/*---------------------------------------------------------------------------*
  Project:  Horizon
  File:     tpl_crc32.cpp

  Copyright (C)2009-2012 Nintendo Co., Ltd.  All rights reserved.

  These coded instructions, statements, and computer programs contain
  proprietary information of Nintendo of America Inc. and/or Nintendo
  Company Ltd., and are protected by Federal copyright law.  They may
  not be disclosed to third parties or copied or duplicated in any form,
  in whole or in part, without the prior written consent of Nintendo.

  $Rev: 46347 $
 *---------------------------------------------------------------------------*/

#include <stdlib.h>
#include <nn/util.h>
#include <nn/tpl.h>
#include <cstring>

#include "tpl_crc32.h"
#include "tpl_Internal.h"

namespace nn { namespace tpl { namespace CTR {


static const unsigned int _crcTable_[256] =
{
    0x00000000,0x77073096,0xee0e612c,0x990951ba,
    0x076dc419,0x706af48f,0xe963a535,0x9e6495a3,
    0x0edb8832,0x79dcb8a4,0xe0d5e91e,0x97d2d988,
    0x09b64c2b,0x7eb17cbd,0xe7b82d07,0x90bf1d91,
    0x1db71064,0x6ab020f2,0xf3b97148,0x84be41de,
    0x1adad47d,0x6ddde4eb,0xf4d4b551,0x83d385c7,
    0x136c9856,0x646ba8c0,0xfd62f97a,0x8a65c9ec,
    0x14015c4f,0x63066cd9,0xfa0f3d63,0x8d080df5,
    0x3b6e20c8,0x4c69105e,0xd56041e4,0xa2677172,
    0x3c03e4d1,0x4b04d447,0xd20d85fd,0xa50ab56b,
    0x35b5a8fa,0x42b2986c,0xdbbbc9d6,0xacbcf940,
    0x32d86ce3,0x45df5c75,0xdcd60dcf,0xabd13d59,
    0x26d930ac,0x51de003a,0xc8d75180,0xbfd06116,
    0x21b4f4b5,0x56b3c423,0xcfba9599,0xb8bda50f,
    0x2802b89e,0x5f058808,0xc60cd9b2,0xb10be924,
    0x2f6f7c87,0x58684c11,0xc1611dab,0xb6662d3d,
    0x76dc4190,0x01db7106,0x98d220bc,0xefd5102a,
    0x71b18589,0x06b6b51f,0x9fbfe4a5,0xe8b8d433,
    0x7807c9a2,0x0f00f934,0x9609a88e,0xe10e9818,
    0x7f6a0dbb,0x086d3d2d,0x91646c97,0xe6635c01,
    0x6b6b51f4,0x1c6c6162,0x856530d8,0xf262004e,
    0x6c0695ed,0x1b01a57b,0x8208f4c1,0xf50fc457,
    0x65b0d9c6,0x12b7e950,0x8bbeb8ea,0xfcb9887c,
    0x62dd1ddf,0x15da2d49,0x8cd37cf3,0xfbd44c65,
    0x4db26158,0x3ab551ce,0xa3bc0074,0xd4bb30e2,
    0x4adfa541,0x3dd895d7,0xa4d1c46d,0xd3d6f4fb,
    0x4369e96a,0x346ed9fc,0xad678846,0xda60b8d0,
    0x44042d73,0x33031de5,0xaa0a4c5f,0xdd0d7cc9,
    0x5005713c,0x270241aa,0xbe0b1010,0xc90c2086,
    0x5768b525,0x206f85b3,0xb966d409,0xce61e49f,
    0x5edef90e,0x29d9c998,0xb0d09822,0xc7d7a8b4,
    0x59b33d17,0x2eb40d81,0xb7bd5c3b,0xc0ba6cad,
    0xedb88320,0x9abfb3b6,0x03b6e20c,0x74b1d29a,
    0xead54739,0x9dd277af,0x04db2615,0x73dc1683,
    0xe3630b12,0x94643b84,0x0d6d6a3e,0x7a6a5aa8,
    0xe40ecf0b,0x9309ff9d,0x0a00ae27,0x7d079eb1,
    0xf00f9344,0x8708a3d2,0x1e01f268,0x6906c2fe,
    0xf762575d,0x806567cb,0x196c3671,0x6e6b06e7,
    0xfed41b76,0x89d32be0,0x10da7a5a,0x67dd4acc,
    0xf9b9df6f,0x8ebeeff9,0x17b7be43,0x60b08ed5,
    0xd6d6a3e8,0xa1d1937e,0x38d8c2c4,0x4fdff252,
    0xd1bb67f1,0xa6bc5767,0x3fb506dd,0x48b2364b,
    0xd80d2bda,0xaf0a1b4c,0x36034af6,0x41047a60,
    0xdf60efc3,0xa867df55,0x316e8eef,0x4669be79,
    0xcb61b38c,0xbc66831a,0x256fd2a0,0x5268e236,
    0xcc0c7795,0xbb0b4703,0x220216b9,0x5505262f,
    0xc5ba3bbe,0xb2bd0b28,0x2bb45a92,0x5cb36a04,
    0xc2d7ffa7,0xb5d0cf31,0x2cd99e8b,0x5bdeae1d,
    0x9b64c2b0,0xec63f226,0x756aa39c,0x026d930a,
    0x9c0906a9,0xeb0e363f,0x72076785,0x05005713,
    0x95bf4a82,0xe2b87a14,0x7bb12bae,0x0cb61b38,
    0x92d28e9b,0xe5d5be0d,0x7cdcefb7,0x0bdbdf21,
    0x86d3d2d4,0xf1d4e242,0x68ddb3f8,0x1fda836e,
    0x81be16cd,0xf6b9265b,0x6fb077e1,0x18b74777,
    0x88085ae6,0xff0f6a70,0x66063bca,0x11010b5c,
    0x8f659eff,0xf862ae69,0x616bffd3,0x166ccf45,
    0xa00ae278,0xd70dd2ee,0x4e048354,0x3903b3c2,
    0xa7672661,0xd06016f7,0x4969474d,0x3e6e77db,
    0xaed16a4a,0xd9d65adc,0x40df0b66,0x37d83bf0,
    0xa9bcae53,0xdebb9ec5,0x47b2cf7f,0x30b5ffe9,
    0xbdbdf21c,0xcabac28a,0x53b39330,0x24b4a3a6,
    0xbad03605,0xcdd70693,0x54de5729,0x23d967bf,
    0xb3667a2e,0xc4614ab8,0x5d681b02,0x2a6f2b94,
    0xb40bbe37,0xc30c8ea1,0x5a05df1b,0x2d02ef8d,
};

