// Version: $Id: bfd62f8a98673b5b2ed2c111fee6e32dd8028c8b $
//
//

// Commentary:
//
//

// Change Log:
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// Code:

#pragma once

#include <QtCore>

template <typename T> class dtkAbstractIterator;

// ///////////////////////////////////////////////////////////////////
// dtkIterator
// ///////////////////////////////////////////////////////////////////

template <typename T> class dtkIterator
{
public:
    dtkAbstractIterator<T> *it;

public:
    typedef qlonglong difference_type;
    typedef T  value_type;
    typedef T *pointer;
    typedef T& reference;

public:
    explicit dtkIterator(dtkAbstractIterator<T> *iterator = 0);

public:
    dtkIterator(const dtkIterator& o);
    dtkIterator(dtkIterator&& o);
    ~dtkIterator(void);

public:
    dtkIterator& operator = (const dtkIterator& o);
    dtkIterator& operator = (dtkIterator&& o);

public:
    bool operator == (const dtkIterator& o) const;
    bool operator != (const dtkIterator& o) const;
    bool operator <  (const dtkIterator& o) const;
    bool operator <= (const dtkIterator& o) const;
    bool operator >  (const dtkIterator& o) const;
    bool operator >= (const dtkIterator& o) const;

public:
    T& operator *  (void) const;
    T *operator -> (void) const;
    T& operator [] (qlonglong j) const;

public:
    dtkIterator& operator ++ (void);
    dtkIterator  operator ++ (int);
    dtkIterator& operator -- (void);
    dtkIterator  operator -- (int);
    dtkIterator& operator += (qlonglong j);
    dtkIterator& operator -= (qlonglong j);
    dtkIterator  operator +  (qlonglong j) const;
    dtkIterator  operator -  (qlonglong j) const;

public:
    operator T *() const;
};

// ///////////////////////////////////////////////////////////////////
// dtkAbstractIterator
// ///////////////////////////////////////////////////////////////////

template <typename T> class dtkAbstractIterator
{
public:
    virtual ~dtkAbstractIterator(void) {
        ;
    }

public:
    virtual dtkAbstractIterator *clone(void) const = 0;
    virtual void copy(const dtkAbstractIterator& o) = 0;

public:
    virtual bool equal(const dtkAbstractIterator& o) const = 0;
    virtual bool lowerThan(const dtkAbstractIterator& o) const = 0;
    virtual bool greaterThan(const dtkAbstractIterator& o) const = 0;

public:
    virtual T& ref(void) const = 0;

public:
    virtual void advance(void) = 0;
    virtual void  rewind(void) = 0;
    virtual void advance(qlonglong j) = 0;
    virtual void  rewind(qlonglong j) = 0;
};

// ///////////////////////////////////////////////////////////////////
//
// ///////////////////////////////////////////////////////////////////

template <typename T> inline dtkIterator<T>::dtkIterator(dtkAbstractIterator<T> *iterator) : it(iterator)
{
}

template <typename T> inline dtkIterator<T>::dtkIterator(const dtkIterator& o) : it(o.it->clone())
{
}

template <typename T> inline dtkIterator<T>::dtkIterator(dtkIterator&& o) : it(o.it)
{
    o.it = 0;
}

template <typename T> inline dtkIterator<T>::~dtkIterator(void)
{
    if (it)
        delete it;

    it = 0;
}

template <typename T> inline dtkIterator<T>& dtkIterator<T>::operator = (const dtkIterator& o)
{
    it->copy(*(o.it));
    return *this;
}

template <typename T> inline dtkIterator<T>& dtkIterator<T>::operator = (dtkIterator&& o)
{
    std::swap(it, o.it);
    return *this;
}

template <typename T> inline bool dtkIterator<T>::operator == (const dtkIterator& o) const
{
    return it->equal(*(o.it));
}

template <typename T> inline bool dtkIterator<T>::operator != (const dtkIterator& o) const
{
    return !(it->equal(*(o.it)));
}

