/*****************************************************************************/
/* SCompression.cpp                       Copyright (c) Ladislav Zezula 2003 */
/*---------------------------------------------------------------------------*/
/* This module serves as a bridge between StormLib code and (de)compression  */
/* functions. All (de)compression calls go (and should only go) through this */
/* module. No system headers should be included in this module to prevent    */
/* compile-time problems.                                                    */
/*---------------------------------------------------------------------------*/
/*   Date    Ver   Who  Comment                                              */
/* --------  ----  ---  -------                                              */
/* 01.04.03  1.00  Lad  The first version of SCompression.cpp                */
/* 19.11.03  1.01  Dan  Big endian handling                                  */
/*****************************************************************************/

#define __STORMLIB_SELF__
#include "StormLib.h"
#include "StormCommon.h"

//-----------------------------------------------------------------------------
// Local structures

// Information about the input and output buffers for pklib
typedef struct
{
    unsigned char * pbInBuff;           // Pointer to input data buffer
    unsigned char * pbInBuffEnd;        // End of the input buffer
    unsigned char * pbOutBuff;          // Pointer to output data buffer
    unsigned char * pbOutBuffEnd;       // Pointer to output data buffer
} TDataInfo;

// Prototype of the compression function
// Function doesn't return an error. A success means that the size of compressed buffer
// is lower than size of uncompressed buffer.
typedef void (*COMPRESS)(
    void * pvOutBuffer,                 // [out] Pointer to the buffer where the compressed data will be stored
    int  * pcbOutBuffer,                // [in]  Pointer to length of the buffer pointed by pvOutBuffer
    void * pvInBuffer,                  // [in]  Pointer to the buffer with data to compress
    int cbInBuffer,                     // [in]  Length of the buffer pointer by pvInBuffer
    int * pCmpType,                     // [in]  Compression-method specific value. ADPCM Setups this for the following Huffman compression
    int nCmpLevel);                     // [in]  Compression specific value. ADPCM uses this. Should be set to zero.

// Prototype of the decompression function
// Returns 1 if success, 0 if failure
typedef int (*DECOMPRESS)(
    void * pvOutBuffer,                 // [out] Pointer to the buffer where to store decompressed data
    int  * pcbOutBuffer,                // [in]  Pointer to total size of the buffer pointed by pvOutBuffer
                                        // [out] Contains length of the decompressed data
    void * pvInBuffer,                  // [in]  Pointer to data to be decompressed
    int cbInBuffer);                    // [in]  Length of the data to be decompressed

// Table of compression functions
typedef struct
{
    unsigned long uMask;                // Compression mask
    COMPRESS Compress;                  // Compression function
} TCompressTable;

// Table of decompression functions
typedef struct
{
    unsigned long uMask;                // Decompression bit
    DECOMPRESS    Decompress;           // Decompression function
} TDecompressTable;


/*****************************************************************************/
/*                                                                           */
/*  Support for Huffman compression (0x01)                                   */
/*                                                                           */
/*****************************************************************************/

void Compress_huff(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer, int * pCmpType, int nCmpLevel)
{
    THuffmannTree ht(true);
    TOutputStream os(pvOutBuffer, *pcbOutBuffer);

    STORMLIB_UNUSED(nCmpLevel);
    *pcbOutBuffer = ht.Compress(&os, pvInBuffer, cbInBuffer, *pCmpType);
}

int Decompress_huff(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    THuffmannTree ht(false);
    TInputStream is(pvInBuffer, cbInBuffer);

    *pcbOutBuffer = ht.Decompress(pvOutBuffer, *pcbOutBuffer, &is);
    return (*pcbOutBuffer == 0) ? 0 : 1;
}

/******************************************************************************/
/*                                                                            */
/*  Support for ZLIB compression (0x02)                                       */
/*                                                                            */
/******************************************************************************/

void Compress_ZLIB(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer, int * pCmpType, int nCmpLevel)
{
    z_stream z;                        // Stream information for zlib
    int windowBits;
    int nResult;

    // Keep compilers happy
    STORMLIB_UNUSED(pCmpType);
    STORMLIB_UNUSED(nCmpLevel);

    // Fill the stream structure for zlib
    z.next_in   = (Bytef *)pvInBuffer;
    z.avail_in  = (uInt)cbInBuffer;
    z.total_in  = cbInBuffer;
    z.next_out  = (Bytef *)pvOutBuffer;
    z.avail_out = *pcbOutBuffer;
    z.total_out = 0;
    z.zalloc    = NULL;
    z.zfree     = NULL;

    // Determine the proper window bits (WoW.exe build 12694)
    if(cbInBuffer <= 0x100)
        windowBits = 8;
    else if(cbInBuffer <= 0x200)
        windowBits = 9;
    else if(cbInBuffer <= 0x400)
        windowBits = 10;
    else if(cbInBuffer <= 0x800)
        windowBits = 11;
    else if(cbInBuffer <= 0x1000)
        windowBits = 12;
    else if(cbInBuffer <= 0x2000)
        windowBits = 13;
    else if(cbInBuffer <= 0x4000)
        windowBits = 14;
    else
        windowBits = 15;

