/* ScummVM - Scumm Interpreter
 * Copyright (C) 2002-2004 The ScummVM project
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 *
 */

#include "stdafx.h"

#include "scumm/smush/channel.h"
#include "scumm/smush/chunk.h"
#include "scumm/smush/chunk_type.h"

namespace Scumm {

void SaudChannel::handleStrk(Chunk &b) {
	int32 size = b.getSize();
	if (size != 14 && size != 10) {
		error("STRK has a invalid size : %d", size);
	}
}

void SaudChannel::handleSmrk(Chunk &b) {
	_markReached = true;
}

void SaudChannel::handleShdr(Chunk &b) {
	int32 size = b.getSize();
	if (size != 4)
		warning("SMRK has a invalid size : %d", size);
}

bool SaudChannel::handleSubTags(int32 &offset) {
	if (_tbufferSize - offset >= 8) {
		Chunk::type type = READ_BE_UINT32(_tbuffer + offset);
		uint32 size = READ_BE_UINT32(_tbuffer + offset + 4);
		uint32 available_size = _tbufferSize - offset;

		switch(type) {
		case TYPE_STRK:
			_inData = false;
			if (available_size >= (size + 8)) {
				MemoryChunk c((byte *)_tbuffer + offset);
				handleStrk(c);
			} else
				return false;
			break;
		case TYPE_SMRK:
			_inData = false;
			if (available_size >= (size + 8)) {
				MemoryChunk c((byte *)_tbuffer + offset);
				handleSmrk(c);
			} else
				return false;
			break;
		case TYPE_SHDR:
			_inData = false;
			if (available_size >= (size + 8)) {
				MemoryChunk c((byte *)_tbuffer + offset);
				handleShdr(c);
			} else
				return false;
			break;
		case TYPE_SDAT: 
			_inData = true;
			_dataSize = size;
			offset += 8;
			return false;
		default:
			error("unknown Chunk in SAUD track : %s ", Chunk::ChunkString(type));
		}
		offset += size + 8;
		return true;
	}
	return false;
}

bool SaudChannel::processBuffer() {
	assert(_tbuffer != 0);
	assert(_tbufferSize != 0);
	assert(_sbuffer == 0);
	assert(_sbufferSize == 0);
	
	if (_keepSize) {
		_sbufferSize = _tbufferSize;
		_sbuffer = _tbuffer;
		_tbufferSize = 0;
		_tbuffer = 0;
	} else if (_inData) {
		if (_dataSize < _tbufferSize) {
			int32 offset = _dataSize;
			while (handleSubTags(offset));
			_sbufferSize = _dataSize;
			_sbuffer = _tbuffer;
			if (offset < _tbufferSize) {
				int new_size = _tbufferSize - offset;
				_tbuffer = new byte[new_size];
				if (!_tbuffer)
					error("SaudChannel failed to allocate memory");
				memcpy(_tbuffer, _sbuffer + offset, new_size);
				_tbufferSize = new_size;
			} else {
				_tbuffer = 0;
				_tbufferSize = 0;
			}
			if (_sbufferSize == 0) {
				delete []_sbuffer; 
				_sbuffer = 0;
			}
		} else {
			_sbufferSize = _tbufferSize;
			_sbuffer = _tbuffer;
			_tbufferSize = 0;
			_tbuffer = 0;
		}
	} else {
		int32 offset = 0;
		while (handleSubTags(offset));
		if (_inData) {
			_sbufferSize = _tbufferSize - offset;
			assert(_sbufferSize);
			_sbuffer = new byte[_sbufferSize];
			if (!_sbuffer)
				error("saud_channel failed to allocate memory");
			memcpy(_sbuffer, _tbuffer + offset, _sbufferSize);
			delete []_tbuffer;
			_tbuffer = 0;
			_tbufferSize = 0;
		} else {
			if (offset) {
				byte *old = _tbuffer;
				int32 new_size = _tbufferSize - offset;
				_tbuffer = new byte[new_size];
				if (!_tbuffer)
					error("SaudChannel failed to allocate memory");
				memcpy(_tbuffer, old + offset, new_size);
				_tbufferSize = new_size;
				delete []old;
			}
		}
	}
	return true;
}

SaudChannel::SaudChannel(int32 track, int32 freq) : 
	_track(track), 
	_nbframes(0),
	_dataSize(-1),
	_frequency(freq),
	_inData(false),
	_markReached(false),
	_tbuffer(0),
	_tbufferSize(0),
	_sbuffer(0),
	_sbufferSize(0),
	_keepSize(false) {
}

SaudChannel::~SaudChannel() {
	if (_tbuffer)
		delete []_tbuffer;
	if (_sbuffer) {
		warning("this should never happen !!!! (_sbuffer not NULL here)");
		delete []_sbuffer;
	}
}

bool SaudChannel::isTerminated() const {
	return (_markReached && _dataSize == 0 && _sbuffer == 0);
}

bool SaudChannel::setParameters(int32 nb, int32 flags, int32 volume, int32 pan, int32 index) {
	_nbframes = nb;
	_flags = flags; // bit 7 == IS_VOICE, bit 6 == IS_BACKGROUND_MUSIC, other ??
	_volume = volume;
	_pan = pan;
	_index = index;
	if (index != 0) {
		_dataSize = -2;
		_keepSize = true;
		_inData = true;
	}
	return true;
}

bool SaudChannel::checkParameters(int32 index, int32 nb, int32 flags, int32 volume, int32 pan) {
	if (++_index != index)
		error("invalid index in SaudChannel::checkParameters()");
	if (_nbframes != nb)
		error("invalid duration in SaudChannel::checkParameters()");
	if (_flags != flags)
		error("invalid flags in SaudChannel::checkParameters()");
	if (_volume != volume || _pan != pan) {
		_volume = volume;
		_pan = pan;
	}
	return true;
}

bool SaudChannel::appendData(Chunk &b, int32 size) {
	if (_dataSize == -1) {
		assert(size > 8);
		Chunk::type saud_type = b.getDword();
		saud_type = SWAP_BYTES_32(saud_type);
		uint32 saud_size = b.getDword();
		saud_size = SWAP_BYTES_32(saud_size);
		if (saud_type != TYPE_SAUD)
			error("Invalid Chunk for SaudChannel : %X", saud_type);
		size -= 8;
		_dataSize = -2;
	}
	if (_tbuffer) {
		byte *old = _tbuffer;
		_tbuffer = new byte[_tbufferSize + size];
		if (!_tbuffer)
			error("saud_channel failed to allocate memory");
		memcpy(_tbuffer, old, _tbufferSize);
		delete []old;
		b.read(_tbuffer + _tbufferSize, size);
		_tbufferSize += size;
	} else {
		_tbufferSize = size;
		_tbuffer = new byte[_tbufferSize];
		if (!_tbuffer)
			error("saud_channel failed to allocate memory");
		b.read(_tbuffer, _tbufferSize);
	}
	return processBuffer();
}

int32 SaudChannel::availableSoundData(void) const {
	return _sbufferSize;
}

void SaudChannel::getSoundData(int16 *snd, int32 size) {
	for (int32 i = 0; i < size; i++) {
		snd[2 * i] = _sbuffer[i] ^ 0x80;
		snd[2 * i + 1] = _sbuffer[i] ^ 0x80;
	}
	if (!_keepSize)
		_dataSize -= size;
	delete []_sbuffer;
	_sbuffer = 0;
	_sbufferSize = 0;
}

} // End of namespace Scumm