/*
 * Copyright (C) 2006-2016 David Robillard <d@drobilla.net>
 * Copyright (C) 2007-2012 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2007-2018 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2008 Hans Baier <hansfbaier@googlemail.com>
 * Copyright (C) 2013-2019 Robin Gareus <robin@gareus.org>
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <cassert>
#include <iostream>

#include "pbd/compose.h"
#include "pbd/debug.h"

#include "ardour/audioengine.h"
#include "ardour/data_type.h"
#include "ardour/debug.h"
#include "ardour/midi_buffer.h"
#include "ardour/midi_port.h"
#include "ardour/session.h"

using namespace std;
using namespace ARDOUR;
using namespace PBD;

#define port_engine AudioEngine::instance()->port_engine()

MidiPort::MidiPort (const std::string& name, PortFlags flags)
	: Port (name, DataType::MIDI, flags)
	, _resolve_required (false)
	, _input_active (true)
	, _trace_parser (0)
	, _data_fetched_for_cycle (false)
{
	_buffer = new MidiBuffer (AudioEngine::instance()->raw_buffer_size (DataType::MIDI));
}

MidiPort::~MidiPort()
{
	if (_shadow_port) {
		AudioEngine::instance()->unregister_port (_shadow_port);
		_shadow_port.reset ();
	}

	delete _buffer;
}

void
MidiPort::parse_input (pframes_t nframes, MIDI::Parser& parser)
{
}

void
MidiPort::cycle_start (pframes_t nframes)
{
	Port::cycle_start (nframes);

	_buffer->clear ();

	if (sends_output () && _port_handle) {
		port_engine.midi_clear (port_engine.get_buffer (_port_handle, nframes));
	}

	if (receives_input() && _trace_parser) {
		read_and_parse_entire_midi_buffer_with_no_speed_adjustment (nframes, *_trace_parser, AudioEngine::instance()->sample_time_at_cycle_start());
	}

	if (_inbound_midi_filter) {
		MidiBuffer& mb (get_midi_buffer (nframes));
		_inbound_midi_filter (mb, mb);
	}

	if (_shadow_port) {
		MidiBuffer& mb (get_midi_buffer (nframes));
		if (_shadow_midi_filter (mb, _shadow_port->get_midi_buffer (nframes))) {
			_shadow_port->flush_buffers (nframes);
		}
	}

}

MidiBuffer &
MidiPort::get_midi_buffer (pframes_t nframes)
{
	if (_data_fetched_for_cycle) {
		return *_buffer;
	}

	if (receives_input () && _input_active) {
		_buffer->clear ();

		void* buffer = port_engine.get_buffer (_port_handle, nframes);
		const pframes_t event_count = port_engine.get_midi_event_count (buffer);

		/* suck all MIDI events for this cycle of nframes from
		   the MIDI port buffer into our MidiBuffer.
		*/

		for (pframes_t i = 0; i < event_count; ++i) {

			pframes_t timestamp;
			size_t size;
			uint8_t const* buf;

			port_engine.midi_event_get (timestamp, size, &buf, buffer, i);

			if (buf[0] == 0xfe) {
				/* throw away active sensing */
				continue;
			}

			timestamp = floor (timestamp * _speed_ratio);

			/* check that the event is in the acceptable time range */
			if ((timestamp <  (_global_port_buffer_offset)) ||
			    (timestamp >= (_global_port_buffer_offset + nframes))) {
				/* This is normal after a split cycles.
				 *
				 * The engine buffer contains the data for the
				 * complete cycle, but only the part after
				 * _global_port_buffer_offset is needed.
				 *
				 * But of course ... if
				 * _global_port_buffer_offset is zero,
				 * something wierd is happening.
				 */
#ifndef NDEBUG
				if (_global_port_buffer_offset == 0) {
					cerr << "Ignored incoming MIDI at time " << timestamp << "; offset="
					     << _global_port_buffer_offset << " limit="
					     << (_global_port_buffer_offset + nframes)
					     << " = (" << _global_port_buffer_offset
					     << " + " << nframes
					     << ")";
					for (size_t xx = 0; xx < size; ++xx) {
						cerr << ' ' << hex << (int) buf[xx];
					}
					cerr << dec << endl;
				}
#endif
				continue;
			}

			timestamp -= _global_port_buffer_offset;

			if ((buf[0] & 0xF0) == 0x90 && buf[2] == 0) {
				/* normalize note on with velocity 0 to proper note off */
				uint8_t ev[3];
				ev[0] = 0x80 | (buf[0] & 0x0F);  /* note off */
				ev[1] = buf[1];
				ev[2] = 0x40;  /* default velocity */
				_buffer->push_back (timestamp, size, ev);
			} else {
				_buffer->push_back (timestamp, size, buf);
			}
		}

