// Copyright (c) 2005  INRIA (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
// You can redistribute it and/or modify it under the terms of the GNU
// General Public License as published by the Free Software Foundation,
// either version 3 of the License, or (at your option) any later version.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL$
// $Id$
//
//
// Author(s)     : Laurent Saboret, Pierre Alliez, Bruno Levy


#ifndef CGAL_PARAM_MESH_PATCH_VERTEX_H
#define CGAL_PARAM_MESH_PATCH_VERTEX_H

#include <CGAL/surface_mesh_parameterization_assertions.h>

#include <list>

namespace CGAL {

/// \cond SKIP_IN_MANUAL

// Forward reference
template<class ParameterizationPatchableMesh_3> class Param_mesh_patch_vertex_const_handle;


/// The class Param_mesh_patch_vertex represents a vertex
/// of a Parameterization_mesh_patch_3<ParameterizationPatchableMesh_3> mesh.
///
/// Implementation note:
/// A Param_mesh_patch_vertex object is basically a handle to a
/// ParameterizationPatchableMesh_3::Vertex + its position / seam.
/// Param_mesh_patch_vertex comparison methods compare the pointers.
///
template<class ParameterizationPatchableMesh_3>
class Param_mesh_patch_vertex
{
// Private types
private:

    typedef Param_mesh_patch_vertex         Self;

// Public types
public:

    /// Export template parameter type
    typedef ParameterizationPatchableMesh_3 Adaptor;

// Public operations
public:

    /// Default constructor
    Param_mesh_patch_vertex()
    {
        m_vertex            = NULL;
        m_last_cw_neighbor  = NULL;
        m_first_cw_neighbor = NULL;
    }

    /// Constructor:
    /// - for an INNER adaptor vertex, last_cw_neighbor and first_cw_neighbor
    ///   must be NULL
    /// - for a SEAM/MAIN BORDER vertex, [first_cw_neighbor, last_cw_neighbor]
    /// defines the range of the valid neighbors of adaptor_vertex (included).
    explicit Param_mesh_patch_vertex(
        typename Adaptor::Vertex_handle adaptor_vertex,
        typename Adaptor::Vertex_handle last_cw_neighbor  = typename Adaptor::Vertex_handle(),
        typename Adaptor::Vertex_handle first_cw_neighbor = typename Adaptor::Vertex_handle())
    {
        CGAL_surface_mesh_parameterization_assertion(adaptor_vertex != NULL);
        CGAL_surface_mesh_parameterization_assertion( (last_cw_neighbor == NULL) ==
                                                      (first_cw_neighbor == NULL) );

        m_vertex            = adaptor_vertex;
        m_last_cw_neighbor  = last_cw_neighbor;
        m_first_cw_neighbor = first_cw_neighbor;
    }

    /// Copy constructor
    Param_mesh_patch_vertex(const Self& hdl)
    {
        m_vertex            = hdl.m_vertex;
        m_last_cw_neighbor  = hdl.m_last_cw_neighbor;
        m_first_cw_neighbor = hdl.m_first_cw_neighbor;
    }

    /// operator =()
    Self& operator =(const Self& hdl)
    {
        m_vertex            = hdl.m_vertex;
        m_last_cw_neighbor  = hdl.m_last_cw_neighbor;
        m_first_cw_neighbor = hdl.m_first_cw_neighbor;

        return *this;
    }

    /// Comparison
    bool operator==(const Param_mesh_patch_vertex& vertex) const {
        return m_vertex            == vertex.m_vertex
            && m_last_cw_neighbor  == vertex.m_last_cw_neighbor
            && m_first_cw_neighbor == vertex.m_first_cw_neighbor;
    }
    bool operator!=(const Param_mesh_patch_vertex& vertex) const {
        return ! (*this == vertex);
    }

    /// Get content
    typename Adaptor::Vertex_handle vertex() {
        return m_vertex;
    }
    typename Adaptor::Vertex_const_handle vertex() const {
        return m_vertex;
    }
    typename Adaptor::Vertex_handle last_cw_neighbor() {
        return m_last_cw_neighbor;
    }
    typename Adaptor::Vertex_const_handle last_cw_neighbor() const {
        return m_last_cw_neighbor;
    }
    typename Adaptor::Vertex_handle first_cw_neighbor() {
        return m_first_cw_neighbor;
    }
    typename Adaptor::Vertex_const_handle first_cw_neighbor() const {
        return m_first_cw_neighbor;
    }

// Fields
private:
    /// The decorated vertex
    typename Adaptor::Vertex_handle m_vertex;

    /// [m_first_cw_neighbor, m_last_cw_neighbor] defines the range of the valid
    /// neighbors of m_vertex (included) if m_vertex is on the main border/seam
    /// (NULL if inner vertex)
    typename Adaptor::Vertex_handle m_last_cw_neighbor;
    typename Adaptor::Vertex_handle m_first_cw_neighbor;

