/*
    * 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.exception.LocalizedCoreFormats;
  import org.hipparchus.exception.MathIllegalArgumentException;
  import org.hipparchus.util.Binary64;
  import org.hipparchus.util.Binary64Field;
  import org.hipparchus.util.FastMath;
  import org.junit.jupiter.api.Test;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.fail;
  
  /**
   * Test of the {@link FieldLegendreRuleFactory}.
   *
   */
  class FieldLegendreTest {
      private static final FieldGaussIntegratorFactory<Binary64> factory = new FieldGaussIntegratorFactory<>(Binary64Field.getInstance());
  
      @Test
      void testTooLArgeNumberOfPoints() {
          try {
              factory.legendre(10000, new Binary64(0), new Binary64(Math.PI / 2));
              fail("an exception should have been thrown");
          } catch (MathIllegalArgumentException miae) {
              assertEquals(LocalizedCoreFormats.NUMBER_TOO_LARGE, miae.getSpecifier());
              assertEquals(10000, ((Integer) miae.getParts()[0]).intValue());
              assertEquals(1000,  ((Integer) miae.getParts()[1]).intValue());
          }
      }
  
      @Test
      void testCos() {
          final FieldGaussIntegrator<Binary64> integrator = factory.legendre(7, new Binary64(0), new Binary64(Math.PI / 2));
          final double s = integrator.integrate(x -> FastMath.cos(x)).getReal();
          // System.out.println("s=" + s + " e=" + 1);
          assertEquals(1, s, Math.ulp(1d));
      }
  
  
      @Test
      void testInverse() {
  
          final Binary64 lo = new Binary64(12.34);
          final Binary64 hi = new Binary64(456.78);
  
          final FieldGaussIntegrator<Binary64> integrator = factory.legendre(60, lo, hi);
          final double s = integrator.integrate(x -> x.reciprocal()).getReal();
          final double expected = FastMath.log(hi).subtract(FastMath.log(lo)).getReal();
          // System.out.println("s=" + s + " e=" + expected);
          assertEquals(expected, s, 1e-14);
      }
  }