	} else {
		_buffer->silence (nframes);
	}

	if (nframes) {
		_data_fetched_for_cycle = true;
	}

	return *_buffer;
}

void
MidiPort::read_and_parse_entire_midi_buffer_with_no_speed_adjustment (pframes_t nframes, MIDI::Parser& parser, samplepos_t now)
{
	void* buffer = port_engine.get_buffer (_port_handle, nframes);
	const pframes_t event_count = port_engine.get_midi_event_count (buffer);

	for (pframes_t i = 0; i < event_count; ++i) {

		pframes_t timestamp;
		size_t size;
		uint8_t const* buf;

		port_engine.midi_event_get (timestamp, size, &buf, buffer, i);

		if (buf[0] == 0xfe) {
			/* throw away active sensing */
			continue;
		}

		parser.set_timestamp (now + timestamp);

		/* During this parsing stage, signals will be emitted from the
		 * Parser, which will update anything connected to it.
		 *
		 * As of July 2018, this is only used by TransportMasters which
		 * read MIDI before the process() cycle really gets started.
		 */

		if ((buf[0] & 0xF0) == 0x90 && buf[2] == 0) {
			/* normalize note on with velocity 0 to proper note off */
			parser.scanner (0x80 | (buf[0] & 0x0F));  /* note off */
			parser.scanner (buf[1]);
			parser.scanner (0x40);  /* default (off) velocity */

			if (_trace_parser) {
				_trace_parser->scanner (0x80 | (buf[0] & 0x0F));
				_trace_parser->scanner (buf[1]);
				_trace_parser->scanner (0x40);
			}
		} else {
			for (size_t n = 0; n < size; ++n) {
				parser.scanner (buf[n]);
			}
			if (_trace_parser) {
				for (size_t n = 0; n < size; ++n) {
					_trace_parser->scanner (buf[n]);
				}
			}
		}
	}
}

void
MidiPort::cycle_end (pframes_t /*nframes*/)
{
	_data_fetched_for_cycle = false;
}

void
MidiPort::cycle_split ()
{
	_data_fetched_for_cycle = false;
}

void
MidiPort::resolve_notes (void* port_buffer, MidiBuffer::TimeType when)
{
	for (uint8_t channel = 0; channel <= 0xF; channel++) {

		uint8_t ev[3] = { ((uint8_t) (MIDI_CMD_CONTROL | channel)), MIDI_CTL_SUSTAIN, 0 };
		pframes_t tme = floor (when / _speed_ratio);

		/* we need to send all notes off AND turn the
		 * sustain/damper pedal off to handle synths
		 * that prioritize sustain over AllNotesOff
		 */

		if (port_engine.midi_event_put (port_buffer, tme, ev, 3) != 0) {
			cerr << "failed to deliver sustain-zero on channel " << (int)channel << " on port " << name() << endl;
		}

		ev[1] = MIDI_CTL_ALL_NOTES_OFF;

		if (port_engine.midi_event_put (port_buffer, tme, ev, 3) != 0) {
			cerr << "failed to deliver ALL NOTES OFF on channel " << (int)channel << " on port " << name() << endl;
		}
	}
}

void
MidiPort::flush_buffers (pframes_t nframes)
{
	if (sends_output ()) {

		void* port_buffer = 0;

		if (_resolve_required) {
			port_buffer = port_engine.get_buffer (_port_handle, nframes);
			/* resolve all notes at the start of the buffer */
			resolve_notes (port_buffer, _global_port_buffer_offset);
			_resolve_required = false;
		}

		if (_buffer->empty()) {
			return;
		}

		if (!port_buffer) {
			port_buffer = port_engine.get_buffer (_port_handle, nframes);
		}


		for (MidiBuffer::iterator i = _buffer->begin(); i != _buffer->end(); ++i) {

			const Evoral::Event<MidiBuffer::TimeType> ev (*i, false);

			const samplepos_t adjusted_time = ev.time() + _global_port_buffer_offset;

			if (sends_output() && _trace_parser) {
				uint8_t const * const buf = ev.buffer();
				const samplepos_t now = AudioEngine::instance()->sample_time_at_cycle_start();

