/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** 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 either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** 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.
**
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** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
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****************************************************************************/

#ifndef QSTRINGBUILDER_H
#define QSTRINGBUILDER_H

#include <QtCore/qstring.h>

#include <string.h>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(Core)

// ### Qt 5: merge with QLatin1String
class QLatin1Literal
{
public:
    int size() const { return m_size; }
    const char *data() const { return m_data; }

    template <int N>
    QLatin1Literal(const char (&str)[N]) 
        : m_size(N - 1), m_data(str) {}

private:
    const int m_size;
    const char *m_data;
};


template <typename T> struct QConcatenable {};

template <typename A, typename B>
class QStringBuilder
{
public:
    QStringBuilder(const A &a_, const B &b_) : a(a_), b(b_) {}

    operator QString() const
    {
        QString s(QConcatenable< QStringBuilder<A, B> >::size(*this),
            Qt::Uninitialized);
        
        QChar *d = s.data();
        QConcatenable< QStringBuilder<A, B> >::appendTo(*this, d);
        return s;
    }
    QByteArray toLatin1() const { return QString(*this).toLatin1(); }

    const A &a;
    const B &b;
};


template <> struct QConcatenable<char>
{
    typedef char type;
    static int size(const char) { return 1; }
    static inline void appendTo(const char c, QChar *&out)
    {
        *out++ = QLatin1Char(c);
    }
};

template <> struct QConcatenable<QLatin1Char>
{
    typedef QLatin1Char type;
    static int size(const QLatin1Char) { return 1; }
    static inline void appendTo(const QLatin1Char c, QChar *&out)
    {
        *out++ = c;
    }
};

template <> struct QConcatenable<QChar>
{
    typedef QChar type;
    static int size(const QChar) { return 1; }
    static inline void appendTo(const QChar c, QChar *&out)
    {
        *out++ = c;
    }
};

template <> struct QConcatenable<QCharRef>
{
    typedef QCharRef type;
    static int size(const QCharRef &) { return 1; }
    static inline void appendTo(const QCharRef &c, QChar *&out)
    {
        *out++ = QChar(c);
    }
};

template <> struct QConcatenable<QLatin1String>
{
    typedef QLatin1String type;
    static int size(const QLatin1String &a) { return qstrlen(a.latin1()); }
    static inline void appendTo(const QLatin1String &a, QChar *&out)
    {
        for (const char *s = a.latin1(); *s; )
            *out++ = QLatin1Char(*s++);
    }

};

template <> struct QConcatenable<QLatin1Literal>
{
    typedef QLatin1Literal type;
    static int size(const QLatin1Literal &a) { return a.size(); }
    static inline void appendTo(const QLatin1Literal &a, QChar *&out)
    {
        for (const char *s = a.data(); *s; )
            *out++ = QLatin1Char(*s++);
    }
};

template <> struct QConcatenable<QString>
{
    typedef QString type;
    static int size(const QString &a) { return a.size(); }
    static inline void appendTo(const QString &a, QChar *&out)
    {
        const int n = a.size();
        memcpy(out, reinterpret_cast<const char*>(a.constData()), sizeof(QChar) * n);
        out += n; 
    }
};

template <> struct QConcatenable<QStringRef>
{
    typedef QStringRef type;
    static int size(const QStringRef &a) { return a.size(); }
    static inline void appendTo(QStringRef a, QChar *&out)
    {
        const int n = a.size();
        memcpy(out, reinterpret_cast<const char*>(a.constData()), sizeof(QChar) * n);
        out += n; 
    }
};

#ifndef QT_NO_CAST_FROM_ASCII
template <int N> struct QConcatenable<char[N]>
{
    typedef char type[N];
    static int size(const char[N]) { return N - 1; }
    static inline void appendTo(const char a[N], QChar *&out)
    {
        for (int i = 0; i < N - 1; ++i)
            *out++ = QLatin1Char(a[i]);
    }
};

template <> struct QConcatenable<const char *>
{
    typedef char const *type;
    static int size(const char *a) { return qstrlen(a); }
    static inline void appendTo(const char *a, QChar *&out)
    {
        while (*a)
            *out++ = QLatin1Char(*a++);
    }
};

template <> struct QConcatenable<QByteArray>
{
    typedef QByteArray type;
    static int size(const QByteArray &ba) { return qstrnlen(ba.constData(), ba.size()); }
    static inline void appendTo(const QByteArray &ba, QChar *&out)
    {
        const char *data = ba.constData();
        while (*data)
            *out++ = QLatin1Char(*data++);
    }
};
#endif

template <typename A, typename B>
struct QConcatenable< QStringBuilder<A, B> >
{
    typedef QStringBuilder<A, B> type;
    static int size(const type &p) 
    {
        return QConcatenable<A>::size(p.a) + QConcatenable<B>::size(p.b);
    }
    static inline void appendTo(const QStringBuilder<A, B> &p, QChar *&out)
    {
        QConcatenable<A>::appendTo(p.a, out);
        QConcatenable<B>::appendTo(p.b, out);
    }
};

template <typename A, typename B>
QStringBuilder<typename QConcatenable<A>::type, typename QConcatenable<B>::type>
operator%(const A &a, const B &b)
{
   return QStringBuilder<A, B>(a, b);
}

#ifdef QT_USE_FAST_OPERATOR_PLUS
template <typename A, typename B>
QStringBuilder<typename QConcatenable<A>::type, typename QConcatenable<B>::type>
operator+(const A &a, const B &b)
{
   return QStringBuilder<A, B>(a, b);
}
#endif

QT_END_NAMESPACE

QT_END_HEADER

#endif // QSTRINGBUILDER_H