/* -*- 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 <osl/interlck.h>
#include <osl/diagnose.h>
#include <rtl/character.hxx>
#include <rtl/ustrbuf.hxx>
#include "strimp.hxx"

#if USE_SDT_PROBES
#define RTL_LOG_STRING_BITS         16
#endif

void SAL_CALL rtl_uStringbuffer_newFromStr_WithLength( rtl_uString ** newStr,
                                                       const sal_Unicode * value,
                                                       sal_Int32 count)
{
    assert(newStr);
    assert(count >= 0);
    if (!value)
    {
        rtl_uString_new_WithLength( newStr, 16 );
        return;
    }

    // use raw alloc to avoid overwriting the buffer twice
    if ( *newStr)
        rtl_uString_release( *newStr );
    *newStr = rtl_uString_ImplAlloc( count + 16 );
    (*newStr)->length = count;
    memcpy( (*newStr)->buffer, value, count * sizeof(sal_Unicode) );
    memset( (*newStr)->buffer + count, 0, 16 * sizeof(sal_Unicode) );
    RTL_LOG_STRING_NEW( *newStr );
}

rtl_uString * SAL_CALL rtl_uStringBuffer_refReturn( rtl_uString * pThis )
{
    RTL_LOG_STRING_NEW( pThis );
    rtl_uString_acquire( pThis );
    return pThis;
}

rtl_uString * SAL_CALL rtl_uStringBuffer_makeStringAndClear( rtl_uString ** ppThis,
                                                             sal_Int32 *nCapacity )
{
    assert(ppThis);
    assert(nCapacity);
    // avoid an un-necessary atomic ref/unref pair
    rtl_uString *pStr = *ppThis;
    *ppThis = nullptr;

    rtl_uString_new (ppThis);
    *nCapacity = 0;

    RTL_LOG_STRING_NEW( pStr );

    return pStr;
}

sal_Int32 SAL_CALL rtl_uStringbuffer_newFromStringBuffer( rtl_uString ** newStr,
                                                          sal_Int32 capacity,
                                                          rtl_uString * oldStr )
{
    assert(newStr);
    assert(capacity >= 0);
    assert(oldStr);
    sal_Int32 newCapacity = capacity;

    if (newCapacity < oldStr->length)
        newCapacity = oldStr->length;

    rtl_uString_new_WithLength( newStr, newCapacity );

    if (oldStr->length > 0) {
        (*newStr)->length = oldStr->length;
        memcpy( (*newStr)->buffer, oldStr->buffer, oldStr->length * sizeof(sal_Unicode));
    }
    RTL_LOG_STRING_NEW( *newStr );
    return newCapacity;
}

void SAL_CALL rtl_uStringbuffer_ensureCapacity
    (rtl_uString ** This, sal_Int32* capacity, sal_Int32 minimumCapacity)
{
    assert(This);
    assert(capacity && *capacity >= 0);
    assert(minimumCapacity >= 0);
    if (minimumCapacity <= *capacity)
        return;

    rtl_uString * pTmp = *This;
    rtl_uString * pNew = nullptr;
    auto nLength = (*This)->length;
    *capacity = (nLength + 1) * 2;
    if (minimumCapacity > *capacity)
        /* still lower, set to the minimum capacity */
        *capacity = minimumCapacity;

    // use raw alloc to avoid overwriting the buffer twice
    pNew = rtl_uString_ImplAlloc( *capacity );
    pNew->length = nLength;
    *This = pNew;

    memcpy( (*This)->buffer, pTmp->buffer, nLength * sizeof(sal_Unicode) );
    memset( (*This)->buffer + nLength, 0, (*capacity - nLength) * sizeof(sal_Unicode) );

    RTL_LOG_STRING_NEW( pTmp ); // with accurate contents
    rtl_uString_release( pTmp );
}

void SAL_CALL rtl_uStringbuffer_insert( rtl_uString ** This,
                                        sal_Int32 * capacity,
                                        sal_Int32 offset,
                                        const sal_Unicode * str,
                                        sal_Int32 len)
{
    assert(This);
    assert(capacity && *capacity >= 0);
    assert(offset >= 0 && offset <= (**This).length);
    assert(len >= 0);
    sal_Int32 nOldLen;
    sal_Unicode * pBuf;
    sal_Int32 n;
    if( len == 0 )
        return;

    if (*capacity < (*This)->length + len)
        rtl_uStringbuffer_ensureCapacity( This, capacity, (*This)->length + len );

    nOldLen = (*This)->length;
    pBuf = (*This)->buffer;

