/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the qmake application of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL-EXCEPT$
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** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
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****************************************************************************/

#include "ioutils.h"

#include <qdir.h>
#include <qfile.h>

#ifdef Q_OS_WIN
#  include <windows.h>
#else
#  include <sys/types.h>
#  include <sys/stat.h>
#  include <unistd.h>
#endif

QT_BEGIN_NAMESPACE

using namespace QMakeInternal;

IoUtils::FileType IoUtils::fileType(const QString &fileName)
{
    Q_ASSERT(fileName.isEmpty() || isAbsolutePath(fileName));
#ifdef Q_OS_WIN
    DWORD attr = GetFileAttributesW((WCHAR*)fileName.utf16());
    if (attr == INVALID_FILE_ATTRIBUTES)
        return FileNotFound;
    return (attr & FILE_ATTRIBUTE_DIRECTORY) ? FileIsDir : FileIsRegular;
#else
    struct ::stat st;
    if (::stat(fileName.toLocal8Bit().constData(), &st))
        return FileNotFound;
    return S_ISDIR(st.st_mode) ? FileIsDir : FileIsRegular;
#endif
}

bool IoUtils::isRelativePath(const QString &path)
{
    if (path.startsWith(QLatin1Char('/')))
        return false;
#ifdef QMAKE_BUILTIN_PRFS
    if (path.startsWith(QLatin1String(":/")))
        return false;
#endif
#ifdef Q_OS_WIN
    if (path.startsWith(QLatin1Char('\\')))
        return false;
    // Unlike QFileInfo, this won't accept a relative path with a drive letter.
    // Such paths result in a royal mess anyway ...
    if (path.length() >= 3 && path.at(1) == QLatin1Char(':') && path.at(0).isLetter()
        && (path.at(2) == QLatin1Char('/') || path.at(2) == QLatin1Char('\\')))
        return false;
#endif
    return true;
}

QStringRef IoUtils::pathName(const QString &fileName)
{
    return fileName.leftRef(fileName.lastIndexOf(QLatin1Char('/')) + 1);
}

QStringRef IoUtils::fileName(const QString &fileName)
{
    return fileName.midRef(fileName.lastIndexOf(QLatin1Char('/')) + 1);
}

QString IoUtils::resolvePath(const QString &baseDir, const QString &fileName)
{
    if (fileName.isEmpty())
        return QString();
    if (isAbsolutePath(fileName))
        return QDir::cleanPath(fileName);
    return QDir::cleanPath(baseDir + QLatin1Char('/') + fileName);
}

inline static
bool isSpecialChar(ushort c, const uchar (&iqm)[16])
{
    if ((c < sizeof(iqm) * 8) && (iqm[c / 8] & (1 << (c & 7))))
        return true;
    return false;
}

inline static
bool hasSpecialChars(const QString &arg, const uchar (&iqm)[16])
{
    for (int x = arg.length() - 1; x >= 0; --x) {
        if (isSpecialChar(arg.unicode()[x].unicode(), iqm))
            return true;
    }
    return false;
}

QString IoUtils::shellQuoteUnix(const QString &arg)
{
    // Chars that should be quoted (TM). This includes:
    static const uchar iqm[] = {
        0xff, 0xff, 0xff, 0xff, 0xdf, 0x07, 0x00, 0xd8,
        0x00, 0x00, 0x00, 0x38, 0x01, 0x00, 0x00, 0x78
    }; // 0-32 \'"$`<>|;&(){}*?#!~[]

    if (!arg.length())
        return QString::fromLatin1("''");

    QString ret(arg);
    if (hasSpecialChars(ret, iqm)) {
        ret.replace(QLatin1Char('\''), QLatin1String("'\\''"));
        ret.prepend(QLatin1Char('\''));
        ret.append(QLatin1Char('\''));
    }
    return ret;
}

QString IoUtils::shellQuoteWin(const QString &arg)
{
    // Chars that should be quoted (TM). This includes:
    // - control chars & space
    // - the shell meta chars "&()<>^|
    // - the potential separators ,;=
    static const uchar iqm[] = {
        0xff, 0xff, 0xff, 0xff, 0x45, 0x13, 0x00, 0x78,
        0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x10
    };
    // Shell meta chars that need escaping.
    static const uchar ism[] = {
        0x00, 0x00, 0x00, 0x00, 0x40, 0x03, 0x00, 0x50,
        0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x10
    }; // &()<>^|

    if (!arg.length())
        return QString::fromLatin1("\"\"");

    QString ret(arg);
    if (hasSpecialChars(ret, iqm)) {
        // The process-level standard quoting allows escaping quotes with backslashes (note
        // that backslashes don't escape themselves, unless they are followed by a quote).
        // Consequently, quotes are escaped and their preceding backslashes are doubled.
        ret.replace(QRegExp(QLatin1String("(\\\\*)\"")), QLatin1String("\\1\\1\\\""));
        // Trailing backslashes must be doubled as well, as they are followed by a quote.
        ret.replace(QRegExp(QLatin1String("(\\\\+)$")), QLatin1String("\\1\\1"));
        // However, the shell also interprets the command, and no backslash-escaping exists
        // there - a quote always toggles the quoting state, but is nonetheless passed down
        // to the called process verbatim. In the unquoted state, the circumflex escapes
        // meta chars (including itself and quotes), and is removed from the command.
        bool quoted = true;
        for (int i = 0; i < ret.length(); i++) {
            QChar c = ret.unicode()[i];
            if (c.unicode() == '"')
                quoted = !quoted;
            else if (!quoted && isSpecialChar(c.unicode(), ism))
                ret.insert(i++, QLatin1Char('^'));
        }
        if (!quoted)
            ret.append(QLatin1Char('^'));
        ret.append(QLatin1Char('"'));
        ret.prepend(QLatin1Char('"'));
    }
    return ret;
}

QT_END_NAMESPACE