/*
    * 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
    *
    *      http://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.
   */
  package org.apache.commons.math4.legacy.fitting;
  
  import java.util.List;
  
  import org.junit.Assert;
  import org.junit.Test;
  import org.apache.commons.numbers.core.Precision;
  
  /**
   * Tests {@link WeightedObservedPoints}.
   *
   */
  public class WeightedObservedPointsTest {
      @Test
      public void testAdd1() {
          final WeightedObservedPoints store = new WeightedObservedPoints();
  
          final double x = 1.2;
          final double y = 34.56;
          final double w = 0.789;
  
          store.add(w, x, y);
  
          Assert.assertTrue(lastElementIsSame(store, new WeightedObservedPoint(w, x, y)));
      }
  
      @Test
      public void testAdd2() {
          final WeightedObservedPoints store = new WeightedObservedPoints();
  
          final double x = 1.2;
          final double y = 34.56;
          final double w = 0.789;
  
          store.add(new WeightedObservedPoint(w, x, y));
  
          Assert.assertTrue(lastElementIsSame(store, new WeightedObservedPoint(w, x, y)));
      }
  
      @Test
      public void testAdd3() {
          final WeightedObservedPoints store = new WeightedObservedPoints();
  
          final double x = 1.2;
          final double y = 34.56;
  
          store.add(x, y);
  
          Assert.assertTrue(lastElementIsSame(store, new WeightedObservedPoint(1, x, y)));
      }
  
      @Test
      public void testClear() {
          final WeightedObservedPoints store = new WeightedObservedPoints();
  
          store.add(new WeightedObservedPoint(1, 2, 3));
          store.add(new WeightedObservedPoint(2, -1, -2));
          Assert.assertTrue(store.toList().size() == 2);
  
          store.clear();
          Assert.assertTrue(store.toList().isEmpty());
      }
  
      // Ensure that an instance returned by "toList()" is independent from
      // the original container.
      @Test
      public void testToListCopy() {
          final WeightedObservedPoints store = new WeightedObservedPoints();
  
          store.add(new WeightedObservedPoint(1, 2, 3));
          store.add(new WeightedObservedPoint(2, -3, -4));
  
          final List<WeightedObservedPoint> list = store.toList();
          Assert.assertEquals(2, list.size());
  
          // Adding an element to "list" has no impact on "store".
          list.add(new WeightedObservedPoint(1.2, 3.4, 5.6));
          Assert.assertNotEquals(list.size(), store.toList().size());
  
          // Clearing "store" has no impact on "list".
          store.clear();
          Assert.assertFalse(list.isEmpty());
      }
 
     /**
      * Checks that the contents of the last element is equal to the
      * contents of {@code p}.
      *
      * @param store Container.
      * @param point Observation.
      * @return {@code true} if both elements have the same contents.
      */
     private boolean lastElementIsSame(WeightedObservedPoints store,
                                       WeightedObservedPoint point) {
         final List<WeightedObservedPoint> list = store.toList();
         final WeightedObservedPoint lastPoint = list.get(list.size() - 1);
 
         if (!Precision.equals(lastPoint.getX(), point.getX())) {
             return false;
         }
         if (!Precision.equals(lastPoint.getY(), point.getY())) {
             return false;
         }
         if (!Precision.equals(lastPoint.getWeight(), point.getWeight())) {
             return false;
         }
 
         return true;
     }
 }