// Copyright 2014 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com

#include <stddef.h>  // For offsetof().

#include "../../include/fxcrt/fx_basic.h"
#include "../../../third_party/base/numerics/safe_math.h"

// static
CFX_WideString::StringData* CFX_WideString::StringData::Create(int nLen)
{
    // TODO(palmer): |nLen| should really be declared as |size_t|, or
    // at least unsigned.
    if (nLen == 0 || nLen < 0) {
        return NULL;
    }

    // Fixed portion of header plus a NUL wide char not in m_nAllocLength.
    int overhead = offsetof(StringData, m_String) + sizeof(FX_WCHAR);
    pdfium::base::CheckedNumeric<int> iSize = nLen;
    iSize *= sizeof(FX_WCHAR);
    iSize += overhead;

    // Now round to an 8-byte boundary. We'd expect that this is the minimum
    // granularity of any of the underlying allocators, so there may be cases
    // where we can save a re-alloc when adding a few characters to a string
    // by using this otherwise wasted space.
    iSize += 7;
    int totalSize = iSize.ValueOrDie() & ~7;
    int usableLen = (totalSize - overhead) / sizeof(FX_WCHAR);
    FXSYS_assert(usableLen >= nLen);

    void* pData = FX_Alloc(uint8_t, iSize.ValueOrDie());
    return new (pData) StringData(nLen, usableLen);
}
CFX_WideString::~CFX_WideString()
{
    if (m_pData) {
        m_pData->Release();
    }
}
CFX_WideString::CFX_WideString(const CFX_WideString& stringSrc)
{
    if (stringSrc.m_pData == NULL) {
        m_pData = NULL;
        return;
    }
    if (stringSrc.m_pData->m_nRefs >= 0) {
        m_pData = stringSrc.m_pData;
        m_pData->Retain();
    } else {
        m_pData = NULL;
        *this = stringSrc;
    }
}
CFX_WideString::CFX_WideString(const FX_WCHAR* lpsz, FX_STRSIZE nLen) {
    if (nLen < 0) {
        nLen = lpsz ? FXSYS_wcslen(lpsz) : 0;
    }
    if (nLen) {
        m_pData = StringData::Create(nLen);
        if (m_pData) {
            FXSYS_memcpy32(m_pData->m_String, lpsz, nLen * sizeof(FX_WCHAR));
        }
    } else {
        m_pData = NULL;
    }
}
CFX_WideString::CFX_WideString(FX_WCHAR ch)
{
    m_pData = StringData::Create(1);
    if (m_pData) {
        m_pData->m_String[0] = ch;
    }
}
CFX_WideString::CFX_WideString(const CFX_WideStringC& str)
{
    if (str.IsEmpty()) {
        m_pData = NULL;
        return;
    }
    m_pData = StringData::Create(str.GetLength());
    if (m_pData) {
        FXSYS_memcpy32(m_pData->m_String, str.GetPtr(), str.GetLength()*sizeof(FX_WCHAR));
    }
}
CFX_WideString::CFX_WideString(const CFX_WideStringC& str1, const CFX_WideStringC& str2)
{
    m_pData = NULL;
    int nNewLen = str1.GetLength() + str2.GetLength();
    if (nNewLen == 0) {
        return;
    }
    m_pData = StringData::Create(nNewLen);
    if (m_pData) {
        FXSYS_memcpy32(m_pData->m_String, str1.GetPtr(), str1.GetLength()*sizeof(FX_WCHAR));
        FXSYS_memcpy32(m_pData->m_String + str1.GetLength(), str2.GetPtr(), str2.GetLength()*sizeof(FX_WCHAR));
    }
}
void CFX_WideString::ReleaseBuffer(FX_STRSIZE nNewLength)
{
    if (m_pData == NULL) {
        return;
    }
    CopyBeforeWrite();
    if (nNewLength == -1) {
        nNewLength = m_pData ? FXSYS_wcslen(m_pData->m_String) : 0;
    }
    if (nNewLength == 0) {
        Empty();
        return;
    }
    FXSYS_assert(nNewLength <= m_pData->m_nAllocLength);
    m_pData->m_nDataLength = nNewLength;
    m_pData->m_String[nNewLength] = 0;
}
const CFX_WideString& CFX_WideString::operator=(const FX_WCHAR* lpsz)
{
    if (lpsz == NULL || lpsz[0] == 0) {
        Empty();
    } else {
        AssignCopy(FXSYS_wcslen(lpsz), lpsz);
    }
    return *this;
}
