/*
    * 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.stat.inference;
  
  import org.hipparchus.exception.MathIllegalArgumentException;
  import org.hipparchus.exception.NullArgumentException;
  import org.junit.jupiter.api.Test;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.fail;
  
  /**
   * Test cases for the WilcoxonSignedRangTest class.
   */
  
  class WilcoxonSignedRankTestTest {
  
      protected WilcoxonSignedRankTest testStatistic = new WilcoxonSignedRankTest();
  
      @Test
      void testWilcoxonSignedRankSimple() {
          /*
           * Hollandar and Wolfe data from R docs.
           * Target values computed using R version 3.4.4.
           * x <- c(1.83, 0.50, 1.62, 2.48, 1.68, 1.88, 1.55, 3.06, 1.30)
           * y <- c(0.878, 0.647, 0.598, 2.05, 1.06, 1.29, 1.06, 3.14, 1.29)
           */
          final double[] x = {
              1.83, 0.50, 1.62, 2.48, 1.68, 1.88, 1.55, 3.06, 1.30
          };
          final double[] y = {
              0.878, 0.647, 0.598, 2.05, 1.06, 1.29, 1.06, 3.14, 1.29
          };
  
          /*
           * EXACT:
           * wilcox.test(x, y, alternative = "two.sided", mu = 0, paired = TRUE
           * exact = TRUE, correct = FALSE)
           * V = 40, p-value = 0.03906
           * Expected values are from R, version 3.4.4.
           */
          assertEquals(40, testStatistic.wilcoxonSignedRank(x, y), 1e-10);
          assertEquals(0.03906,
                              testStatistic.wilcoxonSignedRankTest(x, y, true),
                              1e-5);
  
          /*
           * ASYMPTOTIC:
           * wilcox.test(x, y, alternative = "two.sided", mu = 0,
           * paired = TRUE, exact = FALSE, correct = TRUE)
           * V = 40, p-value = 0.044010984013
           */
          assertEquals(40, testStatistic.wilcoxonSignedRank(x, y), 1e-10);
          assertEquals(0.044010984013,
                              testStatistic.wilcoxonSignedRankTest(x, y, false),
                              1e-10);
      }
  
      @Test
      void testWilcoxonSignedRankSimple2() {
          /*
           * x <- c(0.80, 0.83, 1.89, 1.04, 1.45, 1.38, 1.91)
           * y <- c(1.15, 0.88, 0.90, 0.74, 1.21, 2.0, 1.72)
           * Expected values are from R, version 3.4.4.
           */
          final double[] x = {0.80, 0.83, 1.89, 1.04, 1.45, 1.38, 1.91};
          final double[] y = {1.15, 0.88, 0.90, 0.74, 1.21, 2.0, 1.72};
          assertEquals(16,  testStatistic.wilcoxonSignedRank(x, y), 0);
          // Exact
          assertEquals(0.8125,
                              testStatistic.wilcoxonSignedRankTest(x, y, true),
                              1e-10);
          // Asymptotic
          assertEquals(0.79984610566,
                              testStatistic.wilcoxonSignedRankTest(x, y, false),
                              1e-10);
      }
  
  
     @Test
     void testWilcoxonSignedRankTiesDiscarded() {
         /*
          * Verify that tied pairs are discarded.
          */
         final double[] x = {
             1.83, 0.50, 1.62, 2.48, 1.68, 1.88, 1.55, 3.06, 1.30
         };
         final double[] y = {
             1.83, 0.647, 0.598, 2.05, 1.06, 1.29, 1.06, 3.14, 1.29
         };
         final double[] xp = {
             0.50, 1.62, 2.48, 1.68, 1.88, 1.55, 3.06, 1.30
         };
         final double[] yp = {
             0.647, 0.598, 2.05, 1.06, 1.29, 1.06, 3.14, 1.29
         };
         assertEquals(testStatistic.wilcoxonSignedRank(xp, yp),
                             testStatistic.wilcoxonSignedRank(x, y),
                             0);
         assertEquals(testStatistic.wilcoxonSignedRankTest(xp, yp, true),
                             testStatistic.wilcoxonSignedRankTest(x, y, true),
                             0);
         assertEquals(testStatistic.wilcoxonSignedRankTest(xp, yp, false),
                             testStatistic.wilcoxonSignedRankTest(x, y, false),
                             0);
     }
 
     @Test
     void testWilcoxonSignedRankInputValidation() {
         /*
          * Exact only for sample size <= 30
          */
         final double[] x1 = new double[30];
         final double[] x2 = new double[31];
         final double[] y1 = new double[30];
         final double[] y2 = new double[31];
         for (int i = 0; i < 30; ++i) {
             x1[i] = x2[i] = y1[i] = y2[i] = i;
         }
 
         // Exactly 30 is okay
         // testStatistic.wilcoxonSignedRankTest(x1, y1, true);
 
         try {
             testStatistic.wilcoxonSignedRankTest(x2, y2, true);
             fail("More than 30 samples and exact chosen, MathIllegalArgumentException expected");
         } catch (MathIllegalArgumentException ex) {
             // expected
         }
 
         /*
          * Samples must be present, i.e. length > 0
          */
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] {}, new double[] {
                 1.0
             }, true);
             fail("x does not contain samples (exact), MathIllegalArgumentException expected");
         } catch (MathIllegalArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] {}, new double[] {
                 1.0
             }, false);
             fail("x does not contain samples (asymptotic), MathIllegalArgumentException expected");
         } catch (MathIllegalArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] {
                 1.0
             }, new double[] {}, true);
             fail("y does not contain samples (exact), MathIllegalArgumentException expected");
         } catch (MathIllegalArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] {
                 1.0
             }, new double[] {}, false);
             fail("y does not contain samples (asymptotic), MathIllegalArgumentException expected");
         } catch (MathIllegalArgumentException ex) {
             // expected
         }
 
         /*
          * Samples not same size, i.e. cannot be paired
          */
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] {
                 1.0, 2.0
             }, new double[] {
                 3.0
             }, true);
             fail("x and y not same size (exact), MathIllegalArgumentException expected");
         } catch (MathIllegalArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] {
                 1.0, 2.0
             }, new double[] {
                 3.0
             }, false);
             fail("x and y not same size (asymptotic), MathIllegalArgumentException expected");
         } catch (MathIllegalArgumentException ex) {
             // expected
         }
 
         /*
          * x and y is null
          */
         try {
             testStatistic.wilcoxonSignedRankTest(null, null, true);
             fail("x and y is null (exact), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(null, null, false);
             fail("x and y is null (asymptotic), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
 
         /*
          * x or y is null
          */
         try {
             testStatistic.wilcoxonSignedRankTest(null, new double[] {
                 1.0
             }, true);
             fail("x is null (exact), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(null, new double[] {
                 1.0
             }, false);
             fail("x is null (asymptotic), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] {
                 1.0
             }, null, true);
             fail("y is null (exact), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] {
                 1.0
             }, null, false);
             fail("y is null (asymptotic), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
     }
 
     @Test
     void testBadInputAllTies() {
         assertThrows(MathIllegalArgumentException.class, () -> {
             testStatistic.wilcoxonSignedRankTest(new double[]{
                 1.0, 2.0, 3.0
             }, new double[]{
                 1.0, 2.0, 3.0
             }, true);
         });
     }
 
     @Test
     void testDegenerateOnePair() {
         final double[] x = {1};
         final double[] y = {2};
         assertEquals(1.0, testStatistic.wilcoxonSignedRank(x,y), 0);
         assertEquals(1.0, testStatistic.wilcoxonSignedRankTest(x,y, true), 0);
     }
 
 }