/*
 * $Id$
 * Copyright (c) 2008-2010, Matroska (non-profit organisation)
 * All rights reserved.
 *
 * Redistribution and use 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 the Matroska assocation nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY the Matroska association ``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 Matroska Foundation 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 "ebml/ebml.h"
#include "ebml/ebml_internal.h"

struct ebml_crc
{
    ebml_element Base;
    uint32_t CRC;
};

/* Compute the CRC 32 IEEE Little Endian */

const uint32_t CRC32_NEGL = 0xffffffffL;
const uint32_t m_tab[] = {
#ifdef IS_BIG_ENDIAN
	0x00000000L, 0x96300777L, 0x2c610eeeL, 0xba510999L, 0x19c46d07L,
	0x8ff46a70L, 0x35a563e9L, 0xa395649eL, 0x3288db0eL, 0xa4b8dc79L,
	0x1ee9d5e0L, 0x88d9d297L, 0x2b4cb609L, 0xbd7cb17eL, 0x072db8e7L,
	0x911dbf90L, 0x6410b71dL, 0xf220b06aL, 0x4871b9f3L, 0xde41be84L,
	0x7dd4da1aL, 0xebe4dd6dL, 0x51b5d4f4L, 0xc785d383L, 0x56986c13L,
	0xc0a86b64L, 0x7af962fdL, 0xecc9658aL, 0x4f5c0114L, 0xd96c0663L,
	0x633d0ffaL, 0xf50d088dL, 0xc8206e3bL, 0x5e10694cL, 0xe44160d5L,
	0x727167a2L, 0xd1e4033cL, 0x47d4044bL, 0xfd850dd2L, 0x6bb50aa5L,
	0xfaa8b535L, 0x6c98b242L, 0xd6c9bbdbL, 0x40f9bcacL, 0xe36cd832L,
	0x755cdf45L, 0xcf0dd6dcL, 0x593dd1abL, 0xac30d926L, 0x3a00de51L,
	0x8051d7c8L, 0x1661d0bfL, 0xb5f4b421L, 0x23c4b356L, 0x9995bacfL,
	0x0fa5bdb8L, 0x9eb80228L, 0x0888055fL, 0xb2d90cc6L, 0x24e90bb1L,
	0x877c6f2fL, 0x114c6858L, 0xab1d61c1L, 0x3d2d66b6L, 0x9041dc76L,
	0x0671db01L, 0xbc20d298L, 0x2a10d5efL, 0x8985b171L, 0x1fb5b606L,
	0xa5e4bf9fL, 0x33d4b8e8L, 0xa2c90778L, 0x34f9000fL, 0x8ea80996L,
	0x18980ee1L, 0xbb0d6a7fL, 0x2d3d6d08L, 0x976c6491L, 0x015c63e6L,
	0xf4516b6bL, 0x62616c1cL, 0xd8306585L, 0x4e0062f2L, 0xed95066cL,
	0x7ba5011bL, 0xc1f40882L, 0x57c40ff5L, 0xc6d9b065L, 0x50e9b712L,
	0xeab8be8bL, 0x7c88b9fcL, 0xdf1ddd62L, 0x492dda15L, 0xf37cd38cL,
	0x654cd4fbL, 0x5861b24dL, 0xce51b53aL, 0x7400bca3L, 0xe230bbd4L,
	0x41a5df4aL, 0xd795d83dL, 0x6dc4d1a4L, 0xfbf4d6d3L, 0x6ae96943L,
	0xfcd96e34L, 0x468867adL, 0xd0b860daL, 0x732d0444L, 0xe51d0333L,
	0x5f4c0aaaL, 0xc97c0dddL, 0x3c710550L, 0xaa410227L, 0x10100bbeL,
	0x86200cc9L, 0x25b56857L, 0xb3856f20L, 0x09d466b9L, 0x9fe461ceL,
	0x0ef9de5eL, 0x98c9d929L, 0x2298d0b0L, 0xb4a8d7c7L, 0x173db359L,
	0x810db42eL, 0x3b5cbdb7L, 0xad6cbac0L, 0x2083b8edL, 0xb6b3bf9aL,
	0x0ce2b603L, 0x9ad2b174L, 0x3947d5eaL, 0xaf77d29dL, 0x1526db04L,
	0x8316dc73L, 0x120b63e3L, 0x843b6494L, 0x3e6a6d0dL, 0xa85a6a7aL,
	0x0bcf0ee4L, 0x9dff0993L, 0x27ae000aL, 0xb19e077dL, 0x44930ff0L,
	0xd2a30887L, 0x68f2011eL, 0xfec20669L, 0x5d5762f7L, 0xcb676580L,
	0x71366c19L, 0xe7066b6eL, 0x761bd4feL, 0xe02bd389L, 0x5a7ada10L,
	0xcc4add67L, 0x6fdfb9f9L, 0xf9efbe8eL, 0x43beb717L, 0xd58eb060L,
	0xe8a3d6d6L, 0x7e93d1a1L, 0xc4c2d838L, 0x52f2df4fL, 0xf167bbd1L,
	0x6757bca6L, 0xdd06b53fL, 0x4b36b248L, 0xda2b0dd8L, 0x4c1b0aafL,
	0xf64a0336L, 0x607a0441L, 0xc3ef60dfL, 0x55df67a8L, 0xef8e6e31L,
	0x79be6946L, 0x8cb361cbL, 0x1a8366bcL, 0xa0d26f25L, 0x36e26852L,
	0x95770cccL, 0x03470bbbL, 0xb9160222L, 0x2f260555L, 0xbe3bbac5L,
	0x280bbdb2L, 0x925ab42bL, 0x046ab35cL, 0xa7ffd7c2L, 0x31cfd0b5L,
	0x8b9ed92cL, 0x1daede5bL, 0xb0c2649bL, 0x26f263ecL, 0x9ca36a75L,
	0x0a936d02L, 0xa906099cL, 0x3f360eebL, 0x85670772L, 0x13570005L,
	0x824abf95L, 0x147ab8e2L, 0xae2bb17bL, 0x381bb60cL, 0x9b8ed292L,
	0x0dbed5e5L, 0xb7efdc7cL, 0x21dfdb0bL, 0xd4d2d386L, 0x42e2d4f1L,
