/* XzEnc.c -- Xz Encode
2015-09-16 : Igor Pavlov : Public domain */

#include "Precomp.h"

#include <stdlib.h>
#include <string.h>

#include "7zCrc.h"
#include "Alloc.h"
#include "Bra.h"
#include "CpuArch.h"

#ifdef USE_SUBBLOCK
#include "Bcj3Enc.c"
#include "SbFind.c"
#include "SbEnc.c"
#endif

#include "XzEnc.h"

#define XzBlock_ClearFlags(p)       (p)->flags = 0;
#define XzBlock_SetNumFilters(p, n) (p)->flags |= ((n) - 1);
#define XzBlock_SetHasPackSize(p)   (p)->flags |= XZ_BF_PACK_SIZE;
#define XzBlock_SetHasUnpackSize(p) (p)->flags |= XZ_BF_UNPACK_SIZE;

static SRes WriteBytes(ISeqOutStream* s, const void* buf, UInt32 size)
{
    return (s->Write(s, buf, size) == size) ? SZ_OK : SZ_ERROR_WRITE;
}

static SRes WriteBytesAndCrc(ISeqOutStream* s, const void* buf, UInt32 size, UInt32* crc)
{
    *crc = CrcUpdate(*crc, buf, size);
    return WriteBytes(s, buf, size);
}

static SRes Xz_WriteHeader(CXzStreamFlags f, ISeqOutStream* s)
{
    UInt32 crc;
    Byte header[XZ_STREAM_HEADER_SIZE];
    memcpy(header, XZ_SIG, XZ_SIG_SIZE);
    header[XZ_SIG_SIZE] = (Byte)(f >> 8);
    header[XZ_SIG_SIZE + 1] = (Byte)(f & 0xFF);
    crc = CrcCalc(header + XZ_SIG_SIZE, XZ_STREAM_FLAGS_SIZE);
    SetUi32(header + XZ_SIG_SIZE + XZ_STREAM_FLAGS_SIZE, crc);
    return WriteBytes(s, header, XZ_STREAM_HEADER_SIZE);
}


static SRes XzBlock_WriteHeader(const CXzBlock* p, ISeqOutStream* s)
{
    Byte header[XZ_BLOCK_HEADER_SIZE_MAX];

    unsigned pos = 1;
    unsigned numFilters, i;
    header[pos++] = p->flags;

    if (XzBlock_HasPackSize(p)) pos += Xz_WriteVarInt(header + pos, p->packSize);
    if (XzBlock_HasUnpackSize(p)) pos += Xz_WriteVarInt(header + pos, p->unpackSize);
    numFilters = XzBlock_GetNumFilters(p);

    for (i = 0; i < numFilters; i++)
    {
        const CXzFilter* f = &p->filters[i];
        pos += Xz_WriteVarInt(header + pos, f->id);
        pos += Xz_WriteVarInt(header + pos, f->propsSize);
        memcpy(header + pos, f->props, f->propsSize);
        pos += f->propsSize;
    }

    while ((pos & 3) != 0)
        header[pos++] = 0;

    header[0] = (Byte)(pos >> 2);
    SetUi32(header + pos, CrcCalc(header, pos));
    return WriteBytes(s, header, pos + 4);
}


static SRes Xz_WriteFooter(CXzStream* p, ISeqOutStream* s)
{
    Byte buf[32];
    UInt64 globalPos;
    {
        UInt32 crc = CRC_INIT_VAL;
        unsigned pos = 1 + Xz_WriteVarInt(buf + 1, p->numBlocks);
        size_t i;

        globalPos = pos;
        buf[0] = 0;
        RINOK(WriteBytesAndCrc(s, buf, pos, &crc));

        for (i = 0; i < p->numBlocks; i++)
        {
            const CXzBlockSizes* block = &p->blocks[i];
            pos = Xz_WriteVarInt(buf, block->totalSize);
            pos += Xz_WriteVarInt(buf + pos, block->unpackSize);
            globalPos += pos;
            RINOK(WriteBytesAndCrc(s, buf, pos, &crc));
        }

        pos = ((unsigned)globalPos & 3);

        if (pos != 0)
        {
            buf[0] = buf[1] = buf[2] = 0;
            RINOK(WriteBytesAndCrc(s, buf, 4 - pos, &crc));
            globalPos += 4 - pos;
        }
        {
            SetUi32(buf, CRC_GET_DIGEST(crc));
            RINOK(WriteBytes(s, buf, 4));
            globalPos += 4;
        }
    }

