/*
    * 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.collections4.bloomfilter;
  
  import static org.junit.jupiter.api.Assertions.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.util.ArrayList;
  import java.util.BitSet;
  import java.util.List;
  import java.util.SplittableRandom;
  import java.util.concurrent.ThreadLocalRandom;
  import java.util.function.IntPredicate;
  
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.params.ParameterizedTest;
  import org.junit.jupiter.params.provider.CsvSource;
  
  /**
   * Tests the Filter class.
   */
  public class IndexFilterTest {
  
      @ParameterizedTest
      @CsvSource({
          "1, 64",
          "2, 64",
          "3, 64",
          "7, 357",
          "7, 17",
      })
      void testFilter(final int k, final int m) {
          final Shape shape = Shape.fromKM(k, m);
          final BitSet used = new BitSet(m);
          for (int n = 0; n < 10; n++) {
              used.clear();
              final List<Integer> consumer = new ArrayList<>();
              final IntPredicate filter = IndexFilter.create(shape, consumer::add);
  
              // Make random indices; these may be duplicates
              final long seed = ThreadLocalRandom.current().nextLong();
              final SplittableRandom rng = new SplittableRandom(seed);
              for (int i = Math.min(k, m / 2); i-- > 0;) {
                  final int bit = rng.nextInt(m);
                  // duplicates should not alter the list size
                  final int newSize = consumer.size() + (used.get(bit) ? 0 : 1);
                  assertTrue(filter.test(bit));
                  assertEquals(newSize, consumer.size(), () -> String.format("Bad filter. Seed=%d, bit=%d", seed, bit));
                  used.set(bit);
              }
  
              // The list should have unique entries
              assertArrayEquals(used.stream().toArray(), consumer.stream().mapToInt(i -> (int) i).sorted().toArray());
              final int size = consumer.size();
  
              // Second observations do not change the list size
              used.stream().forEach(bit -> {
                  assertTrue(filter.test(bit));
                  assertEquals(size, consumer.size(), () -> String.format("Bad filter. Seed=%d, bit=%d", seed, bit));
              });
  
              assertThrows(IndexOutOfBoundsException.class, () -> filter.test(m));
              assertThrows(IndexOutOfBoundsException.class, () -> filter.test(-1));
          }
      }
  
      @Test
      public void testFiltering() {
          final Shape shape = Shape.fromKM(3, 12);
          final List<Integer> consumer = new ArrayList<>();
          final IntPredicate filter = IndexFilter.create(shape, consumer::add);
  
          for (int i = 0; i < 12; i++) {
              assertTrue(filter.test(i));
          }
          assertEquals(12, consumer.size());
  
          for (int i = 0; i < 12; i++) {
              assertTrue(filter.test(i));
          }
          assertEquals(12, consumer.size());
      }
  }