/**
 * J3DGeomGroupFactory -- A factory for creating J3DGeomGroup objects appropriate for a
 * given GeomElement.
 *
 * Copyright (C) 2009-2017, Joseph A. Huwaldt. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place -
 * Suite 330, Boston, MA 02111-1307, USA. Or visit: http://www.gnu.org/licenses/lgpl.html
 */
package geomss.j3d;

import geomss.app.GeomSSCanvas3D;
import geomss.geom.*;
import static java.util.Objects.requireNonNull;

/**
 * A factory for creating {@link J3DGeomGroup} objects appropriate to the provided
 * GeomElement object.
 *
 * <p> Modified by: Joseph A. Huwaldt </p>
 *
 * @author Joseph A. Huwaldt, Date: May 1, 2009
 * @version January 30, 2017
 */
public class J3DGeomGroupFactory {

    /**
     * Return a {@link J3DGeomGroup} object appropriate to the supplied GeomElement or
     * <code>null</code> if an appropriate J3DGeomGroup can not be found.
     *
     * @param canvas  The 3D canvas the geometry is being rendered into.
     * @param element The geometry element to have a J3DGeomGroup created for.
     * @return A J3DGeomGroup object representing the supplied GeomElement or null.
     */
    public static J3DGeomGroup newGroup(GeomSSCanvas3D canvas, GeomElement element) {
        requireNonNull(canvas, "null canvas");
        
        //      Reject non-numeric geometry elements.
        if (element == null || !element.isValid())
            return null;

        //  Try to recycle a previous rendering of this geometry element if at all possible.
        J3DGeomGroup j3dGroup = (J3DGeomGroup)element.getUserData(J3DGeomGroup.USERDATA_KEY);
        if (j3dGroup != null) {
            //  This geometry was previously rendered.  Have the rendering preferences changed?
            J3DRenderingPrefs currentPrefs = J3DGeomGroup.getDefaultRenderingPrefs();
            J3DRenderingPrefs oldPrefs = j3dGroup.getRenderingPrefs();

            //  Does this group already have a parent (it is already displayed)?
            //  If it is already displayed and the draw prefs have not changed, detach it from
            //  the 3D scene graph (it will get re-attached when it is re-used).
            if (j3dGroup.getParent() != null && oldPrefs.equals(currentPrefs)) {
                try {
                    j3dGroup.detach();

                    //  The "detach()" method may have removed the group from the object's meta-data
                    //  as a way of indicating that the group should not be re-used.
                    j3dGroup = (J3DGeomGroup)element.getUserData(J3DGeomGroup.USERDATA_KEY);

                } catch (Exception e) {
                    //  Just force the creation of a new group.
                    j3dGroup = null;
                }
            }
            if (j3dGroup != null) {
                //  This geometry was previously rendered.  Have the rendering preferences changed?
                if (oldPrefs.equals(currentPrefs)) {
                    //System.out.println("Recycling " + element.getID());
                    //  The rendering prefs are unchanged, so re-use as is.
                    return j3dGroup;
                }
                j3dGroup = null;
            }
        }

        if (element instanceof GeomPoint)
            j3dGroup = new J3DGeomPoint(canvas, (GeomPoint)element);
        else if (element instanceof PointString) {
            PointString<?> str = (PointString)element;
            if (str.isEmpty())
                return null;
            if (str.size() < 2)
                j3dGroup = new J3DGeomPoint(canvas, str.get(0));
            else
                j3dGroup = new J3DPointString(canvas, str);

        } else if (element instanceof PointArray) {
            PointArray<?> arr = (PointArray)element;
            if (arr.isEmpty())
                return null;
            if (arr.size() < 2)
                j3dGroup = new J3DPointString(canvas, arr.get(0));
            else
                j3dGroup = new J3DPointArray(canvas, arr);

        } else if (element instanceof TriangleList) {
            TriangleList<? extends GeomTriangle> lst = (TriangleList)element;
            if (lst.isEmpty())
                return null;
            j3dGroup = new J3DTriangleList(canvas, lst);

        } else if (element instanceof AbstractGeomList) {
            AbstractGeomList list = (AbstractGeomList)element;
            if (!list.containsGeometry())
                return null;
            j3dGroup = new J3DGeomList(canvas, list);

        } else if (element instanceof GeomVector)
            j3dGroup = new J3DGeomVector(canvas, (GeomVector)element);
        else if (element instanceof GeomPlane)
            j3dGroup = new J3DGeomPlane(canvas, (GeomPlane)element);
        else if (element instanceof Curve)
            j3dGroup = new J3DCurve(canvas, (Curve)element);
        else if (element instanceof Surface)
            j3dGroup = new J3DSurface(canvas, (Surface)element);
        else if (element instanceof GenScreenNote)
            j3dGroup = new J3DGenScreenNote(canvas, (GenScreenNote)element);
        else if (element instanceof GenModelNote)
            j3dGroup = new J3DGenModelNote(canvas, (GenModelNote)element);
        else if (element instanceof GeomTriangle) {
            if (!((GeomTriangle)element).getArea().isApproxZero())
                j3dGroup = new J3DTriangle(canvas, (GeomTriangle)element);
        }

        return j3dGroup;
    }
}