/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

#include <oox/ole/vbaexport.hxx>

#include <tools/stream.hxx>

#include <com/sun/star/script/XLibraryContainer.hpp>
#include <com/sun/star/frame/XModel.hpp>

#include <oox/helper/binaryoutputstream.hxx>
#include "oox/helper/propertyset.hxx"
#include "oox/token/properties.hxx"

#define USE_UTF8_CODEPAGE 0
#if USE_UTF8_CODEPAGE
#define CODEPAGE_MS 65001
#define CODEPAGE RTL_TEXTENCODING_UTF8
#else
#define CODEPAGE_MS 1252
#define CODEPAGE RTL_TEXTENCODING_MS_1252
#endif

namespace {

void exportString(SvStream& rStrm, const OUString& rString)
{
    OString aStringCorrectCodepage = OUStringToOString(rString, CODEPAGE);
    rStrm.WriteOString(aStringCorrectCodepage);
}

void exportUTF16String(SvStream& rStrm, const OUString& rString)
{
    sal_Int32 n = rString.getLength();
    const sal_Unicode* pString = rString.getStr();
    for (sal_Int32 i = 0; i < n; ++i)
    {
        sal_Unicode character = pString[i];
        rStrm.WriteUnicode(character);
    }
}

class VBACompressionChunk
{
public:

    VBACompressionChunk(SvStream& rCompressedStream, const sal_uInt8* pData, sal_Size nChunkSize);

    void write();

private:
    SvStream& mrCompressedStream;
    const sal_uInt8* mpUncompressedData;
    sal_uInt8* mpCompressedChunkStream;

    // same as DecompressedChunkEnd in the spec
    sal_Size mnChunkSize;

    // CompressedCurrent according to the spec
    sal_uInt64 mnCompressedCurrent;

    // CompressedEnd according to the spec
    sal_uInt64 mnCompressedEnd;

    // DecompressedCurrent according to the spec
    sal_uInt64 mnDecompressedCurrent;

    // DecompressedEnd according to the spec
    sal_uInt64 mnDecompressedEnd;

    // Start of the current decompressed chunk
    sal_uInt64 mnChunkStart;

    void PackCompressedChunkSize(size_t nSize, sal_uInt16& rHeader);

    void PackCompressedChunkFlag(bool bCompressed, sal_uInt16& rHeader);

    void PackCompressedChunkSignature(sal_uInt16& rHeader);

    void compressTokenSequence();

    void compressToken(size_t index, sal_uInt8& nFlagByte);

    void SetFlagBit(size_t index, bool bVal, sal_uInt8& rFlag);

    sal_uInt16 CopyToken(size_t nLength, size_t nOffset);

    void match(size_t& rLength, size_t& rOffset);

    void CopyTokenHelp(sal_uInt16& rLengthMask, sal_uInt16& rOffsetMask,
            sal_uInt16& rBitCount, sal_uInt16& rMaximumLength);

    void writeRawChunk();
};

VBACompressionChunk::VBACompressionChunk(SvStream& rCompressedStream, const sal_uInt8* pData, sal_Size nChunkSize):
    mrCompressedStream(rCompressedStream),
    mpUncompressedData(pData),
    mnChunkSize(nChunkSize)
{
}

// section 2.4.1.3.7
void VBACompressionChunk::write()
{
    mnChunkStart = mrCompressedStream.Tell();

    // we need to fill these two bytes later
    mrCompressedStream.WriteUInt16(0x0);

    mnDecompressedCurrent = 0;
    mnCompressedCurrent = 2;
    mnCompressedEnd = 4098;
    mnDecompressedEnd = std::min<sal_uInt64>(4096, mnChunkSize);

    // if that stream becomes larger than 4096 bytes then
    // we use the uncompressed stream
    sal_uInt8 pCompressedChunkStream[4098];
    mpCompressedChunkStream = pCompressedChunkStream;

    while (mnDecompressedCurrent < mnDecompressedEnd
            && mnCompressedCurrent < mnCompressedEnd)
    {
        // compress token sequence
        compressTokenSequence();
    }

    bool bCompressedFlag = true;
    if (mnDecompressedCurrent < mnDecompressedEnd)
    {
        writeRawChunk();
        bCompressedFlag = false;
    }
    else
    {
        // copy the compressed stream to our output stream
        mrCompressedStream.Write(pCompressedChunkStream, mnCompressedCurrent);
    }

