/*
	Software License Agreement (BSD License)
	
	Copyright (c) 1997-2008, David Lindauer, (LADSoft).
	All rights reserved.
	
	Redistribution and use of this software in source and binary forms, with or without modification, are
	permitted provided that the following conditions are met:
	
	* Redistributions of source code must retain the above
	  copyright notice, this list of conditions and the
	  following disclaimer.
	
	* Redistributions in binary form must reproduce the above
	  copyright notice, this list of conditions and the
	  following disclaimer in the documentation and/or other
	  materials provided with the distribution.
	
	* Neither the name of LADSoft nor the names of its
	  contributors may be used to endorse or promote products
	  derived from this software without specific prior
	  written permission of LADSoft.
	
	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
	WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
	PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
	ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
	TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
	ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <setjmp.h>
#include <string.h>

#ifdef XXXXX
static unsigned CRCtab[256];
static unsigned currentcrc;
#endif
static unsigned char masktab[9] = 
{
    0, 1, 3, 7, 0xf, 0x1f, 0x3f, 0x7f, 0xff
};
static unsigned char tab7_rearrange[0x13] = 
{
    0x10, 0x11, 0x12, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
};
static unsigned accum, accum_count;
static int inflatepos = 0;

static jmp_buf inflate_sync, inflate_badtab;

static char inflate_tab_1[0x140];
static unsigned char inflate_tab_2[32];
static short inflate_tab_3[256];
static short inflate_tab_4[256];
static unsigned short inflate_tab_5[0x240];
static unsigned short inflate_tab_6[64];
static unsigned char inflate_tab_7[0x13];
static unsigned short inflate_tab_8[0x116];
static unsigned short intermed_tab[16];
static unsigned short intermed_tab_2[16];
static unsigned short intermed_tab_3[0x140];
static int if1_count, if2_count;
static int outputPos = 0;
static unsigned char *inflatebuf,  *outputQueue;
#ifdef XXXXX
static void CreateCRCTab(void)
{
    int i;
    for (i = 0; i < 256; i++)
    {
        unsigned k = i, j;
        for (j = 0; j < 8; j++)
        {
            if (k &1)
            {
                k >>= 1;
                k ^= 0xEdB88320;
            }
            else
                k >>= 1;
        }
        CRCtab[i] = k;
    }
}
#endif
//-------------------------------------------------------------------------

static void increment_crc(unsigned char *data, int len)
{
#ifdef XXXXX
    int i;
    for (i = 0; i < len; i++)
        currentcrc = (currentcrc >> 8) ^ CRCtab[ *data++ ^ (unsigned char)
            currentcrc];
#endif
}

//-------------------------------------------------------------------------

static void fetchbyte(void)
{
    accum |= (inflatebuf[inflatepos++]) << 8;
    accum_count = 8;
}

//-------------------------------------------------------------------------

static void shr_n_bits(int count)
{
    if (count >= accum_count)
    {
        accum >>= accum_count;
        count = count - accum_count;
        fetchbyte();
    }
    accum >>= count;
    accum_count -= count;
}

//-------------------------------------------------------------------------

static unsigned get_n_bits_b(int count)
{
    int rv = accum &masktab[count];
    shr_n_bits(count);
    return rv;
}

//-------------------------------------------------------------------------

static unsigned get_n_bits_w(int count)
{
    int rv = get_n_bits_b(8);
    rv += (get_n_bits_b(count - 8) << 8);
    return rv;
}

//-------------------------------------------------------------------------

static unsigned get_n_bits(int count)
{
    if (count > 8)
        return get_n_bits_w(count);
    else
        return get_n_bits_b(count);
}