template <typename T> inline bool dtkIterator<T>::operator < (const dtkIterator& o) const
{
    return it->lowerThan(*(o.it));
}

template <typename T> inline bool dtkIterator<T>::operator <= (const dtkIterator& o) const
{
    return (it->lowerThan(*(o.it)) || it->equal(*(o.it)));
}

template <typename T> inline bool dtkIterator<T>::operator > (const dtkIterator& o) const
{
    return it->greaterThan(*(o.it));
}

template <typename T> inline bool dtkIterator<T>::operator >= (const dtkIterator& o) const
{
    return (it->greaterThan(*(o.it)) || it->equal(*(o.it)));
}

template <typename T> inline T& dtkIterator<T>::operator * (void) const
{
    return it->ref();
}

template <typename T> inline T *dtkIterator<T>::operator -> (void) const
{
    return &(it->ref());
}

template <typename T> inline T& dtkIterator<T>::operator [] (qlonglong j) const
{
    return *(*this + j);
}

template <typename T> inline dtkIterator<T>& dtkIterator<T>::operator ++ (void)
{
    it->advance();
    return *this;
}

template <typename T> inline dtkIterator<T> dtkIterator<T>::operator ++ (int)
{
    dtkIterator o(*this);
    it->advance();
    return o;
}

template <typename T> inline dtkIterator<T>& dtkIterator<T>::operator -- (void)
{
    it->rewind();
    return *this;

}

template <typename T> inline dtkIterator<T> dtkIterator<T>::operator -- (int)
{
    dtkIterator o(*this);
    it->rewind();
    return o;
}

template <typename T> inline dtkIterator<T>& dtkIterator<T>::operator += (qlonglong j)
{
    it->advance(j);
    return *this;
}

template <typename T> inline dtkIterator<T>& dtkIterator<T>::operator -= (qlonglong j)
{
    it->rewind(j);
    return *this;
}

template <typename T> inline dtkIterator<T> dtkIterator<T>::operator + (qlonglong j) const
{
    dtkIterator o(*this);
    o += j;
    return o;
}

template <typename T> inline dtkIterator<T> dtkIterator<T>::operator - (qlonglong j) const
{
    dtkIterator o(*this);
    o -= j;
    return o;
}

template <typename T> inline dtkIterator<T>::operator T *() const
{
    return &(it->ref());
}

// ///////////////////////////////////////////////////////////////////
// dtkIteratorBase CRTP
// ///////////////////////////////////////////////////////////////////

template <typename T, typename Iterator> class dtkIteratorBase : public dtkAbstractIterator<T>
{
public:
    dtkIteratorBase *clone(void) const;
    void copy(const dtkAbstractIterator<T>& o);

public:
    bool equal(const dtkAbstractIterator<T>& o) const;
    bool lowerThan(const dtkAbstractIterator<T>& o) const;
    bool greaterThan(const dtkAbstractIterator<T>& o) const;

public:
    T& ref(void) const;

public:
    void advance(void);
    void  rewind(void);
    void advance(qlonglong j);
    void  rewind(qlonglong j);
};

// ///////////////////////////////////////////////////////////////////

template <typename T, typename Iterator> inline dtkIteratorBase<T, Iterator> *dtkIteratorBase<T, Iterator>::clone(void) const
{
    return new Iterator(static_cast<const Iterator&>(*this));
}

template <typename T, typename Iterator> inline void dtkIteratorBase<T, Iterator>::copy(const dtkAbstractIterator<T>& o)
{
    static_cast<Iterator&>(*this) = static_cast<const Iterator&>(o);
}

template <typename T, typename Iterator> inline bool dtkIteratorBase<T, Iterator>::equal(const dtkAbstractIterator<T>& o) const
{
    return (static_cast<const Iterator&>(*this) == static_cast<const Iterator&>(o));
}

