/* This file is part of Machina.
 * Copyright 2007-2011 David Robillard <http://drobilla.net>
 *
 * Machina 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, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Machina 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 Machina.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <iostream>
#include <iomanip>

#include "machina/Context.hpp"
#include "machina/URIs.hpp"
#include "machina/Updates.hpp"
#include "machina_config.h"

#include "JackDriver.hpp"
#include "LearnRequest.hpp"
#include "MidiAction.hpp"
#include "jack_compat.h"

using namespace Machina;
using namespace std;

namespace Machina {

JackDriver::JackDriver(Raul::Forge& forge, SharedPtr<Machine> machine)
	: Driver(forge, machine)
	, _client(NULL)
	, _machine_changed(0)
	, _input_port(NULL)
	, _output_port(NULL)
	, _context(forge, 48000, MACHINA_PPQN, 120.0)
	, _frames_unit(TimeUnit::FRAMES, 48000)
	, _beats_unit(TimeUnit::BEATS, 19200)
	, _bpm(120.0)
	, _quantization(0.0f)
	, _stop(0)
	, _stop_flag(false)
	, _record_dur(_frames_unit) // = 0
	, _recording(false)
	, _is_activated(false)
{
}

JackDriver::~JackDriver()
{
	detach();
}

void
JackDriver::attach(const std::string& client_name)
{
	// Already connected
	if (_client)
		return;

	jack_set_error_function(jack_error_cb);

	_client = jack_client_open(client_name.c_str(), JackNullOption, NULL, NULL);

	if (_client == NULL) {
		_is_activated = false;
	} else {
		jack_set_error_function(jack_error_cb);
		jack_on_shutdown(_client, jack_shutdown_cb, this);
		jack_set_process_callback(_client, jack_process_cb, this);
	}

	if (jack_client()) {

		_context.time().set_tick_rate(sample_rate());

		_input_port = jack_port_register(jack_client(),
		                                 "in",
		                                 JACK_DEFAULT_MIDI_TYPE, JackPortIsInput,
		                                 0);

		if (!_input_port)
			std:: cerr << "WARNING: Failed to create MIDI input port." << std::endl;

		_output_port = jack_port_register(jack_client(),
		                                  "out",
		                                  JACK_DEFAULT_MIDI_TYPE, JackPortIsOutput,
		                                  0);

		if (!_output_port)
			std::cerr << "WARNING: Failed to create MIDI output port." << std::endl;

		if (!_machine)
			_machine = SharedPtr<Machine>(
				new Machine(TimeUnit::frames(jack_get_sample_rate(jack_client()))));

		_machine->activate();
	}
}

void
JackDriver::detach()
{
	_machine->deactivate();

	if (_input_port) {
		jack_port_unregister(jack_client(), _input_port);
		_input_port = NULL;
	}

	if (_output_port) {
		jack_port_unregister(jack_client(), _output_port);
		_output_port = NULL;
	}

	if (_client) {
		deactivate();
		jack_client_close(_client);
		_client = NULL;
		_is_activated = false;
	}
}

void
JackDriver::activate()
{
	if (!jack_activate(_client)) {
		_is_activated = true;
	} else {
		_is_activated = false;
	}
}

void
JackDriver::deactivate()
{
	if (_client)
		jack_deactivate(_client);

	_is_activated = false;
}

void
JackDriver::set_machine(SharedPtr<Machine> machine)
{
	if (machine == _machine)
		return;

	SharedPtr<Machine> last_machine = _last_machine; // Keep a reference
	_machine_changed.reset(0);
	assert(!last_machine.unique());
	_machine = machine;
	if (is_activated())
		_machine_changed.wait();
	assert(_machine == machine);
	last_machine.reset();
}

void
JackDriver::process_input(SharedPtr<Machine> machine, const Raul::TimeSlice& time)
{
	// We only actually read Jack input at the beginning of a cycle
	//assert(time.offset_ticks().is_zero());
	assert(_input_port);

	if (_recording) {

		const jack_nframes_t nframes     = time.length_ticks().ticks();
		void*                jack_buffer = jack_port_get_buffer(_input_port, nframes);
		const jack_nframes_t event_count = jack_midi_get_event_count(jack_buffer);

		for (jack_nframes_t i=0; i < event_count; ++i) {
			jack_midi_event_t ev;
			jack_midi_event_get(&ev, jack_buffer, i);

			const TimeStamp rel_time_frames = TimeStamp(_frames_unit, ev.time);
			const TimeStamp time_frames     = _record_dur + rel_time_frames;
			_recorder->write(time.ticks_to_beats(time_frames), ev.size, ev.buffer);
		}

		if (event_count > 0)
			_recorder->whip();

