/*
    * 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.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.util.Arrays;
  import java.util.function.LongPredicate;
  
  import org.junit.jupiter.api.Test;
  
  public abstract class AbstractBitMapProducerTest {
  
      /**
       * A testing consumer that always returns false.
       */
      static final LongPredicate FALSE_CONSUMER = arg0 -> false;
  
      /**
       * A testing consumer that always returns true.
       */
      static final LongPredicate TRUE_CONSUMER = arg0 -> true;
  
      /**
       * Creates an producer without data.
       * @return a producer that has no data.
       */
      protected abstract BitMapProducer createEmptyProducer();
  
      /**
       * Creates a producer with some data.
       * @return a producer with some data
       */
      protected abstract BitMapProducer createProducer();
  
      protected boolean emptyIsZeroLength() {
          return false;
      }
  
      @Test
      public final void testAsBitMapArray() {
          long[] array = createEmptyProducer().asBitMapArray();
          for (int i = 0; i < array.length; i++) {
              assertEquals(0, array[i], "Wrong value at " + i);
          }
  
          array = createProducer().asBitMapArray();
          assertFalse(array.length == 0);
      }
  
      @Test
      public final void testForEachBitMap() {
          assertFalse(createProducer().forEachBitMap(FALSE_CONSUMER), "non-empty should be false");
          if (emptyIsZeroLength()) {
              assertTrue(createEmptyProducer().forEachBitMap(FALSE_CONSUMER), "empty should be true");
          } else {
              assertFalse(createEmptyProducer().forEachBitMap(FALSE_CONSUMER), "empty should be false");
          }
  
          assertTrue(createProducer().forEachBitMap(TRUE_CONSUMER), "non-empty should be true");
          assertTrue(createEmptyProducer().forEachBitMap(TRUE_CONSUMER), "empty should be true");
      }
  
      @Test
      public void testForEachBitMapEarlyExit() {
          final int[] passes = new int[1];
          assertFalse(createProducer().forEachBitMap(l -> {
              passes[0]++;
              return false;
          }));
          assertEquals(1, passes[0]);
  
          passes[0] = 0;
          if (emptyIsZeroLength()) {
              assertTrue(createEmptyProducer().forEachBitMap(l -> {
                  passes[0]++;
                  return false;
              }));
              assertEquals(0, passes[0]);
          } else {
              assertFalse(createEmptyProducer().forEachBitMap(l -> {
                  passes[0]++;
                  return false;
             }));
             assertEquals(1, passes[0]);
         }
     }
 
     @Test
     public final void testForEachBitMapPair() {
         final LongBiPredicate func = (x, y) -> x == y;
         assertTrue(createEmptyProducer().forEachBitMapPair(createEmptyProducer(), func), "empty == empty failed");
         assertFalse(createEmptyProducer().forEachBitMapPair(createProducer(), func), "empty == not_empty failed");
         assertFalse(createProducer().forEachBitMapPair(createEmptyProducer(), func), "not_empty == empty passed");
         assertTrue(createProducer().forEachBitMapPair(createProducer(), func), "not_empty == not_empty failed");
 
         // test BitMapProducers of different length send 0 for missing values.
         final int[] count = new int[3];
         final LongBiPredicate lbp = (x, y) -> {
             if (x == 0) {
                 count[0]++;
             }
             if (y == 0) {
                 count[1]++;
             }
             count[2]++;
             return true;
         };
         createEmptyProducer().forEachBitMapPair(createProducer(), lbp);
         assertEquals(count[2], count[0]);
 
         Arrays.fill(count, 0);
         createProducer().forEachBitMapPair(createEmptyProducer(), lbp);
         assertEquals(count[2], count[1]);
 
         // test where the created producer does not process all records because the predicate function
         // returns false before the processing is completed.
         final int[] limit = new int[1];
         final LongBiPredicate shortFunc =  (x, y) -> {
             limit[0]++;
             return limit[0] < 2;
         };
         final BitMapProducer shortProducer = l -> true;
         assertFalse(createProducer().forEachBitMapPair(shortProducer, shortFunc));
     }
 
     @Test
     public void testForEachBitMapPairEarlyExit() {
 
         // test BitMapProducers of different length send 0 for missing values.
         final int[] count = new int[1];
         final LongBiPredicate lbp = (x, y) -> {
             count[0]++;
             return false;
         };
         createProducer().forEachBitMapPair(createEmptyProducer(), lbp);
         assertEquals(1, count[0]);
 
         Arrays.fill(count, 0);
         createEmptyProducer().forEachBitMapPair(createProducer(), lbp);
         assertEquals(1, count[0]);
     }
 }