}; // Param_mesh_patch_vertex


/// Param_mesh_patch_vertex_handle represents a handle to a
/// Param_mesh_patch_vertex object, thus has the same behavior
/// as Param_mesh_patch_vertex* pointer type.
///
/// ## Design Pattern ##
/// Param_mesh_patch_vertex_handle is a Bridge [GHJV95].
///
/// Implementation note:
/// A Param_mesh_patch_vertex_handle contains in fact a
/// Param_mesh_patch_vertex object, which is basically
/// a handle to a ParameterizationPatchableMesh_3::Vertex.
/// Param_mesh_patch_vertex_handle comparison methods simply compare
/// the address of the ParameterizationPatchableMesh_3::Vertex pointed by the handles.
///
template<class ParameterizationPatchableMesh_3>
class Param_mesh_patch_vertex_handle
{
// Private types
private:

    typedef Param_mesh_patch_vertex_handle  Self;

// Public types
public:

    /// Export template parameter type
    typedef ParameterizationPatchableMesh_3 Adaptor;

    // Iterator types
    typedef Param_mesh_patch_vertex<ParameterizationPatchableMesh_3>
                                            Vertex;
    typedef Vertex                          value_type;
    typedef std::ptrdiff_t                  difference_type;
    typedef std::size_t                     size_type;
    typedef Vertex&                         reference;
    typedef Vertex*                         pointer;

// Public operations
public:

    /// Constructor from ParameterizationPatchableMesh_3::Vertex pointer
    Param_mesh_patch_vertex_handle(Vertex* ptr = NULL)
    {
        if (ptr == NULL)
        {
            m_vertex = Vertex();
            m_ptr = NULL;
        }
        else
        {
            m_vertex = *ptr;
            m_ptr = &m_vertex;
        }

        CGAL_surface_mesh_parameterization_assertion(m_ptr == NULL || m_ptr == &m_vertex);
    }

    /// Extra constructor that will create the Parameterization_mesh_patch_3<ParameterizationPatchableMesh_3>::Vertex on the fly
    /// - for an INNER adaptor vertex, last_cw_neighbor and first_cw_neighbor
    ///   must be NULL
    /// - for a SEAM/MAIN BORDER vertex, [first_cw_neighbor, last_cw_neighbor]
    /// defines the range of the valid neighbors of adaptor_vertex (included).
    explicit Param_mesh_patch_vertex_handle(
        typename Adaptor::Vertex_handle adaptor_vertex,
        typename Adaptor::Vertex_handle last_cw_neighbor  = typename Adaptor::Vertex_handle(),
        typename Adaptor::Vertex_handle first_cw_neighbor = typename Adaptor::Vertex_handle())
    {
        CGAL_surface_mesh_parameterization_assertion(adaptor_vertex != NULL);
        m_vertex = Vertex(adaptor_vertex, last_cw_neighbor, first_cw_neighbor);
        m_ptr = &m_vertex;
    }

    /// Copy constructor
    Param_mesh_patch_vertex_handle(const Self& hdl)
    {
        if (hdl.m_ptr == NULL)
        {
            m_vertex = Vertex();
            m_ptr = NULL;
        }
        else
        {
            m_vertex = hdl.m_vertex;
            m_ptr = &m_vertex;
        }

        CGAL_surface_mesh_parameterization_assertion(m_ptr == NULL || m_ptr == &m_vertex);
    }

    /// operator =()
    Self& operator =(const Self& hdl)
    {
        if (hdl.m_ptr == NULL)
        {
            m_vertex = Vertex();
            m_ptr = NULL;
        }
        else
        {
            m_vertex = hdl.m_vertex;
            m_ptr = &m_vertex;
        }

        CGAL_surface_mesh_parameterization_assertion(m_ptr == NULL || m_ptr == &m_vertex);

        return *this;
    }

    /// Compare patch vertices instead of patch vertex pointers (two patch
    /// vertex handles are equal iff they point to the same adaptor vertex)
    bool operator==(const Self& hdl) const
    {
        if (m_ptr == NULL || hdl.m_ptr == NULL)
            return m_ptr == hdl.m_ptr;
        else
            return *m_ptr == *(hdl.m_ptr);
    }
    bool operator!=(const Self& hdl) const { return ! (*this == hdl); }

    /// Comparison to NULL pointer
  
    bool operator==(Nullptr_t ptr) const {
        CGAL_surface_mesh_parameterization_assertion(ptr == NULL);
        return m_ptr == ptr;
    }
    bool operator!=(Nullptr_t ptr) const { return ! (*this == ptr); }

    pointer operator->()  const { return  m_ptr; }
    reference operator*() const { return *m_ptr; }
    operator Param_mesh_patch_vertex_const_handle<Adaptor>() const {
        return m_ptr;
    }

// Fields
private:
    /// The actual pointer
    pointer m_ptr;

    /// Internal Parameterization_mesh_patch_3<ParameterizationPatchableMesh_3> vertex
    /// pointed to by m_ptr (except if NULL)
    Vertex m_vertex;

