recursive_mutex> lock(midiMutex);
 		ssize_t length = snd_rawmidi_write(output, midiMessage.data(), midiMessage.size());
-		std::cerr << "AlsaBridgeImpl::send(): length = " << length << std::endl; // TODO: do not mess STDIO
+		logger->log(L::INFO, "AlsaBridgeImpl::send(): length = " + std::to_string(length));
 	}
 
 };
 
-AlsaBridge* create(djmfix::DJMFix* djmFix, const std::string& deviceName) {
-	return new AlsaBridgeImpl(djmFix, deviceName);
+AlsaBridge* create(djmfix::DJMFix* djmFix, const std::string& deviceName, djmfix::logging::Logger* logger) {
+	return new AlsaBridgeImpl(djmFix, deviceName, logger);
 }
 
 }
diff -r 5b351628a377 -r 15d87fdd6e6c AlsaBridge.h
--- a/AlsaBridge.h	Mon Jan 04 13:38:08 2021 +0100
+++ b/AlsaBridge.h	Mon Jan 04 15:45:12 2021 +0100
@@ -19,6 +19,7 @@
 #include <string>
 
 #include "DJMFix.h"
+#include "Logger.h"
 
 namespace djmfix {
 namespace alsa {
@@ -31,7 +32,7 @@
 
 };
 
-AlsaBridge* create(djmfix::DJMFix* djmFix, const std::string& cardNamePattern);
+AlsaBridge* create(djmfix::DJMFix* djmFix, const std::string& cardNamePattern, djmfix::logging::Logger* logger);
 
 }
 }
diff -r 5b351628a377 -r 15d87fdd6e6c DJMFix.cpp
--- a/DJMFix.cpp	Mon Jan 04 13:38:08 2021 +0100
+++ b/DJMFix.cpp	Mon Jan 04 15:45:12 2021 +0100
@@ -15,6 +15,7 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 #include <iostream>
+#include <sstream>
 #include <iomanip>
 #include <thread>
 #include <mutex>
@@ -27,11 +28,13 @@
 
 namespace djmfix {
 
+using L = djmfix::logging::Level;
 using Bytes = std::vector<uint8_t>;
 
 class DJMFixImpl : public DJMFix {
 private:
 	MidiSender* midiSender;
+	djmfix::logging::Logger* logger;
 	std::thread keepAliveThread;
 	std::recursive_mutex midiMutex;
 	std::atomic<bool> running{false};
@@ -41,7 +44,7 @@
 
 	void run() {
 		while (!stopped) {
-			std::cerr << "DJMFixImpl::run()" << std::endl; // TODO: do not mess STDIO
+			logger->log(L::FINE, "DJMFixImpl::run()");
 			if (sendKeepAlive) send({0xf0, 0x00, 0x40, 0x05, 0x00, 0x00, 0x00, 0x17, 0x00, 0x50, 0x01, 0xf7});
 			std::this_thread::sleep_for(std::chrono::milliseconds(200));
 		}
@@ -117,18 +120,21 @@
 
 public:
 
+	DJMFixImpl(djmfix::logging::Logger* logger) : logger(logger ? logger : djmfix::logging::blackhole()) {
+	}
+
 	virtual ~DJMFixImpl() override {
-		std::cerr << "~DJMFixImpl()" << std::endl; // TODO: do not mess STDIO
+		logger->log(L::FINE, "~DJMFixImpl()");
 		if (running) stop();
 	}
 
 	void setMidiSender(MidiSender* midiSender) {
-		std::cerr << "DJMFixImpl::setMidiSender()" << std::endl; // TODO: do not mess STDIO
+		logger->log(L::FINE, "DJMFixImpl::setMidiSender()");
 		this->midiSender = midiSender;
 	}
 
 	virtual void receive(const MidiMessage& midiMessage) override {
-		std::cerr << "DJMFixImpl::receive(): size = " << midiMessage.size() << " data = " << toString(midiMessage) << std::endl; // TODO: do not mess STDIO
+		logger->log(L::INFO, "received message: size = " + std::to_string(midiMessage.size()) + " data = " + toString(midiMessage));
 		std::lock_guard<std::recursive_mutex> lock(midiMutex);
 
 
@@ -139,7 +145,7 @@
 			seed2 = Bytes(midiMessage.begin() + 45, midiMessage.begin() + 45 + 8);
 			hash1 = normalize(hash1);
 			seed2 = normalize(seed2);
-			std::cerr << "DJMFixImpl::receive(): got message with hash1 = " << toString(hash1) << " and seed2 = " << toString(seed2) << std::endl; // TODO: do not mess STDIO
+			logger->log(L::INFO, "got message with hash1 = " + toString(hash1) + " and seed2 = " + toString(seed2));
 
