/*
    * 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.rng.core.source32;
  
  import org.apache.commons.rng.core.RandomAssert;
  import org.junit.jupiter.api.Test;
  
  class XoRoShiRo64StarStarTest {
      /** The size of the array seed. */
      private static final int SEED_SIZE = 2;
  
      @Test
      void testReferenceCode() {
          /*
           * Data from running the executable compiled from the author's C code:
           *   http://xoshiro.di.unimi.it/xoroshiro64starstar.c
           */
          final int[] seed = {
              0x012de1ba, 0xa5a818b8,
          };
  
          final int[] expectedSequence = {
              0x7ac00b42, 0x1f638399, 0x09e4aea4, 0x05cbbd64,
              0x1c967b7b, 0x1cf852fd, 0xc666f4e8, 0xeea9f1ae,
              0xca0fa6bc, 0xa65d0905, 0xa69afc95, 0x34965e62,
              0xdd4f04a9, 0xff1c9342, 0x638ff769, 0x03419ca0,
              0xb46e6dfd, 0xf7555b22, 0x8cab4e68, 0x5a44b6ee,
              0x4e5e1eed, 0xd03c5963, 0x782d05ed, 0x41bda3e3,
              0xd1d65005, 0x88f43a8a, 0xfffe02ea, 0xb326624a,
              0x1ec0034c, 0xb903d8df, 0x78454bd7, 0xaec630f8,
              0x2a0c9a3a, 0xc2594988, 0xe71e767e, 0x4e0e1ddc,
              0xae945004, 0xf178c293, 0xa04081d6, 0xdd9c062f,
          };
  
          RandomAssert.assertEquals(expectedSequence, new XoRoShiRo64StarStar(seed));
      }
  
      @Test
      void testConstructorWithZeroSeedIsNonFunctional() {
          RandomAssert.assertNextIntZeroOutput(new XoRoShiRo64StarStar(new int[SEED_SIZE]), 2 * SEED_SIZE);
      }
  
      @Test
      void testConstructorWithSingleBitSeedIsFunctional() {
          RandomAssert.assertIntArrayConstructorWithSingleBitSeedIsFunctional(XoRoShiRo64StarStar.class, SEED_SIZE);
      }
  
      @Test
      void testConstructorWithoutFullLengthSeed() {
          // Hit the case when the input seed is self-seeded when not full length
          RandomAssert.assertNextLongNonZeroOutput(new XoRoShiRo64StarStar(new int[] {0x012de1ba}),
                  SEED_SIZE, SEED_SIZE);
      }
  
      @Test
      void testElementConstructor() {
          final int[] seed = {
              0x012de1ba, 0xa5a818b8,
          };
          final XoRoShiRo64StarStar rng1 = new XoRoShiRo64StarStar(seed);
          final XoRoShiRo64StarStar rng2 = new XoRoShiRo64StarStar(seed[0], seed[1]);
          RandomAssert.assertNextIntEquals(seed.length * 2, rng1, rng2);
      }
  }