/*
 * Seldon -- open source prediction engine
 * =======================================
 *
 * Copyright 2011-2015 Seldon Technologies Ltd and Rummble Ltd (http://www.seldon.io/)
 *
 * ********************************************************************************************
 *
 * Licensed 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 io.seldon.general.jdo;

import javax.jdo.PersistenceManager;
import javax.jdo.Query;

import java.util.Collection;
import java.util.Iterator;

import io.seldon.general.Version;
import io.seldon.general.VersionPeer;

/**
 * Created by: marc on 12/08/2011 at 16:21
 */
public class SqlVersionPeer implements VersionPeer {

    private final PersistenceManager persistenceManager;

    public SqlVersionPeer(PersistenceManager persistenceManager) {
        this.persistenceManager = persistenceManager;
    }

    @SuppressWarnings({"unchecked"})
    public Version getVersion() {
        Query query = persistenceManager.newQuery(Version.class);
        Collection<Version> retrieved = (Collection<Version>) query.execute();
        Iterator<Version> iterator = retrieved.iterator();
        return (iterator.hasNext() ? iterator.next() : null);
    }

}