const CFX_WideString& CFX_WideString::operator=(const CFX_WideStringC& stringSrc)
{
    if (stringSrc.IsEmpty()) {
        Empty();
    } else {
        AssignCopy(stringSrc.GetLength(), stringSrc.GetPtr());
    }
    return *this;
}
const CFX_WideString& CFX_WideString::operator=(const CFX_WideString& stringSrc)
{
    if (m_pData == stringSrc.m_pData) {
        return *this;
    }
    if (stringSrc.IsEmpty()) {
        Empty();
    } else if ((m_pData && m_pData->m_nRefs < 0) ||
               (stringSrc.m_pData && stringSrc.m_pData->m_nRefs < 0)) {
        AssignCopy(stringSrc.m_pData->m_nDataLength, stringSrc.m_pData->m_String);
    } else {
        Empty();
        m_pData = stringSrc.m_pData;
        if (m_pData) {
            m_pData->Retain();
        }
    }
    return *this;
}
const CFX_WideString& CFX_WideString::operator+=(FX_WCHAR ch)
{
    ConcatInPlace(1, &ch);
    return *this;
}
const CFX_WideString& CFX_WideString::operator+=(const FX_WCHAR* lpsz)
{
    if (lpsz) {
        ConcatInPlace(FXSYS_wcslen(lpsz), lpsz);
    }
    return *this;
}
const CFX_WideString& CFX_WideString::operator+=(const CFX_WideString& string)
{
    if (string.m_pData == NULL) {
        return *this;
    }
    ConcatInPlace(string.m_pData->m_nDataLength, string.m_pData->m_String);
    return *this;
}
const CFX_WideString& CFX_WideString::operator+=(const CFX_WideStringC& string)
{
    if (string.IsEmpty()) {
        return *this;
    }
    ConcatInPlace(string.GetLength(), string.GetPtr());
    return *this;
}
bool CFX_WideString::Equal(const wchar_t* ptr) const
{
    if (!m_pData) {
        return !ptr || ptr[0] == L'\0';
    }
    if (!ptr) {
        return m_pData->m_nDataLength == 0;
    }
    return wcslen(ptr) == m_pData->m_nDataLength &&
            wmemcmp(ptr, m_pData->m_String, m_pData->m_nDataLength) == 0;
}
bool CFX_WideString::Equal(const CFX_WideStringC& str) const
{
    if (m_pData == NULL) {
        return str.IsEmpty();
    }
    return str.GetLength() == m_pData->m_nDataLength &&
        wmemcmp(str.GetPtr(), m_pData->m_String, m_pData->m_nDataLength) == 0;
}
bool CFX_WideString::Equal(const CFX_WideString& other) const
{
    if (IsEmpty()) {
        return other.IsEmpty();
    }
    if (other.IsEmpty()) {
        return false;
    }
    return other.m_pData->m_nDataLength == m_pData->m_nDataLength &&
        wmemcmp(other.m_pData->m_String,
                m_pData->m_String,
                m_pData->m_nDataLength) == 0;
}
void CFX_WideString::Empty()
{
    if (m_pData) {
        m_pData->Release();
        m_pData = NULL;
    }
}
void CFX_WideString::ConcatInPlace(FX_STRSIZE nSrcLen, const FX_WCHAR* lpszSrcData)
{
    if (nSrcLen == 0 || lpszSrcData == NULL) {
        return;
    }
    if (m_pData == NULL) {
        m_pData = StringData::Create(nSrcLen);
        if (m_pData) {
            FXSYS_memcpy32(m_pData->m_String, lpszSrcData, nSrcLen * sizeof(FX_WCHAR));
        }
        return;
    }
    if (m_pData->m_nRefs > 1 || m_pData->m_nDataLength + nSrcLen > m_pData->m_nAllocLength) {
        ConcatCopy(m_pData->m_nDataLength, m_pData->m_String, nSrcLen, lpszSrcData);
    } else {
        FXSYS_memcpy32(m_pData->m_String + m_pData->m_nDataLength, lpszSrcData, nSrcLen * sizeof(FX_WCHAR));
        m_pData->m_nDataLength += nSrcLen;
        m_pData->m_String[m_pData->m_nDataLength] = 0;
    }
}
void CFX_WideString::ConcatCopy(FX_STRSIZE nSrc1Len, const FX_WCHAR* lpszSrc1Data,
                                FX_STRSIZE nSrc2Len, const FX_WCHAR* lpszSrc2Data)
{
    FX_STRSIZE nNewLen = nSrc1Len + nSrc2Len;
    if (nNewLen <= 0) {
        return;
    }
    // Don't release until done copying, might be one of the arguments.
