#ifndef CGAL_PSURF_RINGS_H_
#define CGAL_PSURF_RINGS_H_

// This file adapted from
//     CGAL-3.7/examples/Jet_fitting_3//PolyhedralSurf_rings.h
// Licensed under CGAL-3.7/LICENSE.FREE_USE

// Copyright (c) 1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006,2007
// Utrecht University (The Netherlands), ETH Zurich (Switzerland), Freie
// Universitaet Berlin (Germany), INRIA Sophia-Antipolis (France),
// Martin-Luther-University Halle-Wittenberg (Germany), Max-Planck-Institute
// Saarbruecken (Germany), RISC Linz (Austria), and Tel-Aviv University
// (Israel).  All rights reserved.

// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.


#include <cassert>

using namespace std;

template
<
    class TPoly,
    class VertexPropertyMap
>

class T_PolyhedralSurf_rings
{

protected:

    // Polyhedron
    typedef typename TPoly::Vertex Vertex;
    typedef typename TPoly::Halfedge Halfedge;
    typedef typename TPoly::Facet Facet;
    typedef typename TPoly::Halfedge_around_vertex_circulator
        Halfedge_around_vertex_circulator;
    typedef typename TPoly::Vertex_iterator Vertex_iterator;

    // vertex indices are initialised to -1
    static void reset_ring_indices
    (
        std::vector< Vertex* >& vces,
        VertexPropertyMap& vpm
    );

    // i >= 1; from a start vertex on the current i-1 ring, push non-visited
    // neighbors of start in the nextRing and set indices to i. Also add these
    // vertices in all.
    static void push_neighbours_of
    (
        Vertex* start,
        int ith,
        std::vector< Vertex* >& nextRing,
        std::vector< Vertex* >& all,
        VertexPropertyMap& vpm
    );

    // i >= 1, from a currentRing i-1, collect all neighbors, set indices
    // to i and store them in nextRing and all.
    static void collect_ith_ring
    (
        int ith,
        std::vector< Vertex* >& currentRing,
        std::vector< Vertex* >& nextRing,
        std::vector< Vertex* >& all,
        VertexPropertyMap& vpm
    );


public:

    // collect i>=1 rings : all neighbours up to the ith ring,
    static void collect_i_rings
    (
        Vertex* v,
        int ring_i,
        std::vector< Vertex* >& all,
        VertexPropertyMap& vpm
    );

    //collect enough rings (at least 1), to get at least min_nb of neighbors
    static void collect_enough_rings
    (
        Vertex* v,
        unsigned int min_nb,
        std::vector< Vertex* >& all,
        VertexPropertyMap& vpm
    );
};


////IMPLEMENTATION////////////////////////////////////////////////////

template < class TPoly , class VertexPropertyMap>
void T_PolyhedralSurf_rings <TPoly, VertexPropertyMap>::
push_neighbours_of(Vertex* start, int ith,
                   std::vector< Vertex* >& nextRing,
                   std::vector< Vertex* >& all,
                   VertexPropertyMap& vpm)
{
    Vertex *v;
    Halfedge_around_vertex_circulator
        hedgeb = start->vertex_begin(), hedgee = hedgeb;

    CGAL_For_all(hedgeb, hedgee)
    {
        v = &*(hedgeb->opposite()->vertex());
        if (get(vpm, v) != -1) continue; //if visited: next

        put(vpm, v, ith);
        nextRing.push_back(v);
        all.push_back(v);
    }
}


template <class TPoly, class VertexPropertyMap>
void T_PolyhedralSurf_rings <TPoly, VertexPropertyMap>::
collect_ith_ring(int ith, std::vector< Vertex* >& currentRing,
                 std::vector< Vertex* >& nextRing,
                 std::vector< Vertex* >& all,
                 VertexPropertyMap& vpm)
{
    typename std::vector< Vertex* >::iterator
        itb = currentRing.begin(), ite = currentRing.end();

    CGAL_For_all(itb, ite)
    {
        push_neighbours_of(*itb, ith, nextRing, all, vpm);
    }
}


template <class TPoly, class VertexPropertyMap>
void T_PolyhedralSurf_rings <TPoly, VertexPropertyMap>::
reset_ring_indices(std::vector< Vertex* >& vces,
                   VertexPropertyMap& vpm)
{
    typename std::vector< Vertex* >::iterator
        itb = vces.begin(), ite = vces.end();

    CGAL_For_all(itb, ite)
    {
        put(vpm, *itb, -1);
    }
}


template <class TPoly, class VertexPropertyMap>
void T_PolyhedralSurf_rings <TPoly, VertexPropertyMap>::
collect_i_rings(Vertex* v,
                int ring_i,
                std::vector< Vertex* >& all,
                VertexPropertyMap& vpm)
{
    std::vector<Vertex*> current_ring, next_ring;
    std::vector<Vertex*> *p_current_ring, *p_next_ring;
    assert(ring_i >= 1);

    //initialize
    p_current_ring = &current_ring;
    p_next_ring = &next_ring;
    put(vpm, v, 0);
    current_ring.push_back(v);
    all.push_back(v);

    for (int i=1; i<=ring_i; i++)
    {
      collect_ith_ring(i, *p_current_ring, *p_next_ring, all, vpm);
      //next round must be launched from p_nextRing...
      p_current_ring->clear();
      std::swap(p_current_ring, p_next_ring);
    }

    //clean up
    reset_ring_indices(all, vpm);
}


template <class TPoly, class VertexPropertyMap>
void T_PolyhedralSurf_rings <TPoly, VertexPropertyMap>::
collect_enough_rings(Vertex* v,
                     unsigned int min_nb,
                     std::vector< Vertex* >& all,
                     VertexPropertyMap& vpm)
{
    std::vector<Vertex*> current_ring, next_ring;
    std::vector<Vertex*> *p_current_ring, *p_next_ring;

    //initialize
    p_current_ring = &current_ring;
    p_next_ring = &next_ring;
    put(vpm, v, 0);
    current_ring.push_back(v);
    all.push_back(v);

    int i = 1;

    while ( (all.size() < min_nb) &&  (p_current_ring->size() != 0) )
    {
        collect_ith_ring(i, *p_current_ring, *p_next_ring, all, vpm);
        //next round must be launched from p_nextRing...
        p_current_ring->clear();
        std::swap(p_current_ring, p_next_ring);
        i++;
    }

    //clean up
    reset_ring_indices(all, vpm);
}


#endif