//-------------------------------------------------------------------------

static void BadTable(void)
{
    longjmp(inflate_badtab, 1);
}

//-------------------------------------------------------------------------

static void ExpandTables(unsigned short *dest2, unsigned short *dest, unsigned char
    *source, int len)
{
    int i;
    short sum = 0, xlen = 0;
    unsigned short *idest;
    if (!len)
        return ;
    memset(intermed_tab, 0, sizeof(intermed_tab));
    for (i = 0; i < len; i++)
        intermed_tab[source[i]]++;
    intermed_tab_2[1] = 0;
    for (i = 1; i < 16; i++)
    {
        sum += intermed_tab[i];
        sum <<= 1;
        intermed_tab_2[i + 1] = sum;
    }
    if (sum)
    {
        sum = 0;
        for (i = 1; i < 16; i++)
            sum += intermed_tab[i];
        if (sum > 1)
        {
            BadTable();
        }

    }
    for (i = 0; i < len; i++)
        if (source[i] == 0)
            intermed_tab_3[i] = 0;
        else
            intermed_tab_3[i] = intermed_tab_2[source[i]]++;

    idest = intermed_tab_3;
    for (i = 0; i < len; i++)
    {
        sum = source[i] - 1;
        if (sum <= 0)
            idest++;
        else
        {
            short shift =  *idest;
            short shift1 = 0;
            do
            {
                shift1 <<= 1;
                if (shift &1)
                    shift1 |= 1;
                shift >>= 1;
            }
            while (--sum && shift != 0);
            shift1 <<= 1;
            if (shift &1)
                shift1 |= 1;
            shift1 <<= sum;
            *(idest)++ = shift1;
        }
    }
    memset(dest, 0, 256 *2);
    idest = intermed_tab_3;
    source += len - 1;
    idest += len - 1;
    for (i = len - 1; i >= 0; i--)
    {
        if (sum =  *source--)
        {
            if (sum > 8)
            {
                short *xdest = dest + (*idest &0xff);
                int j, shift = 1, mask =  *idest >> 8;
                sum -= 8;
                for (j = 0; j < sum; j++)
                {
                    unsigned val;
                    if (*xdest == 0)
                    {
                        *xdest = ~xlen;
                        dest2[xlen] = dest2[xlen + 1] = 0;
                        xlen += 2;
                    }
                    xdest = ~ * xdest + dest2;
                    if (mask &shift)
                        xdest++;
                    shift <<= 1;
                }
                *xdest = i;
            }
            else
            {
                int pos =  *idest;
                sum = 1 << sum;
                do
                {
                    dest[pos] = i;
                    pos += sum;
                }
                while (pos < 0x100);
            }
        }
        idest--;
    }



}

//-------------------------------------------------------------------------

static void GetInflateTables(void)
{
    int v = get_n_bits(2);
    int count, scount, i, len, val, shift;
    unsigned char *xdest;
    switch (v)
    {
        case 0:
             /* copy data in the clear */
            if (accum_count != 8)
                shr_n_bits(accum_count);
            count = accum;
            scount = inflatebuf[inflatepos++];
            scount |= inflatebuf[inflatepos++] << 8;
            if ((((count ^ scount) + 1) & 0xffff) == 0)
            {
                do
                {

                    outputQueue[outputPos++] = inflatebuf[inflatepos++];
                }
                while (--count);
                longjmp(inflate_sync, 1);
            }
            else
            {
                BadTable();
            }