    StringData* pOldData = m_pData;
    m_pData = StringData::Create(nNewLen);
    if (m_pData) {
        wmemcpy(m_pData->m_String, lpszSrc1Data, nSrc1Len);
        wmemcpy(m_pData->m_String + nSrc1Len, lpszSrc2Data, nSrc2Len);
    }
    pOldData->Release();
}
void CFX_WideString::CopyBeforeWrite()
{
    if (m_pData == NULL || m_pData->m_nRefs <= 1) {
        return;
    }
    StringData* pData = m_pData;
    m_pData->Release();
    FX_STRSIZE nDataLength = pData->m_nDataLength;
    m_pData = StringData::Create(nDataLength);
    if (m_pData != NULL) {
        FXSYS_memcpy32(m_pData->m_String, pData->m_String, (nDataLength + 1) * sizeof(FX_WCHAR));
    }
}
void CFX_WideString::AllocBeforeWrite(FX_STRSIZE nLen)
{
    if (m_pData && m_pData->m_nRefs <= 1 && m_pData->m_nAllocLength >= nLen) {
        return;
    }
    Empty();
    m_pData = StringData::Create(nLen);
}
void CFX_WideString::AssignCopy(FX_STRSIZE nSrcLen, const FX_WCHAR* lpszSrcData)
{
    AllocBeforeWrite(nSrcLen);
    FXSYS_memcpy32(m_pData->m_String, lpszSrcData, nSrcLen * sizeof(FX_WCHAR));
    m_pData->m_nDataLength = nSrcLen;
    m_pData->m_String[nSrcLen] = 0;
}
int CFX_WideString::Compare(const FX_WCHAR* lpsz) const
{
    if (m_pData == NULL) {
        return (lpsz == NULL || lpsz[0] == 0) ? 0 : -1;
    }
    return FXSYS_wcscmp(m_pData->m_String, lpsz);
}
CFX_ByteString CFX_WideString::UTF8Encode() const
{
    return FX_UTF8Encode(*this);
}
CFX_ByteString CFX_WideString::UTF16LE_Encode() const
{
    if (m_pData == NULL) {
        return CFX_ByteString(FX_BSTRC("\0\0"));
    }
    int len = m_pData->m_nDataLength;
    CFX_ByteString result;
    FX_CHAR* buffer = result.GetBuffer(len * 2 + 2);
    for (int i = 0; i < len; i ++) {
        buffer[i * 2] = m_pData->m_String[i] & 0xff;
        buffer[i * 2 + 1] = m_pData->m_String[i] >> 8;
    }
    buffer[len * 2] = 0;
    buffer[len * 2 + 1] = 0;
    result.ReleaseBuffer(len * 2 + 2);
    return result;
}
void CFX_WideString::ConvertFrom(const CFX_ByteString& str, CFX_CharMap* pCharMap)
{
    if (pCharMap == NULL) {
        pCharMap = CFX_CharMap::GetDefaultMapper();
    }
    *this = pCharMap->m_GetWideString(pCharMap, str);
}
void CFX_WideString::Reserve(FX_STRSIZE len)
{
    GetBuffer(len);
    ReleaseBuffer(GetLength());
}
FX_WCHAR* CFX_WideString::GetBuffer(FX_STRSIZE nMinBufLength)
{
    if (m_pData == NULL && nMinBufLength == 0) {
        return NULL;
    }
    if (m_pData && m_pData->m_nRefs <= 1 && m_pData->m_nAllocLength >= nMinBufLength) {
        return m_pData->m_String;
    }
    if (m_pData == NULL) {
        m_pData = StringData::Create(nMinBufLength);
        if (!m_pData) {
            return NULL;
        }
        m_pData->m_nDataLength = 0;
        m_pData->m_String[0] = 0;
        return m_pData->m_String;
    }
    StringData* pOldData = m_pData;
    FX_STRSIZE nOldLen = pOldData->m_nDataLength;
    if (nMinBufLength < nOldLen) {
        nMinBufLength = nOldLen;
    }
    m_pData = StringData::Create(nMinBufLength);
    if (!m_pData) {
        return NULL;
    }
    FXSYS_memcpy32(m_pData->m_String, pOldData->m_String, (nOldLen + 1)*sizeof(FX_WCHAR));
    m_pData->m_nDataLength = nOldLen;
    pOldData->Release();
    return m_pData->m_String;
}
CFX_WideString CFX_WideString::FromLocal(const char* str, FX_STRSIZE len)
{
    CFX_WideString result;
    result.ConvertFrom(CFX_ByteString(str, len));
    return result;
}
CFX_WideString CFX_WideString::FromUTF8(const char* str, FX_STRSIZE len)
{
    if (!str || 0 == len) {
        return CFX_WideString();
    }

    CFX_UTF8Decoder decoder;
    for (FX_STRSIZE i = 0; i < len; i ++) {
        decoder.Input(str[i]);
    }
    return decoder.GetResult();
}
CFX_WideString CFX_WideString::FromUTF16LE(const unsigned short* wstr, FX_STRSIZE wlen)
{
    if (!wstr || 0 == wlen) {
        return CFX_WideString();
    }

    CFX_WideString result;
    FX_WCHAR* buf = result.GetBuffer(wlen);
    for (int i = 0; i < wlen; i ++) {
        buf[i] = wstr[i];
    }
    result.ReleaseBuffer(wlen);
    return result;
}
FX_STRSIZE CFX_WideString::WStringLength(const unsigned short* str)
{
    FX_STRSIZE len = 0;
    if (str)
        while (str[len]) len++;
    return len;
}


void CFX_WideString::AllocCopy(CFX_WideString& dest, FX_STRSIZE nCopyLen, FX_STRSIZE nCopyIndex) const
{
    // |FX_STRSIZE| is currently typedef'd as in |int|. TODO(palmer): It
    // should be a |size_t|, or at least unsigned.
