/*
    * Licensed to the Hipparchus project under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The Hipparchus project 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.
   */
  package org.hipparchus.analysis.polynomials;
  
  import org.hipparchus.Field;
  import org.hipparchus.exception.MathIllegalArgumentException;
  import org.hipparchus.util.Binary64;
  import org.hipparchus.util.Binary64Field;
  import org.junit.jupiter.api.Test;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  class SmoothStepFactoryTest {
  
      final double THRESHOLD = 1e-15;
  
      @Test
      void testExceptionBelowBoundary() {
          assertThrows(MathIllegalArgumentException.class, () -> {
              // Given
              final double                               x = 2;
              final SmoothStepFactory.SmoothStepFunction smoothstep = SmoothStepFactory.getGeneralOrder(1);
  
              // When
              smoothstep.value(x);
          });
      }
  
      @Test
      void testExceptionOverBoundary() {
          assertThrows(MathIllegalArgumentException.class, () -> {
              // Given
              final double                               x = 17;
              final SmoothStepFactory.SmoothStepFunction smoothstep = SmoothStepFactory.getGeneralOrder(1);
  
              // When
              smoothstep.value(x);
          });
      }
  
      @Test
      void testEdgesConsistency() {
          assertThrows(MathIllegalArgumentException.class, () -> {
              // Given
              final double                               leftEdge = 5;
              final double                               rightEdge = 2;
              final double                               x = 3;
              final SmoothStepFactory.SmoothStepFunction smoothstep = SmoothStepFactory.getGeneralOrder(1);
  
              // When
              smoothstep.value(leftEdge, rightEdge, x);
          });
      }
  
      @Test
      void testBoundaries() {
          // Given
          final double leftEdge  = 5;
          final double rightEdge = 10;
          final double x1        = 2;
          final double x2        = 11;
  
          final SmoothStepFactory.SmoothStepFunction clamp = SmoothStepFactory.getClamp();
  
          // When
          final double computedResult1 = clamp.value(leftEdge, rightEdge, x1);
          final double computedResult2 = clamp.value(leftEdge, rightEdge, x2);
  
          // Then
          assertEquals(0, computedResult1, THRESHOLD);
          assertEquals(1, computedResult2, THRESHOLD);
      }
  
      @Test
      void testNormalizedInput() {
  
          // Given
          final double                               x     = 0.4;
          final SmoothStepFactory.SmoothStepFunction cubic = SmoothStepFactory.getCubic();
  
          // When
          final double computedResult = cubic.value(x);
  
          // Then
         assertEquals(0.352, computedResult, THRESHOLD);
 
     }
 
     @Test
     void testClampFunction() {
 
         // Given
         final double leftEdge  = 5;
         final double rightEdge = 10;
         final double x         = 7;
 
         final SmoothStepFactory.SmoothStepFunction clamp = SmoothStepFactory.getClamp();
 
         // When
         final double computedResult = clamp.value(leftEdge, rightEdge, x);
 
         // Then
         assertEquals(0.4, computedResult, THRESHOLD);
 
     }
 
     @Test
     void testQuadraticFunction1() {
 
         // Given
         final double leftEdge  = 5;
         final double rightEdge = 10;
         final double x         = 7;
 
         final SmoothStepFactory.SmoothStepFunction quadratic = SmoothStepFactory.getQuadratic();
 
         // When
         final double computedResult = quadratic.value(leftEdge, rightEdge, x);
 
         // Then
         assertEquals(0.32, computedResult, THRESHOLD);
 
     }
 
     @Test
     void testQuadraticFunction2() {
 
         // Given
         final double leftEdge  = 5;
         final double rightEdge = 10;
         final double x         = 8;
 
         final SmoothStepFactory.SmoothStepFunction quadratic = SmoothStepFactory.getQuadratic();
 
         // When
         final double computedResult = quadratic.value(leftEdge, rightEdge, x);
 
         // Then
         assertEquals(0.68, computedResult, THRESHOLD);
 
     }
 
     @Test
     void testCubicFunction() {
 
         // Given
         final double leftEdge  = 5;
         final double rightEdge = 10;
         final double x         = 7;
 
         final SmoothStepFactory.SmoothStepFunction cubic = SmoothStepFactory.getCubic();
 
         // When
         final double computedResult = cubic.value(leftEdge, rightEdge, x);
 
         // Then
         assertEquals(0.352, computedResult, THRESHOLD);
 
     }
 
     @Test
     void testQuinticFunction() {
 
         // Given
         final double leftEdge  = 5;
         final double rightEdge = 10;
         final double x         = 7;
 
         final SmoothStepFactory.SmoothStepFunction quintic = SmoothStepFactory.getQuintic();
 
         // When
         final double computedResult = quintic.value(leftEdge, rightEdge, x);
 
         // Then
         assertEquals(0.31744, computedResult, THRESHOLD);
 
     }
 
     @Test
     void testFieldEdgesConsistency() {
         assertThrows(MathIllegalArgumentException.class, () -> {
             // Given
             final Field<Binary64> field = Binary64Field.getInstance();
 
             final double   leftEdge = 5;
             final double   rightEdge = 2;
             final Binary64 x = new Binary64(3);
             final SmoothStepFactory.FieldSmoothStepFunction<Binary64> smoothstep =
                 SmoothStepFactory.getFieldGeneralOrder(field, 1);
 
