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#ifndef QPROPERTYPRIVATE_H
#define QPROPERTYPRIVATE_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of qapplication_*.cpp, qwidget*.cpp and qfiledialog.cpp.  This header
// file may change from version to version without notice, or even be removed.
//
// We mean it.
//

#include <QtCore/qglobal.h>
#include <QtCore/QExplicitlySharedDataPointer>

QT_BEGIN_NAMESPACE

class QUntypedPropertyBinding;
struct QPropertyBindingPrivate;
using QPropertyBindingPrivatePtr = QExplicitlySharedDataPointer<QPropertyBindingPrivate>;
struct QPropertyBasePointer;

namespace QtPrivate {

class Q_CORE_EXPORT QPropertyBase
{
    // Mutable because the address of the observer of the currently evaluating binding is stored here, for
    // notification later when the value changes.
    mutable quintptr d_ptr = 0;
    friend struct QT_PREPEND_NAMESPACE(QPropertyBasePointer);
public:
    QPropertyBase() = default;
    Q_DISABLE_COPY(QPropertyBase)
    QPropertyBase(QPropertyBase &&other) = delete;
    QPropertyBase(QPropertyBase &&other, void *propertyDataPtr);
    QPropertyBase &operator=(QPropertyBase &&other) = delete;
    ~QPropertyBase();

    void moveAssign(QPropertyBase &&other, void *propertyDataPtr);

    bool hasBinding() const { return d_ptr & BindingBit; }

    QUntypedPropertyBinding setBinding(const QUntypedPropertyBinding &newBinding, void *propertyDataPtr);
    QPropertyBindingPrivatePtr binding();

    void evaluateIfDirty();
    void removeBinding();

    void registerWithCurrentlyEvaluatingBinding() const;
    void notifyObservers();

    void setExtraBit(bool b)
    {
        if (b)
            d_ptr |= ExtraBit;
        else
            d_ptr &= ~ExtraBit;
    }

    bool extraBit() const { return d_ptr & ExtraBit; }

    static const quintptr ExtraBit = 0x1;   // Used for QProperty<bool> specialization
    static const quintptr BindingBit = 0x2; // Is d_ptr pointing to a binding (1) or list of notifiers (0)?
    static const quintptr FlagMask = BindingBit | ExtraBit;
};

template <typename T>
struct QPropertyValueStorage
{
private:
    T value;
public:
    QPropertyBase priv;

    QPropertyValueStorage() : value() {}
    Q_DISABLE_COPY(QPropertyValueStorage)
    explicit QPropertyValueStorage(const T &initialValue) : value(initialValue) {}
    QPropertyValueStorage &operator=(const T &newValue) { value = newValue; return *this; }
    explicit QPropertyValueStorage(T &&initialValue) : value(std::move(initialValue)) {}
    QPropertyValueStorage &operator=(T &&newValue) { value = std::move(newValue); return *this; }
    QPropertyValueStorage(QPropertyValueStorage &&other) : value(std::move(other.value)), priv(std::move(other.priv), this) {}
    QPropertyValueStorage &operator=(QPropertyValueStorage &&other) { value = std::move(other.value); priv.moveAssign(std::move(other.priv), &value); return *this; }

    T getValue() const { return value; }
    bool setValueAndReturnTrueIfChanged(T &&v)
    {
        if (v == value)
            return false;
        value = std::move(v);
        return true;
    }
    bool setValueAndReturnTrueIfChanged(const T &v)
    {
        if (v == value)
            return false;
        value = v;
        return true;
    }
};

template<>
struct QPropertyValueStorage<bool>
{
    QPropertyBase priv;

    QPropertyValueStorage() = default;
    Q_DISABLE_COPY(QPropertyValueStorage)
    explicit QPropertyValueStorage(bool initialValue) { priv.setExtraBit(initialValue); }
    QPropertyValueStorage &operator=(bool newValue) { priv.setExtraBit(newValue); return *this; }
    QPropertyValueStorage(QPropertyValueStorage &&other) : priv(std::move(other.priv), this) {}
    QPropertyValueStorage &operator=(QPropertyValueStorage &&other) { priv.moveAssign(std::move(other.priv), this); return *this; }

    bool getValue() const { return priv.extraBit(); }
    bool setValueAndReturnTrueIfChanged(bool v)
    {
        if (v == priv.extraBit())
            return false;
        priv.setExtraBit(v);
        return true;
    }
};

template <typename T> class QTaggedPointer;

template <typename T, quintptr Mask = 0x3>
class QPropertyTagPreservingPointerToPointer
{
    quintptr *data = nullptr;

public:
    QPropertyTagPreservingPointerToPointer() = default;
    QPropertyTagPreservingPointerToPointer(T **ptr)
        : data(reinterpret_cast<quintptr*>(ptr))
    {}
    QPropertyTagPreservingPointerToPointer(quintptr *ptr)
        : data(ptr)
    {}

    QPropertyTagPreservingPointerToPointer<T> &operator=(T **ptr)
    {
        data = reinterpret_cast<quintptr*>(ptr);
        return *this;
    }

    QPropertyTagPreservingPointerToPointer<T> &operator=(QTaggedPointer<T> *ptr)
    {
        data = reinterpret_cast<quintptr*>(ptr);
        return *this;
    }

    void clear()
    {
        data = nullptr;
    }

    void set(T *ptr)
    {
        *data = (*data & Mask) | (reinterpret_cast<quintptr>(ptr) & ~Mask);
    }

    T *get() const
    {
        return reinterpret_cast<T*>(*data & ~Mask);
    }

    explicit operator bool() const { return data != nullptr; }
};

template <typename T>
class QTaggedPointer
{
public:
    QTaggedPointer() = default;
    QTaggedPointer(T *ptr) : tagAndPointer(reinterpret_cast<quintptr>(ptr)) {}

    void setFlag(bool b)
    {
        if (b)
            tagAndPointer |= Flag1Mask;
        else
            tagAndPointer &= ~Flag1Mask;
    }

    bool flag() const { return tagAndPointer & Flag1Mask; }

    QTaggedPointer &operator=(T *ptr)
    {
        quintptr tag = tagAndPointer & TagMask;
        tagAndPointer = reinterpret_cast<quintptr>(ptr) | tag;
        return *this;
    }

    T *data() const { return reinterpret_cast<T*>(tagAndPointer & ~TagMask); }

    explicit operator bool() const { return tagAndPointer & ~TagMask; }
    T *operator->() const { return data(); }

private:
    quintptr tagAndPointer = 0;
    static const quintptr Flag1Mask = 0x1;
    static const quintptr TagMask = 0x3;
};

} // namespace QtPrivate

QT_END_NAMESPACE

#endif // QPROPERTYPRIVATE_H