    // Initialize the compression.
    // Storm.dll uses zlib version 1.1.3
    // Wow.exe uses zlib version 1.2.3
    nResult = deflateInit2(&z,
                            6,                  // Compression level used by WoW MPQs
                            Z_DEFLATED,
                            windowBits,
                            8,
                            Z_DEFAULT_STRATEGY);
    if(nResult == Z_OK)
    {
        // Call zlib to compress the data
        nResult = deflate(&z, Z_FINISH);

        if(nResult == Z_OK || nResult == Z_STREAM_END)
            *pcbOutBuffer = z.total_out;

        deflateEnd(&z);
    }
}

int Decompress_ZLIB(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    z_stream z;                        // Stream information for zlib
    int nResult;

    // Fill the stream structure for zlib
    z.next_in   = (Bytef *)pvInBuffer;
    z.avail_in  = (uInt)cbInBuffer;
    z.total_in  = cbInBuffer;
    z.next_out  = (Bytef *)pvOutBuffer;
    z.avail_out = *pcbOutBuffer;
    z.total_out = 0;
    z.zalloc    = NULL;
    z.zfree     = NULL;

    // Initialize the decompression structure. Storm.dll uses zlib version 1.1.3
    if((nResult = inflateInit(&z)) == Z_OK)
    {
        // Call zlib to decompress the data
        nResult = inflate(&z, Z_FINISH);
        *pcbOutBuffer = z.total_out;
        inflateEnd(&z);
    }

	return (nResult >= Z_OK);
}

/******************************************************************************/
/*                                                                            */
/*  Support functions for PKWARE Data Compression Library compression (0x08)  */
/*                                                                            */
/******************************************************************************/

// Function loads data from the input buffer. Used by Pklib's "implode"
// and "explode" function as user-defined callback
// Returns number of bytes loaded
//
//   char * buf          - Pointer to a buffer where to store loaded data
//   unsigned int * size - Max. number of bytes to read
//   void * param        - Custom pointer, parameter of implode/explode

static unsigned int ReadInputData(char * buf, unsigned int * size, void * param)
{
    TDataInfo * pInfo = (TDataInfo *)param;
    unsigned int nMaxAvail = (unsigned int)(pInfo->pbInBuffEnd - pInfo->pbInBuff);
    unsigned int nToRead = *size;

    // Check the case when not enough data available
    if(nToRead > nMaxAvail)
        nToRead = nMaxAvail;

    // Load data and increment offsets
    memcpy(buf, pInfo->pbInBuff, nToRead);
    pInfo->pbInBuff += nToRead;
    assert(pInfo->pbInBuff <= pInfo->pbInBuffEnd);
    return nToRead;
}

// Function for store output data. Used by Pklib's "implode" and "explode"
// as user-defined callback
//
//   char * buf          - Pointer to data to be written
//   unsigned int * size - Number of bytes to write
//   void * param        - Custom pointer, parameter of implode/explode

static void WriteOutputData(char * buf, unsigned int * size, void * param)
{
    TDataInfo * pInfo = (TDataInfo *)param;
    unsigned int nMaxWrite = (unsigned int)(pInfo->pbOutBuffEnd - pInfo->pbOutBuff);
    unsigned int nToWrite = *size;

    // Check the case when not enough space in the output buffer
    if(nToWrite > nMaxWrite)
        nToWrite = nMaxWrite;

    // Write output data and increments offsets
    memcpy(pInfo->pbOutBuff, buf, nToWrite);
    pInfo->pbOutBuff += nToWrite;
    assert(pInfo->pbOutBuff <= pInfo->pbOutBuffEnd);
}

static void Compress_PKLIB(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer, int * pCmpType, int nCmpLevel)
{
    TDataInfo Info;                                      // Data information
    char * work_buf = STORM_ALLOC(char, CMP_BUFFER_SIZE);// Pklib's work buffer
    unsigned int dict_size;                              // Dictionary size
    unsigned int ctype = CMP_BINARY;                     // Compression type

    // Keep compilers happy
    STORMLIB_UNUSED(pCmpType);
    STORMLIB_UNUSED(nCmpLevel);

    // Handle no-memory condition
    if(work_buf != NULL)
    {
        // Fill data information structure
        memset(work_buf, 0, CMP_BUFFER_SIZE);
        Info.pbInBuff     = (unsigned char *)pvInBuffer;
        Info.pbInBuffEnd  = (unsigned char *)pvInBuffer + cbInBuffer;
        Info.pbOutBuff    = (unsigned char *)pvOutBuffer;
        Info.pbOutBuffEnd = (unsigned char *)pvOutBuffer + *pcbOutBuffer;

        //
        // Set the dictionary size
        //
        // Diablo I uses fixed dictionary size of CMP_IMPLODE_DICT_SIZE3
        // Starcraft I uses the variable dictionary size based on algorithm below
        //

        if (cbInBuffer < 0x600)
            dict_size = CMP_IMPLODE_DICT_SIZE1;
        else if(0x600 <= cbInBuffer && cbInBuffer < 0xC00)
            dict_size = CMP_IMPLODE_DICT_SIZE2;
        else
            dict_size = CMP_IMPLODE_DICT_SIZE3;

