// Copyright (c) 2002,2011 Utrecht University (The Netherlands).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL: https://github.com/CGAL/cgal/blob/v6.1/Spatial_searching/include/CGAL/Kd_tree_rectangle.h $
// $Id: include/CGAL/Kd_tree_rectangle.h b26b07a1242 $
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s)     : Hans Tangelder (<hanst@cs.uu.nl>)

#ifndef CGAL_KD_TREE_RECTANGLE_H
#define CGAL_KD_TREE_RECTANGLE_H

#include <CGAL/license/Spatial_searching.h>


#include <functional>
#include <algorithm>
#include <new>
#include <CGAL/assertions.h>
#include <CGAL/array.h>
#include <CGAL/Dimension.h>

namespace CGAL {

  template <class Construct_cartesian_const_iterator_d, class P, class T>
  struct set_bounds_from_pointer : public CGAL::cpp98::unary_function<P, void> {
    int dim;
    T *lower;
    T *upper;
    Construct_cartesian_const_iterator_d construct_it;

    set_bounds_from_pointer(int d, T *l, T *u,Construct_cartesian_const_iterator_d construct_it_)
      : dim(d), lower(l), upper(u), construct_it(construct_it_)
    {}

    void
    operator()(P p)
    {
      T h;
      auto pit = construct_it(*p);
      for (int i = 0; i < dim; ++i, ++pit) {
        h=(*pit);
        if (h < lower[i]) lower[i] = h;
        if (h > upper[i]) upper[i] = h;
      }
    }
  };


  template <class FT_, typename D = Dynamic_dimension_tag>
  class Kd_tree_rectangle {
  public:
    typedef FT_ FT;
    typedef FT T;

  private:

    //int dim;
    std::array<T,D::value> lower_;
    std::array<T,D::value> upper_;
    int max_span_coord_;

  public:

    inline void
    set_upper_bound(int i, const FT& x)
    {
      CGAL_assertion(i >= 0 && i < D::value);
      CGAL_assertion(x >= lower_[i]);
      upper_[i] = x;
      set_max_span();
    }

    inline void
    set_lower_bound(int i, const FT& x)
    {
      CGAL_assertion(i >= 0 && i < D::value);
      CGAL_assertion(x <= upper_[i]);
      lower_[i] = x;
      set_max_span();
    }

    inline void
    set_max_span()
    {
      FT span = upper_[0]-lower_[0];
      max_span_coord_ = 0;
      for (int i = 1; i < D::value; ++i) {
        FT tmp = upper_[i] - lower_[i];
        if (span < tmp) {
          span = tmp;
          max_span_coord_ = i;
        }
      }
    }

    Kd_tree_rectangle(int)
      : max_span_coord_(0)
    {
      lower_.fill(FT(0));
      upper_.fill(FT(0));
    }

    Kd_tree_rectangle()
      : max_span_coord_(-1)
    {}


    explicit
    Kd_tree_rectangle(const Kd_tree_rectangle& r)
    : lower_(r.lower_), upper_(r.upper_), max_span_coord_(r.max_span_coord_) {}

    template <class Construct_cartesian_const_iterator_d,class PointPointerIter>
    void update_from_point_pointers(PointPointerIter begin,
                                    PointPointerIter end,
                                    const Construct_cartesian_const_iterator_d& construct_it
    )
    {
      if (begin ==end)
        return;
      // initialize with values of first point
      auto bit = construct_it(**begin);

      for (int i=0; i < D::value; ++i, ++bit) {
        lower_[i]= *bit; upper_[i]=lower_[i];
      }
      begin++;
      typedef typename std::iterator_traits<PointPointerIter>::value_type P;
      std::for_each(begin, end,set_bounds_from_pointer<Construct_cartesian_const_iterator_d,P,T>(D::value, &(lower_[0]), &(upper_[0]), construct_it));
      set_max_span();
    }

