/*
 * Copyright (c) 1998, 2021 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Denise Smith - Initial implementation June 12, 2009
package org.eclipse.persistence.internal.jaxb.many;

import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import org.eclipse.persistence.core.mappings.CoreAttributeAccessor;
import org.eclipse.persistence.exceptions.DescriptorException;
import org.eclipse.persistence.exceptions.XMLMarshalException;
import org.eclipse.persistence.internal.core.queries.CoreContainerPolicy;
import org.eclipse.persistence.internal.security.PrivilegedAccessHelper;
import org.eclipse.persistence.mappings.AttributeAccessor;

/**
* AttributeAccessor used in conjunction with an XMLCompositeDirectCollectionMapping
* or XMLCompositeCollectionMapping to enable support for mapping to Maps in JAXB
*/
public class MapValueAttributeAccessor extends AttributeAccessor {

    private CoreAttributeAccessor nestedAccessor;
    private String mapClassName;
    private Class mapClass;
    private CoreContainerPolicy containerPolicy;
    private Class generatedEntryClass;
    private ClassLoader classLoader;

    public MapValueAttributeAccessor(CoreAttributeAccessor nestedAccessor, CoreContainerPolicy cp, Class generatedEntryClass, String mapClassName, ClassLoader classLoader) {
        this.nestedAccessor = nestedAccessor;
        this.mapClassName = mapClassName;
        this.containerPolicy = cp;
        this.generatedEntryClass = generatedEntryClass;
        this.classLoader = classLoader;
    }

    @Override
    public Object getAttributeValueFromObject(Object object)throws DescriptorException {
        Object value = nestedAccessor.getAttributeValueFromObject(object);
        if(null == value) {
            return null;
        }

        Object results = containerPolicy.containerInstance(((Map)value).size());
        Set<Entry> entrySet = ((Map)value).entrySet();
        if(null == entrySet) {
            return results;
        }
        for(Entry entry : entrySet) {
            MapEntry nextEntry;
            try {
                nextEntry = (MapEntry)generatedEntryClass.getConstructor().newInstance();
            } catch (Exception e) {
                return null;
            }
            nextEntry.setKey(entry.getKey());
            nextEntry.setValue(entry.getValue());
            containerPolicy.addInto(nextEntry, results, null);
        }
        return results;
    }

    @Override
    public void setAttributeValueInObject(Object object, Object value) throws DescriptorException {

        Map mapValue = null;;
        try{
            mapValue = (Map)mapClass.getConstructor().newInstance();
        } catch (ReflectiveOperationException e) {
            throw XMLMarshalException.unmarshalException(e);
        }
        if(value != null) {
            Object iterator = containerPolicy.iteratorFor(value);
            while(containerPolicy.hasNext(iterator)){
                Object next = containerPolicy.next(iterator, null);
                Object nextKey = ((MapEntry)next).getKey();
                Object nextValue = ((MapEntry)next).getValue();
                mapValue.put(nextKey, nextValue);
            }
        }
        nestedAccessor.setAttributeValueInObject(object, mapValue);
    }

    @Override
    public void initializeAttributes(Class theJavaClass) throws DescriptorException {
        nestedAccessor.initializeAttributes(theJavaClass);

        if(mapClassName.equals("java.util.Map")){
            mapClassName = "java.util.HashMap";
        } else if(mapClassName.equals("java.util.concurrent.ConcurrentMap")){
            mapClassName = "java.util.concurrent.ConcurrentHashMap";
        } else if(mapClassName.equals("java.util.SortedMap")){
            mapClassName = "java.util.TreeMap";
        }

        try{
            mapClass =PrivilegedAccessHelper.getClassForName(mapClassName, true, classLoader);
        }catch (ClassNotFoundException e){
            throw XMLMarshalException.unmarshalException(e);
        }
    }

}