        // Do the compression
        if(implode(ReadInputData, WriteOutputData, work_buf, &Info, &ctype, &dict_size) == CMP_NO_ERROR)
            *pcbOutBuffer = (int)(Info.pbOutBuff - (unsigned char *)pvOutBuffer);

        STORM_FREE(work_buf);
    }
}

static int Decompress_PKLIB(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    TDataInfo Info;                             // Data information
	char * work_buf;
	int nResult = 0;

    // Allocate Pklib's work buffer
    if((work_buf = STORM_ALLOC(char, EXP_BUFFER_SIZE)) != NULL)
	{
		// Fill data information structure
		memset(work_buf, 0, EXP_BUFFER_SIZE);
		Info.pbInBuff     = (unsigned char *)pvInBuffer;
		Info.pbInBuffEnd  = (unsigned char *)pvInBuffer + cbInBuffer;
		Info.pbOutBuff    = (unsigned char *)pvOutBuffer;
		Info.pbOutBuffEnd = (unsigned char *)pvOutBuffer + *pcbOutBuffer;

		// Do the decompression
		if(explode(ReadInputData, WriteOutputData, work_buf, &Info) == CMP_NO_ERROR)
			nResult = 1;

		// Give away the number of decompressed bytes
		*pcbOutBuffer = (int)(Info.pbOutBuff - (unsigned char *)pvOutBuffer);
        STORM_FREE(work_buf);
	}

    return nResult;
}

/******************************************************************************/
/*                                                                            */
/*  Support for Bzip2 compression (0x10)                                      */
/*                                                                            */
/******************************************************************************/

static void Compress_BZIP2(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer, int * pCmpType, int nCmpLevel)
{
    bz_stream strm;
    int blockSize100k = 9;
    int workFactor = 30;
    int bzError;

    // Keep compilers happy
    STORMLIB_UNUSED(pCmpType);
    STORMLIB_UNUSED(nCmpLevel);

    // Initialize the BZIP2 compression
    strm.bzalloc = NULL;
    strm.bzfree  = NULL;
    strm.opaque  = NULL;

    // Blizzard uses 9 as blockSize100k, (0x30 as workFactor)
    // Last checked on Starcraft II
    if(BZ2_bzCompressInit(&strm, blockSize100k, 0, workFactor) == BZ_OK)
    {
        strm.next_in   = (char *)pvInBuffer;
        strm.avail_in  = cbInBuffer;
        strm.next_out  = (char *)pvOutBuffer;
        strm.avail_out = *pcbOutBuffer;

        // Perform the compression
        for(;;)
        {
            bzError = BZ2_bzCompress(&strm, (strm.avail_in != 0) ? BZ_RUN : BZ_FINISH);
            if(bzError == BZ_STREAM_END || bzError < 0)
                break;
        }

        // Put the stream into idle state
        BZ2_bzCompressEnd(&strm);

        if(bzError > 0)
            *pcbOutBuffer = strm.total_out_lo32;
    }
}

static int Decompress_BZIP2(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    bz_stream strm;
    int nResult;

    // Initialize the BZIP2 decompression
    strm.next_in   = (char *)pvInBuffer;
    strm.avail_in  = cbInBuffer;
    strm.next_out  = (char *)pvOutBuffer;
    strm.avail_out = *pcbOutBuffer;
    strm.bzalloc   = NULL;
    strm.bzfree    = NULL;
    strm.opaque    = NULL;

    // Initialize decompression
    if((nResult = BZ2_bzDecompressInit(&strm, 0, 0)) == BZ_OK)
    {
        // Perform the decompression
        nResult = BZ2_bzDecompress(&strm);
        *pcbOutBuffer = strm.total_out_lo32;
        BZ2_bzDecompressEnd(&strm);
    }

	return (nResult >= BZ_OK);
}

/******************************************************************************/
/*                                                                            */
/*  Support functions for LZMA compression (0x12)                             */
/*                                                                            */
/******************************************************************************/

#define LZMA_HEADER_SIZE (1 + LZMA_PROPS_SIZE + 8)

static SRes LZMA_Callback_Progress(void * /* p */, UInt64 /* inSize */, UInt64 /* outSize */)
{
    return SZ_OK;
}

static void * LZMA_Callback_Alloc(void *p, size_t size)
{
    p = p;
    return STORM_ALLOC(BYTE, size);
}

/* address can be 0 */
static void LZMA_Callback_Free(void *p, void *address)
{
    p = p;
    if(address != NULL)
        STORM_FREE(address);
}

//
// Note: So far, I haven't seen any files compressed by LZMA.
// This code haven't been verified against code ripped from Starcraft II Beta,
// but we know that Starcraft LZMA decompression code is able to decompress
// the data compressed by StormLib.
//

static void Compress_LZMA(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer, int * pCmpType, int nCmpLevel)
{
    ICompressProgress Progress;
    CLzmaEncProps props;
    ISzAlloc SzAlloc;
    Byte * pbOutBuffer = (Byte *)pvOutBuffer;
    Byte * destBuffer;
    SizeT destLen = *pcbOutBuffer;
    SizeT srcLen = cbInBuffer;
    Byte encodedProps[LZMA_PROPS_SIZE];
    size_t encodedPropsSize = LZMA_PROPS_SIZE;
    SRes nResult;

