/* -*- 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/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */


#include <string.h>
#include <rtl/ustring.hxx>
#include <com/sun/star/lang/Locale.hpp>
#include <unotools/charclass.hxx>
#include "sot/stg.hxx"
#include "stgelem.hxx"
#include "stgcache.hxx"
#include "stgstrms.hxx"
#include "stgdir.hxx"
#include "stgio.hxx"

static const sal_uInt16 nMaxLegalStr = 31;

static const sal_uInt8 cStgSignature[ 8 ] = { 0xD0,0xCF,0x11,0xE0,0xA1,0xB1,0x1A,0xE1 };

////////////////////////////// struct ClsId

SvStream& ReadClsId( SvStream& r, ClsId& rId )
{
    r.ReadUInt32( rId.Data1 )
     .ReadUInt16( rId.Data2 )
     .ReadUInt16( rId.Data3 )
     .ReadUChar( rId.Data4[0] )
     .ReadUChar( rId.Data4[1] )
     .ReadUChar( rId.Data4[2] )
     .ReadUChar( rId.Data4[3] )
     .ReadUChar( rId.Data4[4] )
     .ReadUChar( rId.Data4[5] )
     .ReadUChar( rId.Data4[6] )
     .ReadUChar( rId.Data4[7] );
    return r;
}

SvStream& WriteClsId( SvStream& r, const ClsId& rId )
{
    return
       r .WriteUInt32( rId.Data1 )
         .WriteUInt16( rId.Data2 )
         .WriteUInt16( rId.Data3 )
         .WriteUChar( rId.Data4[0] )
         .WriteUChar( rId.Data4[1] )
         .WriteUChar( rId.Data4[2] )
         .WriteUChar( rId.Data4[3] )
         .WriteUChar( rId.Data4[4] )
         .WriteUChar( rId.Data4[5] )
         .WriteUChar( rId.Data4[6] )
         .WriteUChar( rId.Data4[7] );
}

///////////////////////////// class StgHeader

StgHeader::StgHeader()
: m_nVersion( 0 )
, m_nByteOrder( 0 )
, m_nPageSize( 0 )
, m_nDataPageSize( 0 )
, m_bDirty( sal_uInt8(false) )
, m_nFATSize( 0 )
, m_nTOCstrm( 0 )
, m_nReserved( 0 )
, m_nThreshold( 0 )
, m_nDataFAT( 0 )
, m_nDataFATSize( 0 )
, m_nMasterChain( 0 )
, m_nMaster( 0 )
{
    memset( m_cSignature, 0, sizeof( m_cSignature ) );
    memset( &m_aClsId, 0, sizeof( ClsId ) );
    memset( m_cReserved, 0, sizeof( m_cReserved ) );
    memset( m_nMasterFAT, 0, sizeof( m_nMasterFAT ) );
}

void StgHeader::Init()
{
    memcpy( m_cSignature, cStgSignature, 8 );
    memset( &m_aClsId, 0, sizeof( ClsId ) );
    m_nVersion      = 0x0003003B;
    m_nByteOrder    = 0xFFFE;
    m_nPageSize     = 9;          // 512 bytes
    m_nDataPageSize = 6;          // 64 bytes
    m_bDirty = sal_uInt8(false);
    memset( m_cReserved, 0, sizeof( m_cReserved ) );
    m_nFATSize = 0;
    m_nTOCstrm = 0;
    m_nReserved = 0;
    m_nThreshold    = 4096;
    m_nDataFAT = 0;
    m_nDataFATSize  = 0;
    m_nMasterChain  = STG_EOF;

    SetTOCStart( STG_EOF );
    SetDataFATStart( STG_EOF );
    for( short i = 0; i < cFATPagesInHeader; i++ )
        SetFATPage( i, STG_FREE );
}

bool StgHeader::Load( StgIo& rIo )
{
    bool bResult = false;
    if ( rIo.GetStrm() )
    {
        SvStream& r = *rIo.GetStrm();
        bResult = Load( r );
        bResult = ( bResult && rIo.Good() );
    }

