/**

 * Relational pipes

 * 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 <cstdlib>

#include <cstring>

#include <memory>

#include <unistd.h>

#include <pthread.h>

#include <sys/mman.h>

#include <atomic>

#include <functional>

#include <jack/jack.h>

#include <jack/midiport.h>

#include <jack/ringbuffer.h>

#include <relpipe/writer/RelationalWriter.h>

#include <relpipe/writer/RelpipeWriterException.h>

#include <relpipe/writer/AttributeMetadata.h>

#include <relpipe/writer/Factory.h>

#include <relpipe/writer/TypeId.h>

#include <relpipe/cli/CLI.h>

#include "JackException.h"

using namespace relpipe::writer;

namespace relpipe {

namespace in {

namespace jack {

int enqueueMessage(jack_nframes_t frames, void* arg);

class JackCommand {

private:

	jack_port_t* jackPort = nullptr;

	jack_ringbuffer_t* ringBuffer = nullptr;

	pthread_mutex_t messageThreadLock = PTHREAD_MUTEX_INITIALIZER;

	pthread_cond_t dataReady = PTHREAD_COND_INITIALIZER;

	std::atomic<bool> continueProcessing{true};

	const int RING_BUFFER_SIZE = 100;

	struct MidiMessage {

		uint8_t buffer[4096];

		uint32_t size;

		uint32_t time;

	};

public:

	int enqueueMessage(jack_nframes_t frames) {

		void* buffer = jack_port_get_buffer(jackPort, frames);

		if (buffer == nullptr) throw JackException(L"Unable to get port buffer."); // TODO: exception in RT callback?

		for (jack_nframes_t i = 0, eventCount = jack_midi_get_event_count(buffer); i < eventCount; i++) {

			jack_midi_event_t event;

			int noData = jack_midi_event_get(&event, buffer, i);

			if (noData) continue;

			if (event.size > sizeof (MidiMessage::buffer)) {

				// TODO: should not printf in RT callback:

				fwprintf(stderr, L"Error: MIDI message was too large → skipping event. Maximum allowed size: %lu bytes.\n", sizeof (MidiMessage::buffer));

			} else if (jack_ringbuffer_write_space(ringBuffer) >= sizeof (MidiMessage)) {

				MidiMessage m;

				m.time = event.time;

				m.size = event.size;

				memcpy(m.buffer, event.buffer, event.size);

				jack_ringbuffer_write(ringBuffer, (const char *) &m, sizeof (MidiMessage));

			} else {

				// TODO: should not printf in RT callback:

				fwprintf(stderr, L"Error: ring buffer is full → skipping event.\n");

			}

		}

		// TODO: just count skipped events and bytes and report them in next successful message instead of printing to STDERR

		if (pthread_mutex_trylock(&messageThreadLock) == 0) {

			pthread_cond_signal(&dataReady);

			pthread_mutex_unlock(&messageThreadLock);

		}

		return 0;

	}

private:

	static void writeRecord(std::shared_ptr<RelationalWriter> writer,

			string_t eventType, integer_t channel,

			boolean_t noteOn, integer_t pitch, integer_t velocity,

		writer->writeAttribute(eventType);

		writer->writeAttribute(&channel, typeid (channel));

		writer->writeAttribute(&noteOn, typeid (noteOn));

		writer->writeAttribute(&pitch, typeid (pitch));

		writer->writeAttribute(&velocity, typeid (velocity));

		writer->writeAttribute(&controllerId, typeid (controllerId));

		writer->writeAttribute(&value, typeid (value));

	}

	void processMessage(std::shared_ptr<RelationalWriter> writer, MidiMessage* event) {

		if (event->size == 0) {

			return;

		} else {

			uint8_t type = event->buffer[0] & 0xF0;

			uint8_t channel = event->buffer[0] & 0x0F;

			// TODO: write timestamp, message number

			if ((type == 0x90 || type == 0x80) && event->size == 3) {

			} else if (type == 0xB0 && event->size == 3) {

			} else {

			}

		}

	}

public:

	void finish(int sig) {

		continueProcessing = false;

	}

	void processJackStream(std::shared_ptr<writer::RelationalWriter> writer, std::function<void() > relationalWriterFlush) {

		// Relation headers:

		vector<AttributeMetadata> metadata;

		metadata.push_back({L"event", TypeId::STRING});

		metadata.push_back({L"channel", TypeId::INTEGER});

		metadata.push_back({L"note_on", TypeId::BOOLEAN});

		metadata.push_back({L"note_pitch", TypeId::INTEGER});

		metadata.push_back({L"note_velocity", TypeId::INTEGER});

		metadata.push_back({L"controller_id", TypeId::INTEGER});

		metadata.push_back({L"controller_value", TypeId::INTEGER});

		writer->startRelation(L"midi", metadata, true);

		relationalWriterFlush();

		// Initialize JACK connection:

		std::string clientName = "relpipe-in-jack";

		jack_client_t* client = jack_client_open(clientName.c_str(), JackNullOption, nullptr);

		if (client == nullptr) throw JackException(L"Could not create JACK client.");

		ringBuffer = jack_ringbuffer_create(RING_BUFFER_SIZE * sizeof (MidiMessage));

		jack_set_process_callback(client, relpipe::in::jack::enqueueMessage, this);

		// TODO: report also other events (connections etc.)

		jackPort = jack_port_register(client, "input", JACK_DEFAULT_MIDI_TYPE, JackPortIsInput, 0);

		if (jackPort == nullptr) throw JackException(L"Could not register port.");

		if (mlockall(MCL_CURRENT | MCL_FUTURE)) fwprintf(stderr, L"Warning: Can not lock memory.\n");

		int jackError = jack_activate(client);

		if (jackError) throw JackException(L"Could not activate client.");

		// Process messages from the ring buffer queue:

		pthread_mutex_lock(&messageThreadLock);

		while (continueProcessing) {

			const size_t queuedMessages = jack_ringbuffer_read_space(ringBuffer) / sizeof (MidiMessage);

			for (size_t i = 0; i < queuedMessages; ++i) {

				MidiMessage m;

				jack_ringbuffer_read(ringBuffer, (char*) &m, sizeof (MidiMessage));

				processMessage(writer, &m);

				relationalWriterFlush();

			}

			pthread_cond_wait(&dataReady, &messageThreadLock);

		}

		pthread_mutex_unlock(&messageThreadLock);

		// Close JACK connection:

		jack_deactivate(client);

		jack_client_close(client);

		jack_ringbuffer_free(ringBuffer);

	}

};

int enqueueMessage(jack_nframes_t frames, void* arg) {

	JackCommand* instance = (JackCommand*) arg;

	return instance->enqueueMessage(frames);

}

}

}

}