    template <class Construct_cartesian_const_iterator_d,class PointPointerIter> // was PointIter
    Kd_tree_rectangle(int,  PointPointerIter begin,  PointPointerIter end,const Construct_cartesian_const_iterator_d& construct_it)
      : max_span_coord_(-1)
    {
      update_from_point_pointers<Construct_cartesian_const_iterator_d>(begin,end,construct_it);
    }

    inline int
    max_span_coord() const
    {
      return max_span_coord_;
    }

    inline FT
    max_span() const
    {
      return upper_[max_span_coord_] - lower_[max_span_coord_];
    }

    inline FT
    min_coord(int i) const
    {
      CGAL_assume(i<D::value);
      CGAL_assertion(lower_.size() != 0);
      return lower_[i];
    }

    inline FT
    max_coord(int i) const
    {
      CGAL_assume(i<D::value);
      return upper_[i];
    }

    std::ostream&
    print(std::ostream& s) const
    {
      s << "Rectangle dimension = " << D::value;
      s << "\n lower: ";
      for (int i=0; i < D::value; ++i)
        s << lower_[i] << " ";
      // std::copy(lower_, lower_ + D,
      //               std::ostream_iterator<FT>(s," "));
      s << "\n upper: ";
      for (int j=0; j < D::value; ++j)
        s << upper_[j] << " ";
      // std::copy(upper_, upper_ + D,
      //              std::ostream_iterator<FT>(s," "));
      s << "\n maximum span " << max_span() <<
        " at coordinate " << max_span_coord() << std::endl;
      return s;
    }

    // Splits rectangle by modifying itself to lower half
    // and returns upper half
    //    Kd_tree_rectangle*
    void
    split(Kd_tree_rectangle& r, int d, FT value)
    {
      CGAL_assertion(d >= 0 && d < D::value);
      CGAL_assertion(lower_[d] <= value && value <= upper_[d]);

      //Kd_tree_rectangle* r = new Kd_tree_rectangle(*this);
      upper_[d]=value;
      r.lower_[d]=value;
      //return r;
    }


    int
    dimension() const
    {
      return D::value;
    }

    T* lower() {return lower_.data();}
    T* upper() {return upper_.data();}
    const T* lower() const {return lower_.data();}
    const T* upper() const {return upper_.data();}

    Kd_tree_rectangle&
    operator=(const Kd_tree_rectangle& r)
    {
      CGAL_assertion(dimension() == r.dimension());
      if (this != &r) {
        lower_ = r.lower_;
        upper_ = r.upper_;
        set_max_span();
      }
      return *this;
    }



  }; // of class Kd_tree_rectangle


  // Partial specialization for dynamic dimension, which means dimension at runtime

  template <class FT_>
  class Kd_tree_rectangle<FT_, Dynamic_dimension_tag> {

  public:
    typedef FT_ FT;
    typedef FT T;

  private:

    T* coords_;
    int dim;
    int max_span_coord_;

  public:

    inline void
    set_upper_bound(int i, const FT& x)
    {
      CGAL_assertion(i >= 0 && i < dim);
      CGAL_assertion(x >= lower()[i]);
      upper()[i] = x;
      set_max_span();
    }

    inline void
    set_lower_bound(int i, const FT& x)
    {
      CGAL_assertion(i >= 0 && i < dim);
      CGAL_assertion(x <= upper()[i]);
      lower()[i] = x;
      set_max_span();
    }

    inline void
    set_max_span()
    {
      FT span = upper()[0]-lower()[0];
      max_span_coord_ = 0;
      for (int i = 1; i < dim; ++i) {
        FT tmp = upper()[i] - lower()[i];
        if (span < tmp) {
          span = tmp;
          max_span_coord_ = i;
        }
      }
    }