		_record_dur += time.length_ticks();

	} else {

		const jack_nframes_t nframes     = time.length_ticks().ticks();
		void*                jack_buffer = jack_port_get_buffer(_input_port, nframes);
		const jack_nframes_t event_count = jack_midi_get_event_count(jack_buffer);

		for (jack_nframes_t i=0; i < event_count; ++i) {
			jack_midi_event_t ev;
			jack_midi_event_get(&ev, jack_buffer, i);

			if (ev.buffer[0] == 0x90) {

				const SharedPtr<LearnRequest> learn = machine->pending_learn();
				if (learn) {
					learn->enter_action()->set_event(ev.size, ev.buffer);
					learn->start(_quantization.get(),
					             TimeStamp(TimeUnit::frames(sample_rate()),
					                       jack_last_frame_time(_client) + ev.time, 0));
				}

			} else if (ev.buffer[0] == 0x80) {

				const SharedPtr<LearnRequest> learn = machine->pending_learn();

				if (learn) {
					if (learn->started()) {
						learn->exit_action()->set_event(ev.size, ev.buffer);
						learn->finish(
							TimeStamp(TimeUnit::frames(sample_rate()),
							          jack_last_frame_time(_client) + ev.time, 0));

						const uint64_t id = Stateful::next_id();
						write_set(_updates, id,
						          URIs::instance().rdf_type,
						          _forge.make_urid(URIs::instance().machina_MidiAction));
						write_set(_updates, learn->node()->id(),
						          URIs::instance().machina_enter_action,
						          _forge.make((int32_t)id));
						write_set(_updates, id,
						          URIs::instance().machina_note_number,
						          _forge.make((int32_t)ev.buffer[1]));

						machine->clear_pending_learn();
					}
				}
			}
		}

	}
}

void
JackDriver::write_event(Raul::TimeStamp time,
                        size_t          size,
                        const byte*     event)
{
	if (!_output_port)
		return;

	const Raul::TimeSlice& slice = _context.time();

	if (slice.beats_to_ticks(time) + slice.offset_ticks() < slice.start_ticks()) {
		std::cerr << "ERROR: Missed event by "
		          << slice.start_ticks()
			- (slice.beats_to_ticks(time) + slice.offset_ticks())
		          << " ticks"
		          << "\n\tbpm: " << slice.bpm()
		          << "\n\tev time: " << slice.beats_to_ticks(time)
		          << "\n\tcycle_start: " << slice.start_ticks()
		          << "\n\tcycle_end: " << slice.start_ticks() + slice.length_ticks()
		          << "\n\tcycle_length: " << slice.length_ticks() << std::endl << std::endl;
		return;
	}

	const TimeDuration nframes = slice.length_ticks();
	const TimeStamp    offset  = slice.beats_to_ticks(time)
		+ slice.offset_ticks() - slice.start_ticks();

	if ( ! (offset < slice.offset_ticks() + nframes)) {
		std::cerr << "ERROR: Event offset " << offset << " outside cycle "
		          << "\n\tbpm: " << slice.bpm()
		          << "\n\tev time: " << slice.beats_to_ticks(time)
		          << "\n\tcycle_start: " << slice.start_ticks()
		          << "\n\tcycle_end: " << slice.start_ticks() + slice.length_ticks()
		          << "\n\tcycle_length: " << slice.length_ticks() << std::endl;
	} else {
#ifdef JACK_MIDI_NEEDS_NFRAMES
		jack_midi_event_write(
			jack_port_get_buffer(_output_port, nframes), offset,
			event, size, nframes);
#else
		jack_midi_event_write(
			jack_port_get_buffer(_output_port, nframes.ticks()), offset.ticks(),
			event, size);
#endif
	}
}

void
JackDriver::on_process(jack_nframes_t nframes)
{
	_context.time().set_bpm(_bpm.get());

	assert(_output_port);
#ifdef JACK_MIDI_NEEDS_NFRAMES
	jack_midi_clear_buffer(jack_port_get_buffer(_output_port, nframes), nframes);
#else
	jack_midi_clear_buffer(jack_port_get_buffer(_output_port, nframes));
#endif