    {
        UInt32 indexSize = (UInt32)((globalPos >> 2) - 1);
        SetUi32(buf + 4, indexSize);
        buf[8] = (Byte)(p->flags >> 8);
        buf[9] = (Byte)(p->flags & 0xFF);
        SetUi32(buf, CrcCalc(buf + 4, 6));
        memcpy(buf + 10, XZ_FOOTER_SIG, XZ_FOOTER_SIG_SIZE);
        return WriteBytes(s, buf, 12);
    }
}


static SRes Xz_AddIndexRecord(CXzStream* p, UInt64 unpackSize, UInt64 totalSize, ISzAlloc* alloc)
{
    if (!p->blocks || p->numBlocksAllocated == p->numBlocks)
    {
        size_t num = p->numBlocks * 2 + 1;
        size_t newSize = sizeof(CXzBlockSizes) * num;
        CXzBlockSizes* blocks;
        if (newSize / sizeof(CXzBlockSizes) != num)
            return SZ_ERROR_MEM;
        blocks = (CXzBlockSizes*)alloc->Alloc(alloc, newSize);
        if (!blocks)
            return SZ_ERROR_MEM;
        if (p->numBlocks != 0)
        {
            memcpy(blocks, p->blocks, p->numBlocks * sizeof(CXzBlockSizes));
            alloc->Free(alloc, p->blocks);
        }
        p->blocks = blocks;
        p->numBlocksAllocated = num;
    }
    {
        CXzBlockSizes* block = &p->blocks[p->numBlocks++];
        block->unpackSize = unpackSize;
        block->totalSize = totalSize;
    }
    return SZ_OK;
}


/* ---------- CSeqCheckInStream ---------- */

typedef struct
{
    ISeqInStream p;
    ISeqInStream* realStream;
    UInt64 processed;
    CXzCheck check;
} CSeqCheckInStream;

static void SeqCheckInStream_Init(CSeqCheckInStream* p, unsigned mode)
{
    p->processed = 0;
    XzCheck_Init(&p->check, mode);
}

static void SeqCheckInStream_GetDigest(CSeqCheckInStream* p, Byte* digest)
{
    XzCheck_Final(&p->check, digest);
}

static SRes SeqCheckInStream_Read(void* pp, void* data, size_t* size)
{
    CSeqCheckInStream* p = (CSeqCheckInStream*)pp;
    SRes res = p->realStream->Read(p->realStream, data, size);
    XzCheck_Update(&p->check, data, *size);
    p->processed += *size;
    return res;
}


/* ---------- CSeqSizeOutStream ---------- */

typedef struct
{
    ISeqOutStream p;
    ISeqOutStream* realStream;
    UInt64 processed;
} CSeqSizeOutStream;

static size_t MyWrite(void* pp, const void* data, size_t size)
{
    CSeqSizeOutStream* p = (CSeqSizeOutStream*)pp;
    size = p->realStream->Write(p->realStream, data, size);
    p->processed += size;
    return size;
}


/* ---------- CSeqInFilter ---------- */

#define FILTER_BUF_SIZE (1 << 20)

typedef struct
{
    ISeqInStream p;
    ISeqInStream* realStream;
    IStateCoder StateCoder;
    Byte* buf;
    size_t curPos;
    size_t endPos;
    int srcWasFinished;
} CSeqInFilter;

static SRes SeqInFilter_Read(void* pp, void* data, size_t* size)
{
    CSeqInFilter* p = (CSeqInFilter*)pp;
    size_t sizeOriginal = *size;
    if (sizeOriginal == 0)
        return SZ_OK;
    *size = 0;

    for (;;)
    {
        if (!p->srcWasFinished && p->curPos == p->endPos)
        {
            p->curPos = 0;
            p->endPos = FILTER_BUF_SIZE;
            RINOK(p->realStream->Read(p->realStream, p->buf, &p->endPos));
            if (p->endPos == 0)
                p->srcWasFinished = 1;
        }
        {
            SizeT srcLen = p->endPos - p->curPos;
            int wasFinished;
            SRes res;
            *size = sizeOriginal;
            res = p->StateCoder.Code(p->StateCoder.p, data, size, p->buf + p->curPos, &srcLen,
                p->srcWasFinished, CODER_FINISH_ANY, &wasFinished);
            p->curPos += srcLen;
            if (*size != 0 || srcLen == 0 || res != 0)
                return res;
        }
    }
}

static void SeqInFilter_Construct(CSeqInFilter* p)
{
    p->buf = NULL;
    p->p.Read = SeqInFilter_Read;
}

static void SeqInFilter_Free(CSeqInFilter* p)
{
    if (p->buf)
    {
        g_Alloc.Free(&g_Alloc, p->buf);
        p->buf = NULL;
    }
}