    // Keep compilers happy
    STORMLIB_UNUSED(pCmpType);
    STORMLIB_UNUSED(nCmpLevel);

    // Fill the callbacks in structures
    Progress.Progress = LZMA_Callback_Progress;
    SzAlloc.Alloc = LZMA_Callback_Alloc;
    SzAlloc.Free = LZMA_Callback_Free;

    // Initialize properties
    LzmaEncProps_Init(&props);

    // Perform compression
    destBuffer = (Byte *)pvOutBuffer + LZMA_HEADER_SIZE;
    destLen = *pcbOutBuffer - LZMA_HEADER_SIZE;
    nResult = LzmaEncode(destBuffer,
                        &destLen,
                 (Byte *)pvInBuffer,
                         srcLen,
                        &props,
                         encodedProps,
                        &encodedPropsSize,
                         0,
                        &Progress,
                        &SzAlloc,
                        &SzAlloc);
    if(nResult != SZ_OK)
        return;

    // If we failed to compress the data
    if(destLen >= (SizeT)(*pcbOutBuffer - LZMA_HEADER_SIZE))
        return;

    // Write "useFilter" variable. Blizzard MPQ must not use filter.
    *pbOutBuffer++ = 0;

    // Copy the encoded properties to the output buffer
    memcpy(pvOutBuffer, encodedProps, encodedPropsSize);
    pbOutBuffer += encodedPropsSize;

    // Copy the size of the data
    *pbOutBuffer++ = (unsigned char)(srcLen >> 0x00);
    *pbOutBuffer++ = (unsigned char)(srcLen >> 0x08);
    *pbOutBuffer++ = (unsigned char)(srcLen >> 0x10);
    *pbOutBuffer++ = (unsigned char)(srcLen >> 0x18);
    *pbOutBuffer++ = 0;
    *pbOutBuffer++ = 0;
    *pbOutBuffer++ = 0;
    *pbOutBuffer++ = 0;

    // Give the size of the data to the caller
    *pcbOutBuffer = (unsigned int)(destLen + LZMA_HEADER_SIZE);
}

static int Decompress_LZMA(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    ELzmaStatus LzmaStatus;
    ISzAlloc SzAlloc;
    Byte * destBuffer = (Byte *)pvOutBuffer;
    Byte * srcBuffer = (Byte *)pvInBuffer;
    SizeT destLen = *pcbOutBuffer;
    SizeT srcLen = cbInBuffer;
    SRes nResult;

    // There must be at least 0x0E bytes in the buffer
    if(srcLen <= LZMA_HEADER_SIZE)
        return 0;

    // We only accept blocks that have no filter used
    if(*srcBuffer != 0)
        return 0;

    // Fill the callbacks in structures
    SzAlloc.Alloc = LZMA_Callback_Alloc;
    SzAlloc.Free = LZMA_Callback_Free;

    // Perform compression
    srcLen = cbInBuffer - LZMA_HEADER_SIZE;
    nResult = LzmaDecode(destBuffer,
                        &destLen,
                         srcBuffer + LZMA_HEADER_SIZE,
                        &srcLen,
                         srcBuffer + 1,
                         LZMA_PROPS_SIZE,
                         LZMA_FINISH_END,
                        &LzmaStatus,
                        &SzAlloc);
    if(nResult != SZ_OK)
        return 0;

    *pcbOutBuffer = (unsigned int)destLen;
    return 1;
}

static int Decompress_LZMA_MPK(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    ELzmaStatus LzmaStatus;
    ISzAlloc SzAlloc;
    Byte * destBuffer = (Byte *)pvOutBuffer;
    Byte * srcBuffer = (Byte *)pvInBuffer;
    SizeT destLen = *pcbOutBuffer;
    SizeT srcLen = cbInBuffer;
    SRes nResult;
    BYTE LZMA_Props[] = {0x5D, 0x00, 0x00, 0x00, 0x01};

    // There must be at least 0x0E bytes in the buffer
    if(srcLen <= sizeof(LZMA_Props))
        return 0;

    // Verify the props header
    if(memcmp(pvInBuffer, LZMA_Props, sizeof(LZMA_Props)))
        return 0;

    // Fill the callbacks in structures
    SzAlloc.Alloc = LZMA_Callback_Alloc;
    SzAlloc.Free = LZMA_Callback_Free;

    // Perform compression
    srcLen = cbInBuffer - sizeof(LZMA_Props);
    nResult = LzmaDecode(destBuffer,
                        &destLen,
                         srcBuffer + sizeof(LZMA_Props),
                        &srcLen,
                         srcBuffer,
                         sizeof(LZMA_Props),
                         LZMA_FINISH_END,
                        &LzmaStatus,
                        &SzAlloc);
    if(nResult != SZ_OK)
        return 0;

