/****************************************************************************
**
** Copyright (c) 2008-2020 C.B. Barber. All rights reserved.
** $Id: //main/2019/qhull/src/libqhullcpp/QhullSet.h#5 $$Change: 3018 $
** $DateTime: 2020/08/15 19:58:23 $$Author: bbarber $
**
****************************************************************************/

#ifndef QhullSet_H
#define QhullSet_H

#include "libqhull_r/qhull_ra.h"
#include "libqhullcpp/QhullError.h"
#include "libqhullcpp/QhullQh.h"

#include <cstddef>  // ptrdiff_t, size_t

#ifndef QHULL_NO_STL
#include <vector>
#endif

#ifdef QHULL_USES_QT
 #include <QtCore/QList>
#endif

namespace orgQhull {

#//!\name Used here
    class Qhull;

#//!\name Defined here
    class QhullSetBase;  //! Base class for QhullSet<T>
    //! QhullSet<T> defined below
    //! QhullSetIterator<T> defined below
    //! \see QhullPointSet, QhullLinkedList<T>

//! QhullSetBase is a wrapper for Qhull's setT of void* pointers
//! \see libqhull_r/qset.h
class QhullSetBase {

private:
#//!\name Fields --
    setT *              qh_set;
    QhullQh *           qh_qh;             //! Provides access to setT memory allocator

#//!\name Class objects
    static setT         s_empty_set;  //! Used if setT* is NULL

public:
#//!\name Constructors
                        QhullSetBase(const Qhull &q, setT *s);
                        QhullSetBase(QhullQh *qqh, setT *s) : qh_set(s ? s : &s_empty_set), qh_qh(qqh) {}
                        //! Copy constructor copies the pointer but not the set.  Needed for return by value and parameter passing.
                        QhullSetBase(const QhullSetBase &other) : qh_set(other.qh_set), qh_qh(other.qh_qh) {}
    QhullSetBase &      operator=(const QhullSetBase &other) { qh_set= other.qh_set; qh_qh= other.qh_qh; return *this; }
                        ~QhullSetBase() {}

private:
                        //!disabled since memory allocation for QhullSet not defined
                        QhullSetBase()  : qh_set(NULL), qh_qh(NULL) {}
public:

#//!\name GetSet
    countT              count() const { return QhullSetBase::count(qh_set); }
    void                defineAs(setT *s) { qh_set= s ? s : &s_empty_set; } //!< Not type-safe since setT may contain any type
    void                forceEmpty() { qh_set= &s_empty_set; }
    setT *              getSetT() const { return qh_set; }
    bool                isEmpty() const { return SETempty_(qh_set); }
    QhullQh *           qh() const { return qh_qh; }
    setT **             referenceSetT() { return &qh_set; }
    size_t              size() const { return QhullSetBase::count(qh_set); }

#//!\name Element
protected:
    void **             beginPointer() const { return &qh_set->e[0].p; }
    void **             elementPointer(countT idx) const { QHULL_ASSERT(idx>=0 && idx<qh_set->maxsize); return &SETelem_(qh_set, idx); }
                        //! Always points to 0
    void **             endPointer() const { return qh_setendpointer(qh_set); }

#//!\name Class methods
public:
    static countT       count(const setT *set);
    //s may be null
    static bool         isEmpty(const setT *s) { return SETempty_(s); }
};//QhullSetBase


