
/*
 * 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 2.0
 * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
 * and the Eclipse Distribution License is available at
 *
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */
package org.locationtech.jts.index.quadtree;

import java.util.ArrayList;
import java.util.List;

import org.locationtech.jts.geom.Envelope;
import org.locationtech.jts.index.quadtree.Quadtree;
import org.locationtech.jts.util.Stopwatch;



/**
 * @version 1.7
 */
public class QuadtreeCorrectTest {

  public static void main(String[] args) throws Exception
  {
    //testBinaryPower();
    QuadtreeCorrectTest test = new QuadtreeCorrectTest();
    test.run();
  }

/*
  public static void testBinaryPower()
  {
    printBinaryPower(1004573397.0);
    printBinaryPower(100.0);
    printBinaryPower(0.234);
    printBinaryPower(0.000003455);
  }

  public static void printBinaryPower(double num)
  {
    BinaryPower pow2 = new BinaryPower();
    int exp = BinaryPower.exponent(num);
    double p2 = pow2.power(exp);
    System.out.println(num + " : pow2 = " +  Math.pow(2.0, exp)
        + "   exp = " + exp + "   2^exp = " + p2);
  }
*/
  static final int NUM_ITEMS = 2000;
  static final double MIN_EXTENT = -1000.0;
  static final double MAX_EXTENT = 1000.0;

  EnvelopeList envList = new EnvelopeList();
  Quadtree q = new Quadtree();

  public QuadtreeCorrectTest() {
  }

  public void run()
  {
    fill();
    System.out.println("depth = " + q.depth()
      + "  size = " + q.size() );
    runQueries();
  }

  void fill()
  {
    createGrid(NUM_ITEMS);
  }

  void createGrid(int nGridCells)
  {
    int gridSize = (int) Math.sqrt((double) nGridCells);
    gridSize += 1;
    double extent = MAX_EXTENT - MIN_EXTENT;
    double gridInc = extent / gridSize;
    double cellSize = 2 * gridInc;

    for (int i = 0; i < gridSize; i++) {
      for (int j = 0; j < gridSize; j++) {
        double x = MIN_EXTENT + gridInc * i;
        double y = MIN_EXTENT + gridInc * j;
        Envelope env = new Envelope(x, x + cellSize,
                                    y, y + cellSize);
        q.insert(env, env);
        envList.add(env);
      }
    }
  }

  void runQueries()
  {
    int nGridCells = 100;
    int cellSize = (int) Math.sqrt((double) NUM_ITEMS);
    double extent = MAX_EXTENT - MIN_EXTENT;
    double queryCellSize =  2.0 * extent / cellSize;

    queryGrid(nGridCells, queryCellSize);

    //queryGrid(200);
  }

  void queryGrid(int nGridCells, double cellSize)
  {
    Stopwatch sw = new Stopwatch();
    sw.start();

    int gridSize = (int) Math.sqrt((double) nGridCells);
    gridSize += 1;
    double extent = MAX_EXTENT - MIN_EXTENT;
    double gridInc = extent / gridSize;

    for (int i = 0; i < gridSize; i++) {
      for (int j = 0; j < gridSize; j++) {
        double x = MIN_EXTENT + gridInc * i;
        double y = MIN_EXTENT + gridInc * j;
        Envelope env = new Envelope(x, x + cellSize,
                                    y, y + cellSize);
        queryTest(env);
        //queryTime(env);
      }
    }
    System.out.println("Time = " + sw.getTimeString());
  }

  void queryTime(Envelope env)
  {
    //List finalList = getOverlapping(q.query(env), env);

    List eList = envList.query(env);
  }

  void queryTest(Envelope env)
  {
    List candidateList = q.query(env);
    List finalList = getOverlapping(candidateList, env);

    List eList = envList.query(env);
//System.out.println(finalList.size());

    if (finalList.size() != eList.size() )
      throw new RuntimeException("queries do not match");
  }

  private List getOverlapping(List items, Envelope searchEnv)
  {
    List result = new ArrayList();
    for (int i = 0; i < items.size(); i++) {
      Envelope env = (Envelope) items.get(i);
      if (env.intersects(searchEnv)) result.add(env);
    }
    return result;
  }

}