    *pcbOutBuffer = (unsigned int)destLen;
    return 1;
}

/******************************************************************************/
/*                                                                            */
/*  Support functions for SPARSE compression (0x20)                           */
/*                                                                            */
/******************************************************************************/

void Compress_SPARSE(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer, int * pCmpType, int nCmpLevel)
{
    // Keep compilers happy
    STORMLIB_UNUSED(pCmpType);
    STORMLIB_UNUSED(nCmpLevel);

    CompressSparse(pvOutBuffer, pcbOutBuffer, pvInBuffer, cbInBuffer);
}

int Decompress_SPARSE(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    return DecompressSparse(pvOutBuffer, pcbOutBuffer, pvInBuffer, cbInBuffer);
}

/******************************************************************************/
/*                                                                            */
/*  Support for ADPCM mono compression (0x40)                                 */
/*                                                                            */
/******************************************************************************/

static void Compress_ADPCM_mono(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer, int * pCmpType, int nCmpLevel)
{
    // Prepare the compression level for Huffmann compression,
    // which will be called as next step
    if(0 < nCmpLevel && nCmpLevel <= 2)
    {
        nCmpLevel = 4;
        *pCmpType = 6;
    }
    else if(nCmpLevel == 3)
    {
        nCmpLevel = 6;
        *pCmpType = 8;
    }
    else
    {
        nCmpLevel = 5;
        *pCmpType = 7;
    }
    *pcbOutBuffer = CompressADPCM(pvOutBuffer, *pcbOutBuffer, pvInBuffer, cbInBuffer, 1, nCmpLevel);
}

static int Decompress_ADPCM_mono(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    *pcbOutBuffer = DecompressADPCM(pvOutBuffer, *pcbOutBuffer, pvInBuffer, cbInBuffer, 1);
    return 1;
}

/******************************************************************************/
/*                                                                            */
/*  Support for ADPCM stereo compression (0x80)                               */
/*                                                                            */
/******************************************************************************/

static void Compress_ADPCM_stereo(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer, int * pCmpType, int nCmpLevel)
{
    // Prepare the compression level for Huffmann compression,
    // which will be called as next step
    if(0 < nCmpLevel && nCmpLevel <= 2)
    {
        nCmpLevel = 4;
        *pCmpType = 6;
    }
    else if(nCmpLevel == 3)
    {
        nCmpLevel = 6;
        *pCmpType = 8;
    }
    else
    {
        nCmpLevel = 5;
        *pCmpType = 7;
    }
    *pcbOutBuffer = CompressADPCM(pvOutBuffer, *pcbOutBuffer, pvInBuffer, cbInBuffer, 2, nCmpLevel);
}

static int Decompress_ADPCM_stereo(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    *pcbOutBuffer = DecompressADPCM(pvOutBuffer, *pcbOutBuffer, pvInBuffer, cbInBuffer, 2);
    return 1;
}

/*****************************************************************************/
/*                                                                           */
/*   SCompImplode                                                            */
/*                                                                           */
/*****************************************************************************/

int WINAPI SCompImplode(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    int cbOutBuffer;

    // Check for valid parameters
    if(!pcbOutBuffer || *pcbOutBuffer < cbInBuffer || !pvOutBuffer || !pvInBuffer)
    {
        SetLastError(ERROR_INVALID_PARAMETER);
        return 0;
    }

    // Perform the compression
    cbOutBuffer = *pcbOutBuffer;
    Compress_PKLIB(pvOutBuffer, &cbOutBuffer, pvInBuffer, cbInBuffer, NULL, 0);

    // If the compression was unsuccessful, copy the data as-is
    if(cbOutBuffer >= *pcbOutBuffer)
    {
        memcpy(pvOutBuffer, pvInBuffer, cbInBuffer);
        cbOutBuffer = *pcbOutBuffer;
    }

    *pcbOutBuffer = cbOutBuffer;
    return 1;
}

/*****************************************************************************/
/*                                                                           */
/*   SCompExplode                                                            */
/*                                                                           */
/*****************************************************************************/

int WINAPI SCompExplode(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    int cbOutBuffer;

    // Check for valid parameters
    if(!pcbOutBuffer || *pcbOutBuffer < cbInBuffer || !pvOutBuffer || !pvInBuffer)
    {
        SetLastError(ERROR_INVALID_PARAMETER);
        return 0;
    }

    // If the input length is the same as output length, do nothing.
    cbOutBuffer = *pcbOutBuffer;
    if(cbInBuffer == cbOutBuffer)
    {
        // If the buffers are equal, don't copy anything.
        if(pvInBuffer == pvOutBuffer)
            return 1;

        memcpy(pvOutBuffer, pvInBuffer, cbInBuffer);
        return 1;
    }

    // Perform decompression
    if(!Decompress_PKLIB(pvOutBuffer, &cbOutBuffer, pvInBuffer, cbInBuffer))
    {
        SetLastError(ERROR_FILE_CORRUPT);
        return 0;
    }

    *pcbOutBuffer = cbOutBuffer;
    return 1;
}

/*****************************************************************************/
/*                                                                           */
/*   SCompCompress                                                           */
/*                                                                           */
/*****************************************************************************/