    if (nCopyLen == 0 || nCopyLen < 0) {
        return;
    }
    pdfium::base::CheckedNumeric<FX_STRSIZE> iSize = static_cast<FX_STRSIZE>(sizeof(FX_WCHAR));
    iSize *= nCopyLen;
    ASSERT(dest.m_pData == NULL);
    dest.m_pData = StringData::Create(nCopyLen);
    if (dest.m_pData) {
        FXSYS_memcpy32(dest.m_pData->m_String, m_pData->m_String + nCopyIndex, iSize.ValueOrDie());
    }
}
CFX_WideString CFX_WideString::Left(FX_STRSIZE nCount) const
{
    if (m_pData == NULL) {
        return CFX_WideString();
    }
    if (nCount < 0) {
        nCount = 0;
    }
    if (nCount >= m_pData->m_nDataLength) {
        return *this;
    }
    CFX_WideString dest;
    AllocCopy(dest, nCount, 0);
    return dest;
}
CFX_WideString CFX_WideString::Mid(FX_STRSIZE nFirst) const
{
    return Mid(nFirst, m_pData->m_nDataLength - nFirst);
}
CFX_WideString CFX_WideString::Mid(FX_STRSIZE nFirst, FX_STRSIZE nCount) const
{
    if (m_pData == NULL) {
        return CFX_WideString();
    }
    if (nFirst < 0) {
        nFirst = 0;
    }
    if (nCount < 0) {
        nCount = 0;
    }
    if (nFirst + nCount > m_pData->m_nDataLength) {
        nCount = m_pData->m_nDataLength - nFirst;
    }
    if (nFirst > m_pData->m_nDataLength) {
        nCount = 0;
    }
    if (nFirst == 0 && nFirst + nCount == m_pData->m_nDataLength) {
        return *this;
    }
    CFX_WideString dest;
    AllocCopy(dest, nCount, nFirst);
    return dest;
}
CFX_WideString CFX_WideString::Right(FX_STRSIZE nCount) const
{
    if (m_pData == NULL) {
        return CFX_WideString();
    }
    if (nCount < 0) {
        nCount = 0;
    }
    if (nCount >= m_pData->m_nDataLength) {
        return *this;
    }
    CFX_WideString dest;
    AllocCopy(dest, nCount, m_pData->m_nDataLength - nCount);
    return dest;
}
int CFX_WideString::CompareNoCase(const FX_WCHAR* lpsz) const
{
    if (m_pData == NULL) {
        return (lpsz == NULL || lpsz[0] == 0) ? 0 : -1;
    }
    return FXSYS_wcsicmp(m_pData->m_String, lpsz);
}
int CFX_WideString::Compare(const CFX_WideString& str) const
{
    if (m_pData == NULL) {
        if (str.m_pData == NULL) {
            return 0;
        }
        return -1;
    } else if (str.m_pData == NULL) {
        return 1;
    }
    int this_len = m_pData->m_nDataLength;
    int that_len = str.m_pData->m_nDataLength;
    int min_len = this_len < that_len ? this_len : that_len;
    for (int i = 0; i < min_len; i ++) {
        if (m_pData->m_String[i] < str.m_pData->m_String[i]) {
            return -1;
        } else if (m_pData->m_String[i] > str.m_pData->m_String[i]) {
            return 1;
        }
    }
    if (this_len < that_len) {
        return -1;
    } else if (this_len > that_len) {
        return 1;
    }
    return 0;
}
void CFX_WideString::SetAt(FX_STRSIZE nIndex, FX_WCHAR ch)
{
    if (m_pData == NULL) {
        return;
    }
    ASSERT(nIndex >= 0);
    ASSERT(nIndex < m_pData->m_nDataLength);
    CopyBeforeWrite();
    m_pData->m_String[nIndex] = ch;
}
void CFX_WideString::MakeLower()
{
    if (m_pData == NULL) {
        return;
    }
    CopyBeforeWrite();
    if (GetLength() < 1) {
        return;
    }
    FXSYS_wcslwr(m_pData->m_String);
}
void CFX_WideString::MakeUpper()
{
    if (m_pData == NULL) {
        return;
    }
    CopyBeforeWrite();
    if (GetLength() < 1) {
        return;
    }
    FXSYS_wcsupr(m_pData->m_String);
}
FX_STRSIZE CFX_WideString::Find(const FX_WCHAR* lpszSub, FX_STRSIZE nStart) const
{
    FX_STRSIZE nLength = GetLength();
    if (nLength < 1 || nStart > nLength) {
        return -1;
    }
    const FX_WCHAR* lpsz = FXSYS_wcsstr(m_pData->m_String + nStart, lpszSub);
    return (lpsz == NULL) ? -1 : (int)(lpsz - m_pData->m_String);
}
FX_STRSIZE CFX_WideString::Find(FX_WCHAR ch, FX_STRSIZE nStart) const
{
    if (m_pData == NULL) {
        return -1;
    }
    FX_STRSIZE nLength = m_pData->m_nDataLength;
    if (nStart >= nLength) {
        return -1;
    }
    const FX_WCHAR* lpsz = FXSYS_wcschr(m_pData->m_String + nStart, ch);
    return (lpsz == NULL) ? -1 : (int)(lpsz - m_pData->m_String);
}
void CFX_WideString::TrimRight(const FX_WCHAR* lpszTargetList)
{
    FXSYS_assert(lpszTargetList != NULL);
    if (m_pData == NULL || *lpszTargetList == 0) {
        return;
    }
    CopyBeforeWrite();
    FX_STRSIZE len = GetLength();
    if (len < 1) {
        return;
    }
    FX_STRSIZE pos = len;