				_trace_parser->set_timestamp (now + adjusted_time / _speed_ratio);

				uint32_t limit = ev.size();

				for (size_t n = 0; n < limit; ++n) {
					_trace_parser->scanner (buf[n]);
				}
			}


			// event times are in samples, relative to cycle start

#ifndef NDEBUG
			if (DEBUG_ENABLED (DEBUG::MidiIO)) {
				const Session* s = AudioEngine::instance()->session();
				const samplepos_t now = (s ? s->transport_sample() : 0);
				DEBUG_STR_DECL(a);
				DEBUG_STR_APPEND(a, string_compose ("MidiPort %7 %1 pop event    @ %2[%7] (global %4, within %5 gpbo %6 sz %3 ", _buffer, adjusted_time, ev.size(),
				                                    now + adjusted_time, nframes, _global_port_buffer_offset, name(), ev.time()));
				for (size_t i=0; i < ev.size(); ++i) {
					DEBUG_STR_APPEND(a,hex);
					DEBUG_STR_APPEND(a,"0x");
					DEBUG_STR_APPEND(a,(int)(ev.buffer()[i]));
					DEBUG_STR_APPEND(a,' ');
				}
				DEBUG_STR_APPEND(a,'\n');
				DEBUG_TRACE (DEBUG::MidiIO, DEBUG_STR(a).str());
			}
#endif

			// XXX consider removing this check for optimized builds
			// and just send 'em all, at cycle_end
			// see AudioEngine::split_cycle (), PortManager::cycle_end()
			if ((adjusted_time >= _global_port_buffer_offset) && (adjusted_time < _global_port_buffer_offset + nframes)) {
				pframes_t tme = floor (adjusted_time / _speed_ratio);
				if (port_engine.midi_event_put (port_buffer, tme, ev.buffer(), ev.size()) != 0) {
					cerr << "write failed, dropped event, time " << adjusted_time << '/' << ev.time() << endl;
				}
			} else {
				pframes_t tme = floor (adjusted_time / _speed_ratio);
				cerr << "Dropped outgoing MIDI event. time " << adjusted_time
				     << " (" << ev.time() << ") @" << _speed_ratio << " = " << tme
				     << " out of range [" << _global_port_buffer_offset
				     << " .. " << _global_port_buffer_offset + nframes
				     << "]";
				for (size_t xx = 0; xx < ev.size(); ++xx) {
					cerr << ' ' << hex << (int) ev.buffer()[xx];
				}
				cerr << dec << endl;
			}
		}

		/* done.. the data has moved to the port buffer, mark it so */

		_buffer->clear ();
	}
}

void
MidiPort::require_resolve ()
{
	_resolve_required = true;
}

void
MidiPort::transport_stopped ()
{
	_resolve_required = true;
}

void
MidiPort::realtime_locate (bool)
{
	_resolve_required = true;
}

void
MidiPort::reset ()
{
	Port::reset ();
	delete _buffer;
	cerr << name() << " new MIDI buffer of size " << AudioEngine::instance()->raw_buffer_size (DataType::MIDI) << endl;
	_buffer = new MidiBuffer (AudioEngine::instance()->raw_buffer_size (DataType::MIDI));
}

void
MidiPort::set_input_active (bool yn)
{
	_input_active = yn;
}

void
MidiPort::set_trace (MIDI::Parser * p)
{
	_trace_parser = p;
}

int
MidiPort::add_shadow_port (string const & name, MidiFilter mf)
{
	if (!ARDOUR::Port::receives_input()) {
		return -1;
	}

	if (_shadow_port) {
		return -2;
	}

	_shadow_midi_filter = mf;

	if (!(_shadow_port = boost::dynamic_pointer_cast<MidiPort> (AudioEngine::instance()->register_output_port (DataType::MIDI, name, false, PortFlags (Shadow|IsTerminal))))) {
		return -3;
	}

	/* forward on our port latency to the shadow port.

	   XXX: need to capture latency changes and forward them too.
	*/

	LatencyRange latency = private_latency_range (false);
	_shadow_port->set_private_latency_range (latency, false);

	return 0;
}