


/*
 * The JTS Topology Suite is a collection of Java classes that
 * implement the fundamental operations required to validate a given
 * geo-spatial data set to a known topological specification.
 *
 * Copyright (C) 2001 Vivid Solutions
 *
 * 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; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * For more information, contact:
 *
 *     Vivid Solutions
 *     Suite #1A
 *     2328 Government Street
 *     Victoria BC  V8T 5G5
 *     Canada
 *
 *     (250)385-6040
 *     www.vividsolutions.com
 */
package com.vividsolutions.jts.geomgraph;

import java.io.PrintStream;
import java.util.*;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.index.SpatialIndex;
import com.vividsolutions.jts.index.quadtree.Quadtree;

/**
 * A EdgeList is a list of Edges.  It supports locating edges
 * that are pointwise equals to a target edge.
 * @version 1.7
 */
public class EdgeList
{
  private List edges = new ArrayList();
  /**
   * An index of the edges, for fast lookup.
   *
   * a Quadtree is used, because this index needs to be dynamic
   * (e.g. allow insertions after queries).
   * An alternative would be to use an ordered set based on the values
   * of the edge coordinates
   *
   */
  private SpatialIndex index = new Quadtree();

  public EdgeList() {
  }

  /**
   * Insert an edge unless it is already in the list
   */
  public void add(Edge e)
  {
    edges.add(e);
    index.insert(e.getEnvelope(), e);
  }

  public void addAll(Collection edgeColl)
  {
    for (Iterator i = edgeColl.iterator(); i.hasNext(); ) {
      add((Edge) i.next());
    }
  }

  public List getEdges() { return edges; }

// <FIX> fast lookup for edges
  /**
   * If there is an edge equal to e already in the list, return it.
   * Otherwise return null.
   * @return  equal edge, if there is one already in the list
   *          null otherwise
   */
  public Edge findEqualEdge(Edge e)
  {
    Collection testEdges = index.query(e.getEnvelope());

    for (Iterator i = testEdges.iterator(); i.hasNext(); ) {
      Edge testEdge = (Edge) i.next();
      if (testEdge.equals(e) ) return testEdge;
    }
    return null;
  }

  public Iterator iterator() { return edges.iterator(); }

  public Edge get(int i) { return (Edge) edges.get(i); }

  /**
   * If the edge e is already in the list, return its index.
   * @return  index, if e is already in the list
   *          -1 otherwise
   */
  public int findEdgeIndex(Edge e)
  {
    for (int i = 0; i < edges.size(); i++) {
      if ( ((Edge) edges.get(i)).equals(e) ) return i;
    }
    return -1;
  }

  public void print(PrintStream out)
  {
    out.print("MULTILINESTRING ( ");
    for (int j = 0; j < edges.size(); j++) {
      Edge e = (Edge) edges.get(j);
      if (j > 0) out.print(",");
      out.print("(");
      Coordinate[] pts = e.getCoordinates();
      for (int i = 0; i < pts.length; i++) {
        if (i > 0) out.print(",");
        out.print(pts[i].x + " " + pts[i].y);
      }
      out.println(")");
    }
    out.print(")  ");
  }


}