// This table contains compress functions which can be applied to
// uncompressed data. Each bit means the corresponding
// compression method/function must be applied.
//
//   WAVes compression            Data compression
//   ------------------           -------------------
//   1st sector   - 0x08          0x08 (D, HF, W2, SC, D2)
//   Next sectors - 0x81          0x02 (W3)

static TCompressTable cmp_table[] =
{
    {MPQ_COMPRESSION_SPARSE,       Compress_SPARSE},        // Sparse compression
    {MPQ_COMPRESSION_ADPCM_MONO,   Compress_ADPCM_mono},    // IMA ADPCM mono compression
    {MPQ_COMPRESSION_ADPCM_STEREO, Compress_ADPCM_stereo},  // IMA ADPCM stereo compression
    {MPQ_COMPRESSION_HUFFMANN,     Compress_huff},          // Huffmann compression
    {MPQ_COMPRESSION_ZLIB,         Compress_ZLIB},          // Compression with the "zlib" library
    {MPQ_COMPRESSION_PKWARE,       Compress_PKLIB},         // Compression with Pkware DCL
    {MPQ_COMPRESSION_BZIP2,        Compress_BZIP2}          // Compression Bzip2 library
};

int WINAPI SCompCompress(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer, unsigned uCompressionMask, int nCmpType, int nCmpLevel)
{
    COMPRESS CompressFuncArray[0x10];                       // Array of compression functions, applied sequentially
    unsigned char CompressByte[0x10];                       // CompressByte for each method in the CompressFuncArray array
    unsigned char * pbWorkBuffer = NULL;                    // Temporary storage for decompressed data
    unsigned char * pbOutBuffer = (unsigned char *)pvOutBuffer;
    unsigned char * pbOutput = (unsigned char *)pvOutBuffer;// Current output buffer
    unsigned char * pbInput = (unsigned char *)pvInBuffer;  // Current input buffer
    int nCompressCount = 0;
    int nCompressIndex = 0;
    int nAtLeastOneCompressionDone = 0;
    int cbOutBuffer = 0;
    int cbInLength = cbInBuffer;
    int nResult = 1;

    // Check for valid parameters
    if(!pcbOutBuffer || *pcbOutBuffer < cbInBuffer || !pvOutBuffer || !pvInBuffer)
    {
        SetLastError(ERROR_INVALID_PARAMETER);
        return 0;
    }

    // Zero input length brings zero output length
    if(cbInBuffer == 0)
    {
        *pcbOutBuffer = 0;
        return true;
    }

    // Setup the compression function array
    if(uCompressionMask == MPQ_COMPRESSION_LZMA)
    {
        CompressFuncArray[0] = Compress_LZMA;
        CompressByte[0] = (char)uCompressionMask;
        nCompressCount = 1;
    }
    else
    {
        // Fill the compressions array
        for(size_t i = 0; i < (sizeof(cmp_table) / sizeof(TCompressTable)); i++)
        {
            // If the mask agrees, insert the compression function to the array
            if(uCompressionMask & cmp_table[i].uMask)
            {
                CompressFuncArray[nCompressCount] = cmp_table[i].Compress;
                CompressByte[nCompressCount] = (unsigned char)cmp_table[i].uMask;
                uCompressionMask &= ~cmp_table[i].uMask;
                nCompressCount++;
            }
        }

        // If at least one of the compressions remaing unknown, return an error
        if(uCompressionMask != 0)
        {
            SetLastError(ERROR_NOT_SUPPORTED);
            return 0;
        }
    }

    // If there is at least one compression, do it
    if(nCompressCount > 0)
    {
        // If we need to do more than 1 compression, allocate intermediate buffer
        if(nCompressCount > 1)
        {
            pbWorkBuffer = STORM_ALLOC(unsigned char, *pcbOutBuffer);
            if(pbWorkBuffer == NULL)
            {
                SetLastError(ERROR_NOT_ENOUGH_MEMORY);
                return 0;
            }
        }

        // Get the current compression index
        nCompressIndex = nCompressCount - 1;

        // Perform all compressions in the array
        for(int i = 0; i < nCompressCount; i++)
        {
            // Choose the proper output buffer
            pbOutput = (nCompressIndex & 1) ? pbWorkBuffer : pbOutBuffer;
            nCompressIndex--;

            // Perform the (next) compression
            // Note that if the compression method is unable to compress the input data block
            // by at least 2 bytes, we consider it as failure and will use source data instead
            cbOutBuffer = *pcbOutBuffer - 1;
            CompressFuncArray[i](pbOutput + 1, &cbOutBuffer, pbInput, cbInLength, &nCmpType, nCmpLevel);

            // If the compression failed, we copy the input buffer as-is.
            // Note that there is one extra byte at the end of the intermediate buffer, so it should be OK
            if(cbOutBuffer > (cbInLength - 2))
            {
                memcpy(pbOutput + nAtLeastOneCompressionDone, pbInput, cbInLength);
                cbOutBuffer = cbInLength;
            }
            else
            {
                // Remember that we have done at least one compression
                nAtLeastOneCompressionDone = 1;
                uCompressionMask |= CompressByte[i];
            }