    // handle header bytes
    size_t nSize = mnCompressedCurrent;
    sal_uInt16 nHeader = 0;
    PackCompressedChunkSize(nSize, nHeader);
    PackCompressedChunkFlag(bCompressedFlag, nHeader);
    PackCompressedChunkSignature(nHeader);

    // overwrite the two bytes
    sal_uInt64 nEnd = mrCompressedStream.Tell();
    mrCompressedStream.Seek(mnChunkStart);
    mrCompressedStream.WriteUInt16(nHeader);
    mrCompressedStream.Seek(nEnd);
}

// section 2.4.1.3.13
void VBACompressionChunk::PackCompressedChunkSize(size_t nSize, sal_uInt16& rHeader)
{
    sal_uInt16 nTemp1 = rHeader & 0xF000;
    sal_uInt16 nTemp2 = nSize - 3;
    rHeader = nTemp1 | nTemp2;
}

// section 2.4.1.3.16
void VBACompressionChunk::PackCompressedChunkFlag(bool bCompressed, sal_uInt16& rHeader)
{
    sal_uInt16 nTemp1 = rHeader & 0x7FFF;
    sal_uInt16 nTemp2 = ((sal_uInt16)bCompressed) << 15;
    rHeader = nTemp1 | nTemp2;
}

// section 2.4.1.3.14
void VBACompressionChunk::PackCompressedChunkSignature(sal_uInt16& rHeader)
{
    sal_Int32 nTemp = rHeader & 0x8FFFF;
    rHeader = nTemp | 0x3000;
}

// section 2.4.1.3.8
void VBACompressionChunk::compressTokenSequence()
{
    sal_uInt64 nFlagByteIndex = mnCompressedCurrent;
    sal_uInt8 nFlagByte = 0;
    ++mnCompressedCurrent;
    for (size_t index = 0; index <= 7; ++index)
    {
        if (mnDecompressedCurrent < mnDecompressedEnd
                && mnCompressedCurrent < mnCompressedEnd)
        {
            compressToken(index, nFlagByte);
        }
    }
    mpCompressedChunkStream[nFlagByteIndex] = nFlagByte;
}

void setUInt16(sal_uInt8* pBuffer, size_t nPos, sal_uInt16 nVal)
{
    pBuffer[nPos] = nVal & 0xFFFF;
    pBuffer[nPos+1] = (nVal & 0xFFFF0000) >> 8;
}

// section 2.4.1.3.9
void VBACompressionChunk::compressToken(size_t index, sal_uInt8& nFlagByte)
{
    size_t nLength = 0;
    size_t nOffset = 0;
    match(nLength, nOffset);
    if (nOffset != 0)
    {
        if (mnCompressedCurrent + 1 < mnCompressedEnd)
        {
            sal_uInt16 nToken = CopyToken(nLength, nOffset);
            setUInt16(mpCompressedChunkStream, mnCompressedCurrent, nToken);
            SetFlagBit(index, 1, nFlagByte);
            mnCompressedCurrent += 2;
            mnDecompressedCurrent += nLength;
        }
        else
        {
            mnCompressedCurrent = mnCompressedEnd;
        }
    }
    else
    {
        if (mnCompressedCurrent + 1 < mnCompressedEnd)
        {
            mpCompressedChunkStream[mnCompressedCurrent] = mpUncompressedData[mnDecompressedCurrent];
            ++mnCompressedCurrent;
            ++mnDecompressedCurrent;
        }
        else
        {
            mnCompressedCurrent = mnCompressedEnd;
        }
    }
}

// section 2.4.1.3.18
void VBACompressionChunk::SetFlagBit(size_t index, bool bVal, sal_uInt8& rFlag)
{
    size_t nTemp1 = ((int)bVal) << index;
    sal_uInt8 nTemp2 = rFlag & (~nTemp1);
    rFlag = nTemp2 | nTemp1;
}

// section 2.4.1.3.19.3
sal_uInt16 VBACompressionChunk::CopyToken(size_t nLength, size_t nOffset)
{
    sal_uInt16 nLengthMask = 0;
    sal_uInt16 nOffsetMask = 0;
    sal_uInt16 nBitCount = 0;
    sal_uInt16 nMaxLength;
    CopyTokenHelp(nLengthMask, nOffsetMask, nBitCount, nMaxLength);
    sal_uInt16 nTemp1 = nOffset -1;
    sal_uInt16 nTemp2 = 16 - nBitCount;
    sal_uInt16 nTemp3 = nLength - 3;
    sal_uInt16 nToken = (nTemp1 << nTemp2) | nTemp3;
    return nToken;
}

