/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 "kyra/sound/drivers/midi.h"

namespace Kyra {

MidiOutput::MidiOutput(OSystem *system, MidiDriver *output, bool isMT32, bool defaultMT32) : _system(system), _output(output) {
	_isMT32 = isMT32;
	_defaultMT32 = defaultMT32;

	int ret = _output->open();
	if (ret != MidiDriver::MERR_ALREADY_OPEN && ret != 0)
		error("Couldn't open midi driver");

	static const Controller defaultControllers[] = {
		{ 0x07, 0x7F }, { 0x01, 0x00 }, { 0x0A, 0x40 },
		{ 0x0B, 0x7F }, { 0x40, 0x00 }, { 0x72, 0x00 },
		{ 0x6E, 0x00 }, { 0x6F, 0x00 }, { 0x70, 0x00 }
	};

	static const byte defaultPrograms[] = {
		0x44, 0x30, 0x5F, 0x4E, 0x29, 0x03, 0x6E, 0x7A, 0xFF
	};

	static const byte sysEx1[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
	static const byte sysEx2[] = { 3, 4, 3, 4, 3, 4, 3, 4, 4 };
	static const byte sysEx3[] = { 0, 3, 2 };

	if (_isMT32) {
		sendSysEx(0x7F, 0x00, 0x00, sysEx1, 1);
		sendSysEx(0x10, 0x00, 0x0D, sysEx1, 9);
		sendSysEx(0x10, 0x00, 0x04, sysEx2, 9);
		sendSysEx(0x10, 0x00, 0x01, sysEx3, 3);
	} else {
		_output->sendGMReset();
	}

	memset(_channels, 0, sizeof(_channels));
	for (int i = 0; i < 16; ++i) {
		for (int j = 0; j < 9; ++j)
			_channels[i].controllers[j] = defaultControllers[j];
		_channels[i].pitchWheel = -1;
		_channels[i].program = 0xFF;
	}

	for (int i = 0; i < 9; ++i) {
		for (int j = 1; j <= 9; ++j)
			sendIntern(0xB0, j, defaultControllers[i].controller, defaultControllers[i].value);
	}

	for (int i = 1; i <= 9; ++i) {
		sendIntern(0xE0, i, 0x00, 0x40);
		if (defaultPrograms[i - 1] != 0xFF)
			sendIntern(0xC0, i, defaultPrograms[i - 1], 0x00);
	}

	for (int i = 0; i < 4; ++i) {
		_sources[i].volume = 256;
		initSource(i);
	}
}


MidiOutput::~MidiOutput() {
	_output->close();
	delete _output;
}

void MidiOutput::send(uint32 b) {
	const byte event = b & 0xF0;
	const byte channel = b & 0x0F;
	byte param1 = (b >>  8) & 0xFF;
	byte param2 = (b >> 16) & 0xFF;

	if (event == 0xE0) {							// Pitch-Wheel
		_channels[channel].pitchWheel =
		_sources[_curSource].channelPW[channel] = (param2 << 8) | param1;
	} else if (event == 0xC0) {						// Program change
		_channels[channel].program =
		_sources[_curSource].channelProgram[channel] = param1;
	} else if (event == 0xB0) {						// Controller change
		for (int i = 0; i < 9; ++i) {
			Controller &cont = _sources[_curSource].controllers[channel][i];
			if (cont.controller == param1) {
				cont.value = param2;
				break;
			}
		}

		if (param1 == 0x07) {
			param2 = (param2 * _sources[_curSource].volume) >> 8;
		} else if (param1 == 0x6E) {	// Lock Channel
			if (param2 >= 0x40) {	// Lock Channel
				int chan = lockChannel();
				if (chan < 0)
					chan = channel;
				_sources[_curSource].channelMap[channel] = chan;
			} else {				// Unlock Channel
				stopNotesOnChannel(channel);
				unlockChannel(_sources[_curSource].channelMap[channel]);
				_sources[_curSource].channelMap[channel] = channel;
			}
		} else if (param1 == 0x6F) {	// Protect Channel
			if (param2 >= 0x40) {	// Protect Channel
				_channels[channel].flags |= kChannelProtected;
			} else {				// Unprotect Channel
				_channels[channel].flags &= ~kChannelProtected;
			}
		} else if (param1 == 0x7B) {	// All notes off
			// FIXME: Since the XMIDI parsers sends this
			// on track change, we simply ignore it.
			return;
		}
	} else if (event == 0x90 || event == 0x80) {	// Note On/Off
		if (!(_channels[channel].flags & kChannelLocked)) {
			const bool remove = (event == 0x80) || (param2 == 0x00);
			int note = -1;

			for (int i = 0; i < 32; ++i) {
				if (remove) {
					if (_sources[_curSource].notes[i].channel == channel &&
						_sources[_curSource].notes[i].note == param1) {
						note = i;
						break;
					}
				} else {
					if (_sources[_curSource].notes[i].channel == 0xFF) {
						note = i;
						break;
					}
				}
			}

			if (note != -1) {
				if (remove) {
					_sources[_curSource].notes[note].channel = 0xFF;

					--_channels[_sources[_curSource].channelMap[channel]].noteCount;
				} else {
					_sources[_curSource].notes[note].channel = channel;
					_sources[_curSource].notes[note].note = param1;

					++_channels[_sources[_curSource].channelMap[channel]].noteCount;
				}

				sendIntern(event, _sources[_curSource].channelMap[channel], param1, param2);
			}
		}
		return;
	}

	if (!(_channels[channel].flags & kChannelLocked))
		sendIntern(event, _sources[_curSource].channelMap[channel], param1, param2);
}

void MidiOutput::sendIntern(const byte event, const byte channel, byte param1, const byte param2) {
	if (event == 0xC0) {
		// MT32 -> GM conversion
		if (!_isMT32 && _defaultMT32)
			param1 = MidiDriver::_mt32ToGm[param1];
	}

