/*
    * 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.CollectionSize.ZERO;
  import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_REMOVE;
  import static com.google.common.truth.Truth.assertThat;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.collect.Multimap;
  import com.google.common.collect.testing.features.CollectionSize;
  import com.google.common.collect.testing.features.MapFeature;
  
  import java.util.Collection;
  import java.util.Map;
  import java.util.Map.Entry;
  
  /**
   * Tests for {@link Multimap#clear()}.
   *
   * @author Louis Wasserman
   */
  @GwtCompatible
  public class MultimapClearTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
    @CollectionSize.Require(absent = ZERO)
    @MapFeature.Require(absent = SUPPORTS_REMOVE)
    public void testClearUnsupported() {
      try {
        multimap().clear();
        fail("Expected UnsupportedOperationException");
      } catch (UnsupportedOperationException expected) {}
    }
  
    private void assertCleared() {
      assertEquals(0, multimap().size());
      assertTrue(multimap().isEmpty());
      assertEquals(multimap(), getSubjectGenerator().create());
      assertThat(multimap().entries()).isEmpty();
      assertThat(multimap().asMap()).isEmpty();
      assertThat(multimap().keySet()).isEmpty();
      assertThat(multimap().keys()).isEmpty();
      assertThat(multimap().values()).isEmpty();
      for (K key : sampleKeys()) {
        assertGet(key);
      }
    }
    
    @MapFeature.Require(SUPPORTS_REMOVE)
    public void testClear() {
      multimap().clear();
      assertCleared();
    }
    
    @MapFeature.Require(SUPPORTS_REMOVE)
    public void testClearThroughEntries() {
      multimap().entries().clear();
      assertCleared();
    }
    
    @MapFeature.Require(SUPPORTS_REMOVE)
    public void testClearThroughAsMap() {
      multimap().asMap().clear();
      assertCleared();
    }
    
    @MapFeature.Require(SUPPORTS_REMOVE)
    public void testClearThroughKeySet() {
      multimap().keySet().clear();
      assertCleared();
    }
    
    @MapFeature.Require(SUPPORTS_REMOVE)
    public void testClearThroughKeys() {
      multimap().keys().clear();
      assertCleared();
    }
    
    @MapFeature.Require(SUPPORTS_REMOVE)
    public void testClearThroughValues() {
      multimap().values().clear();
      assertCleared();
    }
    
    @MapFeature.Require(SUPPORTS_REMOVE)
    @CollectionSize.Require(absent = ZERO)
   public void testClearPropagatesToGet() {
     for (K key : sampleKeys()) {
       resetContainer();
       Collection<V> collection = multimap().get(key);
       multimap().clear();
       assertThat(collection).isEmpty();
     }
   }
 
   @MapFeature.Require(SUPPORTS_REMOVE)
   @CollectionSize.Require(absent = ZERO)
   public void testClearPropagatesToAsMapGet() {
     for (K key : sampleKeys()) {
       resetContainer();
       Collection<V> collection = multimap().asMap().get(key);
       if (collection != null) {
         multimap().clear();
         assertThat(collection).isEmpty();
       }
     }
   }
 
   @MapFeature.Require(SUPPORTS_REMOVE)
   public void testClearPropagatesToAsMap() {
     Map<K, Collection<V>> asMap = multimap().asMap();
     multimap().clear();
     assertThat(asMap).isEmpty();
   }
 
   @MapFeature.Require(SUPPORTS_REMOVE)
   public void testClearPropagatesToEntries() {
     Collection<Entry<K, V>> entries = multimap().entries();
     multimap().clear();
     assertThat(entries).isEmpty();
   }
 }