// section 2.4.1.3.19.4
void VBACompressionChunk::match(size_t& rLength, size_t& rOffset)
{
    size_t nBestLen = 0;
    sal_Int32 nCandidate = mnDecompressedCurrent - 1;
    sal_Int32 nBestCandidate = nCandidate;
    while (nCandidate >= 0)
    {
        sal_Int32 nC = nCandidate;
        sal_Int32 nD = mnDecompressedCurrent;
        size_t nLen = 0;
        while (nD < static_cast<sal_Int32>(mnChunkSize) // TODO: check if this needs to be including a minus -1
                && mpUncompressedData[nC] == mpUncompressedData[nD])
        {
            ++nLen;
            ++nC;
            ++nD;
        }
        if (nLen > nBestLen)
        {
            nBestLen = nLen;
            nBestCandidate = nCandidate;
        }
        --nCandidate;
    }

    if (nBestLen >= 3)
    {
        sal_uInt16 nMaximumLength = 0;
        sal_uInt16 nLengthMask, nOffsetMask, nBitCount;
        CopyTokenHelp(nLengthMask, nOffsetMask, nBitCount, nMaximumLength);
        rLength = std::min<sal_uInt16>(nMaximumLength, nBestLen);
        rOffset = mnDecompressedCurrent - nBestCandidate;
    }
    else
    {
        rLength = 0;
        rOffset = 0;
    }
}

// section 2.4.1.3.19.1
void VBACompressionChunk::CopyTokenHelp(sal_uInt16& rLengthMask, sal_uInt16& rOffsetMask,
        sal_uInt16& rBitCount, sal_uInt16& rMaximumLength)
{
    sal_uInt16 nDifference = mnDecompressedCurrent;
    sal_uInt16 nBitCount = std::ceil(std::log2(nDifference));
    rBitCount = std::max<sal_uInt16>(nBitCount, 4);
    rLengthMask = 0xffff >> rBitCount;
    rOffsetMask = ~rLengthMask;
    rMaximumLength = rLengthMask + 3;
}

// section 2.4.1.3.10
void VBACompressionChunk::writeRawChunk()
{
    // we need to use up to 4096 bytes of the original stream
    // and fill the rest with padding
    mrCompressedStream.Write(mpUncompressedData, mnChunkSize);
    sal_Size nPadding = 4096 - mnChunkSize;
    for (size_t i = 0; i < nPadding; ++i)
    {
        mrCompressedStream.WriteUInt8(0);
    }
}

class VBACompression
{
public:
    VBACompression(SvStream& rCompressedStream,
            SvMemoryStream& rUncompressedStream);

    void write();

private:
    SvStream& mrCompressedStream;
    SvMemoryStream& mrUncompressedStream;
};

VBACompression::VBACompression(SvStream& rCompressedStream,
        SvMemoryStream& rUncompressedStream):
    mrCompressedStream(rCompressedStream),
    mrUncompressedStream(rUncompressedStream)
{
}

// section 2.4.1.3.6
void VBACompression::write()
{
    // section 2.4.1.1.1
    mrCompressedStream.WriteUInt8(0x01); // signature byte of a compressed container
    bool bStreamNotEnded = true;
    const sal_uInt8* pData = (const sal_uInt8*)mrUncompressedStream.GetData();
    sal_Size nSize = mrUncompressedStream.GetEndOfData();
    sal_Size nRemainingSize = nSize;
    while(bStreamNotEnded)
    {
        sal_Size nChunkSize = nRemainingSize > 4096 ? 4096 : nRemainingSize;
        VBACompressionChunk aChunk(mrCompressedStream, &pData[nSize - nRemainingSize], nChunkSize);

        // update the uncompressed chunk start marker
        nRemainingSize -= nChunkSize;
        bStreamNotEnded = nRemainingSize != 0;
    }
}

}

VbaExport::VbaExport(css::uno::Reference<css::frame::XModel> xModel):
    mxModel(xModel)
{
    maProjectName = "How to get the correct project name?";
}

namespace {

// section 2.3.4.2.1.1
void writePROJECTSYSKIND(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0001); // id
    rStrm.WriteUInt32(0x00000004); // size
    rStrm.WriteUInt32(0x00000001); // SysKind, hard coded to 32-bin windows for now
}

// section 2.3.4.2.1.2
void writePROJECTLCID(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0002); // id
    rStrm.WriteUInt32(0x00000004); // size
    rStrm.WriteUInt32(0x00000409); // Lcid
}

