package com.ximple.io.dgn7;

//~--- non-JDK imports --------------------------------------------------------

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryFactory;

/**
 * LineElement
 *
 * @author Ulysses
 * @version 0.1
 * @since 2006/5/18 上午 11:34:59
 */
public class LineElement extends Element implements GeometryConverter
{
    public LineElement(byte[] raw)
    {
        super(raw);
    }

    public Coordinate getCentroid(double dTolerance)
    {
        return null;
    }

    public Coordinate getEndPoint()
    {
        int endX = ((raw[22] << 16) & 0xffff0000) | (raw[23] & 0x0000ffff);
        int endY = ((raw[24] << 16) & 0xffff0000) | (raw[25] & 0x0000ffff);


        double x = Utility.converUnitToCoord(endX);
        double y = Utility.converUnitToCoord(endY);

        return new Coordinate(x, y);
    }

    public Coordinate getNormal()
    {
        return null;
    }

    public Coordinate getOrigin()
    {
        return null;
    }

    public Coordinate getStartPoint()
    {
        int startX = ((raw[18] << 16) & 0xffff0000);
        startX = startX + (raw[19] & 0x0000ffff);

        double x      = Utility.converUnitToCoord(startX);
        int    startY = ((raw[20] << 16) & 0xffff0000);

        startY = startY + (raw[21] & 0x0000ffff);

        double y = Utility.converUnitToCoord(startY);

        return new Coordinate(x, y);
    }

    public Coordinate getVertex(int index)
    {
        return (index == 0)
               ? getStartPoint()
               : getEndPoint();
    }

    public double getLength()
    {
        Coordinate p1 = getStartPoint();
        Coordinate p2 = getEndPoint();

        return Utility.getLength(p1.x, p1.y, p2.x, p2.y);
    }

    public Coordinate pointAtDistance(double dDistance, double dTolerance)
    {
        return null;
    }

    public Coordinate[] getVertices()
    {
        Coordinate[] result = new Coordinate[2];

        result[0] = getStartPoint();
        result[1] = getEndPoint();

        return result;
    }

    public Geometry toGeometry(GeometryFactory factory)
    {
        return factory.createLineString(getVertices());
    }

    public static class ElementHandler extends Element.ElementHandler
    {
        private static ElementHandler instance = null;

        public ElementHandler()
        {
            super(ElementType.LINE);
        }

        public static IElementHandler getInstance()
        {
            if (instance == null)
            {
                instance = new ElementHandler();
            }

            return instance;
        }

        protected Element createElement(byte[] raw)
        {
            return new LineElement(raw);
        }
    }
}