/**
 * Copyright 2008-2016 Qualogy Solutions B.V.
 *
 * 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 com.qualogy.qafe.business.resource.rdb.query.enhancer;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.util.Iterator;
import java.util.logging.Logger;

import javax.sql.DataSource;

import org.apache.commons.lang.StringUtils;

import com.qualogy.qafe.bind.resource.query.Batch;
import com.qualogy.qafe.bind.resource.query.Query;
import com.qualogy.qafe.bind.resource.query.QueryContainer;
import com.qualogy.qafe.business.resource.rdb.RDBDatasource;


public class EnhancementManager {
    public final static Logger logger = Logger.getLogger(EnhancementManager.class.getName());

    private static Query enhance(Query query, QueryContainer container,
        DatabaseMetaData md) {
        if (StringUtils.isNotBlank(query.getRef())) {
            Query reference = container.get(query.getRef());

            if (reference == null) {
                throw new EnhancementFailedException(
                    "Referencing to non-existing query, ref=" + query.getRef());
            }

            query.setReference(reference);
        } else {
            Enhancer enhancer = EnhancerFactory.create(query);

            if (enhancer != null) {
                query = enhancer.enhance(query, md);
                logger.info("Enhanced query with id [" + query.getId() + "]");
            }
        }

        return query;
    }

    public static QueryContainer enhance(QueryContainer container,
        RDBDatasource dsResource) {
        if ((dsResource == null) || (dsResource.getDataSource() == null)) {
            throw new IllegalArgumentException(
                "Properties not read correctly or properties are incorrect, loading datasource failed");
        }

        DataSource dataSource = dsResource.getDataSource();

        Connection con = null;

        try {
            con = dataSource.getConnection();

            DatabaseMetaData md = con.getMetaData();

            for (Iterator<Query> iter = container.values().iterator();
                    iter.hasNext();) {
                Query query = (Query) iter.next();

                if (query instanceof Batch) {
                    for (Iterator<Query> iterator = ((Batch) query).getQueries()
                                                     .iterator();
                            iterator.hasNext();) {
                        Query batchQuery = (Query) iterator.next();
                        batchQuery = enhance(batchQuery, container, md);
                    }
                } else {
                    query = enhance(query, container, md);
                }

                container.update(query);
            }
        } catch (SQLException e) {
            String error = e.getMessage() + "[ on source ]" +
                dsResource.toString();
            throw new EnhancementFailedException(error);
        } finally {
            if (con != null) {
                try {
                    con.close();
                } catch (SQLException e) {
                    String error = e.getMessage() + "[ on source ]" +
                        dsResource.toString();
                    throw new EnhancementFailedException(error);
                }
            }
        }

        return container;
    }

    public static Query enhance(Query query, RDBDatasource dsResource) {
        QueryContainer container = new QueryContainer();


        return enhance(container, dsResource).get(query.getId());
    }
}