franta-hg@2: /**
franta-hg@2:  * DJM-Fix
franta-hg@2:  * Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)
franta-hg@2:  *
franta-hg@2:  * This program is free software: you can redistribute it and/or modify
franta-hg@2:  * it under the terms of the GNU General Public License as published by
franta-hg@2:  * the Free Software Foundation, version 3 of the License.
franta-hg@2:  *
franta-hg@2:  * This program is distributed in the hope that it will be useful,
franta-hg@2:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
franta-hg@2:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
franta-hg@2:  * GNU General Public License for more details.
franta-hg@2:  *
franta-hg@2:  * You should have received a copy of the GNU General Public License
franta-hg@2:  * along with this program. If not, see <http://www.gnu.org/licenses/>.
franta-hg@2:  */
franta-hg@2: #include <iostream>
franta-hg@13: #include <iomanip>
franta-hg@12: #include <sstream>
franta-hg@5: #include <stdexcept>
franta-hg@5: #include <thread>
franta-hg@9: #include <mutex>
franta-hg@5: #include <atomic>
franta-hg@11: #include <regex>
franta-hg@2: 
franta-hg@3: #include <alsa/asoundlib.h>
franta-hg@3: 
franta-hg@2: #include "AlsaBridge.h"
franta-hg@12: #include "Logger.h"
franta-hg@2: 
franta-hg@2: namespace djmfix {
franta-hg@2: namespace alsa {
franta-hg@2: 
franta-hg@12: using L = djmfix::logging::Level;
franta-hg@12: 
franta-hg@2: class AlsaBridgeImpl : public AlsaBridge, private djmfix::MidiSender {
franta-hg@2: private:
franta-hg@2: 	djmfix::DJMFix* djmFix;
franta-hg@12: 	djmfix::logging::Logger* logger;
franta-hg@5: 	snd_rawmidi_t* input;
franta-hg@5: 	snd_rawmidi_t* output;
franta-hg@5: 	std::thread receivingThread;
franta-hg@9: 	std::recursive_mutex midiMutex;
franta-hg@5: 	std::atomic<bool> stopped{false};
franta-hg@5: 
franta-hg@11: 	std::string findDeviceName(std::regex cardNamePattern) {
franta-hg@11: 
franta-hg@11: 		std::vector<int> cardNumbers;
franta-hg@11: 
franta-hg@12: 		logger->log(L::INFO, "Looking for available cards:");
franta-hg@11: 
franta-hg@11: 		for (int card = -1; snd_card_next(&card) == 0 && card >= 0;) {
franta-hg@11: 			char* longName = nullptr;
franta-hg@11: 			snd_card_get_longname(card, &longName);
franta-hg@12: 
franta-hg@12: 			std::stringstream logMessage;
franta-hg@12: 			logMessage << " - card: #" << card << ": '" << longName << "'";
franta-hg@12: 
franta-hg@11: 			if (std::regex_match(longName, cardNamePattern)) {
franta-hg@11: 				cardNumbers.push_back(card);
franta-hg@12: 				logMessage << " [matches]";
franta-hg@11: 			}
franta-hg@12: 
franta-hg@12: 			logger->log(L::INFO, logMessage.str());
franta-hg@12: 
franta-hg@11: 			free(longName);
franta-hg@11: 		}
franta-hg@11: 
franta-hg@11: 		if (cardNumbers.size() == 1) {
franta-hg@12: 			logger->log(L::INFO, "Going to fix card #" + std::to_string(cardNumbers[0]));
franta-hg@11: 			return "hw:" + std::to_string(cardNumbers[0]);
franta-hg@11: 		} else if (cardNumbers.empty()) {
franta-hg@11: 			throw std::invalid_argument("No card with matching name found. Is the card connected? Maybe try to provide different name pattern.");
franta-hg@11: 		} else {
franta-hg@11: 			throw std::invalid_argument("Multiple cards with matching name found. Please provide a name pattern that matches only one card");
franta-hg@11: 		}
franta-hg@11: 	}
franta-hg@11: 
franta-hg@13: 	std::string toString(const MidiMessage& midiMessage) {
franta-hg@13: 		std::stringstream result;
franta-hg@13: 		for (uint8_t b : midiMessage) result << std::hex << std::setw(2) << std::setfill('0') << (int) b;
franta-hg@13: 		return result.str();
franta-hg@13: 	}
franta-hg@13: 
franta-hg@5: 	void run() {
franta-hg@5: 		while (!stopped) {
franta-hg@9: 			{
franta-hg@9: 				std::lock_guard<std::recursive_mutex> lock(midiMutex);
franta-hg@9: 				// TODO: poll
franta-hg@9: 				uint8_t buffer[256];
franta-hg@9: 				ssize_t length = snd_rawmidi_read(input, buffer, sizeof (buffer));
franta-hg@9: 				if (length > 0 && length <= sizeof (buffer)) {
franta-hg@9: 					// TODO: multiple messages combined together?