            break;
        case 1:
             /* default tabs */
            memset(inflate_tab_1, 8, 0x90);
            memset(inflate_tab_1 + 0x90, 9, 0x70);
            memset(inflate_tab_1 + 0x100, 7, 0x18);
            memset(inflate_tab_1 + 0x118, 8, 0x8);
            if2_count = 32;
            memset(inflate_tab_2, 5, 32);
            if1_count = 0x120;
            break;
        case 2:
             /* compressed tabs */
            if1_count = get_n_bits(5) + 0x101;
            if2_count = get_n_bits(5) + 1;
            memset(inflate_tab_7, 0, 0x13);
            len = get_n_bits(4) + 4;
            for (i = 0; i < len; i++)
                inflate_tab_7[tab7_rearrange[i]] = get_n_bits(3);
            ExpandTables(tab7_rearrange + len, inflate_tab_8, inflate_tab_7,
                0x13);
            xdest = inflate_tab_1;
            for (i = if1_count + if2_count; i > 0;)
            {
                val = inflate_tab_8[accum &0xff];
                shr_n_bits(inflate_tab_7[val]);
                if (val < 0x10)
                {
                    *xdest++ = val;
                    i--;
                }
                else
                {
                    switch (val)
                    {
                    case 0x10:
                        val = get_n_bits(2) + 3;
                        shift = *(xdest - 1);
                        break;
                    case 0x11:
                        val = get_n_bits(3) + 3;
                        shift = 0;
                        break;
                    default:
                        val = get_n_bits(7) + 11;
                        shift = 0;
                        break;
                    }
                    if ((i -= val) < 0)
                    {
                        BadTable();
                    }
                    memset(xdest, shift, val);
                    xdest += val;
                }
            }
            memcpy(inflate_tab_2, inflate_tab_1 + if1_count, if2_count);
            break;
        case 3:
            BadTable();
            break;

    }
    ExpandTables(inflate_tab_5, inflate_tab_3, inflate_tab_1, if1_count);
    ExpandTables(inflate_tab_6, inflate_tab_4, inflate_tab_2, if2_count);
}

//-------------------------------------------------------------------------

static unsigned fancymove(short b, short *tab, int *count)
{
    short c;
    *count = 0;
    shr_n_bits(8);
    c = accum &0xff;
    do
    {
        b = ~b;
        (*count)++;
        b &= ~1;
        if (c &1)
            b |= 1;
        c >>= 1;
    }
    while ((b = tab[b]) < 0);
    return b;
}

//-------------------------------------------------------------------------

static unsigned consulttabs1(void)
{
    short b = (accum &0xff);
    int count, shift;
    if ((b = inflate_tab_3[b]) >= 0)
        shr_n_bits(count = inflate_tab_1[b]);
    else
    {
        b = fancymove(b, inflate_tab_5, &count);
        shr_n_bits(count);
    }
    if (b < 0x109)
        return b;
    if (b == 0x11d)
    {
        return 0x200;
    }
    b -= 0x101;
    shift = (b >> 2) - 1;
    b = (((b &3) + 4) << shift) + 0x101;
    b += get_n_bits(shift);
    return b;
}

//-------------------------------------------------------------------------

static unsigned consulttabs2(void)
{
    short b = (accum &0xff);
    int count, shift;
    if ((b = inflate_tab_4[b]) >= 0)
        shr_n_bits(count = inflate_tab_2[b]);
    else
    {
        b = fancymove(b, inflate_tab_6, &count);
        shr_n_bits(count);
    }
    if ((b &0xff) >= 4)
    {
        shift = (b &0xff) / 2-1;
        b = ((b &1) + 2) << shift;
        b += get_n_bits(shift);
    }
    return b;
}

//-------------------------------------------------------------------------

int __Inflate(unsigned char *odata, unsigned char *idata)
{
    int i;

    unsigned matchword = 0;

    inflatebuf = idata;
    outputQueue = odata;
    inflatepos = outputPos = 0;
#ifdef XXXXX
    CreateCRCTab();
#endif

    if (setjmp(inflate_badtab))
    {
        printf("Bad Table");
        return 0;
    }
    setjmp(inflate_sync);

    accum = inflatebuf[inflatepos++];
    accum |= inflatebuf[inflatepos++] << 8;
    accum_count = 8;

    while (matchword == 0)
    {
        matchword <<= 1;
        matchword |= accum &1;
        shr_n_bits(1);
        GetInflateTables();
        while (1)
        {
            int val = consulttabs1(), b;
            if (!(val &0xff00))
            {
                outputQueue[outputPos++] = val &0xff;
            }
            else
            {
                char *src;
                if (val == 0x100)
                    break;
                val -= 0xfe;
                b = consulttabs2();
                src = outputQueue + outputPos - 1-b;
                for (i = 0; i < val; i++)
                {
                    outputQueue[outputPos++] =  *src++;
                }
            }
        }
    }
    return 1;
}

