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#ifndef QARRAYDATAPOINTER_H
#define QARRAYDATAPOINTER_H

#include <QtCore/qarraydataops.h>
#include <QtCore/qcontainertools_impl.h>

QT_BEGIN_NAMESPACE

template <class T>
struct QArrayDataPointer
{
private:
    typedef QTypedArrayData<T> Data;
    typedef QArrayDataOps<T> DataOps;

public:
    typedef typename Data::iterator iterator;
    typedef typename Data::const_iterator const_iterator;
    enum { pass_parameter_by_value = std::is_fundamental<T>::value || std::is_pointer<T>::value };

    typedef typename std::conditional<pass_parameter_by_value, T, const T &>::type parameter_type;

    constexpr QArrayDataPointer() noexcept
        : d(nullptr), ptr(nullptr), size(0)
    {
    }

    QArrayDataPointer(const QArrayDataPointer &other) noexcept
        : d(other.d), ptr(other.ptr), size(other.size)
    {
        ref();
    }

    constexpr QArrayDataPointer(Data *header, T *adata, qsizetype n = 0) noexcept
        : d(header), ptr(adata), size(n)
    {
    }

    explicit QArrayDataPointer(QPair<QTypedArrayData<T> *, T *> adata, qsizetype n = 0) noexcept
        : d(adata.first), ptr(adata.second), size(n)
    {
    }

    static QArrayDataPointer fromRawData(const T *rawData, qsizetype length) noexcept
    {
        Q_ASSERT(rawData || !length);
        return { nullptr, const_cast<T *>(rawData), length };
    }

    QArrayDataPointer &operator=(const QArrayDataPointer &other) noexcept
    {
        QArrayDataPointer tmp(other);
        this->swap(tmp);
        return *this;
    }

    QArrayDataPointer(QArrayDataPointer &&other) noexcept
        : d(other.d), ptr(other.ptr), size(other.size)
    {
        other.d = nullptr;
        other.ptr = nullptr;
        other.size = 0;
    }

    QArrayDataPointer &operator=(QArrayDataPointer &&other) noexcept
    {
        QArrayDataPointer moved(std::move(other));
        swap(moved);
        return *this;
    }

    DataOps &operator*() noexcept
    {
        return *static_cast<DataOps *>(this);
    }

    DataOps *operator->() noexcept
    {
        return static_cast<DataOps *>(this);
    }

    const DataOps &operator*() const noexcept
    {
        return *static_cast<const DataOps *>(this);
    }

    const DataOps *operator->() const noexcept
    {
        return static_cast<const DataOps *>(this);
    }

    ~QArrayDataPointer()
    {
        if (!deref()) {
            (*this)->destroyAll();
            Data::deallocate(d);
        }
    }

    bool isNull() const noexcept
    {
        return !ptr;
    }

    T *data() noexcept { return ptr; }
    const T *data() const noexcept { return ptr; }

    iterator begin(iterator = iterator()) noexcept { return data(); }
    iterator end(iterator = iterator()) noexcept { return data() + size; }
    const_iterator begin(const_iterator = const_iterator()) const noexcept { return data(); }
    const_iterator end(const_iterator = const_iterator()) const noexcept { return data() + size; }
    const_iterator constBegin(const_iterator = const_iterator()) const noexcept { return data(); }
    const_iterator constEnd(const_iterator = const_iterator()) const noexcept { return data() + size; }

    void swap(QArrayDataPointer &other) noexcept
    {
        qSwap(d, other.d);
        qSwap(ptr, other.ptr);
        qSwap(size, other.size);
    }

    void clear() noexcept(std::is_nothrow_destructible<T>::value)
    {
        QArrayDataPointer tmp;
        swap(tmp);
    }

    bool detach()
    {
        if (needsDetach()) {
            QPair<Data *, T *> copy = clone(detachFlags());
            QArrayDataPointer old(d, ptr, size);
            d = copy.first;
            ptr = copy.second;
            return true;
        }

        return false;
    }

    // forwards from QArrayData
    size_t allocatedCapacity() noexcept { return d ? d->allocatedCapacity() : 0; }
    size_t constAllocatedCapacity() const noexcept { return d ? d->constAllocatedCapacity() : 0; }
    void ref() noexcept { if (d) d->ref(); }
    bool deref() noexcept { return !d || d->deref(); }
    bool isMutable() const noexcept { return d; }
    bool isShared() const noexcept { return !d || d->isShared(); }
    bool isSharedWith(const QArrayDataPointer &other) const noexcept { return d && d == other.d; }
    bool needsDetach() const noexcept { return !d || d->needsDetach(); }
    size_t detachCapacity(size_t newSize) const noexcept { return d ? d->detachCapacity(newSize) : newSize; }
    const typename Data::ArrayOptions flags() const noexcept { return d ? typename Data::ArrayOption(d->flags) : Data::DefaultAllocationFlags; }
    void setFlag(typename Data::ArrayOptions f) noexcept { Q_ASSERT(d); d->flags |= f; }
    void clearFlag(typename Data::ArrayOptions f) noexcept { Q_ASSERT(d); d->flags &= ~f; }
    typename Data::ArrayOptions detachFlags() const noexcept { return d ? d->detachFlags() : Data::DefaultAllocationFlags; }

    Data *d_ptr() noexcept { return d; }

private:
    Q_REQUIRED_RESULT QPair<Data *, T *> clone(QArrayData::ArrayOptions options) const
    {
        QPair<Data *, T *> pair = Data::allocate(detachCapacity(size), options);
        QArrayDataPointer copy(pair.first, pair.second, 0);
        if (size)
            copy->copyAppend(begin(), end());

        pair.first = copy.d;
        copy.d = nullptr;
        copy.ptr = nullptr;
        return pair;
    }

protected:
    Data *d;
    T *ptr;

public:
    qsizetype size;
};

template <class T>
inline bool operator==(const QArrayDataPointer<T> &lhs, const QArrayDataPointer<T> &rhs) noexcept
{
    return lhs.data() == rhs.data() && lhs.size == rhs.size;
}

template <class T>
inline bool operator!=(const QArrayDataPointer<T> &lhs, const QArrayDataPointer<T> &rhs) noexcept
{
    return lhs.data() != rhs.data() || lhs.size != rhs.size;
}

template <class T>
inline void qSwap(QArrayDataPointer<T> &p1, QArrayDataPointer<T> &p2) noexcept
{
    p1.swap(p2);
}

////////////////////////////////////////////////////////////////////////////////
//  Q_ARRAY_LITERAL

// The idea here is to place a (read-only) copy of header and array data in an
// mmappable portion of the executable (typically, .rodata section).

// Hide array inside a lambda
#define Q_ARRAY_LITERAL(Type, ...) \
    ([]() -> QArrayDataPointer<Type> { \
        static Type const data[] = { __VA_ARGS__ }; \
        return QArrayDataPointer<Type>::fromRawData(const_cast<Type *>(data), std::size(data)); \
    }())
/**/

QT_END_NAMESPACE

#endif // include guard