/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.commons.collections4.set;

import java.util.Set;

import org.apache.commons.collections4.Transformer;
import org.apache.commons.collections4.collection.TransformedCollection;

Decorates another Set to transform objects that are added.

The add methods are affected by this class.
Thus objects must be removed or searched for using their transformed form.
For example, if the transformation converts Strings to Integers, you must
use the Integer form to remove objects.


This class is Serializable from Commons Collections 3.1.

Type parameters:
<E> – the type of the elements in this set
Since:
3.0/**
 * Decorates another <code>Set</code> to transform objects that are added.
 * <p>
 * The add methods are affected by this class.
 * Thus objects must be removed or searched for using their transformed form.
 * For example, if the transformation converts Strings to Integers, you must
 * use the Integer form to remove objects.
 * </p>
 * <p>
 * This class is Serializable from Commons Collections 3.1.
 * </p>
 *
 * @param <E> the type of the elements in this set
 * @since 3.0
 */
public class TransformedSet<E> extends TransformedCollection<E> implements Set<E> {

    
Serialization version /** Serialization version */
    private static final long serialVersionUID = 306127383500410386L;

    
Factory method to create a transforming set.
 If there are any elements already in the set being decorated, they are NOT transformed. Contrast this with transformedSet(Set<Object>, Transformer<? super Object,? extends Object>). 
Params:
set –  the set to decorate, must not be null
transformer –  the transformer to use for conversion, must not be null
Type parameters:
<E> – the element type
Throws:
NullPointerException – if set or transformer is null
Returns:
a new transformed set
Since:
4.0/**
     * Factory method to create a transforming set.
     * <p>
     * If there are any elements already in the set being decorated, they
     * are NOT transformed.
     * Contrast this with {@link #transformedSet(Set, Transformer)}.
     *
     * @param <E> the element type
     * @param set  the set to decorate, must not be null
     * @param transformer  the transformer to use for conversion, must not be null
     * @return a new transformed set
     * @throws NullPointerException if set or transformer is null
     * @since 4.0
     */
    public static <E> TransformedSet<E> transformingSet(final Set<E> set,
            final Transformer<? super E, ? extends E> transformer) {
        return new TransformedSet<>(set, transformer);
    }

    
Factory method to create a transforming set that will transform
existing contents of the specified set.
 If there are any elements already in the set being decorated, they will be transformed by this method. Contrast this with transformingSet(Set<Object>, Transformer<? super Object,? extends Object>). 
Params:
set –  the set to decorate, must not be null
transformer –  the transformer to use for conversion, must not be null
Type parameters:
<E> – the element type
Throws:
NullPointerException – if set or transformer is null
Returns:
a new transformed set
Since:
4.0/**
     * Factory method to create a transforming set that will transform
     * existing contents of the specified set.
     * <p>
     * If there are any elements already in the set being decorated, they
     * will be transformed by this method.
     * Contrast this with {@link #transformingSet(Set, Transformer)}.
     *
     * @param <E> the element type
     * @param set  the set to decorate, must not be null
     * @param transformer  the transformer to use for conversion, must not be null
     * @return a new transformed set
     * @throws NullPointerException if set or transformer is null
     * @since 4.0
     */
    public static <E> Set<E> transformedSet(final Set<E> set, final Transformer<? super E, ? extends E> transformer) {
        final TransformedSet<E> decorated = new TransformedSet<>(set, transformer);
        if (set.size() > 0) {
            @SuppressWarnings("unchecked") // set is type E
            final E[] values = (E[]) set.toArray(); // NOPMD - false positive for generics
            set.clear();
            for (final E value : values) {
                decorated.decorated().add(transformer.transform(value));
            }
        }
        return decorated;
    }

    //-----------------------------------------------------------------------
    
Constructor that wraps (not copies).

If there are any elements already in the set being decorated, they
are NOT transformed.
Params:
set –  the set to decorate, must not be null
transformer –  the transformer to use for conversion, must not be null
Throws:
NullPointerException – if set or transformer is null/**
     * Constructor that wraps (not copies).
     * <p>
     * If there are any elements already in the set being decorated, they
     * are NOT transformed.
     *
     * @param set  the set to decorate, must not be null
     * @param transformer  the transformer to use for conversion, must not be null
     * @throws NullPointerException if set or transformer is null
     */
    protected TransformedSet(final Set<E> set, final Transformer<? super E, ? extends E> transformer) {
        super(set, transformer);
    }

    @Override
    public boolean equals(final Object object) {
        return object == this || decorated().equals(object);
    }

    @Override
    public int hashCode() {
        return decorated().hashCode();
    }

}