/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtCore module of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

**

**

**

**

**

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include "qiconvcodec_p.h"

#include "qtextcodec_p.h"

#include <qlibrary.h>

#include <qdebug.h>

#include <qthreadstorage.h>

#include <errno.h>

#include <locale.h>

#include <stdio.h>

#include <dlfcn.h>

// unistd.h is needed for the _XOPEN_UNIX macro

#include <unistd.h>

#if defined(_XOPEN_UNIX) && !defined(Q_OS_QNX) && !defined(Q_OS_OSF)

#  include <langinfo.h>

#endif

#if defined(Q_OS_HPUX)

#  define NO_BOM

#  define UTF16 "ucs2"

#elif defined(Q_OS_AIX)

#  define NO_BOM

#  define UTF16 "UCS-2"

#elif defined(Q_OS_FREEBSD) || defined(Q_OS_MAC)

#  define NO_BOM

#  if Q_BYTE_ORDER == Q_BIG_ENDIAN

#    define UTF16 "UTF-16BE"

#  else

#    define UTF16 "UTF-16LE"

#  endif

#else

#  define UTF16 "UTF-16"

#endif

#if defined(Q_OS_MAC)

#ifndef GNU_LIBICONV

#define GNU_LIBICONV

#endif

typedef iconv_t (*Ptr_iconv_open) (const char*, const char*);

typedef size_t (*Ptr_iconv) (iconv_t, const char **, size_t *, char **, size_t *);

typedef int (*Ptr_iconv_close) (iconv_t);

static Ptr_iconv_open ptr_iconv_open = 0;

static Ptr_iconv ptr_iconv = 0;

static Ptr_iconv_close ptr_iconv_close = 0;

#endif

QT_BEGIN_NAMESPACE

extern bool qt_locale_initialized;

QIconvCodec::QIconvCodec()

    : utf16Codec(0)

{

    utf16Codec = QTextCodec::codecForMib(1015);

    Q_ASSERT_X(utf16Codec != 0,

               "QIconvCodec::convertToUnicode",

               "internal error, UTF-16 codec not found");

    if (!utf16Codec) {

        fprintf(stderr, "QIconvCodec::convertToUnicode: internal error, UTF-16 codec not found\n");

        utf16Codec = reinterpret_cast<QTextCodec *>(~0);

    }

#if defined(Q_OS_MAC)

    if (ptr_iconv_open == 0) {

        QLibrary libiconv(QLatin1String("/usr/lib/libiconv"));

        libiconv.setLoadHints(QLibrary::ExportExternalSymbolsHint);

        ptr_iconv_open = reinterpret_cast<Ptr_iconv_open>(libiconv.resolve("libiconv_open"));

        if (!ptr_iconv_open)

            ptr_iconv_open = reinterpret_cast<Ptr_iconv_open>(libiconv.resolve("iconv_open"));

        ptr_iconv = reinterpret_cast<Ptr_iconv>(libiconv.resolve("libiconv"));

        if (!ptr_iconv)

            ptr_iconv = reinterpret_cast<Ptr_iconv>(libiconv.resolve("iconv"));

        ptr_iconv_close = reinterpret_cast<Ptr_iconv_close>(libiconv.resolve("libiconv_close"));

        if (!ptr_iconv_close)

            ptr_iconv_close = reinterpret_cast<Ptr_iconv_close>(libiconv.resolve("iconv_close"));

        Q_ASSERT_X(ptr_iconv_open && ptr_iconv && ptr_iconv_close,

        "QIconvCodec::QIconvCodec()",

        "internal error, could not resolve the iconv functions");

#       undef iconv_open

#       define iconv_open ptr_iconv_open

#       undef iconv

#       define iconv ptr_iconv

#       undef iconv_close

#       define iconv_close ptr_iconv_close

    }

#endif

}

QIconvCodec::~QIconvCodec()

{

}

QIconvCodec::IconvState::IconvState(iconv_t x)

    : buffer(array), bufferLen(sizeof array), cd(x)