    while (pos) {
        if (FXSYS_wcschr(lpszTargetList, m_pData->m_String[pos - 1]) == NULL) {
            break;
        }
        pos --;
    }
    if (pos < len) {
        m_pData->m_String[pos] = 0;
        m_pData->m_nDataLength = pos;
    }
}
void CFX_WideString::TrimRight(FX_WCHAR chTarget)
{
    FX_WCHAR str[2] = {chTarget, 0};
    TrimRight(str);
}
void CFX_WideString::TrimRight()
{
    TrimRight(L"\x09\x0a\x0b\x0c\x0d\x20");
}
void CFX_WideString::TrimLeft(const FX_WCHAR* lpszTargets)
{
    FXSYS_assert(lpszTargets != NULL);
    if (m_pData == NULL || *lpszTargets == 0) {
        return;
    }
    CopyBeforeWrite();
    if (GetLength() < 1) {
        return;
    }
    const FX_WCHAR* lpsz = m_pData->m_String;
    while (*lpsz != 0) {
        if (FXSYS_wcschr(lpszTargets, *lpsz) == NULL) {
            break;
        }
        lpsz ++;
    }
    if (lpsz != m_pData->m_String) {
        int nDataLength = m_pData->m_nDataLength - (FX_STRSIZE)(lpsz - m_pData->m_String);
        FXSYS_memmove32(m_pData->m_String, lpsz, (nDataLength + 1)*sizeof(FX_WCHAR));
        m_pData->m_nDataLength = nDataLength;
    }
}
void CFX_WideString::TrimLeft(FX_WCHAR chTarget)
{
    FX_WCHAR str[2] = {chTarget, 0};
    TrimLeft(str);
}
void CFX_WideString::TrimLeft()
{
    TrimLeft(L"\x09\x0a\x0b\x0c\x0d\x20");
}
FX_STRSIZE CFX_WideString::Replace(const FX_WCHAR* lpszOld, const FX_WCHAR* lpszNew)
{
    if (GetLength() < 1) {
        return 0;
    }
    if (lpszOld == NULL) {
        return 0;
    }
    FX_STRSIZE nSourceLen = FXSYS_wcslen(lpszOld);
    if (nSourceLen == 0) {
        return 0;
    }
    FX_STRSIZE nReplacementLen = lpszNew ? FXSYS_wcslen(lpszNew) : 0;
    FX_STRSIZE nCount = 0;
    FX_WCHAR* lpszStart = m_pData->m_String;
    FX_WCHAR* lpszEnd = m_pData->m_String + m_pData->m_nDataLength;
    FX_WCHAR* lpszTarget;
    {
        while ((lpszTarget = (FX_WCHAR*)FXSYS_wcsstr(lpszStart, lpszOld)) != NULL && lpszStart < lpszEnd) {
            nCount++;
            lpszStart = lpszTarget + nSourceLen;
        }
    }
    if (nCount > 0) {
        CopyBeforeWrite();
        FX_STRSIZE nOldLength = m_pData->m_nDataLength;
        FX_STRSIZE nNewLength =  nOldLength + (nReplacementLen - nSourceLen) * nCount;
        if (m_pData->m_nAllocLength < nNewLength || m_pData->m_nRefs > 1) {
            StringData* pOldData = m_pData;
            const FX_WCHAR* pstr = m_pData->m_String;
            m_pData = StringData::Create(nNewLength);
            if (!m_pData) {
                return 0;
            }
            FXSYS_memcpy32(m_pData->m_String, pstr, pOldData->m_nDataLength * sizeof(FX_WCHAR));
            pOldData->Release();
        }
        lpszStart = m_pData->m_String;
        lpszEnd = m_pData->m_String + FX_MAX(m_pData->m_nDataLength, nNewLength);
        {
            while ((lpszTarget = (FX_WCHAR*)FXSYS_wcsstr(lpszStart, lpszOld)) != NULL && lpszStart < lpszEnd) {
                FX_STRSIZE nBalance = nOldLength - (FX_STRSIZE)(lpszTarget - m_pData->m_String + nSourceLen);
                FXSYS_memmove32(lpszTarget + nReplacementLen, lpszTarget + nSourceLen, nBalance * sizeof(FX_WCHAR));
                FXSYS_memcpy32(lpszTarget, lpszNew, nReplacementLen * sizeof(FX_WCHAR));
                lpszStart = lpszTarget + nReplacementLen;
                lpszStart[nBalance] = 0;
                nOldLength += (nReplacementLen - nSourceLen);
            }
        }
        ASSERT(m_pData->m_String[nNewLength] == 0);
        m_pData->m_nDataLength = nNewLength;
    }
    return nCount;
}
FX_STRSIZE CFX_WideString::Insert(FX_STRSIZE nIndex, FX_WCHAR ch)
{
    CopyBeforeWrite();
    if (nIndex < 0) {
        nIndex = 0;
    }
    FX_STRSIZE nNewLength = GetLength();
    if (nIndex > nNewLength) {
        nIndex = nNewLength;
    }
    nNewLength++;
    if (m_pData == NULL || m_pData->m_nAllocLength < nNewLength) {
        StringData* pOldData = m_pData;
        const FX_WCHAR* pstr = m_pData->m_String;
        m_pData = StringData::Create(nNewLength);
        if (!m_pData) {
            return 0;
        }
        if(pOldData != NULL) {
            FXSYS_memmove32(m_pData->m_String, pstr, (pOldData->m_nDataLength + 1)*sizeof(FX_WCHAR));
            pOldData->Release();
        } else {
            m_pData->m_String[0] = 0;
        }
    }
    FXSYS_memmove32(m_pData->m_String + nIndex + 1,