// section 2.3.4.2.1.3
void writePROJECTLCIDINVOKE(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0014); // id
    rStrm.WriteUInt32(0x00000004); // size
    rStrm.WriteUInt32(0x00000409); // LcidInvoke
}

// section 2.3.4.2.1.4
void writePROJECTCODEPAGE(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0003); // id
    rStrm.WriteUInt32(0x00000002); // size
    rStrm.WriteUInt16(CODEPAGE_MS); // CodePage
}

//section 2.3.4.2.1.5
void writePROJECTNAME(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0004); // id
    sal_uInt32 sizeOfProjectName = 0x0000000a; // for project name "VBAProject"
    rStrm.WriteUInt32(sizeOfProjectName); // sizeOfProjectName
    exportString(rStrm, "VBAProject"); // ProjectName
}

//section 2.3.4.2.1.6
void writePROJECTDOCSTRING(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0005); // id
    rStrm.WriteUInt32(0x00000000); // sizeOfDocString
    rStrm.WriteUInt16(0x0040); // Reserved
    rStrm.WriteUInt32(0x00000000); // sizeOfDocStringUnicode, MUST be even
}

//section 2.3.4.2.1.7
void writePROJECTHELPFILEPATH(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0006); // id
    rStrm.WriteUInt32(0x00000000); // sizeOfHelpFile1
    rStrm.WriteUInt16(0x003D); // Reserved
    rStrm.WriteUInt32(0x00000000); // sizeOfHelpFile2
}

//section 2.3.4.2.1.8
void writePROJECTHELPCONTEXT(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0007); // id
    rStrm.WriteUInt32(0x00000004); // size
    rStrm.WriteUInt32(0x00000000); // HelpContext
}

//section 2.3.4.2.1.9
void writePROJECTLIBFLAGS(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0008); // id
    rStrm.WriteUInt32(0x00000004); // size
    rStrm.WriteUInt32(0x00000000); // ProjectLibFlags
}

//section 2.3.4.2.1.10
void writePROJECTVERSION(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0009); // id
    rStrm.WriteUInt32(0x00000004); // Reserved
    rStrm.WriteUInt32(1467127224); // VersionMajor // TODO: where is this magic number comming from
    rStrm.WriteUInt16(5); // VersionMinor // TODO: where is this magic number coming from
}

//section 2.3.4.2.1.11
void writePROJECTCONSTANTS(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x000C); // id
    rStrm.WriteUInt32(0x00000000); // sizeOfConstants
    rStrm.WriteUInt16(0x003C); // Reserved
    rStrm.WriteUInt32(0x00000000); // sizeOfConstantsUnicode
}

// section 2.3.4.2.1
void writePROJECTINFORMATION(SvStream& rStrm)
{
    writePROJECTSYSKIND(rStrm);
    writePROJECTLCID(rStrm);
    writePROJECTLCIDINVOKE(rStrm);
    writePROJECTCODEPAGE(rStrm);
    writePROJECTNAME(rStrm);
    writePROJECTDOCSTRING(rStrm);
    writePROJECTHELPFILEPATH(rStrm);
    writePROJECTHELPCONTEXT(rStrm);
    writePROJECTLIBFLAGS(rStrm);
    writePROJECTVERSION(rStrm);
    writePROJECTCONSTANTS(rStrm);
}

// section 2.3.4.2.2.2
void writeREFERENCENAME(SvStream& rStrm, const OUString name)
{
    rStrm.WriteUInt16(0x0016); // id
    sal_Int32 size = name.getLength();
    rStrm.WriteUInt32(size); // sizeOfName
    exportString(rStrm, name); // name
    rStrm.WriteUInt16(0x003E); // reserved
    sal_Int32 unicodesize = size * 2;
    rStrm.WriteUInt32(unicodesize); // sizeOfNameUnicode
    exportUTF16String(rStrm, name); // nameUnicode
}

// section 2.3.4.2.2.5
void writeREFERENCEREGISTERED(SvStream& rStrm, const OUString libid)
{
    rStrm.WriteUInt16(0x000D); // id
    sal_Int32 sizeOfLibid = libid.getLength();
    sal_Int32 size = sizeOfLibid + 10; // size of Libid, sizeOfLibid(4 bytes), reserved 1(4 bytes) and reserved 2(2 bytes)
    rStrm.WriteUInt32(size); // size
    rStrm.WriteUInt32(sizeOfLibid); // sizeOfLibid
    exportString(rStrm, libid); // Libid
    rStrm.WriteUInt32(0x00000000); // reserved 1
    rStrm.WriteUInt16(0x0000); // reserved 2
}

