/*
    * 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.SEVERAL;
  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_PUT;
  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.Iterables;
  import com.google.common.collect.Multimap;
  import com.google.common.collect.testing.Helpers;
  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.ArrayList;
  import java.util.Collection;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map.Entry;
  import java.util.Set;
  
  /**
   * Tests for {@link Multimap#asMap}.
   *
   * @author Louis Wasserman
   */
  @GwtCompatible
  public class MultimapAsMapTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
    public void testAsMapGet() {
      for (K key : sampleKeys()) {
        List<V> expectedValues = new ArrayList<V>();
        for (Entry<K, V> entry : getSampleElements()) {
          if (entry.getKey().equals(key)) {
            expectedValues.add(entry.getValue());
          }
        }
  
        Collection<V> collection = multimap().asMap().get(key);
        if (expectedValues.isEmpty()) {
          assertThat(collection).isNull();
        } else {
          assertThat(collection).has().exactlyAs(expectedValues);
        }
      }
    }
   
    @CollectionSize.Require(absent = ZERO)
    @MapFeature.Require(ALLOWS_NULL_KEYS)
    public void testAsMapGetNullKeyPresent() {
      initMultimapWithNullKey();
      assertThat(multimap().asMap().get(null)).has().exactly(getValueForNullKey());
    }
   
    @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
    public void testAsMapGetNullKeyAbsent() {
      assertThat(multimap().asMap().get(null)).isNull();
    }
   
    @MapFeature.Require(absent = ALLOWS_NULL_KEY_QUERIES)
    public void testAsMapGetNullKeyUnsupported() {
      try {
        multimap().asMap().get(null);
        fail("Expected NullPointerException");
      } catch (NullPointerException expected) {}
    }
    
    @CollectionSize.Require(absent = ZERO)
    @MapFeature.Require(SUPPORTS_REMOVE)
    public void testAsMapRemove() {
      assertThat(multimap().asMap().remove(sampleKeys().e0)).iteratesAs(sampleValues().e0);
      assertGet(sampleKeys().e0);
      assertEquals(getNumElements() - 1, multimap().size());
    }
  
    @CollectionSize.Require(SEVERAL)
    @MapFeature.Require(SUPPORTS_PUT)
    public void testAsMapEntrySetReflectsPutSameKey() {
      resetContainer(
          Helpers.mapEntry(sampleKeys().e0, sampleValues().e0),
          Helpers.mapEntry(sampleKeys().e0, sampleValues().e3));
     
     Set<Entry<K, Collection<V>>> asMapEntrySet = multimap().asMap().entrySet();
     Collection<V> valueCollection = Iterables.getOnlyElement(asMapEntrySet).getValue();
     assertThat(valueCollection)
         .has().exactly(sampleValues().e0, sampleValues().e3);
     assertTrue(multimap().put(sampleKeys().e0, sampleValues().e4));
     assertThat(valueCollection)
         .has().exactly(sampleValues().e0, sampleValues().e3, sampleValues().e4);
   }
 
   @CollectionSize.Require(SEVERAL)
   @MapFeature.Require(SUPPORTS_PUT)
   public void testAsMapEntrySetReflectsPutDifferentKey() {
     resetContainer(
         Helpers.mapEntry(sampleKeys().e0, sampleValues().e0),
         Helpers.mapEntry(sampleKeys().e0, sampleValues().e3));
     
     Set<Entry<K, Collection<V>>> asMapEntrySet = multimap().asMap().entrySet();
     assertTrue(multimap().put(sampleKeys().e1, sampleValues().e4));
     assertEquals(2, asMapEntrySet.size());
   }
 
   @CollectionSize.Require(SEVERAL)
   @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})
   public void testAsMapEntrySetRemovePropagatesToMultimap() {
     resetContainer(
         Helpers.mapEntry(sampleKeys().e0, sampleValues().e0),
         Helpers.mapEntry(sampleKeys().e0, sampleValues().e3));
     Set<Entry<K, Collection<V>>> asMapEntrySet = multimap().asMap().entrySet();
     Entry<K, Collection<V>> asMapEntry0 = Iterables.getOnlyElement(asMapEntrySet);
     assertTrue(multimap().put(sampleKeys().e1, sampleValues().e4));
     assertTrue(asMapEntrySet.remove(asMapEntry0));
     assertEquals(1, multimap().size());
     assertThat(multimap().keySet()).iteratesAs(sampleKeys().e1);
   }
 
   @CollectionSize.Require(SEVERAL)
   @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
   public void testAsMapEntrySetIteratorRemovePropagatesToMultimap() {
     resetContainer(
         Helpers.mapEntry(sampleKeys().e0, sampleValues().e0),
         Helpers.mapEntry(sampleKeys().e0, sampleValues().e3));
     Set<Entry<K, Collection<V>>> asMapEntrySet = multimap().asMap().entrySet();
     Iterator<Entry<K, Collection<V>>> asMapEntryItr = asMapEntrySet.iterator();
     asMapEntryItr.next();
     asMapEntryItr.remove();
     assertTrue(multimap().isEmpty());
   }
 }