	_output->send(event | channel, param1, param2);
}

void MidiOutput::sysEx(const byte *msg, uint16 length) {
	// Wait the time it takes to send the SysEx data
	uint32 delay = (length + 2) * 1000 / 3125;

	// Plus an additional delay for the MT-32 rev00
	if (_isMT32)
		delay += 40;

	_output->sysEx(msg, length);
	_system->delayMillis(delay);
}

void MidiOutput::sendSysEx(const byte p1, const byte p2, const byte p3, const byte *buffer, const int size) {
	int bufferSize = 8 + size;
	byte *outBuffer = new byte[bufferSize];
	assert(outBuffer);

	outBuffer[0] = 0x41;
	outBuffer[1] = 0x10;
	outBuffer[2] = 0x16;
	outBuffer[3] = 0x12;

	outBuffer[4] = p1;
	outBuffer[5] = p2;
	outBuffer[6] = p3;

	memcpy(outBuffer + 7, buffer, size);

	uint16 checkSum = p1 + p2 + p3;
	for (int i = 0; i < size; ++i)
		checkSum += buffer[i];
	checkSum &= 0x7F;
	checkSum -= 0x80;
	checkSum = -checkSum;
	checkSum &= 0x7F;

	outBuffer[7+size] = checkSum;

	sysEx(outBuffer, bufferSize);

	delete[] outBuffer;
}

void MidiOutput::metaEvent(byte type, byte *data, uint16 length) {
	if (type == 0x2F) // End of Track
		deinitSource(_curSource);

	_output->metaEvent(type, data, length);
}

void MidiOutput::setSourceVolume(int source, int volume, bool apply) {
	_sources[source].volume = volume;

	if (apply) {
		for (int i = 0; i < 16; ++i) {
			// Controller 0 in the state table should always be '7' aka
			// volume control
			byte realVol = (_sources[source].controllers[i][0].value * volume) >> 8;
			sendIntern(0xB0, i, 0x07, realVol);
		}
	}
}

void MidiOutput::initSource(int source) {
	memset(_sources[source].notes, -1, sizeof(_sources[source].notes));

	for (int i = 0; i < 16; ++i) {
		_sources[source].channelMap[i] = i;
		_sources[source].channelProgram[i] = 0xFF;
		_sources[source].channelPW[i] = -1;

		for (int j = 0; j < 9; ++j)
			_sources[source].controllers[i][j] = _channels[i].controllers[j];
	}
}

void MidiOutput::deinitSource(int source) {
	for (int i = 0; i < 16; ++i) {
		for (int j = 0; j < 9; ++j) {
			const Controller &cont = _sources[source].controllers[i][j];

			if (cont.controller == 0x40) {
				if (cont.value >= 0x40)
					sendIntern(0xB0, i, 0x40, 0);
			} else if (cont.controller == 0x6E) {
				if (cont.value >= 0x40) {
					stopNotesOnChannel(i);
					unlockChannel(_sources[source].channelMap[i]);
					_sources[source].channelMap[i] = i;
				}
			} else if (cont.controller == 0x6F) {
				if (cont.value >= 0x40)
					_channels[i].flags &= ~kChannelProtected;
			} else if (cont.controller == 0x70) {
				if (cont.value >= 0x40)
					sendIntern(0xB0, i, 0x70, 0);
			}
		}
	}
}

int MidiOutput::lockChannel() {
	int channel = -1;
	int notes = 0xFF;
	byte flags = kChannelLocked | kChannelProtected;

	while (channel == -1) {
		for (int i = _isMT32 ? 8 : 15; i >= 1; --i) {
			if (_channels[i].flags & flags)
				continue;
			if (_channels[i].noteCount < notes) {
				channel = i;
				notes = _channels[i].noteCount;
			}
		}

		if (channel == -1) {
			if (flags & kChannelProtected)
				flags &= ~kChannelProtected;
			else
				break;
		}
	}

	if (channel == -1)
		return -1;

	sendIntern(0xB0, channel, 0x40, 0);
	stopNotesOnChannel(channel);
	_channels[channel].noteCount = 0;
	_channels[channel].flags |= kChannelLocked;

	return channel;
}

void MidiOutput::unlockChannel(int channel) {
	if (!(_channels[channel].flags & kChannelLocked))
		return;

	_channels[channel].flags &= ~kChannelLocked;
	_channels[channel].noteCount = 0;
	sendIntern(0xB0, channel, 0x40, 0);
	sendIntern(0xB0, channel, 0x7B, 0);

	for (int i = 0; i < 9; ++i) {
		if (_channels[channel].controllers[i].value != 0xFF)
			sendIntern(0xB0, channel, _channels[channel].controllers[i].controller, _channels[channel].controllers[i].value);
	}

	if (_channels[channel].program != 0xFF)
		sendIntern(0xC0, channel, _channels[channel].program, 0);

	if (_channels[channel].pitchWheel != -1)
		sendIntern(0xE0, channel, _channels[channel].pitchWheel & 0xFF, (_channels[channel].pitchWheel >> 8) & 0xFF);
}

void MidiOutput::stopNotesOnChannel(int channel) {
	for (int i = 0; i < 4; ++i) {
		SoundSource &sound = _sources[i];
		for (int j = 0; j < 32; ++j) {
			if (sound.notes[j].channel == channel) {
				sound.notes[j].channel = 0xFF;
				sendIntern(0x80, sound.channelMap[channel], sound.notes[j].note, 0);
				--_channels[sound.channelMap[channel]].noteCount;
			}
		}
	}
}

} // End of namespace Kyra