 			Bytes seed0 = {0x68, 0x01, 0x31, 0xFB};
 			Bytes seed1 = {0x29, 0x00, 0x00, 0x00, 0x23, 0x48, 0x00, 0x00};
@@ -147,19 +153,20 @@
 			Bytes hash1check = toBytes(fnv32hash(concat(seed1, xOR(seed0, seed2))));
 
 			if (equals(hash1, hash1check)) {
-				std::cerr << "DJMFixImpl::receive(): hash1 verification: OK" << std::endl; // TODO: do not mess STDIO
+				logger->log(L::INFO, "hash1 verification: OK");
 				Bytes hash2 = toBytes(fnv32hash(concat(seed2, xOR(seed0, seed2))));
 				send(concat({0xf0, 0x00, 0x40, 0x05, 0x00, 0x00, 0x00, 0x17, 0x00, 0x14, 0x38, 0x01, 0x0b, 0x50, 0x69, 0x6f, 0x6e, 0x65, 0x65, 0x72, 0x44, 0x4a, 0x02, 0x0b, 0x72, 0x65, 0x6b, 0x6f, 0x72, 0x64, 0x62, 0x6f, 0x78, 0x04, 0x0a}, concat(denormalize(hash2),{0x05, 0x16, 0x05, 0x09, 0x0b, 0x05, 0x04, 0x0b, 0x0f, 0x0e, 0x0e, 0x04, 0x04, 0x0a, 0x05, 0x0a, 0x0c, 0x08, 0x0e, 0x04, 0x0c, 0x05, 0xf7})));
 			} else {
-				std::cerr
-						<< "DJMFixImpl::receive(): hash1 verification failed: "
+				std::stringstream logMessage;
+				logMessage
+						<< "hash1 verification failed: "
 						<< " midiMessage = " << toString(midiMessage)
 						<< " seed0 = " << toString(seed0)
 						<< " seed1 = " << toString(seed1)
 						<< " seed2 = " << toString(seed2)
 						<< " hash1 = " << toString(hash1)
-						<< " hash1check = " << toString(hash1check)
-						<< std::endl;
+						<< " hash1check = " << toString(hash1check);
+				logger->log(L::SEVERE, logMessage.str());
 				// TODO: graceful death
 			}
 		} else if (midiMessage.size() == 12 && midiMessage[9] == 0x15) {
@@ -169,7 +176,7 @@
 	}
 
 	void start() override {
-		std::cerr << "DJMFixImpl::start()" << std::endl; // TODO: do not mess STDIO
+		logger->log(L::FINE, "DJMFixImpl::start()");
 		if (midiSender == nullptr) throw std::logic_error("need a midiSender when starting DJMFix");
 
 		// TODO: methods for parsing and constructing messages from parts (TLV)
@@ -184,12 +191,12 @@
 		stopped = true;
 		keepAliveThread.join();
 		running = false;
-		std::cerr << "DJMFixImpl::stop()" << std::endl; // TODO: do not mess STDIO
+		logger->log(L::FINE, "DJMFixImpl::stop()");
 	}
 };
 
-DJMFix* create() {
-	return new DJMFixImpl();
+DJMFix* create(djmfix::logging::Logger* logger) {
+	return new DJMFixImpl(logger);
 }
 
 }
diff -r 5b351628a377 -r 15d87fdd6e6c DJMFix.h
--- a/DJMFix.h	Mon Jan 04 13:38:08 2021 +0100
+++ b/DJMFix.h	Mon Jan 04 15:45:12 2021 +0100
@@ -18,6 +18,8 @@
 
 #include <vector>
 
+#include "Logger.h"
+
 namespace djmfix {
 
 using MidiMessage = std::vector<uint8_t>;
@@ -37,6 +39,6 @@
 	virtual void stop() = 0;
 };
 
-DJMFix* create();
+DJMFix* create(djmfix::logging::Logger* logger);
 
