/*$************************************************************************************************
 **
 ** $Id$
 **
 ** $Source: /cvs/ctree/LiteGO1/src/jar/com/polexis/lite/spatialschema/geometry/complex/CompositeCurveImpl.java,v $
 **
 ** Copyright (C) 2003 Open GIS Consortium, Inc. All Rights Reserved. http://www.opengis.org/Legal/
 **
 *************************************************************************************************/
package org.geotools.geometry.jts.spatialschema.geometry.complex;

// J2SE direct dependencies
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Set;

import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.geometry.complex.Complex;
import org.opengis.geometry.complex.CompositeCurve;
import org.opengis.geometry.primitive.OrientableCurve;
import org.opengis.geometry.primitive.OrientablePrimitive;
import org.opengis.geometry.primitive.Primitive;
import org.opengis.geometry.primitive.Curve;

import org.geotools.geometry.jts.JTSGeometry;
import org.opengis.geometry.primitive.CurveBoundary;

/**
 * A {@linkplain Complex complex} with all the geometric properties of a curve. Thus, this
 * composite can be considered as a type of {@linkplain OrientableCurve orientable curve}.
 * Essentially, a composite curve is a list of {@linkplain OrientableCurve orientable curves}
 * agreeing in orientation in a manner such that each curve (except the first) begins where
 * the previous one ends.
 * <strong>However, this implementation does NOT currently require that the start
 * point for element i+1 must be identical to the end point of element i.</strong>
 * This may change for later versions when arcs are supported.
 * 
 * @UML type GM_CompositeCurve
 * @author ISO/DIS 19107
 * @author <A HREF="http://www.opengis.org">OpenGIS® consortium</A>
 *
 *
 *
 * @source $URL$
 * @version 2.0
 *
 * @revisit This interface extends (indirectly) both {@link org.opengis.geometry.primitive.Primitive} and
 *          {@link org.opengis.geometry.complex.Complex}. Concequently, there is a clash in the semantics
 *          of some set theoretic operation. Specifically, {@code Primitive.contains(...)}
 *          (returns FALSE for end points) is different from {@code Complex.contains(...)}
 *          (returns TRUE for end points).
 */
public class CompositeCurveImpl extends CompositeImpl implements CompositeCurve {
    // A parent curve, if any.
    private CompositeCurve parent;

    public CompositeCurveImpl(CompositeCurve parent) {
        this(parent, parent.getCoordinateReferenceSystem());
    }

    public CompositeCurveImpl(CompositeCurve parent, CoordinateReferenceSystem crs) {
        super(crs);
        this.parent = parent;
    }

    //*************************************************************************
    //  implement the CompositeCurve interface
    //*************************************************************************

    public CurveBoundary getBoundary() {
        return (CurveBoundary) super.getBoundary();
    }
    /**
     * Returns the list of orientable curves in this composite.
     *
     * To get a full representation of the elements in the {@linkplain Complex complex},
     * the {@linkplain org.opengis.geometry.primitive.Point points} on the boundary of the
     * generator set of {@linkplain org.opengis.geometry.primitive.Curve curve} would be
     * added to the curves in the generator list.
     *
     * @return The list of orientable curves in this composite.
     * @UML association generator
     */
    public final List<OrientableCurve> getGenerators() {
        return getElementList();
    }

    //*************************************************************************
    //  implement the OrientableCurve interface
    //*************************************************************************
    
    /**
     * Returns the owner of this orientable curve, or {@code null} if none.
     *
     * @return The owner of this orientable curve, or {@code null} if none.
     * @UML association composite
     *
     * @revisit I'm not sure to interpret correctly the ISO specification.
     *          Sound like ISO returns an array (or a sequence) here.
     */
    public final CompositeCurve getComposite() {
        return parent;
    }

    //*************************************************************************
    //  implement the OrientablePrimitive interface
    //*************************************************************************

    /**
     * This implementation always returns +1, indicating that the curve is to
     * be traversed in its "natural" order.
     */
    public int getOrientation() {
        return +1;
    }

    /**
     * This returns the "positive orientation" primitive.  In this
     * implementation, we only support positively oriented primitives, so this
     * method always returns "null".  (In the future, it might return the
     * positively oriented object for which this object is the negative proxy.)
     */
    public Curve getPrimitive() {
        return null;
    }

    /**
     * This implementation doesn't support traversing this association in
     * this direction, so this method always returns null.
     */
    public final Set<Primitive> getContainingPrimitives() {
        return null;
    }

    public final Set<Complex> getComplexes() {
        return null;
    }

    public final Set getContainedPrimitives() {
        return setViewOfElements;
    }

    /**
     * This implementation currently only supports positively oriented
     * primitives, so this method will always return null, indicating that this
     * object itself is the only instance in existence and that there are no
     * proxies for the positively and negatively oriented versions of this
     * primitive.
     */
    public OrientablePrimitive[] getProxy() {
        return null;
    }
}