SRes BraState_SetFromMethod(IStateCoder* p, UInt64 id, int encodeMode, ISzAlloc* alloc);

static SRes SeqInFilter_Init(CSeqInFilter* p, const CXzFilter* props)
{
    if (!p->buf)
    {
        p->buf = g_Alloc.Alloc(&g_Alloc, FILTER_BUF_SIZE);
        if (!p->buf)
            return SZ_ERROR_MEM;
    }
    p->curPos = p->endPos = 0;
    p->srcWasFinished = 0;
    RINOK(BraState_SetFromMethod(&p->StateCoder, props->id, 1, &g_Alloc));
    RINOK(p->StateCoder.SetProps(p->StateCoder.p, props->props, props->propsSize, &g_Alloc));
    p->StateCoder.Init(p->StateCoder.p);
    return SZ_OK;
}


/* ---------- CSbEncInStream ---------- */

#ifdef USE_SUBBLOCK

typedef struct
{
    ISeqInStream p;
    ISeqInStream* inStream;
    CSbEnc enc;
} CSbEncInStream;

static SRes SbEncInStream_Read(void* pp, void* data, size_t* size)
{
    CSbEncInStream* p = (CSbEncInStream*)pp;
    size_t sizeOriginal = *size;
    if (sizeOriginal == 0)
        return S_OK;

    for (;;)
    {
        if (p->enc.needRead && !p->enc.readWasFinished)
        {
            size_t processed = p->enc.needReadSizeMax;
            RINOK(p->inStream->Read(p->inStream, p->enc.buf + p->enc.readPos, &processed));
            p->enc.readPos += processed;
            if (processed == 0)
            {
                p->enc.readWasFinished = True;
                p->enc.isFinalFinished = True;
            }
            p->enc.needRead = False;
        }

        *size = sizeOriginal;
        RINOK(SbEnc_Read(&p->enc, data, size));
        if (*size != 0 || !p->enc.needRead)
            return S_OK;
    }
}

void SbEncInStream_Construct(CSbEncInStream* p, ISzAlloc* alloc)
{
    SbEnc_Construct(&p->enc, alloc);
    p->p.Read = SbEncInStream_Read;
}

SRes SbEncInStream_Init(CSbEncInStream* p)
{
    return SbEnc_Init(&p->enc);
}

void SbEncInStream_Free(CSbEncInStream* p)
{
    SbEnc_Free(&p->enc);
}

#endif


typedef struct
{
    CLzma2EncHandle lzma2;
#ifdef USE_SUBBLOCK
    CSbEncInStream sb;
#endif
    CSeqInFilter filter;
    ISzAlloc* alloc;
    ISzAlloc* bigAlloc;
} CLzma2WithFilters;


static void Lzma2WithFilters_Construct(CLzma2WithFilters* p, ISzAlloc* alloc, ISzAlloc* bigAlloc)
{
    p->alloc = alloc;
    p->bigAlloc = bigAlloc;
    p->lzma2 = NULL;
#ifdef USE_SUBBLOCK
    SbEncInStream_Construct(&p->sb, alloc);
#endif
    SeqInFilter_Construct(&p->filter);
}

static SRes Lzma2WithFilters_Create(CLzma2WithFilters* p)
{
    p->lzma2 = Lzma2Enc_Create(p->alloc, p->bigAlloc);
    if (!p->lzma2)
        return SZ_ERROR_MEM;
    return SZ_OK;
}

static void Lzma2WithFilters_Free(CLzma2WithFilters* p)
{
    SeqInFilter_Free(&p->filter);
#ifdef USE_SUBBLOCK
    SbEncInStream_Free(&p->sb);
#endif
    if (p->lzma2)
    {
        Lzma2Enc_Destroy(p->lzma2);
        p->lzma2 = NULL;
    }
}


void XzProps_Init(CXzProps* p)
{
    p->lzma2Props = NULL;
    p->filterProps = NULL;
    p->checkId = XZ_CHECK_CRC32;
}

void XzFilterProps_Init(CXzFilterProps* p)
{
    p->id = 0;
    p->delta = 0;
    p->ip = 0;
    p->ipDefined = False;
}


static SRes Xz_Compress(CXzStream* xz, CLzma2WithFilters* lzmaf,
    ISeqOutStream* outStream, ISeqInStream* inStream,
    const CXzProps* props, ICompressProgress* progress)
{
    xz->flags = (Byte)props->checkId;

