/* Lzma86Enc.c -- LZMA + x86 (BCJ) Filter Encoder
2016-05-16 : Igor Pavlov : Public domain */

#include "Precomp.h"

#include <string.h>

#include "Lzma86.h"

#include "Alloc.h"
#include "Bra.h"
#include "LzmaEnc.h"

#define SZE_OUT_OVERFLOW SZE_DATA_ERROR

int Lzma86_Encode(Byte* dest, size_t* destLen, const Byte* src, size_t srcLen,
    int level, UInt32 dictSize, int filterMode)
{
    size_t outSize2 = *destLen;
    Byte* filteredStream;
    Bool useFilter;
    int mainResult = SZ_ERROR_OUTPUT_EOF;
    CLzmaEncProps props;
    LzmaEncProps_Init(&props);
    props.level = level;
    props.dictSize = dictSize;

    *destLen = 0;
    if (outSize2 < LZMA86_HEADER_SIZE)
        return SZ_ERROR_OUTPUT_EOF;

    {
        int i;
        UInt64 t = srcLen;
        for (i = 0; i < 8; i++, t >>= 8)
            dest[LZMA86_SIZE_OFFSET + i] = (Byte)t;
    }

    filteredStream = 0;
    useFilter = (filterMode != SZ_FILTER_NO);
    if (useFilter)
    {
        if (srcLen != 0)
        {
            filteredStream = (Byte*)MyAlloc(srcLen);
            if (filteredStream == 0)
                return SZ_ERROR_MEM;
            memcpy(filteredStream, src, srcLen);
        }
        {
            UInt32 x86State;
            x86_Convert_Init(x86State);
            x86_Convert(filteredStream, srcLen, 0, &x86State, 1);
        }
    }

    {
        size_t minSize = 0;
        Bool bestIsFiltered = False;

        /* passes for SZ_FILTER_AUTO:
            0 - BCJ + LZMA
            1 - LZMA
            2 - BCJ + LZMA agaian, if pass 0 (BCJ + LZMA) is better.
        */
        int numPasses = (filterMode == SZ_FILTER_AUTO) ? 3 : 1;

        int i;
        for (i = 0; i < numPasses; i++)
        {
            size_t outSizeProcessed = outSize2 - LZMA86_HEADER_SIZE;
            size_t outPropsSize = 5;
            SRes curRes;
            Bool curModeIsFiltered = (numPasses > 1 && i == numPasses - 1);
            if (curModeIsFiltered && !bestIsFiltered)
                break;
            if (useFilter && i == 0)
                curModeIsFiltered = True;

            curRes = LzmaEncode(dest + LZMA86_HEADER_SIZE, &outSizeProcessed,
                curModeIsFiltered ? filteredStream : src, srcLen,
                &props, dest + 1, &outPropsSize, 0,
                NULL, &g_Alloc, &g_Alloc);

            if (curRes != SZ_ERROR_OUTPUT_EOF)
            {
                if (curRes != SZ_OK)
                {
                    mainResult = curRes;
                    break;
                }
                if (outSizeProcessed <= minSize || mainResult != SZ_OK)
                {
                    minSize = outSizeProcessed;
                    bestIsFiltered = curModeIsFiltered;
                    mainResult = SZ_OK;
                }
            }
        }
        dest[0] = (Byte)(bestIsFiltered ? 1 : 0);
        *destLen = LZMA86_HEADER_SIZE + minSize;
    }
    if (useFilter)
        MyFree(filteredStream);
    return mainResult;
}