                    m_pData->m_String + nIndex, (nNewLength - nIndex)*sizeof(FX_WCHAR));
    m_pData->m_String[nIndex] = ch;
    m_pData->m_nDataLength = nNewLength;
    return nNewLength;
}
FX_STRSIZE CFX_WideString::Delete(FX_STRSIZE nIndex, FX_STRSIZE nCount)
{
    if (GetLength() < 1) {
        return 0;
    }
    if (nIndex < 0) {
        nIndex = 0;
    }
    FX_STRSIZE nOldLength = m_pData->m_nDataLength;
    if (nCount > 0 && nIndex < nOldLength) {
        CopyBeforeWrite();
        int nBytesToCopy = nOldLength - (nIndex + nCount) + 1;
        FXSYS_memmove32(m_pData->m_String + nIndex,
                        m_pData->m_String + nIndex + nCount, nBytesToCopy * sizeof(FX_WCHAR));
        m_pData->m_nDataLength = nOldLength - nCount;
    }
    return m_pData->m_nDataLength;
}
FX_STRSIZE CFX_WideString::Remove(FX_WCHAR chRemove)
{
    if (m_pData == NULL) {
        return 0;
    }
    CopyBeforeWrite();
    if (GetLength() < 1) {
        return 0;
    }
    FX_WCHAR* pstrSource = m_pData->m_String;
    FX_WCHAR* pstrDest = m_pData->m_String;
    FX_WCHAR* pstrEnd = m_pData->m_String + m_pData->m_nDataLength;
    while (pstrSource < pstrEnd) {
        if (*pstrSource != chRemove) {
            *pstrDest = *pstrSource;
            pstrDest ++;
        }
        pstrSource ++;
    }
    *pstrDest = 0;
    FX_STRSIZE nCount = (FX_STRSIZE)(pstrSource - pstrDest);
    m_pData->m_nDataLength -= nCount;
    return nCount;
}
#define FORCE_ANSI      0x10000
#define FORCE_UNICODE   0x20000
#define FORCE_INT64     0x40000
void CFX_WideString::FormatV(const FX_WCHAR* lpszFormat, va_list argList)
{
    va_list argListSave;
#if defined(__ARMCC_VERSION) || (!defined(_MSC_VER) && (_FX_CPU_ == _FX_X64_ || _FX_CPU_ == _FX_IA64_ || _FX_CPU_ == _FX_ARM64_)) || defined(__native_client__)
    va_copy(argListSave, argList);
#else
    argListSave = argList;
#endif
    int nMaxLen = 0;
    for (const FX_WCHAR* lpsz = lpszFormat; *lpsz != 0; lpsz ++) {
        if (*lpsz != '%' || *(lpsz = lpsz + 1) == '%') {
            nMaxLen += FXSYS_wcslen(lpsz);
            continue;
        }
        int nItemLen = 0;
        int nWidth = 0;
        for (; *lpsz != 0; lpsz ++) {
            if (*lpsz == '#') {
                nMaxLen += 2;
            } else if (*lpsz == '*') {
                nWidth = va_arg(argList, int);
            } else if (*lpsz == '-' || *lpsz == '+' || *lpsz == '0' ||
                       *lpsz == ' ')
                ;
            else {
                break;
            }
        }
        if (nWidth == 0) {
            nWidth = FXSYS_wtoi(lpsz);
            for (; *lpsz != 0 && (*lpsz) <= '9' && (*lpsz) >= '0'; lpsz ++)
                ;
        }
        if (nWidth < 0 || nWidth > 128 * 1024) {
            lpszFormat = L"Bad width";
            nMaxLen = 10;
            break;
        }
        int nPrecision = 0;
        if (*lpsz == '.') {
            lpsz ++;
            if (*lpsz == '*') {
                nPrecision = va_arg(argList, int);
                lpsz ++;
            } else {
                nPrecision = FXSYS_wtoi(lpsz);
                for (; *lpsz != 0 && (*lpsz) >= '0' && (*lpsz) <= '9'; lpsz ++)
                    ;
            }
        }
        if (nPrecision < 0 || nPrecision > 128 * 1024) {
            lpszFormat = L"Bad precision";
            nMaxLen = 14;
            break;
        }
        int nModifier = 0;
        if (*lpsz == L'I' && *(lpsz + 1) == L'6' && *(lpsz + 2) == L'4') {
            lpsz += 3;
            nModifier = FORCE_INT64;
        } else {
            switch (*lpsz) {
                case 'h':
                    nModifier = FORCE_ANSI;
                    lpsz ++;
                    break;
                case 'l':
                    nModifier = FORCE_UNICODE;
                    lpsz ++;
                    break;
                case 'F':
                case 'N':
                case 'L':
                    lpsz ++;
                    break;
            }
        }
        switch (*lpsz | nModifier) {
            case 'c':
            case 'C':
                nItemLen = 2;
                va_arg(argList, int);
                break;
            case 'c'|FORCE_ANSI:
            case 'C'|FORCE_ANSI:
                nItemLen = 2;
                va_arg(argList, int);
                break;
            case 'c'|FORCE_UNICODE:
            case 'C'|FORCE_UNICODE:
                nItemLen = 2;
