/* -*- 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 <sal/config.h>

#include <cassert>
#include <cstdlib>

#include <osl/interlck.h>
#include <rtl/alloc.h>
#include <osl/diagnose.h>
#include <rtl/tencinfo.h>

#include "strimp.hxx"
#include <rtl/character.hxx>
#include <rtl/string.h>

#include <rtl/math.h>

/* ======================================================================= */

/* static data to be referenced by all empty strings
 * the refCount is predefined to 1 and must never become 0 !
 */
static rtl_String const aImplEmpty_rtl_String =
{
    SAL_STRING_STATIC_FLAG|1,
            /* sal_Int32    refCount;   */
    0,      /* sal_Int32    length;     */
    { 0 }   /* char     buffer[1];  */
};

/* ======================================================================= */
/* These macros are for the "poor-man templates" included from
 * the strtmpl.cxx just below, used to share code between here and
 * ustring.cxx
 */

#define IMPL_RTL_IS_USTRING         0

#define IMPL_RTL_STRCODE            char
#define IMPL_RTL_USTRCODE( c )      (static_cast<unsigned char>(c))
#define IMPL_RTL_STRNAME( n )       rtl_str_ ## n

#define IMPL_RTL_STRINGNAME( n )    rtl_string_ ## n
#define IMPL_RTL_STRINGDATA         rtl_String
#define IMPL_RTL_EMPTYSTRING        aImplEmpty_rtl_String

#if USE_SDT_PROBES
#define RTL_LOG_STRING_BITS         8
#endif

/* ======================================================================= */

/* Include String/UString template code */

#include "strtmpl.cxx"

#undef IMPL_RTL_EMPTYSTRING
#undef IMPL_RTL_IS_USTRING
#undef IMPL_RTL_STRCODE
#undef IMPL_RTL_STRINGDATA
#undef IMPL_RTL_STRINGNAME
#undef IMPL_RTL_STRNAME
#undef IMPL_RTL_USTRCODE
#undef RTL_LOG_STRING_BITS

sal_Int32 SAL_CALL rtl_str_valueOfFloat(char * pStr, float f)
    SAL_THROW_EXTERN_C()
{
    assert(pStr);
    rtl_String * pResult = nullptr;
    sal_Int32 nLen;
    rtl_math_doubleToString(
        &pResult, nullptr, 0, f, rtl_math_StringFormat_G,
        RTL_STR_MAX_VALUEOFFLOAT - RTL_CONSTASCII_LENGTH("-x.E-xxx"), '.', nullptr, 0,
        true);
    nLen = pResult->length;
    OSL_ASSERT(nLen < RTL_STR_MAX_VALUEOFFLOAT);
    memcpy(pStr, pResult->buffer, (nLen + 1) * sizeof(char));
    rtl_string_release(pResult);
    return nLen;
}

sal_Int32 SAL_CALL rtl_str_valueOfDouble(char * pStr, double d)
    SAL_THROW_EXTERN_C()
{
    assert(pStr);
    rtl_String * pResult = nullptr;
    sal_Int32 nLen;
    rtl_math_doubleToString(
        &pResult, nullptr, 0, d, rtl_math_StringFormat_G,
        RTL_STR_MAX_VALUEOFDOUBLE - RTL_CONSTASCII_LENGTH("-x.E-xxx"), '.', nullptr,
        0, true);
    nLen = pResult->length;
    OSL_ASSERT(nLen < RTL_STR_MAX_VALUEOFDOUBLE);
    memcpy(pStr, pResult->buffer, (nLen + 1) * sizeof(char));
    rtl_string_release(pResult);
    return nLen;
}

float SAL_CALL rtl_str_toFloat(char const * pStr) SAL_THROW_EXTERN_C()
{
    assert(pStr);
    return static_cast<float>(rtl_math_stringToDouble(pStr, pStr + rtl_str_getLength(pStr),
                                           '.', 0, nullptr, nullptr));
}

double SAL_CALL rtl_str_toDouble(char const * pStr) SAL_THROW_EXTERN_C()
{
    assert(pStr);
    return rtl_math_stringToDouble(pStr, pStr + rtl_str_getLength(pStr), '.', 0,
                                   nullptr, nullptr);
}