	0xf8b3dd68L, 0x6e83da1fL, 0xcd16be81L, 0x5b26b9f6L, 0xe177b06fL,
	0x7747b718L, 0xe65a0888L, 0x706a0fffL, 0xca3b0666L, 0x5c0b0111L,
	0xff9e658fL, 0x69ae62f8L, 0xd3ff6b61L, 0x45cf6c16L, 0x78e20aa0L,
	0xeed20dd7L, 0x5483044eL, 0xc2b30339L, 0x612667a7L, 0xf71660d0L,
	0x4d476949L, 0xdb776e3eL, 0x4a6ad1aeL, 0xdc5ad6d9L, 0x660bdf40L,
	0xf03bd837L, 0x53aebca9L, 0xc59ebbdeL, 0x7fcfb247L, 0xe9ffb530L,
	0x1cf2bdbdL, 0x8ac2bacaL, 0x3093b353L, 0xa6a3b424L, 0x0536d0baL,
	0x9306d7cdL, 0x2957de54L, 0xbf67d923L, 0x2e7a66b3L, 0xb84a61c4L,
	0x021b685dL, 0x942b6f2aL, 0x37be0bb4L, 0xa18e0cc3L, 0x1bdf055aL,
	0x8def022dL
#else
	0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
	0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
	0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
	0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
	0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
	0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
	0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
	0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
	0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
	0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
	0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
	0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
	0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
	0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
	0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
	0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
	0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
	0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
	0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
	0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
	0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
	0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
	0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
	0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
	0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
	0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
	0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
	0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
	0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
	0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
	0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
	0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
	0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
	0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
	0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
	0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
	0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
	0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
	0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
	0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
	0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
	0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
	0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
	0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
	0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
	0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
	0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
	0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
	0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
	0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
	0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
	0x2d02ef8dL
#endif
};