            // Now point input buffer to the output buffer
            pbInput = pbOutput + nAtLeastOneCompressionDone;
            cbInLength = cbOutBuffer;
        }

        // If at least one compression succeeded, put the compression
        // mask to the begin of the output buffer
        if(nAtLeastOneCompressionDone)
            *pbOutBuffer  = (unsigned char)uCompressionMask;
        *pcbOutBuffer = cbOutBuffer + nAtLeastOneCompressionDone;
    }
    else
    {
        memcpy(pvOutBuffer, pvInBuffer, cbInBuffer);
        *pcbOutBuffer = cbInBuffer;
    }

    // Cleanup and return
    if(pbWorkBuffer != NULL)
        STORM_FREE(pbWorkBuffer);
    return nResult;
}

/*****************************************************************************/
/*                                                                           */
/*   SCompDecompress                                                         */
/*                                                                           */
/*****************************************************************************/

// This table contains decompress functions which can be applied to
// uncompressed data. The compression mask is stored in the first byte
// of compressed data
static TDecompressTable dcmp_table[] =
{
    {MPQ_COMPRESSION_BZIP2,        Decompress_BZIP2},        // Decompression with Bzip2 library
    {MPQ_COMPRESSION_PKWARE,       Decompress_PKLIB},        // Decompression with Pkware Data Compression Library
    {MPQ_COMPRESSION_ZLIB,         Decompress_ZLIB},         // Decompression with the "zlib" library
    {MPQ_COMPRESSION_HUFFMANN,     Decompress_huff},         // Huffmann decompression
    {MPQ_COMPRESSION_ADPCM_STEREO, Decompress_ADPCM_stereo}, // IMA ADPCM stereo decompression
    {MPQ_COMPRESSION_ADPCM_MONO,   Decompress_ADPCM_mono},   // IMA ADPCM mono decompression
    {MPQ_COMPRESSION_SPARSE,       Decompress_SPARSE}        // Sparse decompression
};

int WINAPI SCompDecompress(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    unsigned char * pbWorkBuffer = NULL;
    unsigned char * pbOutBuffer = (unsigned char *)pvOutBuffer;
    unsigned char * pbInBuffer = (unsigned char *)pvInBuffer;
    unsigned char * pbOutput = (unsigned char *)pvOutBuffer;
    unsigned char * pbInput;
    unsigned uCompressionMask;              // Decompressions applied to the data
    unsigned uCompressionCopy;              // Decompressions applied to the data
    int      cbOutBuffer = *pcbOutBuffer;   // Current size of the output buffer
    int      cbInLength;                    // Current size of the input buffer
    int      nCompressCount = 0;            // Number of compressions to be applied
    int      nCompressIndex = 0;
    int      nResult = 1;

    // Verify buffer sizes
    if(cbOutBuffer < cbInBuffer || cbInBuffer < 1)
        return 0;

    // If the input length is the same as output length, do nothing.
    if(cbOutBuffer == cbInBuffer)
    {
        // If the buffers are equal, don't copy anything.
        if(pvInBuffer != pvOutBuffer)
            memcpy(pvOutBuffer, pvInBuffer, cbInBuffer);
        return 1;
    }

    // Get applied compression types and decrement data length
    uCompressionMask = uCompressionCopy = (unsigned char)*pbInBuffer++;
    cbInBuffer--;

    // Get current compressed data and length of it
    pbInput = pbInBuffer;
    cbInLength = cbInBuffer;

    // This compression function doesn't support LZMA
    assert(uCompressionMask != MPQ_COMPRESSION_LZMA);

    // Parse the compression mask
    for(size_t i = 0; i < (sizeof(dcmp_table) / sizeof(TDecompressTable)); i++)
    {
        // If the mask agrees, insert the compression function to the array
        if(uCompressionMask & dcmp_table[i].uMask)
        {
            uCompressionCopy &= ~dcmp_table[i].uMask;
            nCompressCount++;
        }
    }

    // If at least one of the compressions remaing unknown, return an error
    if(nCompressCount == 0 || uCompressionCopy != 0)
    {
        SetLastError(ERROR_NOT_SUPPORTED);
        return 0;
    }

    // If there is more than one compression, we have to allocate extra buffer
    if(nCompressCount > 1)
    {
        pbWorkBuffer = STORM_ALLOC(unsigned char, cbOutBuffer);
        if(pbWorkBuffer == NULL)
        {
            SetLastError(ERROR_NOT_ENOUGH_MEMORY);
            return 0;
        }
    }

    // Get the current compression index
    nCompressIndex = nCompressCount - 1;

    // Apply all decompressions
    for(size_t i = 0; i < (sizeof(dcmp_table) / sizeof(TDecompressTable)); i++)
    {
        // Perform the (next) decompression
        if(uCompressionMask & dcmp_table[i].uMask)
        {
            // Get the correct output buffer
            pbOutput = (nCompressIndex & 1) ? pbWorkBuffer : pbOutBuffer;
            nCompressIndex--;

            // Perform the decompression
            cbOutBuffer = *pcbOutBuffer;
            nResult = dcmp_table[i].Decompress(pbOutput, &cbOutBuffer, pbInput, cbInLength);
            if(nResult == 0 || cbOutBuffer == 0)
            {
                SetLastError(ERROR_FILE_CORRUPT);
                nResult = 0;
                break;
            }