    RINOK(Lzma2Enc_SetProps(lzmaf->lzma2, props->lzma2Props));
    RINOK(Xz_WriteHeader(xz->flags, outStream));

    {
        CSeqCheckInStream checkInStream;
        CSeqSizeOutStream seqSizeOutStream;
        CXzBlock block;
        unsigned filterIndex = 0;
        CXzFilter* filter = NULL;
        const CXzFilterProps* fp = props->filterProps;

        XzBlock_ClearFlags(&block);
        XzBlock_SetNumFilters(&block, 1 + (fp ? 1 : 0));

        if (fp)
        {
            filter = &block.filters[filterIndex++];
            filter->id = fp->id;
            filter->propsSize = 0;

            if (fp->id == XZ_ID_Delta)
            {
                filter->props[0] = (Byte)(fp->delta - 1);
                filter->propsSize = 1;
            }
            else if (fp->ipDefined)
            {
                SetUi32(filter->props, fp->ip);
                filter->propsSize = 4;
            }
        }

        {
            CXzFilter* f = &block.filters[filterIndex++];
            f->id = XZ_ID_LZMA2;
            f->propsSize = 1;
            f->props[0] = Lzma2Enc_WriteProperties(lzmaf->lzma2);
        }

        seqSizeOutStream.p.Write = MyWrite;
        seqSizeOutStream.realStream = outStream;
        seqSizeOutStream.processed = 0;

        RINOK(XzBlock_WriteHeader(&block, &seqSizeOutStream.p));

        checkInStream.p.Read = SeqCheckInStream_Read;
        checkInStream.realStream = inStream;
        SeqCheckInStream_Init(&checkInStream, XzFlags_GetCheckType(xz->flags));

        if (fp)
        {
#ifdef USE_SUBBLOCK
            if (fp->id == XZ_ID_Subblock)
            {
                lzmaf->sb.inStream = &checkInStream.p;
                RINOK(SbEncInStream_Init(&lzmaf->sb));
            }
            else
#endif
            {
                lzmaf->filter.realStream = &checkInStream.p;
                RINOK(SeqInFilter_Init(&lzmaf->filter, filter));
            }
        }

        {
            UInt64 packPos = seqSizeOutStream.processed;

            SRes res = Lzma2Enc_Encode(lzmaf->lzma2, &seqSizeOutStream.p,
                fp ?
#ifdef USE_SUBBLOCK
                (fp->id == XZ_ID_Subblock) ? &lzmaf->sb.p :
#endif
                & lzmaf->filter.p :
                &checkInStream.p,
                progress);

            RINOK(res);
            block.unpackSize = checkInStream.processed;
            block.packSize = seqSizeOutStream.processed - packPos;
        }

        {
            unsigned padSize = 0;
            Byte buf[128];
            while ((((unsigned)block.packSize + padSize) & 3) != 0)
                buf[padSize++] = 0;
            SeqCheckInStream_GetDigest(&checkInStream, buf + padSize);
            RINOK(WriteBytes(&seqSizeOutStream.p, buf, padSize + XzFlags_GetCheckSize(xz->flags)));
            RINOK(Xz_AddIndexRecord(xz, block.unpackSize, seqSizeOutStream.processed - padSize, &g_Alloc));
        }
    }
    return Xz_WriteFooter(xz, outStream);
}


SRes Xz_Encode(ISeqOutStream* outStream, ISeqInStream* inStream,
    const CXzProps* props, ICompressProgress* progress)
{
    SRes res;
    CXzStream xz;
    CLzma2WithFilters lzmaf;
    Xz_Construct(&xz);
    Lzma2WithFilters_Construct(&lzmaf, &g_Alloc, &g_BigAlloc);
    res = Lzma2WithFilters_Create(&lzmaf);
    if (res == SZ_OK)
        res = Xz_Compress(&xz, &lzmaf, outStream, inStream, props, progress);
    Lzma2WithFilters_Free(&lzmaf);
    Xz_Free(&xz, &g_Alloc);
    return res;
}


SRes Xz_EncodeEmpty(ISeqOutStream* outStream)
{
    SRes res;
    CXzStream xz;
    Xz_Construct(&xz);
    res = Xz_WriteHeader(xz.flags, outStream);
    if (res == SZ_OK)
        res = Xz_WriteFooter(&xz, outStream);
    Xz_Free(&xz, &g_Alloc);
    return res;
}