//! QhullSet<T> -- A read-only wrapper to Qhull's collection class, setT.
//!  QhullSet is similar to STL's <vector> and Qt's QVector
//!  QhullSet is unrelated to STL and Qt's set and map types (e.g., QSet and QMap)
//!  T is a Qhull type that defines 'base_type' and getBaseT() (e.g., QhullFacet with base_type 'facetT *'
//!  A QhullSet does not own its contents -- erase(), clear(), removeFirst(), removeLast(), pop_back(), pop_front(), fromStdList() not defined
//!  QhullSetIterator is faster than STL-style iterator/const_iterator
//!  Qhull's FOREACHelement_() [qset_r.h] maybe more efficient than QhullSet.  It uses a NULL terminator instead of an end pointer.  STL requires an end pointer.
//!  Derived from QhullLinkedList.h and Qt/core/tools/qlist.h w/o QT_STRICT_ITERATORS
template <typename T>
class QhullSet : public QhullSetBase {

private:
#//!\name Fields -- see QhullSetBase

#//!\name Class objects
    static setT         s_empty_set;  //! Workaround for no setT allocator.  Used if setT* is NULL

public:
#//!\name Defined here
    class iterator;
    class const_iterator;
    typedef typename QhullSet<T>::iterator Iterator;
    typedef typename QhullSet<T>::const_iterator ConstIterator;

#//!\name Constructors
                        QhullSet<T>(const Qhull &q, setT *s) : QhullSetBase(q, s) { }
                        QhullSet<T>(QhullQh *qqh, setT *s) : QhullSetBase(qqh, s) { }
                        //Conversion from setT* is not type-safe.  Implicit conversion for void* to T
                        //Copy constructor copies pointer but not contents.  Needed for return by value.
                        QhullSet<T>(const QhullSet<T> &other) : QhullSetBase(other) {}
    QhullSet<T> &       operator=(const QhullSet<T> &other) { QhullSetBase::operator=(other); return *this; }
                        ~QhullSet<T>() {}

private:
                        //!Disable default constructor.  See QhullSetBase
                        QhullSet<T>();
public:

#//!\name Conversion

#ifndef QHULL_NO_STL
    std::vector<T> toStdVector() const;
#endif
#ifdef QHULL_USES_QT
    QList<T>            toQList() const;
#endif

#//!\name GetSet -- see QhullSetBase for count(), empty(), isEmpty(), size()
    using QhullSetBase::count;
    using QhullSetBase::isEmpty;
    // operator== defined for QhullSets of the same type
    bool                operator==(const QhullSet<T> &other) const { return qh_setequal(getSetT(), other.getSetT()); }
    bool                operator!=(const QhullSet<T> &other) const { return !operator==(other); }

#//!\name Element access
    // Constructs T.  Cannot return reference.
    const T             at(countT idx) const { return operator[](idx); }
    // Constructs T.  Cannot return reference.
    const T             back() const { return last(); }
    T                   back() { return last(); }
    //! end element is NULL
    const typename T::base_type * constData() const { return reinterpret_cast<const typename T::base_type *>(beginPointer()); }
    typename T::base_type *     data() { return reinterpret_cast<typename T::base_type *>(beginPointer()); }
    const typename T::base_type *data() const { return reinterpret_cast<const typename T::base_type *>(beginPointer()); }
    typename T::base_type *     endData() { return reinterpret_cast<typename T::base_type *>(endPointer()); }
    const typename T::base_type * endData() const { return reinterpret_cast<const typename T::base_type *>(endPointer()); }
    // Constructs T.  Cannot return reference.
    const T             first() const { QHULL_ASSERT(!isEmpty()); return T(qh(), *data()); }
    T                   first() { QHULL_ASSERT(!isEmpty()); return T(qh(), *data()); }
    // Constructs T.  Cannot return reference.
    const T             front() const { return first(); }
    T                   front() { return first(); }
    // Constructs T.  Cannot return reference.
    const T             last() const { QHULL_ASSERT(!isEmpty()); return T(qh(), *(endData()-1)); }
    T                   last() { QHULL_ASSERT(!isEmpty()); return T(qh(), *(endData()-1)); }
    // mid() not available.  No setT constructor
    // Constructs T.  Cannot return reference.
    const T             operator[](countT idx) const { const typename T::base_type *p= reinterpret_cast<typename T::base_type *>(elementPointer(idx)); QHULL_ASSERT(idx>=0 && p < endData()); return T(qh(), *p); }
    T                   operator[](countT idx) { typename T::base_type *p= reinterpret_cast<typename T::base_type *>(elementPointer(idx)); QHULL_ASSERT(idx>=0 && p < endData()); return T(qh(), *p); }
    const T             second() const { return operator[](1); }
    T                   second() { return operator[](1); }
    T                   value(countT idx) const;
    T                   value(countT idx, const T &defaultValue) const;