            // Switch buffers
            cbInLength = cbOutBuffer;
            pbInput = pbOutput;
        }
    }

    // Put the length of the decompressed data to the output buffer
    *pcbOutBuffer = cbOutBuffer;

    // Cleanup and return
    if(pbWorkBuffer != NULL)
        STORM_FREE(pbWorkBuffer);
    return nResult;
}

int WINAPI SCompDecompress2(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    DECOMPRESS pfnDecompress1 = NULL;
    DECOMPRESS pfnDecompress2 = NULL;
    unsigned char * pbWorkBuffer = (unsigned char *)pvOutBuffer;
    unsigned char * pbInBuffer = (unsigned char *)pvInBuffer;
    int cbWorkBuffer = *pcbOutBuffer;
    int nResult;
    char CompressionMethod;

    // Verify buffer sizes
    if(*pcbOutBuffer < cbInBuffer || cbInBuffer < 1)
        return 0;

    // If the outputbuffer is as big as input buffer, just copy the block
    if(*pcbOutBuffer == cbInBuffer)
    {
        if(pvOutBuffer != pvInBuffer)
            memcpy(pvOutBuffer, pvInBuffer, cbInBuffer);
        return 1;
    }

    // Get the compression methods
    CompressionMethod = *pbInBuffer++;
    cbInBuffer--;

    // We only recognize a fixed set of compression methods
    switch((unsigned char)CompressionMethod)
    {
        case MPQ_COMPRESSION_ZLIB:
            pfnDecompress1 = Decompress_ZLIB;
            break;

        case MPQ_COMPRESSION_PKWARE:
            pfnDecompress1 = Decompress_PKLIB;
            break;

        case MPQ_COMPRESSION_BZIP2:
            pfnDecompress1 = Decompress_BZIP2;
            break;

        case MPQ_COMPRESSION_LZMA:
            pfnDecompress1 = Decompress_LZMA;
            break;

        case MPQ_COMPRESSION_SPARSE:
            pfnDecompress1 = Decompress_SPARSE;
            break;

        case (MPQ_COMPRESSION_SPARSE | MPQ_COMPRESSION_ZLIB):
            pfnDecompress1 = Decompress_ZLIB;
            pfnDecompress2 = Decompress_SPARSE;
            break;

        case (MPQ_COMPRESSION_SPARSE | MPQ_COMPRESSION_BZIP2):
            pfnDecompress1 = Decompress_BZIP2;
            pfnDecompress2 = Decompress_SPARSE;
            break;

        //
        // Note: Any combination including MPQ_COMPRESSION_ADPCM_MONO,
        // MPQ_COMPRESSION_ADPCM_STEREO or MPQ_COMPRESSION_HUFFMANN
        // is not supported by newer MPQs.
        //

        case (MPQ_COMPRESSION_ADPCM_MONO | MPQ_COMPRESSION_HUFFMANN):
            pfnDecompress1 = Decompress_huff;
            pfnDecompress2 = Decompress_ADPCM_mono;
            break;

        case (MPQ_COMPRESSION_ADPCM_STEREO | MPQ_COMPRESSION_HUFFMANN):
            pfnDecompress1 = Decompress_huff;
            pfnDecompress2 = Decompress_ADPCM_stereo;
            break;

        default:
            SetLastError(ERROR_FILE_CORRUPT);
            return 0;
    }

    // If we have to use two decompressions, allocate temporary buffer
    if(pfnDecompress2 != NULL)
    {
        pbWorkBuffer = STORM_ALLOC(unsigned char, *pcbOutBuffer);
        if(pbWorkBuffer == NULL)
        {
            SetLastError(ERROR_NOT_ENOUGH_MEMORY);
            return 0;
        }
    }

    // Apply the first decompression method
    nResult = pfnDecompress1(pbWorkBuffer, &cbWorkBuffer, pbInBuffer, cbInBuffer);

    // Apply the second decompression method, if any
    if(pfnDecompress2 != NULL && nResult != 0)
    {
        cbInBuffer   = cbWorkBuffer;
        cbWorkBuffer = *pcbOutBuffer;
        nResult = pfnDecompress2(pvOutBuffer, &cbWorkBuffer, pbWorkBuffer, cbInBuffer);
    }

    // Supply the output buffer size
    *pcbOutBuffer = cbWorkBuffer;

    // Free temporary buffer
    if(pbWorkBuffer != pvOutBuffer)
        STORM_FREE(pbWorkBuffer);

    if(nResult == 0)
        SetLastError(ERROR_FILE_CORRUPT);
    return nResult;
}

/*****************************************************************************/
/*                                                                           */
/*   File decompression for MPK archives                                     */
/*                                                                           */
/*****************************************************************************/

int SCompDecompressMpk(void * pvOutBuffer, int * pcbOutBuffer, void * pvInBuffer, int cbInBuffer)
{
    return Decompress_LZMA_MPK(pvOutBuffer, pcbOutBuffer, pvInBuffer, cbInBuffer);
}