    Kd_tree_rectangle(int d)
      : coords_(new FT[2*d]), dim(d), max_span_coord_(0)
    {
      std::fill(coords_, coords_ + 2*dim, FT(0));
    }

    explicit
    Kd_tree_rectangle(const Kd_tree_rectangle& r)
      : coords_(new FT[2*r.dim]), dim(r.dim),
        max_span_coord_(r.max_span_coord_)
    {
      std::copy(r.coords_, r.coords_+2*dim, lower());
    }

    template <class Construct_cartesian_const_iterator_d,class PointPointerIter>
    void update_from_point_pointers(PointPointerIter begin,
                                    PointPointerIter end,
                                    const Construct_cartesian_const_iterator_d& construct_it
    )
    {
      if (begin ==end)
        return;
      // initialize with values of first point
      typename Construct_cartesian_const_iterator_d::result_type bit = construct_it(**begin);

      for (int i=0; i < dim; ++i, ++bit) {
        lower()[i]= *bit; upper()[i]=lower()[i];
      }
      begin++;
      typedef typename std::iterator_traits<PointPointerIter>::value_type P;
      std::for_each(begin, end,set_bounds_from_pointer<Construct_cartesian_const_iterator_d,P,T>(dim, lower(), upper(),construct_it));
      set_max_span();
    }

    template <class Construct_cartesian_const_iterator_d,class PointPointerIter> // was PointIter
    Kd_tree_rectangle(int d,  PointPointerIter begin,  PointPointerIter end,const Construct_cartesian_const_iterator_d& construct_it)
      : coords_(new FT[2*d]), dim(d), max_span_coord_(-1)
    {
      update_from_point_pointers<Construct_cartesian_const_iterator_d>(begin,end,construct_it);
    }

    inline int
    max_span_coord() const
    {
      return max_span_coord_;
    }

    inline FT
    max_span() const
    {
      return upper()[max_span_coord_] - lower()[max_span_coord_];
    }

    inline FT
    min_coord(int i) const
    {
      CGAL_assertion(coords_ != nullptr);
      return lower()[i];
    }

    inline FT
    max_coord(int i) const
    {
      return upper()[i];
    }

    std::ostream&
    print(std::ostream& s) const
    {
      s << "Rectangle dimension = " << dim;
      s << "\n lower: ";
      for (int i=0; i < dim; ++i)
        s << lower()[i] << " ";
      // std::copy(lower(), lower() + dim,
      //               std::ostream_iterator<FT>(s," "));
      s << "\n upper: ";
      for (int j=0; j < dim; ++j)
        s << upper()[j] << " ";
      // std::copy(upper(), upper() + dim,
      //              std::ostream_iterator<FT>(s," "));
      s << "\n maximum span " << max_span() <<
        " at coordinate " << max_span_coord() << std::endl;
      return s;
    }

    // Splits rectangle by modifying itself to lower half
    // and returns upper half
    //    Kd_tree_rectangle*
    void
    split(Kd_tree_rectangle& r, int d, FT value)
    {
      CGAL_assertion(d >= 0 && d < dim);
      CGAL_assertion(lower()[d] <= value && value <= upper()[d]);

      //Kd_tree_rectangle* r = new Kd_tree_rectangle(*this);
      upper()[d]=value;
      r.lower()[d]=value;
      //return r;
    }


    ~Kd_tree_rectangle()
    {
      if (dim) {
        if (coords_) delete [] coords_;
      }
    }

    int
    dimension() const
    {
      return dim;
    }

    T* lower() {return coords_;}
    T* upper() {return coords_ + dim;}
    const T* lower() const {return coords_;}
    const T* upper() const {return coords_ + dim;}

    Kd_tree_rectangle&
    operator=(const Kd_tree_rectangle& r)
    {
      CGAL_assertion(dimension() == r.dimension());
      if (this != &r) {
        std::copy(r.coords_, r.coords_+2*dim, coords_);
        set_max_span();
      }
      return *this;
    }



  }; // of partial specialization of class Kd_tree_rectangle<FT,0>

  template <class FT, typename D>
  std::ostream&
  operator<<(std::ostream& s, const Kd_tree_rectangle<FT,D>& r)
  {
    return r.print(s);
  }


} // namespace CGAL

#endif // CGAL_KD_TREE_RECTANGLE_H