//----------------------------------------------------------------------------
// Calculate CRC32 code for data block.
unsigned int calculate_crc32(
    const void *data,
    unsigned int size)
{
    unsigned int i;
    const unsigned char *m = (const unsigned char *)(data);
    unsigned int crc = 0xffffffff;
    
    for(i = 0; i < size; i++)
    {
        crc = (crc >> 8) ^ _crcTable_[(crc & 0xFF) ^ (unsigned int)(*m) ];
        m++;
    }

    return crc ^ 0xffffffff;
}

//----------------------------------------------------------------------------
// Searches for structure that has CRC32 at the start. (Binary search)
int search_crc32_index(
    const void *_base, unsigned int num, unsigned int width, unsigned int crc)
{
    int n = 0;
    int m = (int)num - 1;
    const char *base = (const char *)_base;

    while(n <= m)
    {
        int c = (n + m) / 2;
        unsigned int k = *(const unsigned int *)(base + (width * c));
        
        // If the data CRC matches the search key, searches for same start values and returns those indices considering that the same value may appear consecutively.
        // 
        if(k == crc)
        {
            while(0 < c)
            {
                unsigned int kk = *(const unsigned int *)(base + (width * (c - 1)));
                if(kk != crc) break;
                c--;
            }
            return c;
        }
        
        // Assuming data is in order by alignment, repeat the process by refining search targets to front and back halves.
        // 
        if(k < crc)
        {
            // Searches the back half since searching for larger values.
            n = c + 1;
        }
        else /* if(crc < k) */
        {
            // Searches the front half since searching for smaller values.
            m = c - 1;
        }
    }

    // Returns -1 if no matching CRC is found.
    return -1;
}


//----------------------------------------------------------------------------
// Gets the texture path string from the texture package memory image.
const char *getTextureFilePath(const void *infoData, int index)
{
    const CtrTexturePackageHeader *header =
        reinterpret_cast<const CtrTexturePackageHeader *>(infoData);
    NN_TASSERT_(index < header->numTexture);

    const CtrTextureInfo *texInfo =
        reinterpret_cast<const CtrTextureInfo *>(header + 1) + index;

    const char *szTexPath =
        reinterpret_cast<const char *>(infoData) + texInfo->filePathOffset;

    return szTexPath;
}

int cmpTpkSearchData(const void *data, const void *value)
{
    const CtrTextureHash &hash = *(const CtrTextureHash *)data;
    const TPK_SEARCH_DATA &s = *(const TPK_SEARCH_DATA *)value;

    // Gets filename recorded in TPK from header information.
    const char *filePath = getTextureFilePath(s.infoData, hash.index);

    // Compares the filename.
    return (::std::strncmp(filePath, s.szFileName, s.fileNameLen) == 0)? 1: 0;
}

//----------------------------------------------------------------------------
// Searches for structure that has CRC32 at the start. (Binary search)
int search_crc32_data(
    const void *_base, unsigned int num, unsigned int width, unsigned int crc,
    const void *value)
{
    const char *base = (const char *)_base;

    // First searches for the index with the CRC32 code.
    // If there is no candidate at this time, -1 is returned and process terminates.
    int t = search_crc32_index(_base, num, width, crc);
    if(t < 0) return -1;

    // Since there can be several of same CRC32 code lined up, compare data in a range where the CRC32 codes matche.
    // 
    for(; t < (int)num; t++)
    {
        // If the CRC32 code is different, no match.
        const unsigned int *k = (const unsigned int *)(base + (width * t));
        if(*k != crc) return -1;

        // Check if the data is really a search target by using a comparison function.
        if(cmpTpkSearchData((const void*)k, value) != 0)
        {
            return t;
        }
    }
    return -1;
}


}}} // Namespace