/* 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.
 *
 * $URL$
 * $Id$
 *
 */

#ifndef SCI_SCICORE_DECOMPRESSOR_H
#define SCI_SCICORE_DECOMPRESSOR_H

#include "common/file.h"

namespace Sci {
enum ResourceCompression {
	kCompUnknown = -1,
	kCompNone = 0,
	kCompLZW,
	kCompHuffman,
	kCompLZW1,			// LZW-like compression used in SCI01 and SCI1
	kCompLZW1View,		// Comp3 + view Post-processing
	kCompLZW1Pic,		// Comp3 + pic Post-processing
	kCompDCL,
	kCompSTACpack	// ? Used in SCI32
};
//----------------------------------------------
// Base class for decompressors
// Simply copies nPacked bytes from src to dest
//----------------------------------------------
class Decompressor {
public:
	Decompressor() {}
	virtual ~Decompressor() {}
	virtual int unpack(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

protected:
	//! Initialize decompressor
	/** @param src - source stream to read from
		@param dest - destination stream to write to
		@param nPacked - size of packed data
		@param nUnpacket - size of unpacked data
		@return (int) 0 on success, non-zero on error
	  */
	virtual void init(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);	
	//! get one bit from _src stream
	/** @return (bool) bit;
	  */
	bool getBitMSB();
	bool getBitLSB();
	//! get a number of bits from _src stream
	/** @param n - number of bits to get
		@return (uint32) n-bits number
	  */
	uint32 getBitsMSB(int n);
	uint32 getBitsLSB(int n);
	//! get one byte from _src stream
	/** @return (byte) byte
	  */
	byte getByteMSB();
	byte getByteLSB();

	void fetchBitsMSB();
	void fetchBitsLSB(); 

	//! put byte to _dest stream
	/** @param b - byte to put
	  */
	virtual void putByte(byte b);
	// Returns true if all expected data has been unpacked to _dest 
	// and there is no more data in _src
	bool isFinished() {
		return (_dwWrote == _szUnpacked) && (_dwRead >= _szPacked);
	}

	uint32 _dwBits; // bits buffer
	byte _nBits; // # of bits in buffer
	uint32 _szPacked;
	uint32 _szUnpacked;
	uint32 _dwRead;	// # of bytes read from _src
	uint32 _dwWrote;
	Common::ReadStream *_src;
	byte *_dest;
};

//----------------------------------------------
// Huffman decompressor
//----------------------------------------------
class DecompressorHuffman : public Decompressor {
public:
	int unpack(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

protected:
	int16 getc2();

	byte *_nodes;
};

//----------------------------------------------
// LZW-like decompressor for SCI01/SCI1
// TODO: Needs clean-up of post-processing fncs
//----------------------------------------------
class DecompressorLZW : public Decompressor {
public:
	DecompressorLZW(int nCompression) {
		_compression = nCompression;
	}
	void init(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);
	int unpack(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

protected:
	enum {
		PIC_OPX_EMBEDDED_VIEW = 1,
		PIC_OPX_SET_PALETTE = 2,
		PIC_OP_OPX = 0xfe
	};
	// unpacking procedures
	// TODO: unpackLZW and unpackLZW1 are similar and should be merged
	int unpackLZW1(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);
	int unpackLZW(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

	// functions to post-process view and pic resources
	void reorderPic(byte *src, byte *dest, int dsize);
	void reorderView(byte *src, byte *dest);
	void decodeRLE(byte **rledata, byte **pixeldata, byte *outbuffer, int size);
	int getRLEsize(byte *rledata, int dsize);
	void buildCelHeaders(byte **seeker, byte **writer, int celindex, int *cc_lengths, int max);
	
	// decompressor data
	struct Tokenlist {
		byte data;
		uint16 next;
	};
	uint16 _numbits;
	uint16 _curtoken, _endtoken;
	int _compression;
};

//----------------------------------------------
// DCL decompressor for SCI1.1
//----------------------------------------------
class DecompressorDCL : public Decompressor {
public:
	int unpack(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);

protected:
	int unpackDCL(byte *dest);
	int huffman_lookup(int *tree);
};

//----------------------------------------------
// STACpack decompressor for SCI32
//----------------------------------------------
class DecompressorLZS : public Decompressor {
public:
	int unpack(Common::ReadStream *src, byte *dest, uint32 nPacked, uint32 nUnpacked);
protected:
	int unpackLZS();
	uint16 getCompLen();
	void copyComp(int offs, int clen);
};

} // End of namespace Sci

#endif // SCI_SCICORE_DECOMPRESSOR_H