	TimeStamp length_ticks(TimeStamp(_context.time().ticks_unit(), nframes));
	TimeStamp length_beats(_context.time().ticks_to_beats(length_ticks));

	_context.time().set_length(length_ticks);
	_context.time().set_offset(TimeStamp(_context.time().ticks_unit(), 0, 0));

	/* Take a reference to machine here and use only it during the process
	 * cycle so _machine can be switched with set_machine during a cycle. */
	SharedPtr<Machine> machine = _machine;

	// Machine was switched since last cycle, finalize old machine.
	if (machine != _last_machine) {
		if (_last_machine) {
			assert(!_last_machine.unique()); // Realtime, can't delete
			_last_machine->set_sink(shared_from_this());
			_last_machine->reset(_last_machine->time()); // Exit all active states
			_last_machine.reset(); // Cut our reference
		}
		_machine_changed.post(); // Signal we're done with it
	}

	if (!machine) {
		_last_machine = machine;
		return;
	}

	machine->set_sink(shared_from_this());

	if (_stop_flag)
		machine->reset(_context.time().start_beats());

	process_input(machine, _context.time());

	if (machine->is_empty() || !machine->is_activated())
		goto end;

	while (true) {
		const uint32_t run_dur_frames = machine->run(_context, _updates);

		if (run_dur_frames == 0) {
			// Machine didn't run at all (machine has no initial states)
			machine->reset(machine->time()); // Try again next cycle
			_context.time().set_slice(TimeStamp(_frames_unit, 0, 0),
			                          TimeStamp(_frames_unit, 0, 0));
			break;

		} else if (machine->is_finished()) {
			// Machine ran for portion of cycle and is finished
			machine->reset(machine->time());

			_context.time().set_slice(TimeStamp(_frames_unit, 0, 0),
			                          TimeStamp(_frames_unit, nframes - run_dur_frames, 0));
			_context.time().set_offset(TimeStamp(_frames_unit, run_dur_frames, 0));

		} else {
			// Machine ran for entire cycle
			_context.time().set_slice(
				_context.time().start_ticks() + _context.time().length_ticks(),
				TimeStamp(_frames_unit, 0, 0));
			break;
		}
	}

end:
	/* Remember the last machine run, in case a switch happens and
	 * we need to finalize it next cycle. */
	_last_machine = machine;

	if (_stop_flag) {
		_context.time().set_slice(TimeStamp(_frames_unit, 0, 0),
		                          TimeStamp(_frames_unit, 0, 0));
		_stop_flag = false;
	}
}

void
JackDriver::stop()
{
	if (recording())
		finish_record();

	_stop_flag= true;
	_stop.wait();
	_machine->deactivate();
}

void
JackDriver::start_record(bool step)
{
	// FIXME: Choose an appropriate maximum ringbuffer size
	_recorder = SharedPtr<Recorder>(new Recorder(_forge, 1024, _beats_unit, _quantization.get(), step));
	_recorder->start();
	_record_dur = 0;
	_recording = true;
}

void
JackDriver::finish_record()
{
	_recording = false;
	SharedPtr<Machine> machine = _recorder->finish();
	_recorder.reset();
	machine->activate();
	_machine->nodes().insert(_machine->nodes().end(),
	                         machine->nodes().begin(),
	                         machine->nodes().end());
}

int
JackDriver::jack_process_cb(jack_nframes_t nframes, void* jack_driver)
{
	JackDriver* me = reinterpret_cast<JackDriver*>(jack_driver);

	assert(me);

	me->on_process(nframes);

	return 0;
}

void
JackDriver::jack_shutdown_cb(void* jack_driver)
{
	JackDriver* me = reinterpret_cast<JackDriver*>(jack_driver);
	assert(me);

	me->_client = NULL;
}

void
JackDriver::jack_error_cb(const char* msg)
{
	cerr << "[JACK] Error: " << msg << endl;
}

} // namespace Machina