/*
 * 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.bag;

import java.util.Set;

import org.apache.commons.collections4.Bag;
import org.apache.commons.collections4.Transformer;
import org.apache.commons.collections4.collection.TransformedCollection;
import org.apache.commons.collections4.set.TransformedSet;

Decorates another Bag 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 elements in this bag
Since:
3.0/**
 * Decorates another {@link Bag} 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>
 * This class is Serializable from Commons Collections 3.1.
 *
 * @param <E> the type of elements in this bag
 * @since 3.0
 */
public class TransformedBag<E> extends TransformedCollection<E> implements Bag<E> {

    
Serialization version /** Serialization version */
    private static final long serialVersionUID = 5421170911299074185L;

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

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

    
Gets the decorated bag.
Returns:
the decorated bag/**
     * Gets the decorated bag.
     *
     * @return the decorated bag
     */
    protected Bag<E> getBag() {
        return (Bag<E>) decorated();
    }

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

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

    //-----------------------------------------------------------------------

    @Override
    public int getCount(final Object object) {
        return getBag().getCount(object);
    }

    @Override
    public boolean remove(final Object object, final int nCopies) {
        return getBag().remove(object, nCopies);
    }

    //-----------------------------------------------------------------------

    @Override
    public boolean add(final E object, final int nCopies) {
        return getBag().add(transform(object), nCopies);
    }

    @Override
    public Set<E> uniqueSet() {
        final Set<E> set = getBag().uniqueSet();
        return TransformedSet.<E>transformingSet(set, transformer);
    }

}