franta-hg@9: 					djmFix->receive(MidiMessage(buffer, buffer + length));
franta-hg@9: 				}
franta-hg@5: 			}
franta-hg@5: 			std::this_thread::sleep_for(std::chrono::milliseconds(100));
franta-hg@5: 		}
franta-hg@5: 	}
franta-hg@2: public:
franta-hg@2: 
franta-hg@12: 	AlsaBridgeImpl(djmfix::DJMFix* djmFix, const std::string& cardNamePattern, djmfix::logging::Logger* logger) : djmFix(djmFix), logger(logger ? logger : djmfix::logging::blackhole()) {
franta-hg@13: 		if (djmFix == nullptr) throw std::invalid_argument("Need a djmFix for AlsaBridge.");
franta-hg@5: 
franta-hg@11: 		std::string deviceName = findDeviceName(std::regex(cardNamePattern));
franta-hg@11: 
franta-hg@5: 		int error = snd_rawmidi_open(&input, &output, deviceName.c_str(), SND_RAWMIDI_NONBLOCK);
franta-hg@13: 		if (error) throw std::invalid_argument("Unable to open ALSA device.");
franta-hg@5: 
franta-hg@5: 
franta-hg@2: 		djmFix->setMidiSender(this);
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: 	virtual ~AlsaBridgeImpl() {
franta-hg@12: 		// TODO: do not use raw/exclusive access to the MIDI device
franta-hg@5: 		snd_rawmidi_close(input);
franta-hg@5: 		snd_rawmidi_close(output);
franta-hg@13: 		logger->log(L::FINER, "~AlsaBridgeImpl()");
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: 	virtual void start() override {
franta-hg@2: 		djmFix->start();
franta-hg@5: 		receivingThread = std::thread(&AlsaBridgeImpl::run, this);
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: 	virtual void stop() override {
franta-hg@5: 		stopped = true;
franta-hg@5: 		receivingThread.join();
franta-hg@2: 		djmFix->stop();
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: 	virtual void send(MidiMessage midiMessage) override {
franta-hg@9: 		std::lock_guard<std::recursive_mutex> lock(midiMutex);
franta-hg@5: 		ssize_t length = snd_rawmidi_write(output, midiMessage.data(), midiMessage.size());
franta-hg@13: 		logger->log(L::FINE, "Sent message: length = " + std::to_string(length) + " data = " + toString(midiMessage));
franta-hg@2: 	}
franta-hg@2: 
franta-hg@2: };
franta-hg@2: 
franta-hg@12: AlsaBridge* create(djmfix::DJMFix* djmFix, const std::string& deviceName, djmfix::logging::Logger* logger) {
franta-hg@12: 	return new AlsaBridgeImpl(djmFix, deviceName, logger);
franta-hg@2: }
franta-hg@2: 
franta-hg@2: }
franta-hg@2: }