// section 2.3.4.2.2.1
void writeREFERENCE(SvStream& rStrm, const OUString name, const OUString libid)
{
    writeREFERENCENAME(rStrm, name);
    writeREFERENCEREGISTERED(rStrm, libid);
}

// section 2.3.4.2.2
void writePROJECTREFERENCES(SvStream& rStrm)
{
    // TODO: find out where these references are coming from
    writeREFERENCE(rStrm, "stdole", "*\\G{00020430-0000-0000-C000-000000000046}#2.0#0#C:\\Windows\\SysWOW64\\stdole2.tlb#OLE Automation");
    writeREFERENCE(rStrm, "Office", "*\\G{2DF8D04C-5BFA-101B-BDE5-00AA0044DE52}#2.0#0#C:\\Program Files (x86)\\Common Files\\Microsoft Shared\\OFFICE14\\MSO.DLL#Microsoft Office 14.0 Object Library");
}

// section 2.3.4.2.3.1
void writePROJECTCOOKIE(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0013); // id
    rStrm.WriteUInt32(0x00000002); // size
    rStrm.WriteUInt16(0xFFFF); // cookie
}

// section 2.3.4.2.3.2.1
void writeMODULENAME(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0019); // id
    rStrm.WriteUInt32(7); // sizeOfModuleName
    exportString(rStrm, "Module1"); // ModuleName // TODO: dependent on the document
}

// section 2.3.4.2.3.2.2
void writeMODULENAMEUNICODE(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x0047); // id
    rStrm.WriteUInt32(14); // sizeOfModuleName
    exportUTF16String(rStrm, "Module1"); // ModuleName // TODO: dependent on the document
}

// section 2.3.4.2.3.2.3
void writeMODULESTREAMNAME(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x001A); // id
    rStrm.WriteUInt32(7); // sizeOfStreamName
    exportString(rStrm, "Module1"); // StreamName // TODO: dependent on the document
    rStrm.WriteUInt16(0x0032); // reserved
    rStrm.WriteUInt32(14); // sizeOfModuleStreamName
    exportUTF16String(rStrm, "Module1"); // ModuleStreamName // TODO: dependent on the document
}

// section 2.3.4.2.3.2.4
void writeMODULEDOCSTRING(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x001C); // id
    rStrm.WriteUInt32(0x00000000); // sizeOfDocString
    rStrm.WriteUInt16(0x0048); // reserved
    rStrm.WriteUInt32(0x00000000); // sizeOfDocStringUnicode
}

// section 2.3.4.2.3.2
void writePROJECTMODULE(SvStream& rStrm)
{
    writeMODULENAME(rStrm);
    writeMODULENAMEUNICODE(rStrm);
    writeMODULESTREAMNAME(rStrm);
    writeMODULEDOCSTRING(rStrm);
}

// section 2.3.4.2.3
void writePROJECTMODULES(SvStream& rStrm)
{
    rStrm.WriteUInt16(0x000F); // id
    rStrm.WriteUInt32(0x00000002); // size of Count
    sal_Int16 count = 5; // Number of modules // TODO: this is dependent on the document
    rStrm.WriteUInt16(count); // Count
    writePROJECTCOOKIE(rStrm);
    writePROJECTMODULE(rStrm);
}

// section 2.3.4.2
void exportDirStream(SvStream& rStrm)
{
    writePROJECTINFORMATION(rStrm);
    writePROJECTREFERENCES(rStrm);
    writePROJECTMODULES(rStrm);
}

}

void VbaExport::exportVBA()
{
    // start here with the VBA export
    const OUString aDirFileName("/tmp/vba_dir_out.bin");
    SvFileStream aDirStream(aDirFileName, StreamMode::WRITE);

    // export
    exportDirStream(aDirStream);
}

css::uno::Reference<css::container::XNameContainer> VbaExport::getBasicLibrary()
{
    css::uno::Reference<css::container::XNameContainer> xLibrary;
    try
    {
        oox::PropertySet aDocProp(mxModel);
        css::uno::Reference<css::script::XLibraryContainer> xLibContainer(aDocProp.getAnyProperty(oox::PROP_BasicLibraries), css::uno::UNO_QUERY_THROW);
        xLibrary.set( xLibContainer->getByName(maProjectName), css::uno::UNO_QUERY_THROW );
    }
    catch(...)
    {
    }

    return xLibrary;
}

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