             // When
             smoothstep.value(leftEdge, rightEdge, x);
         });
     }
 
     @Test
     void testFieldBoundaries() {
         // Given
         final Field<Binary64> field = Binary64Field.getInstance();
 
         final double   leftEdge  = 5;
         final double   rightEdge = 10;
         final Binary64 x1        = new Binary64(2);
         final Binary64 x2        = new Binary64(11);
 
         final SmoothStepFactory.FieldSmoothStepFunction<Binary64> clamp = SmoothStepFactory.getClamp(field);
 
         // When
         final Binary64 computedResult1 = clamp.value(leftEdge, rightEdge, x1);
         final Binary64 computedResult2 = clamp.value(leftEdge, rightEdge, x2);
 
         // Then
         assertEquals(0, computedResult1.getReal(), THRESHOLD);
         assertEquals(1, computedResult2.getReal(), THRESHOLD);
     }
 
     @Test
     void testFieldNormalizedInput() {
 
         // Given
         final Field<Binary64> field = Binary64Field.getInstance();
 
         final double                                              x     = 0.4;
         final SmoothStepFactory.FieldSmoothStepFunction<Binary64> cubic = SmoothStepFactory.getCubic(field);
 
         // When
         final Binary64 computedResult = cubic.value(x);
 
         // Then
         assertEquals(0.352, computedResult.getReal(), THRESHOLD);
 
     }
 
     @Test
     void testFieldClampFunction() {
 
         // Given
         final Field<Binary64> field     = Binary64Field.getInstance();
         final double          leftEdge  = 5;
         final double          rightEdge = 10;
         final Binary64        x         = new Binary64(7);
 
         final SmoothStepFactory.FieldSmoothStepFunction<Binary64> clamp = SmoothStepFactory.getClamp(field);
 
         // When
         final Binary64 computedResult = clamp.value(leftEdge, rightEdge, x);
 
         // Then
         assertEquals(0.4, computedResult.getReal(), THRESHOLD);
 
     }
 
     @Test
     void testFieldQuadraticFunction1() {
 
         // Given
         final Field<Binary64> field     = Binary64Field.getInstance();
         final double          leftEdge  = 5;
         final double          rightEdge = 10;
         final double          x         = 7;
         final Binary64        xField    = new Binary64(x);
 
         final SmoothStepFactory.FieldSmoothStepFunction<Binary64> quadratic = SmoothStepFactory.getQuadratic(field);
 
         // When
         final Binary64 computedResult  = quadratic.value(leftEdge, rightEdge, xField);
         final Binary64 computedResult2 = quadratic.value((x - leftEdge) / (rightEdge - leftEdge));
 
         // Then
         assertEquals(0.32, computedResult.getReal(), THRESHOLD);
         assertEquals(computedResult.getReal(), computedResult2.getReal(), THRESHOLD);
 
     }
 
     @Test
     void testFieldQuadraticFunction2() {
 
         // Given
         final Field<Binary64> field     = Binary64Field.getInstance();
         final double          leftEdge  = 5;
         final double          rightEdge = 10;
         final double          x         = 8;
         final Binary64        xField    = new Binary64(x);
 
         final SmoothStepFactory.FieldSmoothStepFunction<Binary64> quadratic = SmoothStepFactory.getQuadratic(field);
 
         final Binary64 computedResult  = quadratic.value(leftEdge, rightEdge, xField);
         final Binary64 computedResult2 = quadratic.value((x - leftEdge) / (rightEdge - leftEdge));
 
         // Then
         assertEquals(0.68, computedResult.getReal(), THRESHOLD);
         assertEquals(computedResult.getReal(), computedResult2.getReal(), THRESHOLD);
 
     }
 
     @Test
     void testFieldCubicFunction() {
 
         // Given
         final Field<Binary64> field     = Binary64Field.getInstance();
         final double          leftEdge  = 5;
         final double          rightEdge = 10;
         final Binary64        x         = new Binary64(7);
 
         final SmoothStepFactory.FieldSmoothStepFunction<Binary64> cubic = SmoothStepFactory.getCubic(field);
 
         // When
         final Binary64 computedResult = cubic.value(leftEdge, rightEdge, x);
 
         // Then
         assertEquals(0.352, computedResult.getReal(), THRESHOLD);
 
     }
 
     @Test
     void testFieldQuinticFunction() {
 
         // Given
         final Field<Binary64> field       = Binary64Field.getInstance();
         final double          leftEdge    = 5;
         final double          rightEdge   = 10;
         final double          x           = 7;
         final double          xNormalized = (x - leftEdge) / (rightEdge - leftEdge);
         final Binary64        xField      = new Binary64(x);
 
         final SmoothStepFactory.FieldSmoothStepFunction<Binary64> quintic = SmoothStepFactory.getQuintic(field);
 
         // When
         final Binary64 computedResult  = quintic.value(leftEdge, rightEdge, xField);
         final Binary64 computedResult2 = quintic.value(xNormalized);
         final Binary64 computedResult3 = quintic.value(new Binary64(xNormalized));
 
         // Then
         assertEquals(0.31744, computedResult.getReal(), THRESHOLD);
         assertEquals(computedResult.getReal(), computedResult2.getReal(), THRESHOLD);
         assertEquals(computedResult2.getReal(), computedResult3.getReal(), THRESHOLD);
     }
 
 }