/* ======================================================================= */

static int rtl_ImplGetFastUTF8ByteLen( const sal_Unicode* pStr, sal_Int32 nLen )
{
    int                 n;
    sal_Unicode         c;
    sal_uInt32          nUCS4Char;
    const sal_Unicode*  pEndStr;

    n = 0;
    pEndStr  = pStr+nLen;
    while ( pStr < pEndStr )
    {
        c = *pStr;

        if ( c < 0x80 )
            n++;
        else if ( c < 0x800 )
            n += 2;
        else
        {
            if ( !rtl::isHighSurrogate(c) )
                n += 3;
            else
            {
                nUCS4Char = c;

                if ( pStr+1 < pEndStr )
                {
                    c = *(pStr+1);
                    if ( rtl::isLowSurrogate(c) )
                    {
                        nUCS4Char = rtl::combineSurrogates(nUCS4Char, c);
                        pStr++;
                    }
                }

                if ( nUCS4Char < 0x10000 )
                    n += 3;
                else if ( nUCS4Char < 0x200000 )
                    n += 4;
                else if ( nUCS4Char < 0x4000000 )
                    n += 5;
                else
                    n += 6;
            }
        }

        pStr++;
    }

    return n;
}

/* ----------------------------------------------------------------------- */

static bool rtl_impl_convertUStringToString(rtl_String ** pTarget,
                                                  sal_Unicode const * pSource,
                                                  sal_Int32 nLength,
                                                  rtl_TextEncoding nEncoding,
                                                  sal_uInt32 nFlags,
                                                  bool bCheckErrors)
{
    assert(pTarget != nullptr);
    assert(pSource != nullptr || nLength == 0);
    assert(nLength >= 0);
    OSL_ASSERT(nLength == 0 || rtl_isOctetTextEncoding(nEncoding));

    if ( !nLength )
        rtl_string_new( pTarget );
    else
    {
        rtl_String*                 pTemp;
        rtl_UnicodeToTextConverter  hConverter;
        sal_uInt32                  nInfo;
        sal_Size                    nSrcChars;
        sal_Size                    nDestBytes;
        sal_Size                    nNewLen;
        sal_Size                    nNotConvertedChars;
        sal_Size                    nMaxCharLen;

        /* Optimization for UTF-8 - we try to calculate the exact length */
        /* For all other encoding we try a good estimation */
        if ( nEncoding == RTL_TEXTENCODING_UTF8 )
        {
            nNewLen = rtl_ImplGetFastUTF8ByteLen( pSource, nLength );
            /* Includes the string only ASCII, then we could copy
               the buffer faster */
            if ( nNewLen == static_cast<sal_Size>(nLength) )
            {
                char* pBuffer;
                if ( *pTarget )
                    rtl_string_release( *pTarget );
                *pTarget = rtl_string_ImplAlloc( nLength );
                OSL_ASSERT(*pTarget != nullptr);
                pBuffer = (*pTarget)->buffer;
                do
                {
                    /* Check ASCII range */
                    OSL_ENSURE( *pSource <= 127,
                                "rtl_uString2String() - UTF8 test is encoding is wrong" );

                    *pBuffer = static_cast<char>(static_cast<unsigned char>(*pSource));
                    pBuffer++;
                    pSource++;
                    nLength--;
                }
                while ( nLength );
                return true;
            }

            nMaxCharLen = 4;
        }
        else
        {
            rtl_TextEncodingInfo aTextEncInfo;
            aTextEncInfo.StructSize = sizeof( aTextEncInfo );
            if ( !rtl_getTextEncodingInfo( nEncoding, &aTextEncInfo ) )
            {
                aTextEncInfo.AverageCharSize    = 1;
                aTextEncInfo.MaximumCharSize    = 8;
            }

            nNewLen = nLength * static_cast<sal_Size>(aTextEncInfo.AverageCharSize);
            nMaxCharLen = aTextEncInfo.MaximumCharSize;
        }

        nFlags |= RTL_UNICODETOTEXT_FLAGS_FLUSH;
        hConverter = rtl_createUnicodeToTextConverter( nEncoding );

        for (;;)
        {
            pTemp = rtl_string_ImplAlloc( nNewLen );
            OSL_ASSERT(pTemp != nullptr);
            nDestBytes = rtl_convertUnicodeToText( hConverter, nullptr,
                                                   pSource, nLength,
                                                   pTemp->buffer, nNewLen,
                                                   nFlags,
                                                   &nInfo, &nSrcChars );
            if (bCheckErrors && (nInfo & RTL_UNICODETOTEXT_INFO_ERROR) != 0)
            {
                rtl_freeString(pTemp);
                rtl_destroyUnicodeToTextConverter(hConverter);
                return false;
            }

            if ((nInfo & RTL_UNICODETOTEXT_INFO_DESTBUFFERTOSMALL) == 0)
                break;

