/**

  * Copyright 2005-2013 Dozer Project

  *

  * 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 org.dozer.util;

 import java.lang.reflect.Array;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Set;

 import java.util.SortedSet;

 import java.util.TreeSet;

 /**

  * Internal class that contains various Collection utilities specific to Dozer requirements. Not intended for direct use

  * by application code.

  * 

  * @author tierney.matt

  * @author garsombke.franz

  */

 public final class CollectionUtils {

   private CollectionUtils() {}

   public static boolean isArray(Class<?> aClass) {

     return aClass.isArray();

   }

   public static boolean isCollection(Class<?> aClass) {

     return Collection.class.isAssignableFrom(aClass);

   }

   public static boolean isList(Class<?> aClass) {

     return List.class.isAssignableFrom(aClass);

   }

   public static boolean isSet(Class<?> aClass) {

     return Set.class.isAssignableFrom(aClass);

   }

   public static boolean isPrimitiveArray(Class<?> aClass) {

     return aClass.isArray() && aClass.getComponentType().isPrimitive();

   }

   public static int getLengthOfCollection(Object value) {

     if (isArray(value.getClass())) {

       return Array.getLength(value);

     } else {

       return ((Collection<?>) value).size();

     }

   }

   public static Object getValueFromCollection(Object collection, int index) {

     if (isArray(collection.getClass())) {

       return Array.get(collection, index);

     } else {

       return ((Collection<?>) collection).toArray()[index];

     }

   }

   public static <T extends Set<?>> Set<?> createNewSet(Class<T> destType) {

     Set<Object> result;

     if (SortedSet.class.isAssignableFrom(destType)) {

       result = new TreeSet<Object>();

     } else {

       result = new HashSet<Object>();

     }

     return result;

   }

   public static <T extends Set<?>> Set<?> createNewSet(Class<T> destSetType, Collection<?> srcValue) {

     Set<Object> result = (Set<Object>) createNewSet(destSetType);

     if (srcValue != null) {

       result.addAll(srcValue);

     }

     return result;

   }

  public static <T> Object convertListToArray(List<T> list, Class<T> destEntryType) {

     Object outArray = Array.newInstance(destEntryType, list.size());

     int count = 0;

     int size = list.size();

     for (int i = 0; i < size; i++) {

       Object element = list.get(i);

       Array.set(outArray, count, element);

       count++;

     }

     if(destEntryType.isPrimitive())

       return outArray;

     else

     return (T[]) outArray;

   }

   public static List<Object> convertPrimitiveArrayToList(Object primitiveArray) {

     int length = Array.getLength(primitiveArray);

     List<Object> result = new ArrayList<Object>(length);

     // wrap and copy elements

     for (int i = 0; i < length; i++) {

       result.add(Array.get(primitiveArray, i));

     }

     return result;

   }

   public static <E> Set<E> intersection(final Set<E> set1, final Set<?> set2) {

     Set<E> intersection = new HashSet<E>(set1);

     intersection.retainAll(set2);

     return intersection;

   }

 }