    return bResult;
}

bool StgHeader::Load( SvStream& r )
{
    r.Seek( 0L );
    r.ReadBytes( m_cSignature, 8 );
    ReadClsId( r, m_aClsId );         // 08 Class ID
    r.ReadInt32( m_nVersion )                   // 1A version number
     .ReadUInt16( m_nByteOrder )                 // 1C Unicode byte order indicator
     .ReadInt16( m_nPageSize )                  // 1E 1 << nPageSize = block size
     .ReadInt16( m_nDataPageSize );             // 20 1 << this size == data block size
    r.SeekRel( 10 );
    r.ReadInt32( m_nFATSize )                   // 2C total number of FAT pages
     .ReadInt32( m_nTOCstrm )                   // 30 starting page for the TOC stream
     .ReadInt32( m_nReserved )                  // 34
     .ReadInt32( m_nThreshold )                 // 38 minimum file size for big data
     .ReadInt32( m_nDataFAT )                   // 3C page # of 1st data FAT block
     .ReadInt32( m_nDataFATSize )               // 40 # of data FATpages
     .ReadInt32( m_nMasterChain )               // 44 chain to the next master block
     .ReadInt32( m_nMaster );                   // 48 # of additional master blocks
    for(sal_Int32 & i : m_nMasterFAT)
        r.ReadInt32( i );

    return (r.GetErrorCode() == ERRCODE_NONE) && Check();
}

bool StgHeader::Store( StgIo& rIo )
{
    if( !m_bDirty )
        return true;

    SvStream& r = *rIo.GetStrm();
    r.Seek( 0L );
    r.WriteBytes( m_cSignature, 8 );
    WriteClsId( r, m_aClsId );                   // 08 Class ID
    r.WriteInt32( m_nVersion )                   // 1A version number
     .WriteUInt16( m_nByteOrder )                 // 1C Unicode byte order indicator
     .WriteInt16( m_nPageSize )                  // 1E 1 << nPageSize = block size
     .WriteInt16( m_nDataPageSize )              // 20 1 << this size == data block size
     .WriteInt32( 0 ).WriteInt32( 0 ).WriteInt16( 0 )
     .WriteInt32( m_nFATSize )                   // 2C total number of FAT pages
     .WriteInt32( m_nTOCstrm )                   // 30 starting page for the TOC stream
     .WriteInt32( m_nReserved )                  // 34
     .WriteInt32( m_nThreshold )                 // 38 minimum file size for big data
     .WriteInt32( m_nDataFAT )                   // 3C page # of 1st data FAT block
     .WriteInt32( m_nDataFATSize )               // 40 # of data FAT pages
     .WriteInt32( m_nMasterChain )               // 44 chain to the next master block
     .WriteInt32( m_nMaster );                   // 48 # of additional master blocks
    for(sal_Int32 i : m_nMasterFAT)
        r.WriteInt32( i );
    m_bDirty = sal_uInt8(!rIo.Good());
    return !m_bDirty;
}

static bool lcl_wontoverflow(short shift)
{
    return shift >= 0 && shift < (short)sizeof(short) * 8 - 1;
}

static bool isKnownSpecial(sal_Int32 nLocation)
{
    return (nLocation == STG_FREE ||
            nLocation == STG_EOF ||
            nLocation == STG_FAT ||
            nLocation == STG_MASTER);
}

// Perform thorough checks also on unknown variables
bool StgHeader::Check()
{
    return  memcmp( m_cSignature, cStgSignature, 8 ) == 0
            && (short) ( m_nVersion >> 16 ) == 3
            && m_nPageSize == 9
            && lcl_wontoverflow(m_nPageSize)
            && lcl_wontoverflow(m_nDataPageSize)
            && m_nFATSize > 0
            && m_nTOCstrm >= 0
            && m_nThreshold > 0
            && ( isKnownSpecial(m_nDataFAT) || ( m_nDataFAT >= 0 && m_nDataFATSize > 0 ) )
            && ( isKnownSpecial(m_nMasterChain) || m_nMasterChain >=0 )
            && m_nMaster >= 0;
}

sal_Int32 StgHeader::GetFATPage( short n ) const
{
    if( n >= 0 && n < cFATPagesInHeader )
        return m_nMasterFAT[ n ];
    else
        return STG_EOF;
}

void StgHeader::SetFATPage( short n, sal_Int32 nb )
{
    if( n >= 0 && n < cFATPagesInHeader )
    {
        if( m_nMasterFAT[ n ] != nb )
        {
            m_bDirty = sal_uInt8(true);
            m_nMasterFAT[ n ] = nb;
        }
    }
}