            /* Buffer not big enough, try again with enough space */
            rtl_freeString( pTemp );

            /* Try with the max. count of characters with
               additional overhead for replacing functionality */
            nNotConvertedChars = nLength-nSrcChars;
            nNewLen = nDestBytes+(nNotConvertedChars*nMaxCharLen)+nNotConvertedChars+4;
        }

        /* Set the buffer to the correct size or is there to
           much overhead, reallocate to the correct size */
        if ( nNewLen > nDestBytes+8 )
        {
            rtl_String* pTemp2 = rtl_string_ImplAlloc( nDestBytes );
            OSL_ASSERT(pTemp2 != nullptr);
            rtl_str_ImplCopy( pTemp2->buffer, pTemp->buffer, nDestBytes );
            rtl_freeString( pTemp );
            pTemp = pTemp2;
        }
        else
        {
            pTemp->length = nDestBytes;
            pTemp->buffer[nDestBytes] = 0;
        }

        rtl_destroyUnicodeToTextConverter( hConverter );
        if ( *pTarget )
            rtl_string_release( *pTarget );
        *pTarget = pTemp;

        /* Results the conversion in an empty buffer -
           create an empty string */
        if ( pTemp && !nDestBytes )
            rtl_string_new( pTarget );
    }
    return true;
}

void SAL_CALL rtl_uString2String( rtl_String** ppThis,
                                  const sal_Unicode* pUStr,
                                  sal_Int32 nULen,
                                  rtl_TextEncoding eTextEncoding,
                                  sal_uInt32 nCvtFlags )
    SAL_THROW_EXTERN_C()
{
    rtl_impl_convertUStringToString(ppThis, pUStr, nULen, eTextEncoding,
                                    nCvtFlags, false);
}

sal_Bool SAL_CALL rtl_convertUStringToString(rtl_String ** pTarget,
                                             sal_Unicode const * pSource,
                                             sal_Int32 nLength,
                                             rtl_TextEncoding nEncoding,
                                             sal_uInt32 nFlags)
    SAL_THROW_EXTERN_C()
{
    return rtl_impl_convertUStringToString(pTarget, pSource, nLength, nEncoding,
                                           nFlags, true);
}

void rtl_string_newReplaceFirst(
    rtl_String ** newStr, rtl_String * str, char const * from,
    sal_Int32 fromLength, char const * to, sal_Int32 toLength,
    sal_Int32 * index) SAL_THROW_EXTERN_C()
{
    assert(str != nullptr);
    assert(index != nullptr);
    assert(*index >= 0 && *index <= str->length);
    assert(fromLength >= 0);
    assert(toLength >= 0);
    sal_Int32 i = rtl_str_indexOfStr_WithLength(
        str->buffer + *index, str->length - *index, from, fromLength);
    if (i == -1) {
        rtl_string_assign(newStr, str);
    } else {
        assert(i <= str->length - *index);
        i += *index;
        assert(fromLength <= str->length);
        if (str->length - fromLength > SAL_MAX_INT32 - toLength) {
            std::abort();
        }
        sal_Int32 n = str->length - fromLength + toLength;
        rtl_string_acquire(str); // in case *newStr == str
        rtl_string_new_WithLength(newStr, n);
        if (n != 0) {
            (*newStr)->length = n;
            assert(i >= 0 && i < str->length);
            memcpy((*newStr)->buffer, str->buffer, i);
            memcpy((*newStr)->buffer + i, to, toLength);
            memcpy(
                (*newStr)->buffer + i + toLength, str->buffer + i + fromLength,
                str->length - i - fromLength);
        }
        rtl_string_release(str);
    }
    *index = i;
}

void rtl_string_newReplaceAll(
    rtl_String ** newStr, rtl_String * str, char const * from,
    sal_Int32 fromLength, char const * to, sal_Int32 toLength)
    SAL_THROW_EXTERN_C()
{
    rtl_string_assign(newStr, str);
    for (sal_Int32 i = 0;; i += toLength) {
        rtl_string_newReplaceFirst(
            newStr, *newStr, from, fromLength, to, toLength, &i);
        if (i == -1) {
            break;
        }
    }
}

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