/*
 *    GeoTools - The Open Source Java GIS Toolkit
 *    http://geotools.org
 *
 *    (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
 *
 *    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;
 *    version 2.1 of the License.
 *
 *    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.
 */
package org.geotools.renderer.shape.shapehandler.simple;

import java.awt.Rectangle;
import java.nio.ByteBuffer;
import java.util.logging.Logger;

import org.geotools.data.shapefile.shp.ShapeHandler;
import org.geotools.data.shapefile.shp.ShapeType;
import org.geotools.renderer.ScreenMap;
import org.geotools.renderer.shape.GeometryHandlerUtilities;
import org.geotools.renderer.shape.ShapefileRenderer;
import org.geotools.renderer.shape.SimpleGeometry;
import org.opengis.referencing.operation.MathTransform;
import org.opengis.referencing.operation.TransformException;

import com.vividsolutions.jts.geom.Envelope;

/**
 * A ShapeHandler that reads PointHandler objects from a file. It returns a
 * SimpleGeometry and decimates all points that map to the same screen location.
 * 
 * @author jeichar
 * @since 2.1.x
 *
 *
 * @source $URL$
 */
public class PointHandler implements ShapeHandler {
    private ShapeType type;

    private Envelope bbox;

    private MathTransform mt;

    private ScreenMap screenMap;

    Logger LOGGER = ShapefileRenderer.LOGGER;

    int skipped = 0;

    /**
     * Create new instance
     * 
     * @param type
     *            the type of shape.
     * @param env
     *            the area that is visible. If shape is not in area then skip.
     * @param mt
     *            the transform to go from data to the envelope (and that should
     *            be used to transform the shape coords)
     * @param hasOpacity
     */
    public PointHandler(ShapeType type, Envelope env, Rectangle screenSize,
            MathTransform mt, boolean hasOpacity) throws TransformException {
        if (mt == null) {
            throw new NullPointerException();
        }
        this.type = type;
        this.bbox = env;
        this.mt = mt;
        screenMap = GeometryHandlerUtilities.calculateScreenSize(screenSize,
                hasOpacity);
    }

    /**
     * @see org.geotools.data.shapefile.shp.ShapeHandler#getShapeType()
     */
    public ShapeType getShapeType() {
        return type;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.geotools.data.shapefile.shp.ShapeHandler#read(java.nio.ByteBuffer,
     *      org.geotools.data.shapefile.shp.ShapeType)
     */
    public Object read(ByteBuffer buffer, ShapeType type, boolean flatFeature) {
        if (type == ShapeType.NULL) {
            LOGGER.finest("shape type is NULL");
            return null;
        }

        double[][] coords = new double[1][];
        coords[0] = new double[] { buffer.getDouble(), buffer.getDouble() };
        Envelope geomBBox = new Envelope(coords[0][0], coords[0][0],
                coords[0][1], coords[0][1]);

        if (!bbox.intersects(geomBBox)) {
            LOGGER.finest("Point doesn't intersect with envelope");
            return null;
        }

        double[][] transformed = new double[1][];
        transformed[0] = new double[2];
        
        if (!mt.isIdentity()) {
            try {
                mt.transform(coords[0], 0, transformed[0], 0, 1);
            } catch (Exception e) {
                ShapefileRenderer.LOGGER
                        .severe("could not transform coordinates"
                                + e.getLocalizedMessage());
            }
        } else {
            transformed = coords;
        }

        if (screenMap.checkAndSet((int) (transformed[0][0]), (int) transformed[0][1])) {
            LOGGER.finest("Point already rendered" + transformed[0][0] + " "
                    + transformed[0][1]);
            return null;
        }
        return createGeometry(type, geomBBox, transformed);
    }

    protected Object createGeometry(ShapeType type, Envelope geomBBox, double[][] transformed) {
        return new SimpleGeometry(type, transformed, geomBBox);
    }

    /**
     * @see org.geotools.data.shapefile.shp.ShapeHandler#write(java.nio.ByteBuffer,
     *      java.lang.Object)
     */
    public void write(ByteBuffer buffer, Object geometry) {
        // This handler doesnt write
        throw new UnsupportedOperationException(
                "This handler is only for reading");
    }

    /**
     * @see org.geotools.data.shapefile.shp.ShapeHandler#getLength(java.lang.Object)
     */
    public int getLength(Object geometry) {
        // TODO Auto-generated method stub
        return 0;
    }

}