/*
 * Copyright (c) 2016 Vivid Solutions.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 *
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */
package org.locationtech.jts.geomgraph;

import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.IntersectionMatrix;
import org.locationtech.jts.util.Assert;

/**
 * A GraphComponent is the parent class for the objects'
 * that form a graph.  Each GraphComponent can carry a
 * Label.
 * @version 1.7
 */
abstract public class GraphComponent {

  protected Label label;
  /**
   * isInResult indicates if this component has already been included in the result
   */
  private boolean isInResult = false;
  private boolean isCovered = false;
  private boolean isCoveredSet = false;
  private boolean isVisited = false;

  public GraphComponent() {
  }

  public GraphComponent(Label label) {
    this.label = label;
  }

  public Label getLabel() { return label; }
  public void setLabel(Label label) { this.label = label; }
  public void setInResult(boolean isInResult) { this.isInResult = isInResult; }
  public boolean isInResult() { return isInResult; }
  public void setCovered(boolean isCovered)
  {
    this.isCovered = isCovered;
    this.isCoveredSet = true;
  }
  public boolean isCovered()    { return isCovered; }
  public boolean isCoveredSet() { return isCoveredSet; }
  public boolean isVisited() { return isVisited; }
  public void setVisited(boolean isVisited) { this.isVisited = isVisited; }
  /**
   * @return a coordinate in this component (or null, if there are none)
   */
  abstract public Coordinate getCoordinate();
  /**
   * compute the contribution to an IM for this component
   */
  abstract protected void computeIM(IntersectionMatrix im);
  /**
   * An isolated component is one that does not intersect or touch any other
   * component.  This is the case if the label has valid locations for
   * only a single Geometry.
   *
   * @return true if this component is isolated
   */
  abstract public boolean isIsolated();
  /**
   * Update the IM with the contribution for this component.
   * A component only contributes if it has a labelling for both parent geometries
   */
  public void updateIM(IntersectionMatrix im)
  {
    Assert.isTrue(label.getGeometryCount() >= 2, "found partial label");
    computeIM(im);
  }

}