{

}

QIconvCodec::IconvState::~IconvState()

{

    if (cd != reinterpret_cast<iconv_t>(-1))

        iconv_close(cd);

    if (buffer != array)

        delete[] buffer;

}

void QIconvCodec::IconvState::saveChars(const char *c, int count)

{

    if (count > bufferLen) {

        if (buffer != array)

            delete[] buffer;

        buffer = new char[bufferLen = count];

    }

    memcpy(buffer, c, count);

}

static void qIconvCodecStateFree(QTextCodec::ConverterState *state)

{

    delete reinterpret_cast<QIconvCodec::IconvState *>(state->d);

}

Q_GLOBAL_STATIC(QThreadStorage<QIconvCodec::IconvState *>, toUnicodeState)

QString QIconvCodec::convertToUnicode(const char* chars, int len, ConverterState *convState) const

{

    if (utf16Codec == reinterpret_cast<QTextCodec *>(~0))

        return QString::fromAscii(chars, len);

    int invalidCount = 0;

    int remainingCount = 0;

    char *remainingBuffer = 0;

    IconvState **pstate;

    if (convState) {

        // stateful conversion

        pstate = reinterpret_cast<IconvState **>(&convState->d);

        if (convState->d) {

            // restore state

            remainingCount = convState->remainingChars;

            remainingBuffer = (*pstate)->buffer;

        } else {

            // first time

            convState->flags |= FreeFunction;

            QTextCodecUnalignedPointer::encode(convState->state_data, qIconvCodecStateFree);

        }

    } else {

        QThreadStorage<QIconvCodec::IconvState *> *ts = toUnicodeState();

        if (!qt_locale_initialized || !ts) {

            // we're running after the Q_GLOBAL_STATIC has been deleted

            // or before the QCoreApplication initialization

            // bad programmer, no cookie for you

            return QString::fromLatin1(chars, len);

        }

        // stateless conversion -- use thread-local data

        pstate = &toUnicodeState()->localData();

    }

    if (!*pstate) {

        // first time, create the state

        iconv_t cd = QIconvCodec::createIconv_t(UTF16, 0);

        if (cd == reinterpret_cast<iconv_t>(-1)) {

            static int reported = 0;

            if (!reported++) {

                fprintf(stderr,

                        "QIconvCodec::convertToUnicode: using ASCII for conversion, iconv_open failed\n");

            }

            return QString::fromAscii(chars, len);

        }

        *pstate = new IconvState(cd);

    }

    IconvState *state = *pstate;

    size_t inBytesLeft = len;

    // best case assumption, each byte is converted into one UTF-16 character, plus 2 bytes for the BOM

#ifdef GNU_LIBICONV

    // GNU doesn't disagree with POSIX :/

    const char *inBytes = chars;

#else

    char *inBytes = const_cast<char *>(chars);

#endif

    QByteArray in;

    if (remainingCount) {

        // we have to prepend the remaining bytes from the previous conversion

        inBytesLeft += remainingCount;

        in.resize(inBytesLeft);

        inBytes = in.data();

        memcpy(in.data(), remainingBuffer, remainingCount);

        memcpy(in.data() + remainingCount, chars, len);

        remainingCount = 0;

    }

    size_t outBytesLeft = len * 2 + 2;

    QByteArray ba(outBytesLeft, Qt::Uninitialized);

    char *outBytes = ba.data();

    do {

        size_t ret = iconv(state->cd, &inBytes, &inBytesLeft, &outBytes, &outBytesLeft);

        if (ret == (size_t) -1) {

            if (errno == E2BIG) {

                int offset = ba.size() - outBytesLeft;

                ba.resize(ba.size() * 2);

                outBytes = ba.data() + offset;

                outBytesLeft = ba.size() - offset;

                continue;

            }

            if (errno == EILSEQ) {

                // conversion stopped because of an invalid character in the sequence

                ++invalidCount;

            } else if (errno == EINVAL && convState) {

                // conversion stopped because the remaining inBytesLeft make up

                // an incomplete multi-byte sequence; save them for later

                state->saveChars(inBytes, inBytesLeft);

                remainingCount = inBytesLeft;

                break;