void StgHeader::SetTOCStart( sal_Int32 n )
{
    if( n != m_nTOCstrm )
    {
        m_bDirty = sal_uInt8(true);
        m_nTOCstrm = n;
    }
}

void StgHeader::SetDataFATStart( sal_Int32 n )
{
    if( n != m_nDataFAT )
    {
        m_bDirty = sal_uInt8(true);
        m_nDataFAT = n;
    }
}

void StgHeader::SetDataFATSize( sal_Int32 n )
{
    if( n != m_nDataFATSize )
    {
        m_bDirty = sal_uInt8(true);
        m_nDataFATSize = n;
    }
}

void StgHeader::SetFATSize( sal_Int32 n )
{
    if( n != m_nFATSize )
    {
        m_bDirty = sal_uInt8(true);
        m_nFATSize = n;
    }
}

void StgHeader::SetFATChain( sal_Int32 n )
{
    if( n != m_nMasterChain )
    {
        m_bDirty = sal_uInt8(true);
        m_nMasterChain = n;
    }
}

void StgHeader::SetMasters( sal_Int32 n )
{
    if( n != m_nMaster )
    {
        m_bDirty = sal_uInt8(true);
        m_nMaster = n;
    }
}

///////////////////////////// class StgEntry

void StgEntry::Init()
{
    memset( m_nName, 0, sizeof( m_nName ) );
    m_nNameLen = 0;
    m_cType = 0;
    m_cFlags = 0;
    m_nLeft = 0;
    m_nRight = 0;
    m_nChild = 0;
    memset( &m_aClsId, 0, sizeof( m_aClsId ) );
    m_nFlags = 0;
    m_nMtime[0] = 0; m_nMtime[1] = 0;
    m_nAtime[0] = 0; m_nAtime[1] = 0;
    m_nPage1 = 0;
    m_nSize = 0;
    m_nUnknown = 0;

    SetLeaf( STG_LEFT,  STG_FREE );
    SetLeaf( STG_RIGHT, STG_FREE );
    SetLeaf( STG_CHILD, STG_FREE );
    SetLeaf( STG_DATA,  STG_EOF );
}

static OUString ToUpperUnicode( const OUString & rStr )
{
    // I don't know the locale, so en_US is hopefully fine
    static CharClass aCC( LanguageTag( css::lang::Locale( "en", "US", "" )) );
    return aCC.uppercase( rStr );
}

bool StgEntry::SetName( const OUString& rName )
{
    // I don't know the locale, so en_US is hopefully fine
    m_aName = ToUpperUnicode( rName );
    if(m_aName.getLength() > nMaxLegalStr)
    {
        m_aName = m_aName.copy(0, nMaxLegalStr);
    }

    sal_Int32 i;
    for( i = 0; i < rName.getLength() && i <= nMaxLegalStr; i++ )
    {
        m_nName[ i ] = rName[ i ];
    }
    while (i <= nMaxLegalStr)
    {
        m_nName[ i++ ] = 0;
    }
    m_nNameLen = ( rName.getLength() + 1 ) << 1;
    return true;
}

sal_Int32 StgEntry::GetLeaf( StgEntryRef eRef ) const
{
    sal_Int32 n = -1;
    switch( eRef )
    {
    case STG_LEFT:  n = m_nLeft;  break;
    case STG_RIGHT: n = m_nRight; break;
    case STG_CHILD: n = m_nChild; break;
    case STG_DATA:  n = m_nPage1; break;
    }
    return n;
}

void StgEntry::SetLeaf( StgEntryRef eRef, sal_Int32 nPage )
{
    switch( eRef )
    {
    case STG_LEFT:  m_nLeft  = nPage; break;
    case STG_RIGHT: m_nRight = nPage; break;
    case STG_CHILD: m_nChild = nPage; break;
    case STG_DATA:  m_nPage1 = nPage; break;
    }
}

void StgEntry::SetClassId( const ClsId& r )
{
    memcpy( &m_aClsId, &r, sizeof( ClsId ) );
}

void StgEntry::GetName( OUString& rName ) const
{
    sal_uInt16 n = m_nNameLen;
    if( n )
        n = ( n >> 1 ) - 1;
    rName = OUString(m_nName, n);
}

// Compare two entries. Do this case-insensitive.