#//!\name Read-write -- Not available, no setT constructor

#//!\name iterator
    iterator            begin() { return iterator(qh(), reinterpret_cast<typename T::base_type *>(beginPointer())); }
    const_iterator      begin() const { return const_iterator(qh(), data()); }
    const_iterator      constBegin() const { return const_iterator(qh(), data()); }
    const_iterator      constEnd() const { return const_iterator(qh(), endData()); }
    iterator            end() { return iterator(qh(), endData()); }
    const_iterator      end() const { return const_iterator(qh(), endData()); }

#//!\name Search
    bool                contains(const T &t) const;
    countT              count(const T &t) const;
    countT              indexOf(const T &t) const { /* no qh_qh */ return qh_setindex(getSetT(), t.getBaseT()); }
    countT              lastIndexOf(const T &t) const;

    // before const_iterator for conversion with comparison operators
    class iterator {
        friend class const_iterator;
    private:
        typename T::base_type *  i;  // e.g., facetT**, first for debugger
        QhullQh *       qh_qh;

    public:
        typedef ptrdiff_t       difference_type;
        typedef std::bidirectional_iterator_tag  iterator_category;
        typedef T               value_type;

                        iterator(QhullQh *qqh, typename T::base_type *p) : i(p), qh_qh(qqh) {}
                        iterator(const iterator &o) : i(o.i), qh_qh(o.qh_qh) {}
        iterator &      operator=(const iterator &o) { i= o.i; qh_qh= o.qh_qh; return *this; }

        // Constructs T.  Cannot return reference.  
        T               operator*() const { return T(qh_qh, *i); }
        //operator->() n/a, value-type
        // Constructs T.  Cannot return reference.  
        T               operator[](countT idx) const { return T(qh_qh, *(i+idx)); } //!< No error checking
        bool            operator==(const iterator &o) const { return i == o.i; }
        bool            operator!=(const iterator &o) const { return !operator==(o); }
        bool            operator==(const const_iterator &o) const { return (i==reinterpret_cast<const iterator &>(o).i); }
        bool            operator!=(const const_iterator &o) const { return !operator==(o); }

        //! Assumes same point set
        countT          operator-(const iterator &o) const { return static_cast<countT>(i-o.i); } //WARN64
        bool            operator>(const iterator &o) const { return i>o.i; }
        bool            operator<=(const iterator &o) const { return !operator>(o); }
        bool            operator<(const iterator &o) const { return i<o.i; }
        bool            operator>=(const iterator &o) const { return !operator<(o); }
        bool            operator>(const const_iterator &o) const { return (i > reinterpret_cast<const iterator &>(o).i); }
        bool            operator<=(const const_iterator &o) const { return !operator>(o); }
        bool            operator<(const const_iterator &o) const { return (i < reinterpret_cast<const iterator &>(o).i); }
        bool            operator>=(const const_iterator &o) const { return !operator<(o); }

        //! No error checking
        iterator &      operator++() { ++i; return *this; }
        iterator        operator++(int) { iterator o= *this; ++i; return o; }
        iterator &      operator--() { --i; return *this; }
        iterator        operator--(int) { iterator o= *this; --i; return o; }
        iterator        operator+(countT j) const { return iterator(qh_qh, i+j); }
        iterator        operator-(countT j) const { return operator+(-j); }
        iterator &      operator+=(countT j) { i += j; return *this; }
        iterator &      operator-=(countT j) { i -= j; return *this; }
    };//QhullPointSet::iterator

    class const_iterator {
    private:
        const typename T::base_type *  i;  // e.g., const facetT**, first for debugger
        QhullQh *       qh_qh;

    public:
        typedef ptrdiff_t       difference_type;
        typedef std::random_access_iterator_tag  iterator_category;
        typedef T               value_type;