            }

            if (errno == EILSEQ || errno == EINVAL) {

                // skip the next character

                ++inBytes;

                --inBytesLeft;

                continue;

            }

            // some other error

            // note, cannot use qWarning() since we are implementing the codecForLocale :)

            perror("QIconvCodec::convertToUnicode: using ASCII for conversion, iconv failed");

            if (!convState) {

                // reset state

                iconv(state->cd, 0, &inBytesLeft, 0, &outBytesLeft);

            }

            return QString::fromAscii(chars, len);

        }

    } while (inBytesLeft != 0);

    QString s = utf16Codec->toUnicode(ba.constData(), ba.size() - outBytesLeft);

    if (convState) {

        convState->invalidChars = invalidCount;

        convState->remainingChars = remainingCount;

    } else {

        // reset state

        iconv(state->cd, 0, &inBytesLeft, 0, &outBytesLeft);

    }

    return s;

}

Q_GLOBAL_STATIC(QThreadStorage<QIconvCodec::IconvState *>, fromUnicodeState)

QByteArray QIconvCodec::convertFromUnicode(const QChar *uc, int len, ConverterState *convState) const

{

    char *inBytes;

    char *outBytes;

    size_t inBytesLeft;

#if defined(GNU_LIBICONV)

    const char **inBytesPtr = const_cast<const char **>(&inBytes);

#else

    char **inBytesPtr = &inBytes;

#endif

    QThreadStorage<QIconvCodec::IconvState *> *ts = fromUnicodeState();

    if (!qt_locale_initialized || !ts) {

        // we're running after the Q_GLOBAL_STATIC has been deleted

        // or before the QCoreApplication initialization

        // bad programmer, no cookie for you

        if (!len)

            // this is a special case - zero-sized string should be

            // translated to empty but not-null QByteArray.

            return QByteArray("");

        return QString::fromRawData(uc, len).toLatin1();

    }

    IconvState *&state = ts->localData();

    if (!state) {

        state = new IconvState(QIconvCodec::createIconv_t(0, UTF16));

                perror("QIconvCodec::convertFromUnicode: using ASCII for conversion, iconv failed for BOM");

                iconv_close(state->cd);

                state->cd = reinterpret_cast<iconv_t>(-1);

                return QString(uc, len).toAscii();

            }

        }

    }

    if (state->cd == reinterpret_cast<iconv_t>(-1)) {

        static int reported = 0;

        if (!reported++) {

            fprintf(stderr,

                    "QIconvCodec::convertFromUnicode: using ASCII for conversion, iconv_open failed\n");

        }

        return QString(uc, len).toAscii();

    }

    size_t outBytesLeft = len;

    QByteArray ba(outBytesLeft, Qt::Uninitialized);

    outBytes = ba.data();

    // now feed iconv() the real data

    inBytes = const_cast<char *>(reinterpret_cast<const char *>(uc));

    inBytesLeft = len * sizeof(QChar);

    QByteArray in;

    if (convState && convState->remainingChars) {

        // we have one surrogate char to be prepended

        in.resize(sizeof(QChar) + len);

        inBytes = in.data();

        QChar remaining = convState->state_data[0];

        memcpy(in.data(), &remaining, sizeof(QChar));

        memcpy(in.data() + sizeof(QChar), uc, inBytesLeft);

        inBytesLeft += sizeof(QChar);

        convState->remainingChars = 0;

    }

    int invalidCount = 0;

    while (inBytesLeft != 0) {

        if (iconv(state->cd, inBytesPtr, &inBytesLeft, &outBytes, &outBytesLeft) == (size_t) -1) {

            if (errno == EINVAL && convState) {

                // buffer ends in a surrogate

                Q_ASSERT(inBytesLeft == 2);

                convState->remainingChars = 1;

                convState->state_data[0] = uc[len - 1].unicode();

                break;

            }

            switch (errno) {

            case EILSEQ:

                ++invalidCount;

