/*
    * Copyright (C) 2007 The Guava Authors
    *
    * Licensed 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 com.google.common.collect;
  
  import static com.google.common.truth.Truth.assertThat;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.collect.testing.DerivedComparable;
  
  import junit.framework.TestCase;
  
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  
  /**
   * Tests for {@link Multisets}.
   *
   * @author Mike Bostock
   * @author Jared Levy
   * @author Louis Wasserman
   */
  @GwtCompatible(emulated = true)
  public class MultisetsTest extends TestCase {
  
    /* See MultisetsImmutableEntryTest for immutableEntry() tests. */
  
    public void testNewTreeMultisetDerived() {
      TreeMultiset<DerivedComparable> set = TreeMultiset.create();
      assertTrue(set.isEmpty());
      set.add(new DerivedComparable("foo"), 2);
      set.add(new DerivedComparable("bar"), 3);
      assertThat(set).has().exactly(
          new DerivedComparable("bar"), new DerivedComparable("bar"), new DerivedComparable("bar"),
          new DerivedComparable("foo"), new DerivedComparable("foo")).inOrder();
    }
  
    public void testNewTreeMultisetNonGeneric() {
      TreeMultiset<LegacyComparable> set = TreeMultiset.create();
      assertTrue(set.isEmpty());
      set.add(new LegacyComparable("foo"), 2);
      set.add(new LegacyComparable("bar"), 3);
      assertThat(set).has().exactly(new LegacyComparable("bar"),
          new LegacyComparable("bar"), new LegacyComparable("bar"),
          new LegacyComparable("foo"), new LegacyComparable("foo")).inOrder();
    }
  
    public void testNewTreeMultisetComparator() {
      TreeMultiset<String> multiset
          = TreeMultiset.create(Collections.reverseOrder());
      multiset.add("bar", 3);
      multiset.add("foo", 2);
      assertThat(multiset).has().exactly("foo", "foo", "bar", "bar", "bar").inOrder();
    }
  
    public void testRetainOccurrencesEmpty() {
      Multiset<String> multiset = HashMultiset.create();
      Multiset<String> toRetain =
          HashMultiset.create(Arrays.asList("a", "b", "a"));
      assertFalse(Multisets.retainOccurrences(multiset, toRetain));
      assertThat(multiset).isEmpty();
    }
  
    public void testRemoveOccurrencesIterableEmpty() {
      Multiset<String> multiset = HashMultiset.create();
      Iterable<String> toRemove = Arrays.asList("a", "b", "a");
      assertFalse(Multisets.removeOccurrences(multiset, toRemove));
      assertTrue(multiset.isEmpty());
    }
  
    public void testRemoveOccurrencesMultisetEmpty() {
      Multiset<String> multiset = HashMultiset.create();
      Multiset<String> toRemove =
          HashMultiset.create(Arrays.asList("a", "b", "a"));
      assertFalse(Multisets.retainOccurrences(multiset, toRemove));
      assertTrue(multiset.isEmpty());
    }
  
    public void testUnion() {
      Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
      Multiset<String> ms2 = HashMultiset.create(
          Arrays.asList("a", "b", "b", "c"));
      assertThat(Multisets.union(ms1, ms2)).has().exactly("a", "a", "b", "b", "c");
    }
  
   public void testUnionEqualMultisets() {
     Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     assertEquals(ms1, Multisets.union(ms1, ms2));
   }
 
   public void testUnionEmptyNonempty() {
     Multiset<String> ms1 = HashMultiset.create();
     Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     assertEquals(ms2, Multisets.union(ms1, ms2));
   }
 
   public void testUnionNonemptyEmpty() {
     Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> ms2 = HashMultiset.create();
     assertEquals(ms1, Multisets.union(ms1, ms2));
   }
 
   public void testIntersectEmptyNonempty() {
     Multiset<String> ms1 = HashMultiset.create();
     Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     assertThat(Multisets.intersection(ms1, ms2)).isEmpty();
   }
 
   public void testIntersectNonemptyEmpty() {
     Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> ms2 = HashMultiset.create();
     assertThat(Multisets.intersection(ms1, ms2)).isEmpty();
   }
 
   public void testSum() {
     Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> ms2 = HashMultiset.create(Arrays.asList("b", "c"));
     assertThat(Multisets.sum(ms1, ms2)).has().exactly("a", "a", "b", "b", "c");
   }
 
   public void testSumEmptyNonempty() {
     Multiset<String> ms1 = HashMultiset.create();
     Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     assertThat(Multisets.sum(ms1, ms2)).has().exactly("a", "b", "a");
   }
 
   public void testSumNonemptyEmpty() {
     Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> ms2 = HashMultiset.create();
     assertThat(Multisets.sum(ms1, ms2)).has().exactly("a", "b", "a");
   }
 
   public void testDifferenceWithNoRemovedElements() {
     Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a"));
     assertThat(Multisets.difference(ms1, ms2)).has().exactly("a", "b");
   }
 
   public void testDifferenceWithRemovedElement() {
     Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> ms2 = HashMultiset.create(Arrays.asList("b"));
     assertThat(Multisets.difference(ms1, ms2)).has().exactly("a", "a");
   }
 
   public void testDifferenceWithMoreElementsInSecondMultiset() {
     Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a", "b", "b", "b"));
     Multiset<String> diff = Multisets.difference(ms1, ms2);
     assertThat(diff).has().item("a");
     assertEquals(0, diff.count("b"));
     assertEquals(1, diff.count("a"));
     assertFalse(diff.contains("b"));
     assertTrue(diff.contains("a"));
   }
 
   public void testDifferenceEmptyNonempty() {
     Multiset<String> ms1 = HashMultiset.create();
     Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     assertEquals(ms1, Multisets.difference(ms1, ms2));
   }
 
   public void testDifferenceNonemptyEmpty() {
     Multiset<String> ms1 = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> ms2 = HashMultiset.create();
     assertEquals(ms1, Multisets.difference(ms1, ms2));
   }
 
   public void testContainsOccurrencesEmpty() {
     Multiset<String> superMultiset = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> subMultiset = HashMultiset.create();
     assertTrue(Multisets.containsOccurrences(superMultiset, subMultiset));
     assertFalse(Multisets.containsOccurrences(subMultiset, superMultiset));
   }
 
   public void testContainsOccurrences() {
     Multiset<String> superMultiset = HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> subMultiset = HashMultiset.create(Arrays.asList("a", "b"));
     assertTrue(Multisets.containsOccurrences(superMultiset, subMultiset));
     assertFalse(Multisets.containsOccurrences(subMultiset, superMultiset));
     Multiset<String> diffMultiset = HashMultiset.create(Arrays.asList("a", "b", "c"));
     assertFalse(Multisets.containsOccurrences(superMultiset, diffMultiset));
     assertTrue(Multisets.containsOccurrences(diffMultiset, subMultiset));
   }
 
   public void testRetainEmptyOccurrences() {
     Multiset<String> multiset =
         HashMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> toRetain = HashMultiset.create();
     assertTrue(Multisets.retainOccurrences(multiset, toRetain));
     assertTrue(multiset.isEmpty());
   }
 
   public void testRetainOccurrences() {
     Multiset<String> multiset =
         TreeMultiset.create(Arrays.asList("a", "b", "a", "c"));
     Multiset<String> toRetain =
         HashMultiset.create(Arrays.asList("a", "b", "b"));
     assertTrue(Multisets.retainOccurrences(multiset, toRetain));
     assertThat(multiset).has().exactly("a", "b").inOrder();
   }
 
   public void testRemoveEmptyOccurrencesMultiset() {
     Multiset<String> multiset =
         TreeMultiset.create(Arrays.asList("a", "b", "a"));
     Multiset<String> toRemove = HashMultiset.create();
     assertFalse(Multisets.removeOccurrences(multiset, toRemove));
     assertThat(multiset).has().exactly("a", "a", "b").inOrder();
   }
 
   public void testRemoveOccurrencesMultiset() {
     Multiset<String> multiset =
         TreeMultiset.create(Arrays.asList("a", "b", "a", "c"));
     Multiset<String> toRemove =
         HashMultiset.create(Arrays.asList("a", "b", "b"));
     assertTrue(Multisets.removeOccurrences(multiset, toRemove));
     assertThat(multiset).has().exactly("a", "c").inOrder();
   }
 
   public void testRemoveEmptyOccurrencesIterable() {
     Multiset<String> multiset =
         TreeMultiset.create(Arrays.asList("a", "b", "a"));
     Iterable<String> toRemove = ImmutableList.of();
     assertFalse(Multisets.removeOccurrences(multiset, toRemove));
     assertThat(multiset).has().exactly("a", "a", "b").inOrder();
   }
 
   public void testRemoveOccurrencesMultisetIterable() {
     Multiset<String> multiset =
         TreeMultiset.create(Arrays.asList("a", "b", "a", "c"));
     List<String> toRemove = Arrays.asList("a", "b", "b");
     assertTrue(Multisets.removeOccurrences(multiset, toRemove));
     assertThat(multiset).has().exactly("a", "c").inOrder();
   }
 
   @SuppressWarnings("deprecation")
   public void testUnmodifiableMultisetShortCircuit() {
     Multiset<String> mod = HashMultiset.create();
     Multiset<String> unmod = Multisets.unmodifiableMultiset(mod);
     assertNotSame(mod, unmod);
     assertSame(unmod, Multisets.unmodifiableMultiset(unmod));
     ImmutableMultiset<String> immutable = ImmutableMultiset.of("a", "a", "b", "a");
     assertSame(immutable, Multisets.unmodifiableMultiset(immutable));
     assertSame(immutable, Multisets.unmodifiableMultiset((Multiset<String>) immutable));
   }
 
   public void testHighestCountFirst() {
     Multiset<String> multiset = HashMultiset.create(
         Arrays.asList("a", "a", "a", "b", "c", "c"));
     ImmutableMultiset<String> sortedMultiset =
         Multisets.copyHighestCountFirst(multiset);
 
     assertThat(sortedMultiset.entrySet()).has().exactly(
         Multisets.immutableEntry("a", 3), Multisets.immutableEntry("c", 2),
         Multisets.immutableEntry("b", 1)).inOrder();
 
     assertThat(sortedMultiset).has().exactly(
         "a",
         "a",
         "a",
         "c",
         "c",
         "b").inOrder();
 
     assertThat(Multisets.copyHighestCountFirst(ImmutableMultiset.of())).isEmpty();
   }
 }