//----------------------------------------------------------------------------
//
// File:		decode-lzw.hpp
// Date:		15-Sep-2003
// Programmer:	Marc Rousseau
//
// Description: A class to decode an LZW compressed ARK file(Barry Boone's Archive format)
//
// Copyright (c) 2003-2004 Marc Rousseau, All Rights Reserved.
//
// 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.
//
// Revision History:
//
//----------------------------------------------------------------------------

#ifndef DECODE_LZW_HPP_
#define DECODE_LZW_HPP_

namespace decode
{
	const int CODE_CLEAR      = 256;	// clear code
	const int CODE_EOF        = 257;	// CODE_EOF marker
	const int CODE_FIRST_FREE = 258;	// first free code
	const int CODE_ERROR      =( UINT16 ) -1;
}

class cDecodeLZW
{
	int     m_MAX_BITS;
	int     m_CODE_MAX;

	// Used for reading the next token
	int     m_nBits;
	int     m_BitOff;
	UINT32  m_CurWord;
	UINT16  m_CodeMask;

	// History tables
	UINT16  m_FreeCode;
	UINT16 *m_NextCode;
	UINT8  *m_AppendChar;

	// Input buffer related
	const UINT8  *m_InPtr;
	const UINT8  *m_InEnd;

	// Output buffer related
	bool  (*m_WriteCallback)( void *, size_t, void * );
	void   *m_CallbackToken;
	UINT8  *m_WriteBuffer;
	UINT8  *m_OutPtr;
	size_t  m_MaxWriteSize;

	void Init( );
	void Reset( );
	void Done( );

	UINT16 ReadCode( );

	void AddCode( UINT16, UINT8 );
	void WriteChar( UINT8 ch );

public:

	cDecodeLZW( int );
	~cDecodeLZW( );

	int	 BytesLeft( ) const;
	void SetWriteCallback( bool(*)( void *, size_t, void * ), void *, size_t, void * );
	int	 ParseBuffer( const void *, size_t );

private:

	cDecodeLZW( const cDecodeLZW & ) = delete;		// no implementation
	void operator =( const cDecodeLZW & ) = delete;	// no implementation

};

#endif