#ifdef IS_BIG_ENDIAN
# define CRC32_INDEX(c) (c >> 24)
# define CRC32_SHIFTED(c) (c << 8)
#else
# define CRC32_INDEX(c) (c & 0xff)
# define CRC32_SHIFTED(c) (c >> 8)
#endif

static bool_t ValidateSize(const ebml_element *p)
{
    return EBML_ElementIsFiniteSize(p) && (p->DataSize == 4);
}

static err_t ReadData(ebml_crc *Element, stream *Input, const ebml_parser_context *ParserContext, bool_t AllowDummyElt, int Scope, size_t DepthCheckCRC)
{
    err_t Result;
    uint32_t CRCbuffer;
    Result = Stream_Read(Input,&CRCbuffer,4,NULL);
    if (Result == ERR_NONE)
    {
        Element->CRC = LOAD32LE(&CRCbuffer);
        Element->Base.bValueIsSet = 1;
    }
    return Result;
}

#if defined(CONFIG_EBML_WRITING)
static err_t RenderData(ebml_crc *Element, stream *Output, bool_t bForceWithoutMandatory, bool_t bWithDefault, filepos_t *Rendered)
{
    err_t Result;
    size_t Written = 0;
    uint8_t Buf[4];
    STORE32LE(Buf,Element->CRC);
    Result = Stream_Write(Output, Buf, 4, &Written);
    if (Rendered)
        *Rendered = Written;
    return Result;
}
#endif

static ebml_crc *Copy(const ebml_crc *Element, const void *Cookie)
{
    ebml_crc *Result = (ebml_crc*)EBML_ElementCreate(Element,Element->Base.Context,0,Cookie);
    if (Result)
    {
        Result->CRC = Element->CRC;
        Result->Base.bValueIsSet = Element->Base.bValueIsSet;
        Result->Base.DataSize = Element->Base.DataSize;
        Result->Base.ElementPosition = Element->Base.ElementPosition;
        Result->Base.SizeLength = Element->Base.SizeLength;
        Result->Base.SizePosition = Element->Base.SizePosition;
        Result->Base.bNeedDataSizeUpdate = Element->Base.bNeedDataSizeUpdate;
    }
    return Result;
}

static bool_t IsDefaultValue(const ebml_element *Element)
{
    return 0; // CRC has no default value
}

static err_t Create(ebml_crc *Element)
{
    Element->CRC = CRC32_NEGL;
    Element->Base.bNeedDataSizeUpdate = 0;
    Element->Base.DataSize = 4;
    return ERR_NONE;
}

META_START(EBMLCRC_Class,EBML_CRC_CLASS)
META_CLASS(SIZE,sizeof(ebml_crc))
META_CLASS(CREATE,Create)
META_VMT(TYPE_FUNC,ebml_element_vmt,ValidateSize,ValidateSize)
META_VMT(TYPE_FUNC,ebml_element_vmt,ReadData,ReadData)
META_VMT(TYPE_FUNC,ebml_element_vmt,Copy,Copy)
META_VMT(TYPE_FUNC,ebml_element_vmt,IsDefaultValue,IsDefaultValue)
#if defined(CONFIG_EBML_WRITING)
META_VMT(TYPE_FUNC,ebml_element_vmt,RenderData,RenderData)
#endif
META_END(EBML_ELEMENT_CLASS)

bool_t EBML_CRCMatches(ebml_crc *CRC, const uint8_t *Buf, size_t Size)
{
    uint32_t testCRC = CRC32_NEGL;

    assert(CRC->Base.bValueIsSet);

/* TODO: needed for non aligned memory ?
	for(; !aligned(Buf) && Size > 0; Size--)
		testCRC = m_tab[CRC32_INDEX(testCRC) ^ *Buf++] ^ CRC32_SHIFTED(testCRC);
*/
	while (Size >= 4)
	{
		testCRC ^= *(const uint32_t *)Buf;
		testCRC = m_tab[CRC32_INDEX(testCRC)] ^ CRC32_SHIFTED(testCRC);
		testCRC = m_tab[CRC32_INDEX(testCRC)] ^ CRC32_SHIFTED(testCRC);
		testCRC = m_tab[CRC32_INDEX(testCRC)] ^ CRC32_SHIFTED(testCRC);
		testCRC = m_tab[CRC32_INDEX(testCRC)] ^ CRC32_SHIFTED(testCRC);
		Size -= 4;
		Buf += 4;
	}

	while (Size--)
		testCRC = m_tab[CRC32_INDEX(testCRC) ^ *Buf++] ^ CRC32_SHIFTED(testCRC);

	testCRC ^= CRC32_NEGL;

    return (CRC->CRC == testCRC);
}

void EBML_CRCAddBuffer(ebml_crc *CRC, const uint8_t *Buf, size_t Size)
{
	while (Size >= 4)
	{
		CRC->CRC ^= *(const uint32_t *)Buf;
		CRC->CRC = m_tab[CRC32_INDEX(CRC->CRC)] ^ CRC32_SHIFTED(CRC->CRC);
		CRC->CRC = m_tab[CRC32_INDEX(CRC->CRC)] ^ CRC32_SHIFTED(CRC->CRC);
		CRC->CRC = m_tab[CRC32_INDEX(CRC->CRC)] ^ CRC32_SHIFTED(CRC->CRC);
		CRC->CRC = m_tab[CRC32_INDEX(CRC->CRC)] ^ CRC32_SHIFTED(CRC->CRC);
		Size -= 4;
		Buf += 4;
	}

	while (Size--)
		CRC->CRC = m_tab[CRC32_INDEX(CRC->CRC) ^ *Buf++] ^ CRC32_SHIFTED(CRC->CRC);
}

void EBML_CRCFinalize(ebml_crc *CRC)
{
	CRC->CRC ^= CRC32_NEGL;
    CRC->Base.DataSize = 4;
    CRC->Base.bValueIsSet = 1;
}