                        const_iterator(QhullQh *qqh, const typename T::base_type * p) : i(p), qh_qh(qqh) {}
                        const_iterator(const const_iterator &o) : i(o.i), qh_qh(o.qh_qh) {}
                        const_iterator(const iterator &o) : i(o.i), qh_qh(o.qh_qh) {}
        const_iterator &operator=(const const_iterator &o) { i= o.i; qh_qh= o.qh_qh; return *this; }

        // Constructs T.  Cannot return reference.  Retaining 'const T' return type for consistency with QList/QVector
        const T         operator*() const { return T(qh_qh, *i); }
        const T         operator[](countT idx) const { return T(qh_qh, *(i+idx)); }  //!< No error checking
        //operator->() n/a, value-type
        bool            operator==(const const_iterator &o) const { return i == o.i; }
        bool            operator!=(const const_iterator &o) const { return !operator==(o); }

        //! Assumes same point set
        countT          operator-(const const_iterator &o) { return static_cast<countT>(i-o.i); } //WARN64
        bool            operator>(const const_iterator &o) const { return i>o.i; }
        bool            operator<=(const const_iterator &o) const { return !operator>(o); }
        bool            operator<(const const_iterator &o) const { return i<o.i; }
        bool            operator>=(const const_iterator &o) const { return !operator<(o); }

        //!< No error checking
        const_iterator &operator++() { ++i; return *this; }
        const_iterator  operator++(int) { const_iterator o= *this; ++i; return o; }
        const_iterator &operator--() { --i; return *this; }
        const_iterator  operator--(int) { const_iterator o= *this; --i; return o; }
        const_iterator  operator+(int j) const { return const_iterator(qh_qh, i+j); }
        const_iterator  operator-(int j) const { return operator+(-j); }
        const_iterator &operator+=(int j) { i += j; return *this; }
        const_iterator &operator-=(int j) { i -= j; return *this; }
    };//QhullPointSet::const_iterator

};//class QhullSet


//! QhullSetIterator is a Java-style iterator.  It may be used on temporary results.
//! QhullSetIterator copies the qh_set and qh_qh pointers in QhullSetBase
//! Faster then interator/const_iterator due to T::base_type
template <typename T>
class QhullSetIterator {

#//!\name Subtypes
    typedef typename QhullSet<T>::const_iterator const_iterator;

private:
#//!\name Fields
    const typename T::base_type *  i;        // e.g., facetT**, first for debugger
    const typename T::base_type *  begin_i;  // must be initialized after i
    const typename T::base_type *  end_i;
    QhullQh *                qh_qh;

public:
#//!\name Constructors
                        QhullSetIterator<T>(const QhullSet<T> &s) : i(s.data()), begin_i(i), end_i(s.endData()), qh_qh(s.qh()) {}
                        QhullSetIterator<T>(const QhullSetIterator<T> &o) : i(o.i), begin_i(o.begin_i), end_i(o.end_i), qh_qh(o.qh_qh) {}
    QhullSetIterator<T> &operator=(const QhullSetIterator<T> &o) { i= o.i; begin_i= o.begin_i; end_i= o.end_i; qh_qh= o.qh_qh; return *this; }

#//!\name ReadOnly
    countT              countRemaining() { return static_cast<countT>(end_i-i); } // WARN64

#//!\name Search
    bool                findNext(const T &t);
    bool                findPrevious(const T &t);

