/*
    * 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.testing;
  
  import com.google.common.annotations.GwtCompatible;
  
  import java.util.AbstractCollection;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Iterator;
  
  /**
   * A simplistic collection which implements only the bare minimum allowed by the
   * spec, and throws exceptions whenever it can.
   *
   * @author Kevin Bourrillion
   */
  @GwtCompatible
  public class MinimalCollection<E> extends AbstractCollection<E> {
    // TODO: expose allow nulls parameter?
  
    public static <E> MinimalCollection<E> of(E... contents) {
      return new MinimalCollection<E>(Object.class, true, contents);
    }
  
    // TODO: use this
    public static <E> MinimalCollection<E> ofClassAndContents(
        Class<? super E> type, E... contents) {
      return new MinimalCollection<E>(type, true, contents);
    }
  
    private final E[] contents;
    private final Class<? super E> type;
    private final boolean allowNulls;
  
    // Package-private so that it can be extended.
    MinimalCollection(Class<? super E> type, boolean allowNulls, E... contents) {
      // TODO: consider making it shuffle the contents to test iteration order.
      this.contents = Platform.clone(contents);
      this.type = type;
      this.allowNulls = allowNulls;
  
      if (!allowNulls) {
        for (Object element : contents) {
          if (element == null) {
            throw new NullPointerException();
          }
        }
      }
    }
  
    @Override public int size() {
      return contents.length;
    }
  
    @Override public boolean contains(Object object) {
      if (!allowNulls) {
        // behave badly
        if (object == null) {
          throw new NullPointerException();
        }
      }
      Platform.checkCast(type, object);  // behave badly
      return Arrays.asList(contents).contains(object);
    }
  
    @Override public boolean containsAll(Collection<?> collection) {
      if (!allowNulls) {
        for (Object object : collection) {
          // behave badly
          if (object == null) {
            throw new NullPointerException();
          }
        }
      }
      return super.containsAll(collection);
    }
  
    @Override public Iterator<E> iterator() {
      return Arrays.asList(contents).iterator();
    }
  
    @Override public Object[] toArray() {
      Object[] result = new Object[contents.length];
      System.arraycopy(contents, 0, result, 0, contents.length);
     return result;
   }
 
   /*
    * a "type A" unmodifiable collection freaks out proactively, even if there
    * wasn't going to be any actual work to do anyway
    */
 
   @Override public boolean addAll(Collection<? extends E> elementsToAdd) {
     throw up();
   }
   @Override public boolean removeAll(Collection<?> elementsToRemove) {
     throw up();
   }
   @Override public boolean retainAll(Collection<?> elementsToRetain) {
     throw up();
   }
   @Override public void clear() {
     throw up();
   }
   private static UnsupportedOperationException up() {
     throw new UnsupportedOperationException();
   }
 }