/**
 *  \file cgal/internal/knn.h
 *  \brief manipulation of text, and Interconversion between text and numbers
 *  Copyright 2007-2013 IMP Inventors. All rights reserved.
 */

#ifndef IMPCGAL_INTERNAL_KNN_H
#define IMPCGAL_INTERNAL_KNN_H

#include <IMP/cgal/cgal_config.h>
#include <IMP/base/types.h>
#include <IMP/base/Pointer.h>
#include <IMP/algebra/VectorD.h>
#include <boost/static_assert.hpp>
#include <IMP/base/RefCounted.h>


IMPCGAL_BEGIN_INTERNAL_NAMESPACE
struct VectorWithIndex: public algebra::VectorKD {
  int index;
  VectorWithIndex(unsigned int i, const algebra::VectorKD& p):
    algebra::VectorKD(p),
    index(i){}
  VectorWithIndex(): index(-1){}
  operator unsigned int() const {return index;}
  unsigned int dimension() const {
    return algebra::VectorKD::get_dimension();
  }
};

template <class It>
base::Vector<VectorWithIndex > create_vectors_with_index(It b, It e) {
  base::Vector<VectorWithIndex > v(std::distance(b,e));
  It c=b;
  for (unsigned int i=0; i< v.size(); ++i) {
    v[i]= VectorWithIndex(i, get_vector_d_geometry(*c));
    ++c;
  }
  return v;
}

struct IMPCGALEXPORT RCTree: public base::RefCounted {
  virtual ~RCTree();
};


struct IMPCGALEXPORT KNNData {
  mutable base::Pointer<RCTree> tree_;
  base::Vector<VectorWithIndex > vsi_;
  template <class It>
  KNNData(It b, It e) {
    initialize(create_vectors_with_index(b,e));
  }
  void initialize(const base::Vector<VectorWithIndex > &v);
  void fill_nearest_neighbors_v(const algebra::VectorKD &g,
                                unsigned int k,
                                double eps, Ints &ret) const;
  void fill_nearest_neighbors_v(const algebra::VectorKD &g,
                                double dist,
                                double eps, Ints &ret) const;
  template <class G>
    void fill_nearest_neighbors(const G &g, unsigned int k,
                                double eps, Ints &ret) const {
    fill_nearest_neighbors_v(get_vector_d_geometry(g),
                             k, eps, ret);
  }
  template <class G>
    void fill_nearest_neighbors(const G &g, double distance,
                                double eps, Ints &ret) const {
    fill_nearest_neighbors_v(get_vector_d_geometry(g),
                             distance, eps, ret);
  }
  const algebra::VectorKD &get_point(unsigned int i) const {
    return vsi_[i];
  }
  unsigned int get_number_of_points() const {
    return vsi_.size();
  }
};

IMPCGAL_END_INTERNAL_NAMESPACE

#endif  /* IMPCGAL_INTERNAL_KNN_H */