/* ScummVM - Scumm Interpreter
 * Copyright (C) 2004-2005 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $Header$
 *
 */

#include "common/stdafx.h"
#include "kyra/kyra.h"
#include "kyra/screen.h"
#include "kyra/wsamovie.h"


namespace Kyra {
WSAMovieV1::WSAMovieV1(KyraEngine *vm) : Movie(vm) {}
WSAMovieV1::~WSAMovieV1() { close(); }

void WSAMovieV1::open(const char *filename, int offscreenDecode, uint8 *palBuf) {
	debug(9, "WSAMovieV1::open('%s', %d, 0x%X)", filename, offscreenDecode, palBuf);
	close();

	uint32 flags = 0;
	uint32 fileSize;
	uint8 *p = _vm->resource()->fileData(filename, &fileSize);
	assert(p);
	
	const uint8 *wsaData = p;
	_numFrames = READ_LE_UINT16(wsaData); wsaData += 2;
	_width = READ_LE_UINT16(wsaData); wsaData += 2;
	_height = READ_LE_UINT16(wsaData); wsaData += 2;
	_deltaBufferSize = READ_LE_UINT16(wsaData); wsaData += 2;
	_offscreenBuffer = NULL;
	_flags = 0;
	if (_vm->features() & GF_TALKIE) {
		flags = READ_LE_UINT16(wsaData); wsaData += 2;
	}
	
	uint32 offsPal = 0;
	if (flags & 1) {
		offsPal = 0x300;
		_flags |= WF_HAS_PALETTE;
		if (palBuf) {
			memcpy(palBuf, wsaData + (_numFrames + 2) * 4, 0x300);
		}
	}
	
	if (offscreenDecode) {
		_flags |= WF_OFFSCREEN_DECODE;
		const int offscreenBufferSize = _width * _height;
		_offscreenBuffer = new uint8[offscreenBufferSize];
		memset(_offscreenBuffer, 0, offscreenBufferSize);
	}

	if (_numFrames & 0x8000) {
		warning("Unhandled wsa flags 0x80");
		_flags |= 0x80;
		_numFrames &= 0x7FFF;
	}
	_currentFrame = _numFrames;

	_deltaBuffer = new uint8[_deltaBufferSize];
	memset(_deltaBuffer, 0, _deltaBufferSize);
	
	// read frame offsets
	_frameOffsTable = new uint32[_numFrames + 2];
	_frameOffsTable[0] = 0;
	uint32 frameDataOffs = READ_LE_UINT32(wsaData); wsaData += 4;
	bool firstFrame = true;
	if (frameDataOffs == 0) {
		firstFrame = false;
		frameDataOffs = READ_LE_UINT32(wsaData);
		_flags |= WF_NO_FIRST_FRAME;
	}
	for (int i = 1; i < _numFrames + 2; ++i) {
		_frameOffsTable[i] = READ_LE_UINT32(wsaData) - frameDataOffs;
		wsaData += 4;
	}
	
	// skip palette
	wsaData += offsPal;
	
	// read frame data
	const int frameDataSize = p + fileSize - wsaData;
	_frameData = new uint8[frameDataSize];
	memcpy(_frameData, wsaData, frameDataSize);
	
	// decode first frame
	if (firstFrame) {
		Screen::decodeFrame4(_frameData, _deltaBuffer, _deltaBufferSize);
	}
	
	delete [] p;
	_opened = true;
}

void WSAMovieV1::close() {
	debug(9, "WSAMovieV1::close()");
	if (_opened) {
		delete [] _deltaBuffer;
		delete [] _offscreenBuffer;
		delete [] _frameOffsTable;
		delete [] _frameData;
		_opened = false;
	}
}

void WSAMovieV1::displayFrame(int frameNum) {
	debug(9, "WSAMovieV1::displayFrame(%d)", frameNum);
	if (frameNum > _numFrames || !_opened)
		return;

	uint8 *dst;
	if (_flags & WF_OFFSCREEN_DECODE) {
		dst = _offscreenBuffer;
	} else {
		dst = _vm->screen()->getPagePtr(_drawPage) + _y * Screen::SCREEN_W + _x;
	}
		
	if (_currentFrame == _numFrames) {
		if (!(_flags & WF_OFFSCREEN_DECODE) && (_vm->features() & GF_TALKIE))
			_vm->screen()->clearPage(_drawPage);
		if (!(_flags & WF_NO_FIRST_FRAME)) {
			if (_flags & WF_OFFSCREEN_DECODE) {
				Screen::decodeFrameDelta(dst, _deltaBuffer);
			} else {
				Screen::decodeFrameDeltaPage(dst, _deltaBuffer, _width);
			}
		}
		_currentFrame = 0;
	}

	// try to reduce the number of needed frame operations
	int diffCount = ABS(_currentFrame - frameNum);
	int frameStep = 1;
	int frameCount;
	if (_currentFrame < frameNum) {
		frameCount = _numFrames - frameNum + _currentFrame;
		if (diffCount > frameCount) {
			frameStep = -1;
		} else {
			frameCount = diffCount;
		}
	} else {
		frameCount = _numFrames - _currentFrame + frameNum;
		if (frameCount >= diffCount) {
			frameStep = -1;
			frameCount = diffCount;
		}
	}
	
	// process
	if (frameStep > 0) {
		uint16 cf = _currentFrame;
		while (frameCount--) {
			cf += frameStep;
			processFrame(cf, dst);
			if (cf == _numFrames) {
				cf = 0;
			}
		}
	} else {
		uint16 cf = _currentFrame;
		while (frameCount--) {
			if (cf == 0) {
				cf = _numFrames;
			}
			processFrame(cf, dst);
			cf += frameStep;
		}
	}
	
	// display
	_currentFrame = frameNum;
	if (_flags & WF_OFFSCREEN_DECODE) {
		_vm->screen()->copyBlockToPage(_drawPage, _x, _y, _width, _height, _offscreenBuffer);
	}
}

void WSAMovieV1::processFrame(int frameNum, uint8 *dst) {
	debug(9, "WSAMovieV1::processFrame(%d, 0x%X)", frameNum, dst);
	if (!_opened)
		return;
	assert(frameNum <= _numFrames);
	const uint8 *src = _frameData + _frameOffsTable[frameNum];
	Screen::decodeFrame4(src, _deltaBuffer, _deltaBufferSize);
	if (_flags & WF_OFFSCREEN_DECODE) {
		Screen::decodeFrameDelta(dst, _deltaBuffer);
	} else {
		Screen::decodeFrameDeltaPage(dst, _deltaBuffer, _width);
	}
}
} // end of namespace Kyra