#//!\name Foreach
    bool                hasNext() const { return i != end_i; }
    bool                hasPrevious() const { return i != begin_i; }
    T                   next() { return T(qh_qh, *i++); }
    T                   peekNext() const { return T(qh_qh, *i); }
    T                   peekPrevious() const { const typename T::base_type *p= i; return T(qh_qh, *--p); }
    T                   previous() { return T(qh_qh, *--i); }
    void                toBack() { i= end_i; }
    void                toFront() { i= begin_i; }
};//class QhullSetIterator

#//!\name == Definitions =========================================

#//!\name Conversions

// See qt-qhull.cpp for QList conversion

#ifndef QHULL_NO_STL
template <typename T>
std::vector<T> QhullSet<T>::
toStdVector() const
{
    typename QhullSet<T>::const_iterator i= begin();
    typename QhullSet<T>::const_iterator e= end();
    std::vector<T> vs;
    while(i!=e){
        vs.push_back(*i++);
    }
    return vs;
}//toStdVector
#endif //QHULL_NO_STL

#ifdef QHULL_USES_QT
template <typename T>
QList<T> QhullSet<T>::
toQList() const
{
    typename QhullSet<T>::const_iterator i= begin();
    typename QhullSet<T>::const_iterator e= end();
    QList<T> vs;
    while(i!=e){
        vs.append(*i++);
    }
    return vs;
}//toQList
#endif

#//!\name Element

template <typename T>
T QhullSet<T>::
value(countT idx) const
{
    // Avoid call to qh_setsize() and assert in elementPointer()
    const typename T::base_type *p= reinterpret_cast<const typename T::base_type *>(&SETelem_(getSetT(), idx));
    return (idx>=0 && p<endData()) ? T(qh(), *p) : T(qh());
}//value

template <typename T>
T QhullSet<T>::
value(countT idx, const T &defaultValue) const
{
    // Avoid call to qh_setsize() and assert in elementPointer()
    const typename T::base_type *p= reinterpret_cast<const typename T::base_type *>(&SETelem_(getSetT(), idx));
    return (idx>=0 && p<endData() ? T(qh(), *p) : defaultValue);
}//value

#//!\name Search

template <typename T>
bool QhullSet<T>::
contains(const T &t) const
{
    setT *s= getSetT();
    void *p= t.getBaseT();  // contains() is not inline for better error reporting
    int result= qh_setin(s, p);
    return result!=0;
}//contains

template <typename T>
countT QhullSet<T>::
count(const T &t) const
{
    countT n= 0;
    const typename T::base_type *i= data();
    const typename T::base_type *e= endData();
    typename T::base_type p= t.getBaseT();
    while(i<e){
        if(*i==p){
            n++;
        }
        i++;
    }
    return n;
}//count

template <typename T>
countT QhullSet<T>::
lastIndexOf(const T &t) const
{
    const typename T::base_type *b= data();
    const typename T::base_type *i= endData();
    typename T::base_type p= t.getBaseT();
    while(--i>=b){
        if(*i==p){
            break;
        }
    }
    return static_cast<countT>(i-b); // WARN64
}//lastIndexOf

#//!\name QhullSetIterator

template <typename T>
bool QhullSetIterator<T>::
findNext(const T &t)
{
    typename T::base_type p= t.getBaseT();
    while(i!=end_i){
        if(*(++i)==p){
            return true;
        }
    }
    return false;
}//findNext

template <typename T>
bool QhullSetIterator<T>::
findPrevious(const T &t)
{
    typename T::base_type p= t.getBaseT();
    while(i!=begin_i){
        if(*(--i)==p){
            return true;
        }
    }
    return false;
}//findPrevious

}//namespace orgQhull


#//!\name == Global namespace =========================================

template <typename T>
std::ostream &
operator<<(std::ostream &os, const orgQhull::QhullSet<T> &qs)
{
    const typename T::base_type *i= qs.data();
    const typename T::base_type *e= qs.endData();
    while(i!=e){
        os << T(qs.qh(), *i++);
    }
    return os;
}//operator<<

#endif // QhullSet_H