/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2015-2017 Cirilo Bernardo <cirilo.bernardo@gmail.com>
 * Copyright (C) 2020 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * This program is free software; 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 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */

/**
 * @file sg_node.h
 */


#ifndef SG_NODE_H
#define SG_NODE_H

#include <iostream>
#include <string>
#include <list>
#include <vector>
#include <map>
#include <glm/glm.hpp>

#include "plugins/3dapi/c3dmodel.h"
#include "plugins/3dapi/sg_base.h"
#include "plugins/3dapi/sg_types.h"

class SGNODE;
class SGAPPEARANCE;

namespace S3D
{
    /**
     * Return the name of the given type of node
     */
    char const* GetNodeTypeName( S3D::SGTYPES aType ) noexcept;

    struct MATLIST
    {
        std::vector< SGAPPEARANCE const* > matorder;    // materials in order of addition
        std::map< SGAPPEARANCE const*, int > matmap;    // mapping from material to index
    };

    bool GetMatIndex( MATLIST& aList, SGNODE* aNode, int& aIndex );

    void INIT_SMATERIAL( SMATERIAL& aMaterial );
    void INIT_SMESH( SMESH& aMesh ) noexcept;
    void INIT_S3DMODEL( S3DMODEL& aModel ) noexcept;

    void FREE_SMESH( SMESH& aMesh) noexcept;
    void FREE_S3DMODEL( S3DMODEL& aModel );
}


/**
 * The base class of all Scene Graph nodes.
 */
class SGNODE
{
public:
    SGNODE( SGNODE* aParent );
    virtual ~SGNODE();

    /**
     * Return the type of this node instance.
     */
    S3D::SGTYPES GetNodeType( void ) const noexcept;

    /**
     * Returns a pointer to the parent SGNODE of this object or NULL if the object has
     * no parent (ie. top level transform).
     */
    SGNODE* GetParent( void ) const noexcept;

    /**
     * Set the parent #SGNODE of this object.
     *
     * @param aParent [in] is the desired parent node
     * @return true if the operation succeeds; false if the given node is not allowed to
     *         be a parent to the derived object.
     */
    virtual bool SetParent( SGNODE* aParent, bool notify = true ) = 0;

    /**
     * Swap the ownership with the given parent.
     *
     * This operation may be required when reordering nodes for optimization.
     *
     * @param aNewParent will become the new parent to the object; it must be the same type
     *                   as the parent of this instance.
     */
    bool SwapParent( SGNODE* aNewParent );

    const char* GetName( void );
    void SetName(const char *aName);

    const char * GetNodeTypeName( S3D::SGTYPES aNodeType ) const noexcept;

    /**
     * Search the tree of linked nodes and return a reference to the first node found with
     * the given name.
     *
     * The reference is then typically added to another node via AddRefNode().
     *
     * @param aNodeName is the name of the node to search for.
     * @param aCaller is a pointer to the node invoking this function.
     * @return is a valid node pointer on success, otherwise NULL.
     */
    virtual SGNODE* FindNode( const char *aNodeName, const SGNODE *aCaller ) = 0;

    virtual bool AddRefNode( SGNODE* aNode ) = 0;

    virtual bool AddChildNode( SGNODE* aNode ) = 0;

    /**
     * Associate this object with a handle to itself.
     *
     * The handle is typically held by an IFSG* wrapper and the pointer which it refers to
     * is set to NULL upon destruction of this object.  This mechanism provides a scheme
     * by which a wrapper can be notified of the destruction of the object which it wraps.
     */
    void AssociateWrapper( SGNODE** aWrapperRef ) noexcept;

    /**
     * Remove the association between an IFSG* wrapper object and this object.
     */
    void DisassociateWrapper( SGNODE** aWrapperRef ) noexcept;

    /**
     * Reset the global SG* node indices in preparation for write operations.
     */
    void ResetNodeIndex( void ) noexcept;

    /**
     * Rename a node and all its child nodes in preparation for write operations.
     */
    virtual void ReNameNodes( void ) = 0;

    /**
     * Writes this node's data to a VRML file.
     *
     * This includes all data of child and referenced nodes.
     */
    virtual bool WriteVRML( std::ostream& aFile, bool aReuseFlag ) = 0;

    /**
     * Write this node's data to a binary cache file.
     *
     * The data includes all data of children and references to children.  If this function
     * is invoked by the user, parentNode must be set to NULL in order to ensure coherent data.
     */
    virtual bool WriteCache( std::ostream& aFile, SGNODE* parentNode ) = 0;

    /**
     * Reads binary format data from a cache file.
     *
     * To read a cache file, open the file for reading and invoke this function from a new
     * #SCENEGRAPH node.
     */
    virtual bool ReadCache( std::istream& aFile, SGNODE* parentNode ) = 0;

    /**
     * Remove references to an owned child.
     *
     * This is invoked by the child upon destruction to ensure that the parent has no
     * invalid references.
     *
     * @param aNode is the child which is being deleted.
     */
    virtual void unlinkChildNode( const SGNODE* aNode ) = 0;

    /**
     * Remove pointers to a referenced node.
     *
     * This is invoked by the referenced node upon destruction to ensure that the referring
     * node has no invalid references.
     *
     * @param aNode is the node which is being deleted.
     */
    virtual void unlinkRefNode( const SGNODE* aNode ) = 0;

    /**
     * Add a pointer to a node which references this node, but does not own.
     *
     * Such back-pointers are required to ensure that invalidated references are removed
     * when a node is deleted.
     *
     * @param aNode is the node holding a reference to this object.
     */
    void addNodeRef( SGNODE* aNode );

    /**
     * Remove a pointer to a node which references this node, but does not own.
     *
     * @param aNode is the node holding a reference to this object.
     */
    void delNodeRef( const SGNODE* aNode );

    /**
     * Return true if the object had already been written to a cache file or VRML file
     *
     * For internal use only.
     */
    bool isWritten( void ) noexcept
    {
        return m_written;
    }

protected:
    std::list< SGNODE* > m_BackPointers;    ///< nodes which hold a reference to this.
    SGNODE* m_Parent;       ///< Pointer to parent node; may be NULL for top level transform.
    S3D::SGTYPES m_SGtype;  ///< Type of Scene Graph node.
    std::string m_Name;     ///< name to use for referencing the entity by name.
    bool m_written;         ///< Set to true when the object has been written after a ReNameNodes().

private:
    SGNODE** m_Association; ///< Handle to the instance held by a wrapper.
};

#endif  // SG_NODE_H