/*
    * Copyright (C) 2008 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;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.collect.testing.features.CollectionSize;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.List;
  
  /**
   * Generator for collection of a particular size.
   *
   * @author George van den Driessche
   */
  @GwtCompatible
  public final class OneSizeGenerator<T, E>
      implements OneSizeTestContainerGenerator<T, E> {
    private final TestContainerGenerator<T, E> generator;
    private final CollectionSize collectionSize;
  
    public OneSizeGenerator(TestContainerGenerator<T, E> generator,
        CollectionSize collectionSize) {
      this.generator = generator;
      this.collectionSize = collectionSize;
    }
  
    @Override
    public TestContainerGenerator<T, E> getInnerGenerator() {
      return generator;
    }
  
    @Override
    public SampleElements<E> samples() {
      return generator.samples();
    }
  
    @Override
    public T create(Object... elements) {
      return generator.create(elements);
    }
  
    @Override
    public E[] createArray(int length) {
      return generator.createArray(length);
    }
  
    @Override
    public T createTestSubject() {
      Collection<E> elements = getSampleElements(
          getCollectionSize().getNumElements());
      return generator.create(elements.toArray());
    }
  
    @Override
    public Collection<E> getSampleElements(int howMany) {
      SampleElements<E> samples = samples();
      @SuppressWarnings("unchecked")
      List<E> allSampleElements = Arrays.asList(
          samples.e0, samples.e1, samples.e2, samples.e3, samples.e4);
      return new ArrayList<E>(allSampleElements.subList(0, howMany));
    }
  
    @Override
    public CollectionSize getCollectionSize() {
      return collectionSize;
    }
  
    @Override
    public Iterable<E> order(List<E> insertionOrder) {
      return generator.order(insertionOrder);
    }
  }