/*
 * OpenClinica is distributed under the
 * GNU Lesser General Public License (GNU LGPL).

 * For details see: http://www.openclinica.org/license
 * copyright 2003-2005 Akaza Research
 *
 * Created on Feb 23, 2005
 */
package org.akaza.openclinica.bean.extract;

import org.akaza.openclinica.bean.core.EntityBean;

import java.util.ArrayList;
import java.util.HashMap;

/**
 * A class which facilitates holding many unique child beans.
 *
 * @author ssachs
 */
public class OrderedEntityBeansSet {

    /**
     * Key is entity's id, value is Integer whose value is index into entities.
     * If key is present, entity was added to entities; otherwise it was not.
     */
    private HashMap entityIsAdded = new HashMap();

    /**
     * Array of EntityBeans, ordered as they should be retrieved.
     */
    private ArrayList entities = new ArrayList();

    /**
     * Returned by add in case of error.
     */
    private EntityBean defaultEntity;

    public OrderedEntityBeansSet(EntityBean defaultEntity) {
        this.defaultEntity = defaultEntity;
    }

    /**
     * Adds the entity to the set of entities, if it has not yet been added.
     *
     * @param entity
     *            The entity to add.
     * @return The entity which was already in the set, if it had previously
     *         been added, or the entity which was passed as an argument, if it
     *         had not been added.
     */
    public EntityBean add(EntityBean entity) {
        Integer key = new Integer(entity.getId());

        if (entityIsAdded.containsKey(key)) {
            Integer ind = (Integer) entityIsAdded.get(key);

            if (ind == null) {
                return defaultEntity;
            }

            int i = ind.intValue();
            if (i < 0 || i >= entities.size()) {
                return defaultEntity;
            }

            return (EntityBean) entities.get(ind.intValue());
        } else {
            entities.add(entity);
            Integer ind = new Integer(entities.size() - 1);
            entityIsAdded.put(key, ind);
            return entity;
        }
    }

    /**
     * Write the Entity on top of any entity that may already be in the set that
     * has the same id. If no such entity exists, take no action.
     *
     * @param entity
     *            The entity to update.
     */
    public void update(EntityBean entity) {
        Integer key = new Integer(entity.getId());

        if (entityIsAdded.containsKey(key)) {
            Integer ind = (Integer) entityIsAdded.get(key);

            if (ind == null) {
                return;
            }

            int i = ind.intValue();
            if (i < 0 || i >= entities.size()) {
                return;
            }

            entities.set(ind.intValue(), entity);
        }
    }

    /**
     * @return Returns the entities.
     */
    public ArrayList getEntities() {
        return entities;
    }

    public boolean contains(EntityBean eb) {
        Integer key = new Integer(eb.getId());
        return entityIsAdded.containsKey(key);
    }
}