                va_arg(argList, int);
                break;
            case 's': {
                    const FX_WCHAR* pstrNextArg = va_arg(argList, const FX_WCHAR*);
                    if (pstrNextArg == NULL) {
                        nItemLen = 6;
                    } else {
                        nItemLen = FXSYS_wcslen(pstrNextArg);
                        if (nItemLen < 1) {
                            nItemLen = 1;
                        }
                    }
                }
                break;
            case 'S': {
                    const FX_CHAR* pstrNextArg = va_arg(argList, const FX_CHAR*);
                    if (pstrNextArg == NULL) {
                        nItemLen = 6;
                    } else {
                        nItemLen = FXSYS_strlen(pstrNextArg);
                        if (nItemLen < 1) {
                            nItemLen = 1;
                        }
                    }
                }
                break;
            case 's'|FORCE_ANSI:
            case 'S'|FORCE_ANSI: {
                    const FX_CHAR* pstrNextArg = va_arg(argList, const FX_CHAR*);
                    if (pstrNextArg == NULL) {
                        nItemLen = 6;
                    } else {
                        nItemLen = FXSYS_strlen(pstrNextArg);
                        if (nItemLen < 1) {
                            nItemLen = 1;
                        }
                    }
                }
                break;
            case 's'|FORCE_UNICODE:
            case 'S'|FORCE_UNICODE: {
                    FX_WCHAR* pstrNextArg = va_arg(argList, FX_WCHAR*);
                    if (pstrNextArg == NULL) {
                        nItemLen = 6;
                    } else {
                        nItemLen = FXSYS_wcslen(pstrNextArg);
                        if (nItemLen < 1) {
                            nItemLen = 1;
                        }
                    }
                }
                break;
        }
        if (nItemLen != 0) {
            if (nPrecision != 0 && nItemLen > nPrecision) {
                nItemLen = nPrecision;
            }
            if (nItemLen < nWidth) {
                nItemLen = nWidth;
            }
        } else {
            switch (*lpsz) {
                case 'd':
                case 'i':
                case 'u':
                case 'x':
                case 'X':
                case 'o':
                    if (nModifier & FORCE_INT64) {
                        va_arg(argList, int64_t);
                    } else {
                        va_arg(argList, int);
                    }
                    nItemLen = 32;
                    if (nItemLen < nWidth + nPrecision) {
                        nItemLen = nWidth + nPrecision;
                    }
                    break;
                case 'a':
                case 'A':
                case 'e':
                case 'E':
                case 'g':
                case 'G':
                    va_arg(argList, double);
                    nItemLen = 128;
                    if (nItemLen < nWidth + nPrecision) {
                        nItemLen = nWidth + nPrecision;
                    }
                    break;
                case 'f':
                    if (nWidth + nPrecision > 100) {
                        nItemLen = nPrecision + nWidth + 128;
                    } else {
                        double f;
                        char pszTemp[256];
                        f = va_arg(argList, double);
                        FXSYS_snprintf(pszTemp, sizeof(pszTemp), "%*.*f", nWidth, nPrecision + 6, f );
                        nItemLen = FXSYS_strlen(pszTemp);
                    }
                    break;
                case 'p':
                    va_arg(argList, void*);
                    nItemLen = 32;
                    if (nItemLen < nWidth + nPrecision) {
                        nItemLen = nWidth + nPrecision;
                    }
                    break;
                case 'n':
                    va_arg(argList, int*);
                    break;
            }
        }
        nMaxLen += nItemLen;
    }
    GetBuffer(nMaxLen);
    if (m_pData) {
        FXSYS_vswprintf((wchar_t*)m_pData->m_String, nMaxLen + 1, (const wchar_t*)lpszFormat, argListSave);
        ReleaseBuffer();
    }
    va_end(argListSave);
}
void CFX_WideString::Format(const FX_WCHAR* lpszFormat, ...)