    /* copy the tail */
    n = (nOldLen - offset);
    if( n == 1 )
        /* optimized for 1 character */
        pBuf[offset + len] = pBuf[offset];
    else if( n > 1 )
        memmove( pBuf + offset + len, pBuf + offset, n * sizeof(sal_Unicode) );

    /* insert the new characters */
    if( str != nullptr )
    {
        if( len == 1 )
            /* optimized for 1 character */
            pBuf[offset] = *str;
        else
            memcpy( pBuf + offset, str, len * sizeof(sal_Unicode) );
    }
    (*This)->length = nOldLen + len;
    pBuf[ nOldLen + len ] = 0;
}

void rtl_uStringbuffer_insertUtf32(
    rtl_uString ** pThis, sal_Int32 * capacity, sal_Int32 offset, sal_uInt32 c)
    SAL_THROW_EXTERN_C()
{
    sal_Unicode buf[2];
    sal_Int32 len;
    OSL_ASSERT(rtl::isUnicodeScalarValue(c));
    if (c <= 0xFFFF) {
        buf[0] = static_cast<sal_Unicode>(c);
        len = 1;
    } else {
        c -= 0x10000;
        buf[0] = static_cast<sal_Unicode>((c >> 10) | 0xD800);
        buf[1] = static_cast<sal_Unicode>((c & 0x3FF) | 0xDC00);
        len = 2;
    }
    rtl_uStringbuffer_insert(pThis, capacity, offset, buf, len);
}

void SAL_CALL rtl_uStringbuffer_insert_ascii(   /*inout*/rtl_uString ** This,
                                                /*inout*/sal_Int32 * capacity,
                                                sal_Int32 offset,
                                                const char * str,
                                                sal_Int32 len)
{
    assert(This);
    assert(capacity && *capacity >= 0);
    assert(offset >= 0 && offset <= (**This).length);
    assert(len == 0 || str != nullptr);
    assert(len >= 0);
    sal_Int32 nOldLen;
    sal_Unicode * pBuf;
    sal_Int32 n;
    if( len == 0 )
        return;

    if (*capacity < (*This)->length + len)
        rtl_uStringbuffer_ensureCapacity( This, capacity, (*This)->length + len );

    nOldLen = (*This)->length;
    pBuf = (*This)->buffer;

    /* copy the tail */
    n = (nOldLen - offset);
    if( n == 1 )
        /* optimized for 1 character */
        pBuf[offset + len] = pBuf[offset];
    else if( n > 1 )
        memmove( pBuf + offset + len, pBuf + offset, n * sizeof(sal_Unicode) );

    /* insert the new characters */
    for( n = 0; n < len; n++ )
    {
        /* Check ASCII range */
        OSL_ENSURE( (*str & 0x80) == 0, "Found ASCII char > 127");

        pBuf[offset + n] = static_cast<sal_Unicode>(*(str++));
    }

    (*This)->length = nOldLen + len;
    pBuf[ nOldLen + len ] = 0;
}

/*************************************************************************
 *  rtl_uStringbuffer_remove
 */
void SAL_CALL rtl_uStringbuffer_remove( rtl_uString ** This,
                                       sal_Int32 start,
                                       sal_Int32 len )
{
    assert(This);
    assert(start >= 0 && start <= (**This).length);
    assert(len >= 0);
    sal_Int32 nTailLen;
    sal_Unicode * pBuf;

    if (len > (*This)->length - start)
        len = (*This)->length - start;

    //remove nothing
    if (!len)
        return;

    pBuf = (*This)->buffer;
    nTailLen = (*This)->length - ( start + len );

    if (nTailLen)
    {
        /* move the tail */
        memmove(pBuf + start, pBuf + start + len, nTailLen * sizeof(sal_Unicode));
    }

    (*This)->length-=len;
    pBuf[ (*This)->length ] = 0;
}

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