/*
    * 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.analysis.integration.gauss;
  
  import org.hipparchus.analysis.CalculusFieldUnivariateFunction;
  import org.hipparchus.util.Binary64;
  import org.hipparchus.util.Pair;
  import org.junit.jupiter.api.Test;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  /**
   * Test for {@link GaussIntegrator} class.
   *
   */
  class FieldGaussIntegratorTest {
      @Test
      void testGetWeights() {
          final double[] points = { 0, 1.2, 3.4 };
          final double[] weights = { 9.8, 7.6, 5.4 };
  
          final FieldGaussIntegrator<Binary64> integrator
              = new FieldGaussIntegrator<>(new Pair<>(toBinary64(points), toBinary64(weights)));
  
          assertEquals(weights.length, integrator.getNumberOfPoints());
  
          for (int i = 0; i < integrator.getNumberOfPoints(); i++) {
              assertEquals(weights[i], integrator.getWeight(i).getReal(), 0d);
          }
      }
  
      @Test
      void testGetPoints() {
          final double[] points = { 0, 1.2, 3.4 };
          final double[] weights = { 9.8, 7.6, 5.4 };
  
          final FieldGaussIntegrator<Binary64> integrator
          = new FieldGaussIntegrator<>(new Pair<>(toBinary64(points), toBinary64(weights)));
  
          assertEquals(points.length, integrator.getNumberOfPoints());
  
          for (int i = 0; i < integrator.getNumberOfPoints(); i++) {
              assertEquals(points[i], integrator.getPoint(i).getReal(), 0d);
          }
      }
  
      @Test
      void testIntegrate() {
          final double[] points = { 0, 1, 2, 3, 4, 5 };
          final double[] weights = { 1, 1, 1, 1, 1, 1 };
  
          final FieldGaussIntegrator<Binary64> integrator
          = new FieldGaussIntegrator<>(new Pair<>(toBinary64(points), toBinary64(weights)));
  
          final Binary64 val = new Binary64(123.456);
          final CalculusFieldUnivariateFunction<Binary64> c = x -> val;
  
          final Binary64 s = integrator.integrate(c);
          assertEquals(val.multiply(points.length).getReal(), s.getReal(), 0d);
      }
  
      private Binary64[] toBinary64(final double[] a) {
          final Binary64[] d = new Binary64[a.length];
          for (int i = 0; i < a.length; ++i) {
              d[i] = new Binary64(a[i]);
          }
          return d;
      }
  
  }