/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /*
   * This is not the original file distributed by the Apache Software Foundation
   * It has been modified by the Hipparchus project
   */
  
  package org.hipparchus.clustering;
  
  import org.junit.jupiter.api.Test;
  
  import java.util.Arrays;
  import java.util.List;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  class MultiKMeansPlusPlusClustererTest {
  
      @Test
      void dimension2() {
          MultiKMeansPlusPlusClusterer<DoublePoint> transformer =
              new MultiKMeansPlusPlusClusterer<DoublePoint>(
                      new KMeansPlusPlusClusterer<DoublePoint>(3, 10), 5);
  
          DoublePoint[] points = new DoublePoint[] {
  
                  // first expected cluster
                  new DoublePoint(new int[] { -15,  3 }),
                  new DoublePoint(new int[] { -15,  4 }),
                  new DoublePoint(new int[] { -15,  5 }),
                  new DoublePoint(new int[] { -14,  3 }),
                  new DoublePoint(new int[] { -14,  5 }),
                  new DoublePoint(new int[] { -13,  3 }),
                  new DoublePoint(new int[] { -13,  4 }),
                  new DoublePoint(new int[] { -13,  5 }),
  
                  // second expected cluster
                  new DoublePoint(new int[] { -1,  0 }),
                  new DoublePoint(new int[] { -1, -1 }),
                  new DoublePoint(new int[] {  0, -1 }),
                  new DoublePoint(new int[] {  1, -1 }),
                  new DoublePoint(new int[] {  1, -2 }),
  
                  // third expected cluster
                  new DoublePoint(new int[] { 13,  3 }),
                  new DoublePoint(new int[] { 13,  4 }),
                  new DoublePoint(new int[] { 14,  4 }),
                  new DoublePoint(new int[] { 14,  7 }),
                  new DoublePoint(new int[] { 16,  5 }),
                  new DoublePoint(new int[] { 16,  6 }),
                  new DoublePoint(new int[] { 17,  4 }),
                  new DoublePoint(new int[] { 17,  7 })
  
          };
          List<CentroidCluster<DoublePoint>> clusters = transformer.cluster(Arrays.asList(points));
  
          assertEquals(3, clusters.size());
          boolean cluster1Found = false;
          boolean cluster2Found = false;
          boolean cluster3Found = false;
          double epsilon = 1e-6;
          for (CentroidCluster<DoublePoint> cluster : clusters) {
              Clusterable center = cluster.getCenter();
              double[] point = center.getPoint();
              if (point[0] < 0) {
                  cluster1Found = true;
                  assertEquals(8, cluster.getPoints().size());
                  assertEquals(-14, point[0], epsilon);
                  assertEquals( 4, point[1], epsilon);
              } else if (point[1] < 0) {
                  cluster2Found = true;
                  assertEquals(5, cluster.getPoints().size());
                  assertEquals( 0, point[0], epsilon);
                  assertEquals(-1, point[1], epsilon);
              } else {
                  cluster3Found = true;
                  assertEquals(8, cluster.getPoints().size());
                  assertEquals(15, point[0], epsilon);
                  assertEquals(5, point[1], epsilon);
              }
          }
          assertTrue(cluster1Found);
          assertTrue(cluster2Found);
         assertTrue(cluster3Found);
 
     }
 
 }