template <typename T, typename Iterator> inline bool dtkIteratorBase<T, Iterator>::lowerThan(const dtkAbstractIterator<T>& o) const
{
    return (static_cast<const Iterator&>(*this) < static_cast<const Iterator&>(o));
}

template <typename T, typename Iterator> inline bool dtkIteratorBase<T, Iterator>::greaterThan(const dtkAbstractIterator<T>& o) const
{
    return (static_cast<const Iterator&>(*this) > static_cast<const Iterator&>(o));
}

template <typename T, typename Iterator> inline T& dtkIteratorBase<T, Iterator>::ref(void) const
{
    return *(static_cast<const Iterator&>(*this));
}

template <typename T, typename Iterator> inline void dtkIteratorBase<T, Iterator>::advance(void)
{
    ++(static_cast<Iterator&>(*this));
}

template <typename T, typename Iterator> inline void dtkIteratorBase<T, Iterator>::advance(qlonglong j)
{
    static_cast<Iterator&>(*this) += j;
}

template <typename T, typename Iterator> inline void dtkIteratorBase<T, Iterator>::rewind(void)
{
    --(static_cast<Iterator&>(*this));
}

template <typename T, typename Iterator> inline void dtkIteratorBase<T, Iterator>::rewind(qlonglong j)
{
    static_cast<Iterator&>(*this) -= j;
}

// ///////////////////////////////////////////////////////////////////
// dtkIteratorGeneric
// ///////////////////////////////////////////////////////////////////

template <typename Iterator> class dtkIteratorGeneric : public dtkIteratorBase< typename Iterator::value_type, dtkIteratorGeneric<Iterator> >
{
    Iterator it;

public:
    typedef typename Iterator::iterator_category iterator_category;
    typedef typename Iterator::difference_type difference_type;
    typedef typename Iterator::value_type value_type;
    typedef typename Iterator::pointer pointer;
    typedef typename Iterator::reference reference;

public:
    dtkIteratorGeneric(const Iterator ite) : it(ite) {}
    dtkIteratorGeneric(const dtkIteratorGeneric& o) : it(o.it) {}

public:
    dtkIteratorGeneric& operator = (const dtkIteratorGeneric& o) {
        it = o.it;
        return *this;
    }

public:
    bool operator == (const dtkIteratorGeneric& o) const {
        return it == o.it;
    }
    bool operator != (const dtkIteratorGeneric& o) const {
        return it != o.it;
    }
    bool operator <  (const dtkIteratorGeneric& o) const {
        return it <  o.it;
    }
    bool operator <= (const dtkIteratorGeneric& o) const {
        return it <= o.it;
    }
    bool operator >  (const dtkIteratorGeneric& o) const {
        return it >  o.it;
    }
    bool operator >= (const dtkIteratorGeneric& o) const {
        return it >= o.it;
    }

public:
    reference operator *  (void) const {
        return *it;
    }
    pointer   operator -> (void) const {
        return &(*it);
    }
    reference operator [] (qlonglong j) const {
        return it[j];
    }

public:
    dtkIteratorGeneric& operator ++ (void) {
        ++it;
        return *this;
    }
    dtkIteratorGeneric  operator ++ (int)  {
        dtkIteratorGeneric o(it);
        ++it;
        return o;
    }
    dtkIteratorGeneric& operator -- (void) {
        --it;
        return *this;
    }
    dtkIteratorGeneric  operator -- (int)  {
        dtkIteratorGeneric o(it);
        --it;
        return o;
    }
    dtkIteratorGeneric& operator += (qlonglong j) {
        it += j;
        return *this;
    }
    dtkIteratorGeneric& operator -= (qlonglong j) {
        it -= j;
        return *this;
    }
    dtkIteratorGeneric  operator +  (qlonglong j) const {
        return dtkIteratorGeneric(it + j);
    }
    dtkIteratorGeneric  operator -  (qlonglong j) const {
        return dtkIteratorGeneric(it - j);
    }

public:
    operator pointer () const {
        return &(*it);
    }
};
//
// dtkIterator.h ends here