{
    va_list argList;
    va_start(argList, lpszFormat);
    FormatV(lpszFormat, argList);
    va_end(argList);
}
FX_FLOAT FX_wtof(const FX_WCHAR* str, int len)
{
    if (len == 0) {
        return 0.0;
    }
    int cc = 0;
    FX_BOOL bNegative = FALSE;
    if (str[0] == '+') {
        cc++;
    } else if (str[0] == '-') {
        bNegative = TRUE;
        cc++;
    }
    int integer = 0;
    while (cc < len) {
        if (str[cc] == '.') {
            break;
        }
        integer = integer * 10 + str[cc] - '0';
        cc ++;
    }
    FX_FLOAT fraction = 0;
    if (str[cc] == '.') {
        cc ++;
        FX_FLOAT scale = 0.1f;
        while (cc < len) {
            fraction += scale * (str[cc] - '0');
            scale *= 0.1f;
            cc ++;
        }
    }
    fraction += (FX_FLOAT)integer;
    return bNegative ? -fraction : fraction;
}
int CFX_WideString::GetInteger() const
{
    if (m_pData == NULL) {
        return 0;
    }
    return FXSYS_wtoi(m_pData->m_String);
}
FX_FLOAT CFX_WideString::GetFloat() const
{
    if (m_pData == NULL) {
        return 0.0;
    }
    return FX_wtof(m_pData->m_String, m_pData->m_nDataLength);
}
static CFX_ByteString _DefMap_GetByteString(CFX_CharMap* pCharMap, const CFX_WideString& widestr)
{
    int src_len = widestr.GetLength();
    int codepage = pCharMap->m_GetCodePage ? pCharMap->m_GetCodePage() : 0;
    int dest_len = FXSYS_WideCharToMultiByte(codepage, 0, widestr.c_str(), src_len, NULL, 0, NULL, NULL);
    if (dest_len == 0) {
        return CFX_ByteString();
    }
    CFX_ByteString bytestr;
    FX_CHAR* dest_buf = bytestr.GetBuffer(dest_len);
    FXSYS_WideCharToMultiByte(codepage, 0, widestr.c_str(), src_len, dest_buf, dest_len, NULL, NULL);
    bytestr.ReleaseBuffer(dest_len);
    return bytestr;
}
static CFX_WideString _DefMap_GetWideString(CFX_CharMap* pCharMap, const CFX_ByteString& bytestr)
{
    int src_len = bytestr.GetLength();
    int codepage = pCharMap->m_GetCodePage ? pCharMap->m_GetCodePage() : 0;
    int dest_len = FXSYS_MultiByteToWideChar(codepage, 0, bytestr, src_len, NULL, 0);
    if (dest_len == 0) {
        return CFX_WideString();
    }
    CFX_WideString widestr;
    FX_WCHAR* dest_buf = widestr.GetBuffer(dest_len);
    FXSYS_MultiByteToWideChar(codepage, 0, bytestr, src_len, dest_buf, dest_len);
    widestr.ReleaseBuffer(dest_len);
    return widestr;
}
static int _DefMap_GetGBKCodePage()
{
    return 936;
}
static int _DefMap_GetUHCCodePage()
{
    return 949;
}
static int _DefMap_GetJISCodePage()
{
    return 932;
}
static int _DefMap_GetBig5CodePage()
{
    return 950;
}
static const CFX_CharMap g_DefaultMapper = {&_DefMap_GetWideString, &_DefMap_GetByteString, NULL};
static const CFX_CharMap g_DefaultGBKMapper = {&_DefMap_GetWideString, &_DefMap_GetByteString, &_DefMap_GetGBKCodePage};
static const CFX_CharMap g_DefaultJISMapper = {&_DefMap_GetWideString, &_DefMap_GetByteString, &_DefMap_GetJISCodePage};
static const CFX_CharMap g_DefaultUHCMapper = {&_DefMap_GetWideString, &_DefMap_GetByteString, &_DefMap_GetUHCCodePage};
static const CFX_CharMap g_DefaultBig5Mapper = {&_DefMap_GetWideString, &_DefMap_GetByteString, &_DefMap_GetBig5CodePage};
CFX_CharMap* CFX_CharMap::GetDefaultMapper(int32_t codepage)
{
    switch (codepage) {
        case 0:
            return (CFX_CharMap*)&g_DefaultMapper;
        case 932:
            return (CFX_CharMap*)&g_DefaultJISMapper;
        case 936:
            return (CFX_CharMap*)&g_DefaultGBKMapper;
        case 949:
            return (CFX_CharMap*)&g_DefaultUHCMapper;
        case 950:
            return (CFX_CharMap*)&g_DefaultBig5Mapper;
    }
    return NULL;
}