package com.ximple.io.dgn7;

import java.nio.ByteOrder;

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

public class EllipseElement extends Element implements GeometryConverter
{
    public EllipseElement(byte[] raw)
    {
        super(raw);
    }

    public double getStartAngle()
    {
        return 0.0;
    }

    public void setStartAngle(double value)
    {
    }

    public double getSweepAngle()
    {
        return 360.0;
    }

    public void setSweepAngle(double value)
    {
    }

    public double getPrimary()
    {
        rawBuffer.position(18 * 2);
        ByteOrder bo = rawBuffer.order();
        rawBuffer.order(ByteOrder.BIG_ENDIAN);
        byte[] primary = new byte[8];
        rawBuffer.get(primary);
        rawBuffer.order(bo);
        return Utility.convertDGNToIEEEDouble(primary) / 1000.0;
    }

    public void setPrimary(double value)
    {
        double temp = value * 1000.0;
        short[] primary = Utility.convertIEEEDoubleToDGN(temp);

        System.arraycopy(primary, 0, raw, 18, 4);
    }

    public double getSecondary()
    {
        rawBuffer.position(22 * 2);
        ByteOrder bo = rawBuffer.order();
        rawBuffer.order(ByteOrder.BIG_ENDIAN);
        byte[] secondary = new byte[8];
        rawBuffer.get(secondary);
        rawBuffer.order(bo);
        return Utility.convertDGNToIEEEDouble(secondary) / 1000.0;
    }

    public void setSecondary(double value)
    {
        double temp = value * 1000.0;
        short[] secondary = Utility.convertIEEEDoubleToDGN(temp);

        System.arraycopy(secondary, 0, raw, 22, 4);
    }

    public double getRotationAngle()
    {
        int rotation = (raw[26] << 16 & 0xffff0000);
        rotation |= raw[27] & 0x0000ffff;

        return Utility.converIntToRotation(rotation);
    }

    public void setRotationAngle(double value)
    {
        int angle = Utility.converRotatioToInt(value);

        raw[26] = (short) (angle >> 16 & 0x0000ffff);
        raw[27] = (short) (angle & 0x0000ffff);
    }

    public Coordinate getOrigin()
    {
        rawBuffer.position(28 * 2);
        ByteOrder bo = rawBuffer.order();
        rawBuffer.order(ByteOrder.BIG_ENDIAN);
        byte[] rawValue = new byte[8];

        rawBuffer.get(rawValue); // x
        double dx = Utility.converUnitToCoord(Utility.convertDGNToIEEEDouble(rawValue));

        rawBuffer.get(rawValue); // y
        double dy = Utility.converUnitToCoord(Utility.convertDGNToIEEEDouble(rawValue));

        rawBuffer.order(bo);

        return new Coordinate(dx, dy);
    }

    public void setOrigin(Coordinate value)
    {
        double temp = Utility.converCoordToUnit(value.x);
        short[] x = Utility.convertIEEEDoubleToDGN(temp);

        System.arraycopy(x, 0, raw, 28, 4);
        temp = Utility.converCoordToUnit(value.y);

        short[] y = Utility.convertIEEEDoubleToDGN(temp);

        System.arraycopy(y, 0, raw, 32, 4);
    }

    public Geometry toGeometry(GeometryFactory factory)
    {
        double temp = Math.abs(getStartAngle() - getSweepAngle());
        temp /= 4;
        int pts = (temp < 3) ? 3 : (int) temp;
        return factory.createPolygon(factory.createLinearRing(convertToLineString(pts)), null);
    }

    private Coordinate[] convertToLineString(int pts)
    {
        Coordinate[] result = new Coordinate[pts];
        double beta = -getRotationAngle() / 180 * Math.PI;
        double sinbeta = Math.sin(beta);
        double cosbeta = Math.cos(beta);
        double startAngle = getStartAngle();
        double endAngle = getSweepAngle();
        double steps = Math.abs(startAngle - endAngle) / pts;
        int i = 0;
        for (double current = startAngle; current < endAngle; current += steps)
        {
            if (i < pts)
            {
                Coordinate pt = new Coordinate();
                double alpha = current / 180 * Math.PI;
                double sinalpha = Math.sin(alpha);
                double cosalpha = Math.cos(alpha);
                pt.x = getOrigin().x + (getPrimary() * cosalpha * cosbeta -
                        getSecondary() * sinalpha * sinbeta);
                pt.y = getOrigin().y + (getPrimary() * cosalpha * sinbeta +
                        getSecondary() * sinalpha * cosbeta);
                result[i] = pt;
                i++;
            }
        }
        return result;
    }

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

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

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

            return instance;
        }

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