 }
diff -r 5b351628a377 -r 15d87fdd6e6c Logger.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Logger.cpp	Mon Jan 04 15:45:12 2021 +0100
@@ -0,0 +1,78 @@
+/**
+ * DJM-Fix
+ * Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <chrono>
+#include <iomanip>
+#include <sstream>
+
+#include "Logger.h"
+
+namespace djmfix {
+namespace logging {
+
+class Blackhole : public Logger {
+public:
+
+	virtual void log(Level level, const std::string& message) override {
+	}
+};
+
+class LoggerImpl : public Logger {
+private:
+	std::ostream& output;
+	Level minLevel;
+
+	std::string getTimestamp() {
+		auto now = std::chrono::system_clock::now();
+		auto itt = std::chrono::system_clock::to_time_t(now);
+		std::ostringstream ss;
+		ss << std::put_time(localtime(&itt), "%FT%T%z");
+		return ss.str();
+	}
+
+	std::string toString(Level level) {
+		if (level == Level::SEVERE) return "SEVERE";
+		else if (level == Level::WARNING) return "WARNING";
+		else if (level == Level::INFO) return "INFO";
+		else if (level == Level::CONFIG) return "CONFIG";
+		else if (level == Level::FINE) return "FINE";
+		else if (level == Level::FINER) return "FINER";
+		else if (level == Level::FINEST) return "FINEST";
+		else return "UNKNOWN";
+	}
+
+public:
+
+	LoggerImpl(std::ostream& output, Level minLevel) : output(output), minLevel(minLevel) {
+	}
+
+	virtual void log(Level level, const std::string& message) override {
+		if (level <= minLevel) {
+			output << getTimestamp() << " " << std::setw(8) << toString(level) << ":  " << message << std::endl;
+		}
+	}
+};
+
+Logger* create(std::ostream& output, Level minLevel) {
+	return new LoggerImpl(output, minLevel);
+}
+
+Logger* blackhole() {
+	return new Blackhole();
+}
+
+}
+}
diff -r 5b351628a377 -r 15d87fdd6e6c Logger.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Logger.h	Mon Jan 04 15:45:12 2021 +0100
@@ -0,0 +1,44 @@
+/**
+ * DJM-Fix
+ * Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <iostream>
+
+namespace djmfix {
+namespace logging {
+
+enum class Level {
+	SEVERE,
+	WARNING,
+	INFO,
+	CONFIG,
+	FINE,
+	FINER,
+	FINEST,
+};
+
+class Logger {
+public:
+	virtual ~Logger() = default;
+	virtual void log(Level level, const std::string& message) = 0;
+};
+
+Logger* create(std::ostream& output, Level minLevel);
+Logger* blackhole();
+
+}
+}
\ No newline at end of file
diff -r 5b351628a377 -r 15d87fdd6e6c Makefile
--- a/Makefile	Mon Jan 04 13:38:08 2021 +0100
+++ b/Makefile	Mon Jan 04 15:45:12 2021 +0100
@@ -25,6 +25,6 @@
 
 .PHONY: all clean run
 
-build/djm-fix: DJMFix.cpp DJMFix.h AlsaBridge.cpp AlsaBridge.h djm-fix.cpp
+build/djm-fix: DJMFix.cpp DJMFix.h AlsaBridge.cpp AlsaBridge.h Logger.cpp Logger.h djm-fix.cpp
 	mkdir -p build
-	g++ -o $@ DJMFix.cpp AlsaBridge.cpp djm-fix.cpp $(CXXFLAGS)
+	g++ -o $@ DJMFix.cpp AlsaBridge.cpp Logger.cpp djm-fix.cpp $(CXXFLAGS)
diff -r 5b351628a377 -r 15d87fdd6e6c djm-fix.cpp
--- a/djm-fix.cpp	Mon Jan 04 13:38:08 2021 +0100
+++ b/djm-fix.cpp	Mon Jan 04 15:45:12 2021 +0100
@@ -24,12 +24,12 @@
 
 #include "DJMFix.h"
 #include "AlsaBridge.h"
+#include "Logger.h"
 
 static std::atomic<bool> run{true};
 
 void interrupt(int signal) {
 	run = false;
-	std::cerr << "interrupt()" << std::endl; // TODO: do not mess STDIO
 }
 
 /**
@@ -80,19 +80,26 @@
  */
 
 int main(int argc, char**argv) {
+	using L = djmfix::logging::Level;
+	std::unique_ptr<djmfix::logging::Logger> logger(djmfix::logging::create(std::cerr, L::INFO));
 	try {
+		logger->log(L::INFO, "djm-fix started");
 		std::string cardNamePattern = argc == 2 ? argv[1] : "Pioneer DJ.*";
 
 		signal(SIGINT, interrupt);
-		std::unique_ptr<djmfix::DJMFix> djmFix(djmfix::create());
-		std::unique_ptr<djmfix::alsa::AlsaBridge> alsaBridge(djmfix::alsa::create(djmFix.get(), cardNamePattern));
+		std::unique_ptr<djmfix::DJMFix> djmFix(djmfix::create(logger.get()));
+		std::unique_ptr<djmfix::alsa::AlsaBridge> alsaBridge(djmfix::alsa::create(djmFix.get(), cardNamePattern, logger.get()));
 
 		alsaBridge->start();
 		while (run) std::this_thread::sleep_for(std::chrono::milliseconds(100));
+		
+		std::cerr << std::endl;
+		logger->log(L::INFO, "djm-fix stopping");
+		
 		alsaBridge->stop();
 
 		return 0;
 	} catch (const std::exception& e) {
-		std::cerr << "ERROR: " << e.what() << std::endl; // TODO: do not mess STDIO
+		logger->log(L::SEVERE, e.what());
 	}
 }