}; // Param_mesh_patch_vertex_handle


/// Param_mesh_patch_vertex_const_handle represents a handle to a
/// Param_mesh_patch_vertex object, thus has the same behavior
/// as const Param_mesh_patch_vertex* pointer type.
///
/// ## Design Pattern ##
/// Param_mesh_patch_vertex_const_handle is a Bridge [GHJV95].
///
/// Implementation note:
/// A Param_mesh_patch_vertex_const_handle contains in fact a Param_mesh_patch_vertex
/// object, which is basically a handle to a ParameterizationPatchableMesh_3::Vertex.
/// Param_mesh_patch_vertex_const_handle comparison methods basically compare
/// the address of the ParameterizationPatchableMesh_3::Vertex pointed by the handles.
///
template<class ParameterizationPatchableMesh_3>
class Param_mesh_patch_vertex_const_handle
{
// Private types
private:

    typedef Param_mesh_patch_vertex_const_handle
                                            Self;

// Public types
public:

    /// Export template parameter type
    typedef ParameterizationPatchableMesh_3 Adaptor;

    // Iterator types
    typedef Param_mesh_patch_vertex<ParameterizationPatchableMesh_3>
                                            Vertex;
    typedef Vertex                          value_type;
    typedef std::ptrdiff_t                  difference_type;
    typedef std::size_t                     size_type;
    typedef const Vertex&                   reference;
    typedef const Vertex*                   pointer;

// Public operations
public:

    /// Constructor from ParameterizationPatchableMesh_3::Vertex pointer
    Param_mesh_patch_vertex_const_handle(const Vertex* ptr = NULL)
    {
        if (ptr == NULL)
        {
            m_vertex = Vertex();
            m_ptr = NULL;
        }
        else
        {
            m_vertex = *ptr;
            m_ptr = &m_vertex;
        }

        CGAL_surface_mesh_parameterization_assertion(m_ptr == NULL || m_ptr == &m_vertex);
    }

    /// Extra constructor that will create the Parameterization_mesh_patch_3<ParameterizationPatchableMesh_3>::Vertex on the fly
    /// - for an INNER adaptor vertex, last_cw_neighbor and first_cw_neighbor
    ///   must be NULL
    /// - for a SEAM/MAIN BORDER vertex, [first_cw_neighbor, last_cw_neighbor]
    /// defines the range of the valid neighbors of adaptor_vertex (included).
    explicit Param_mesh_patch_vertex_const_handle(
        typename Adaptor::Vertex_const_handle adaptor_vertex,
        typename Adaptor::Vertex_const_handle last_cw_neighbor =typename Adaptor::Vertex_const_handle(),
        typename Adaptor::Vertex_const_handle first_cw_neighbor=typename Adaptor::Vertex_const_handle())
    {
        CGAL_surface_mesh_parameterization_assertion(adaptor_vertex != NULL);
        m_vertex = Vertex((typename Adaptor::Vertex*)&*adaptor_vertex,
                          (typename Adaptor::Vertex*)&*last_cw_neighbor,
                          (typename Adaptor::Vertex*)&*first_cw_neighbor);
        m_ptr = &m_vertex;
    }

    /// Copy constructor
    Param_mesh_patch_vertex_const_handle(const Self& hdl)
    {
        if (hdl.m_ptr == NULL)
        {
            m_vertex = Vertex();
            m_ptr = NULL;
        }
        else
        {
            m_vertex = hdl.m_vertex;
            m_ptr = &m_vertex;
        }

        CGAL_surface_mesh_parameterization_assertion(m_ptr == NULL || m_ptr == &m_vertex);
    }

    /// operator =()
    Self& operator =(const Self& hdl)
    {
        if (hdl.m_ptr == NULL)
        {
            m_vertex = Vertex();
            m_ptr = NULL;
        }
        else
        {
            m_vertex = *hdl.m_ptr;
            m_ptr = &m_vertex;
        }

        CGAL_surface_mesh_parameterization_assertion(m_ptr == NULL || m_ptr == &m_vertex);

        return *this;
    }

    /// Compare patch vertices instead of patch vertex pointers (two patch
    /// vertex handles are equal iff they point to the same adaptor vertex)
    bool operator==(const Self& hdl) const
    {
        if (m_ptr == NULL || hdl.m_ptr == NULL)
            return m_ptr == hdl.m_ptr;
        else
            return *m_ptr == *(hdl.m_ptr);
    }
    bool operator!=(const Self& hdl) const { return ! (*this == hdl); }

    /// Comparison to NULL pointer
    bool operator==(Nullptr_t ptr) const {
        CGAL_surface_mesh_parameterization_assertion(ptr == NULL);
        return m_ptr == ptr;
    }
    bool operator!=(Nullptr_t ptr) const { return ! (*this == ptr); }

    pointer operator->()  const { return  m_ptr; }
    reference operator*() const { return *m_ptr; }

// Fields
private:
    /// The actual pointer
    pointer m_ptr;

    /// Internal Parameterization_mesh_patch_3<ParameterizationPatchableMesh_3> vertex
    /// pointed to by m_ptr (except if NULL)
    Vertex m_vertex;

}; // Param_mesh_patch_vertex_const_handle

/// \endcond

} //namespace CGAL

#endif //CGAL_PARAM_MESH_PATCH_VERTEX_H