                // fall through

            case EINVAL:

                {

                    inBytes += sizeof(QChar);

                    inBytesLeft -= sizeof(QChar);

                    break;

                }

            case E2BIG:

                {

                    int offset = ba.size() - outBytesLeft;

                    ba.resize(ba.size() * 2);

                    outBytes = ba.data() + offset;

                    outBytesLeft = ba.size() - offset;

                    break;

                }

            default:

                {

                    // note, cannot use qWarning() since we are implementing the codecForLocale :)

                    perror("QIconvCodec::convertFromUnicode: using ASCII for conversion, iconv failed");

                    // reset to initial state

                    iconv(state->cd, 0, &inBytesLeft, 0, &outBytesLeft);

                    return QString(uc, len).toAscii();

                }

            }

        }

    }

    // reset to initial state

    iconv(state->cd, 0, &inBytesLeft, 0, &outBytesLeft);

    ba.resize(ba.size() - outBytesLeft);

    if (convState)

        convState->invalidChars = invalidCount;

    return ba;

}

QByteArray QIconvCodec::name() const

{

    return "System";

}

int QIconvCodec::mibEnum() const

{

    return 0;

}

iconv_t QIconvCodec::createIconv_t(const char *to, const char *from)

{

    Q_ASSERT((to == 0 && from != 0) || (to != 0 && from == 0));

    iconv_t cd = (iconv_t) -1;

#if defined(__GLIBC__) || defined(GNU_LIBICONV)

    // both GLIBC and libgnuiconv will use the locale's encoding if from or to is an empty string

    static const char empty_codeset[] = "";

    const char *codeset = empty_codeset;

    cd = iconv_open(to ? to : codeset, from ? from : codeset);

#else

    char *codeset = 0;

#endif

#if defined(_XOPEN_UNIX) && !defined(Q_OS_QNX) && !defined(Q_OS_OSF)

    if (cd == (iconv_t) -1) {

        codeset = nl_langinfo(CODESET);

        if (codeset)

            cd = iconv_open(to ? to : codeset, from ? from : codeset);

    }

#endif

    if (cd == (iconv_t) -1) {

        // Very poorly defined and followed standards causes lots of

        // code to try to get all the cases... This logic is

        // duplicated in QTextCodec, so if you change it here, change

        // it there too.

        // Try to determine locale codeset from locale name assigned to

        // LC_CTYPE category.

        // First part is getting that locale name.  First try setlocale() which

        // definitely knows it, but since we cannot fully trust it, get ready

        // to fall back to environment variables.

        char * ctype = qstrdup(setlocale(LC_CTYPE, 0));

        // Get the first nonempty value from $LC_ALL, $LC_CTYPE, and $LANG

        // environment variables.

        char * lang = qstrdup(qgetenv("LC_ALL").constData());

        if (!lang || lang[0] == 0 || strcmp(lang, "C") == 0) {

            if (lang) delete [] lang;

            lang = qstrdup(qgetenv("LC_CTYPE").constData());

        }

        if (!lang || lang[0] == 0 || strcmp(lang, "C") == 0) {

            if (lang) delete [] lang;

            lang = qstrdup(qgetenv("LANG").constData());

        }

        // Now try these in order:

        // 1. CODESET from ctype if it contains a .CODESET part (e.g. en_US.ISO8859-15)

        // 2. CODESET from lang if it contains a .CODESET part

        // 3. ctype (maybe the locale is named "ISO-8859-1" or something)

        // 4. locale (ditto)

        // 5. check for "@euro"

        // 1. CODESET from ctype if it contains a .CODESET part (e.g. en_US.ISO8859-15)

        codeset = ctype ? strchr(ctype, '.') : 0;

        if (codeset && *codeset == '.') {

            ++codeset;

            cd = iconv_open(to ? to : codeset, from ? from : codeset);

        }

        // 2. CODESET from lang if it contains a .CODESET part

        codeset = lang ? strchr(lang, '.') : 0;

        if (cd == (iconv_t) -1 && codeset && *codeset == '.') {