/*
 * 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.configuration2.builder.combined;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.beanutils.DynaBean;
import org.apache.commons.beanutils.DynaClass;
import org.apache.commons.beanutils.DynaProperty;
import org.apache.commons.configuration2.beanutils.BeanHelper;

 An implementation of the DynaBean interfaces which wraps multiple other beans. 

An instance of this class is constructed with a collection of beans to be
wrapped. When reading or writing a property the wrapped bean which defines
this property is determined, and the operation is executed on this bean.


The wrapped beans should have disjunct properties. Otherwise, it is undefined
which bean property is read or written.

Since:
2.0/**
 * <p>
 * An implementation of the {@code DynaBean} interfaces which wraps multiple
 * other beans.
 * </p>
 * <p>
 * An instance of this class is constructed with a collection of beans to be
 * wrapped. When reading or writing a property the wrapped bean which defines
 * this property is determined, and the operation is executed on this bean.
 * </p>
 * <p>
 * The wrapped beans should have disjunct properties. Otherwise, it is undefined
 * which bean property is read or written.
 * </p>
 *
 * @since 2.0
 */
class MultiWrapDynaBean implements DynaBean
{
    
Stores the class of this DynaBean. /** Stores the class of this DynaBean. */
    private final DynaClass dynaClass;

    
A map which associates property names with their defining beans. /** A map which associates property names with their defining beans. */
    private final Map<String, DynaBean> propsToBeans;

    
Creates a new instance of MultiWrapDynaBean and initializes it with the given collections of beans to be wrapped. 
Params:
beans – the wrapped beans/**
     * Creates a new instance of {@code MultiWrapDynaBean} and initializes it
     * with the given collections of beans to be wrapped.
     *
     * @param beans the wrapped beans
     */
    public MultiWrapDynaBean(final Collection<?> beans)
    {
        propsToBeans = new HashMap<>();
        final Collection<DynaClass> beanClasses =
                new ArrayList<>(beans.size());

        for (final Object bean : beans)
        {
            final DynaBean dynaBean = createDynaBean(bean);
            final DynaClass beanClass = dynaBean.getDynaClass();
            for (final DynaProperty prop : beanClass.getDynaProperties())
            {
                // ensure an order of properties
                if (!propsToBeans.containsKey(prop.getName()))
                {
                    propsToBeans.put(prop.getName(), dynaBean);
                }
            }
            beanClasses.add(beanClass);
        }

        dynaClass = new MultiWrapDynaClass(beanClasses);
    }

    
{@inheritDoc} This operation is not supported by the WrapDynaBean objects used internally by this class. Therefore, just an exception is thrown. /**
     * {@inheritDoc} This operation is not supported by the {@code WrapDynaBean}
     * objects used internally by this class. Therefore, just an exception is
     * thrown.
     */
    @Override
    public boolean contains(final String name, final String key)
    {
        throw new UnsupportedOperationException(
                "contains() operation not supported!");
    }

    @Override
    public Object get(final String name)
    {
        return fetchBean(name).get(name);
    }

    @Override
    public Object get(final String name, final int index)
    {
        return fetchBean(name).get(name, index);
    }

    @Override
    public Object get(final String name, final String key)
    {
        return fetchBean(name).get(name, key);
    }

    
{@inheritDoc} This implementation returns an instance of MultiWrapDynaClass. /**
     * {@inheritDoc} This implementation returns an instance of
     * {@code MultiWrapDynaClass}.
     */
    @Override
    public DynaClass getDynaClass()
    {
        return dynaClass;
    }

    
{@inheritDoc} This operation is not supported by the WrapDynaBean objects used internally by this class. Therefore, just an exception is thrown. /**
     * {@inheritDoc} This operation is not supported by the {@code WrapDynaBean}
     * objects used internally by this class. Therefore, just an exception is
     * thrown.
     */
    @Override
    public void remove(final String name, final String key)
    {
        throw new UnsupportedOperationException(
                "remove() operation not supported!");
    }

    @Override
    public void set(final String name, final Object value)
    {
        fetchBean(name).set(name, value);
    }

    @Override
    public void set(final String name, final int index, final Object value)
    {
        fetchBean(name).set(name, index, value);
    }

    @Override
    public void set(final String name, final String key, final Object value)
    {
        fetchBean(name).set(name, key, value);
    }

    
Returns the bean instance to which the given property belongs. If no such
bean is found, an arbitrary bean is returned. (This causes the operation
on this bean to fail with a meaningful error message.)
Params:
property – the property name
Returns:
the bean defining this property/**
     * Returns the bean instance to which the given property belongs. If no such
     * bean is found, an arbitrary bean is returned. (This causes the operation
     * on this bean to fail with a meaningful error message.)
     *
     * @param property the property name
     * @return the bean defining this property
     */
    private DynaBean fetchBean(final String property)
    {
        DynaBean dynaBean = propsToBeans.get(property);
        if (dynaBean == null)
        {
            dynaBean = propsToBeans.values().iterator().next();
        }
        return dynaBean;
    }

    
Creates a DynaBean object for the given bean. 
Params:
bean – the bean
Returns:
the DynaBean for this bean/**
     * Creates a {@code DynaBean} object for the given bean.
     *
     * @param bean the bean
     * @return the {@code DynaBean} for this bean
     */
    private static DynaBean createDynaBean(final Object bean)
    {
        if (bean instanceof DynaBean)
        {
            return (DynaBean) bean;
        }
        return BeanHelper.createWrapDynaBean(bean);
    }
}