/* -*- 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 "exceldetect.hxx"

#include <com/sun/star/io/XInputStream.hpp>

#include <com/sun/star/ucb/ContentCreationException.hpp>

#include <com/sun/star/uno/XComponentContext.hpp>

#include <cppuhelper/supportsservice.hxx>

#include <sfx2/docfile.hxx>

#include <unotools/mediadescriptor.hxx>

#include <sot/storage.hxx>

#include <comphelper/diagnose_ex.hxx>

#include <comphelper/sequenceashashmap.hxx>

#include <global.hxx>

using namespace com::sun::star;

ScExcelBiffDetect::ScExcelBiffDetect() {}

ScExcelBiffDetect::~ScExcelBiffDetect() {}

OUString ScExcelBiffDetect::getImplementationName()

{

    return u"com.sun.star.comp.calc.ExcelBiffFormatDetector"_ustr;

}

sal_Bool ScExcelBiffDetect::supportsService( const OUString& aName )

{

    return cppu::supportsService(this, aName);

}

uno::Sequence<OUString> ScExcelBiffDetect::getSupportedServiceNames()

{

    return { u"com.sun.star.frame.ExtendedTypeDetection"_ustr };

}

namespace {

bool hasStream(const uno::Reference<io::XInputStream>& xInStream, const OUString& rName)

{

    SfxMedium aMedium;

    aMedium.UseInteractionHandler(false);

    aMedium.setStreamToLoadFrom(xInStream, true);

    SvStream* pStream = aMedium.GetInStream();

    if (!pStream)

        return false;

    sal_uInt64 const nSize = pStream->TellEnd();

    pStream->Seek(0);

    if (!nSize)

    {

        // 0-size stream.  Failed.

        return false;

    }

    try

    {

        rtl::Reference<SotStorage> xStorage = new SotStorage(pStream, false);

        if (!xStorage.is() || xStorage->GetError())

            return false;

        return xStorage->IsStream(rName);

    }

    catch (const css::ucb::ContentCreationException &)

    {

        TOOLS_WARN_EXCEPTION("sc", "hasStream");

    }

    return false;

}

/**

 * We detect BIFF 2, 3 and 4 file types together since the only thing that

 * set them apart is the BOF ID.

 */

bool isExcel40(const uno::Reference<io::XInputStream>& xInStream)

{

    SfxMedium aMedium;

    aMedium.UseInteractionHandler(false);

    aMedium.setStreamToLoadFrom(xInStream, true);

    SvStream* pStream = aMedium.GetInStream();

    if (!pStream)

        return false;

    sal_uInt64 const nSize = pStream->TellEnd();

    pStream->Seek(0);

    if (nSize < 4)

        return false;

    sal_uInt16 nBofId, nBofSize;

    pStream->ReadUInt16( nBofId ).ReadUInt16( nBofSize );

    switch (nBofId)

    {

        case 0x0009: // Excel 2.1 worksheet (BIFF 2)

        case 0x0209: // Excel 3.0 worksheet (BIFF 3)

        case 0x0409: // Excel 4.0 worksheet (BIFF 4)

        case 0x0809: // Excel 5.0 worksheet (BIFF 5), some apps create such files (fdo#70100)

            break;

        default:

            return false;

    }

    if (nBofSize < 4 || 16 < nBofSize)

        // BOF record must be sized between 4 and 16 for BIFF 2, 3 and 4.

        return false;

    sal_uInt64 const nPos = pStream->Tell();

    if (nSize - nPos < nBofSize)

        // BOF record doesn't have required bytes.

        return false;

    return true;

}

bool isTemplate(std::u16string_view rType)

{

    return rType.find(u"_VorlageTemplate") != std::u16string_view::npos;

}

}

OUString ScExcelBiffDetect::detect( uno::Sequence<beans::PropertyValue>& lDescriptor )

{

    comphelper::SequenceAsHashMap aMediaDesc(lDescriptor);

    OUString aType;

    aMediaDesc[utl::MediaDescriptor::PROP_TYPENAME] >>= aType;

    if (aType.isEmpty())

        // Type is not given.  We can't proceed.

        return OUString();

    utl::MediaDescriptor::addInputStream(aMediaDesc);

    uno::Reference<io::XInputStream> xInStream(aMediaDesc[utl::MediaDescriptor::PROP_INPUTSTREAM], uno::UNO_QUERY);

    if (!xInStream.is())

        // No input stream.

        return OUString();

    if (aType == "calc_MS_Excel_97" || aType == "calc_MS_Excel_97_VorlageTemplate")

    {

        // See if this stream is an Excel 97/XP/2003 (BIFF8) stream.

        if (!hasStream(xInStream, u"Workbook"_ustr))

            // BIFF8 is expected to contain a stream named "Workbook".

            return OUString();

        aMediaDesc[utl::MediaDescriptor::PROP_FILTERNAME] <<= isTemplate(aType) ? SC_XL97TMPL_FILTER_NAME : SC_XL97_FILTER_NAME;

    }

    else if (aType == "calc_MS_Excel_95" || aType == "calc_MS_Excel_95_VorlageTemplate")

    {

        // See if this stream is an Excel 95 (BIFF5) stream.

        if (!hasStream(xInStream, u"Book"_ustr))

            return OUString();

        aMediaDesc[utl::MediaDescriptor::PROP_FILTERNAME] <<= isTemplate(aType) ? SC_XL95TMPL_FILTER_NAME : SC_XL95_FILTER_NAME;

    }

    else if (aType == "calc_MS_Excel_5095" || aType == "calc_MS_Excel_5095_VorlageTemplate")

    {

        // See if this stream is an Excel 5.0/95 stream.

        if (!hasStream(xInStream, u"Book"_ustr))

            return OUString();

        aMediaDesc[utl::MediaDescriptor::PROP_FILTERNAME] <<= isTemplate(aType) ? SC_XL5TMPL_FILTER_NAME : SC_XL5_FILTER_NAME;

    }

    else if (aType == "calc_MS_Excel_40" || aType == "calc_MS_Excel_40_VorlageTemplate")

    {

        // See if this stream is an Excel 4.0 stream.

        if (!isExcel40(xInStream))

            return OUString();

        aMediaDesc[utl::MediaDescriptor::PROP_FILTERNAME] <<= isTemplate(aType) ? SC_XL4TMPL_FILTER_NAME : SC_XL4_FILTER_NAME;

    }

    else

        // Nothing to detect.

        return OUString();

    aMediaDesc >> lDescriptor;

    return aType;

}

extern "C" SAL_DLLPUBLIC_EXPORT css::uno::XInterface*

com_sun_star_comp_calc_ExcelBiffFormatDetector_get_implementation(css::uno::XComponentContext* /*context*/,

                                                                  css::uno::Sequence<css::uno::Any> const &)

{

    return cppu::acquire(new ScExcelBiffDetect);

}

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