sal_Int32 StgEntry::Compare( const StgEntry& r ) const
{
    if (r.m_nNameLen != m_nNameLen)
        return r.m_nNameLen > m_nNameLen ? 1 : -1;
    else
        return r.m_aName.compareTo(m_aName);
}

// These load/store operations are a bit more complicated,
// since they have to copy their contents into a packed structure.

bool StgEntry::Load(const void* pFrom, sal_uInt32 nBufSize, sal_uInt64 nUnderlyingStreamSize)
{
    if ( nBufSize < 128 )
        return false;

    SvMemoryStream r( const_cast<void *>(pFrom), nBufSize, StreamMode::READ );
    for(sal_Unicode & i : m_nName)
        r.ReadUtf16( i );             // 00 name as WCHAR
    r.ReadUInt16( m_nNameLen )                   // 40 size of name in bytes including 00H
     .ReadUChar( m_cType )                      // 42 entry type
     .ReadUChar( m_cFlags )                     // 43 0 or 1 (tree balance?)
     .ReadInt32( m_nLeft )                      // 44 left node entry
     .ReadInt32( m_nRight )                     // 48 right node entry
     .ReadInt32( m_nChild );                    // 4C 1st child entry if storage
    ReadClsId( r, m_aClsId );         // 50 class ID (optional)
    r.ReadInt32( m_nFlags )                     // 60 state flags(?)
     .ReadInt32( m_nMtime[ 0 ] )                // 64 modification time
     .ReadInt32( m_nMtime[ 1 ] )                // 64 modification time
     .ReadInt32( m_nAtime[ 0 ] )                // 6C creation and access time
     .ReadInt32( m_nAtime[ 1 ] )                // 6C creation and access time
     .ReadInt32( m_nPage1 )                     // 74 starting block (either direct or translated)
     .ReadInt32( m_nSize )                      // 78 file size
     .ReadInt32( m_nUnknown );                  // 7C unknown

    sal_uInt16 n = m_nNameLen;
    if( n )
        n = ( n >> 1 ) - 1;

    if (n > nMaxLegalStr)
        return false;

    if (m_cType != STG_STORAGE)
    {
        if (m_nPage1 < 0 && !isKnownSpecial(m_nPage1))
        {
            //bad pageid
            return false;
        }
        if (m_nSize < 0)
        {
            // the size makes no sense for the substorage
            // TODO/LATER: actually the size should be an unsigned value, but
            // in this case it would mean a stream of more than 2Gb
            return false;
        }
        if (static_cast<sal_uInt64>(m_nSize) > nUnderlyingStreamSize)
        {
            // surely an entry cannot be larger than the underlying file
            return false;
        }

    }

    m_aName = OUString(m_nName , n);
    // I don't know the locale, so en_US is hopefully fine
    m_aName = ToUpperUnicode( m_aName );
    if(m_aName.getLength() > nMaxLegalStr)
    {
        m_aName = m_aName.copy(0, nMaxLegalStr);
    }

    return true;
}

void StgEntry::Store( void* pTo )
{
    SvMemoryStream r( pTo, 128, StreamMode::WRITE );
    for(sal_Unicode i : m_nName)
        r.WriteUInt16( i );            // 00 name as WCHAR
    r.WriteUInt16( m_nNameLen )                   // 40 size of name in bytes including 00H
     .WriteUChar( m_cType )                      // 42 entry type
     .WriteUChar( m_cFlags )                     // 43 0 or 1 (tree balance?)
     .WriteInt32( m_nLeft )                      // 44 left node entry
     .WriteInt32( m_nRight )                     // 48 right node entry
     .WriteInt32( m_nChild );                    // 4C 1st child entry if storage;
    WriteClsId( r, m_aClsId );                   // 50 class ID (optional)
    r.WriteInt32( m_nFlags )                     // 60 state flags(?)
     .WriteInt32( m_nMtime[ 0 ] )                // 64 modification time
     .WriteInt32( m_nMtime[ 1 ] )                // 64 modification time
     .WriteInt32( m_nAtime[ 0 ] )                // 6C creation and access time
     .WriteInt32( m_nAtime[ 1 ] )                // 6C creation and access time
     .WriteInt32( m_nPage1 )                     // 74 starting block (either direct or translated)
     .WriteInt32( m_nSize )                      // 78 file size
     .WriteInt32( m_nUnknown );                  // 7C unknown
}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */