/*
    * Copyright (C) 2013 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.testing.google;
  
  import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
  import static com.google.common.collect.testing.features.CollectionSize.ZERO;
  import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
  import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEY_QUERIES;
  import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_REMOVE;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.collect.Multimap;
  import com.google.common.collect.testing.features.CollectionFeature;
  import com.google.common.collect.testing.features.CollectionSize;
  import com.google.common.collect.testing.features.MapFeature;
  
  import java.util.Iterator;
  import java.util.Map;
  
  /**
   * Tester for {@code Multimap.keySet}.
   *
   * @author Louis Wasserman
   */
  @GwtCompatible
  public class MultimapKeySetTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
    public void testKeySet() {
      for (Map.Entry<K, V> entry : getSampleElements()) {
        assertTrue(multimap().keySet().contains(entry.getKey()));
      }
    }
    
    @CollectionSize.Require(absent = ZERO)
    @MapFeature.Require(ALLOWS_NULL_KEYS)
    public void testKeySetContainsNullKeyPresent() {
      initMultimapWithNullKey();
      assertTrue(multimap().keySet().contains(null));
    }
    
    @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
    public void testKeySetContainsNullKeyAbsent() {
      assertFalse(multimap().keySet().contains(null));
    }
    
    @MapFeature.Require(SUPPORTS_REMOVE)
    public void testKeySetRemovePropagatesToMultimap() {
      int key0Count = multimap().get(sampleKeys().e0).size();
      assertEquals(key0Count > 0, multimap().keySet().remove(sampleKeys().e0));
      assertEquals(getNumElements() - key0Count, multimap().size());
      assertGet(sampleKeys().e0);
    }
    
    @CollectionSize.Require(absent = ZERO)
    @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
    public void testKeySetIteratorRemove() {
      int key0Count = multimap().get(sampleKeys().e0).size();
      Iterator<K> keyItr = multimap().keySet().iterator();
      while (keyItr.hasNext()) {
        if (keyItr.next().equals(sampleKeys().e0)) {
          keyItr.remove();
        }
      }
      assertEquals(getNumElements() - key0Count, multimap().size());
      assertGet(sampleKeys().e0);
    }
  }