/*
 * Copyright (c) 2005-2011 Grameen Foundation USA
 * All rights reserved.
 *
 * 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.
 *
 * See also http://www.apache.org/licenses/LICENSE-2.0.html for an
 * explanation of the license and how it is applied.
 */

package org.mifos.framework.hibernate.helper;

import java.util.ArrayList;
import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;
import org.mifos.customers.util.helpers.Param;
import org.mifos.framework.exceptions.HibernateSearchException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This is the class that is returned on a search operation. Search would typically result in a set of search result
 * objects , these search result objects would be obtained through hibernate scroll for pagination in the front end ,
 * the associate hibernate session would be held in this object , a call to close from the front end on this interface
 * would result in the hibernate session object getting closed.
 */

public class QueryResultSearchDTOImpl extends QueryResultDTOImpl {

    List<?> list = new ArrayList<Object>();
    private static final Logger logger = LoggerFactory.getLogger(QueryResultSearchDTOImpl.class);

    /** Set the query inputs which will be used for query execution */
    @Override
    public void setQueryInputs(QueryInputs queryInputs) throws HibernateSearchException {
        if (queryInputs == null) {
            throw new HibernateSearchException(HibernateConstants.SEARCH_INPUTNULL);
        }

        if (queryInputs.getBuildDTO()) {
            this.queryInputs = queryInputs;
            dtoBuilder = new DTOBuilder();
            this.buildDTO = queryInputs.getBuildDTO();
        }

    }

    /**
     * Returns the requested set of search result objects based on the pagination at the front end.
     */
    @Override
    public List<Object> get(int position, int noOfObjects) throws HibernateSearchException {
        Session session = null;
        List<Object> returnList = new ArrayList<Object>();
        List<?> list = new ArrayList<Object>();
        try {
            session = StaticHibernateUtil.getSessionTL();
            Query query = prepareQuery(session, queryInputs.getQueryStrings()[1]);
            query.setFirstResult(position);
            query.setMaxResults(noOfObjects);
            list = query.list();
            logger.debug("\n\nInside get of QueryResultSearchDTOImpl.java . size of main query=" + list.size());
            this.queryInputs.setTypes(query.getReturnTypes());
            dtoBuilder.setInputs(queryInputs);
            returnList = new ArrayList<Object>();
            for (int i = 0; i < list.size(); i++) {
                if (buildDTO) {
                    returnList.add(buildDTO((Object[]) list.get(i)));

                } else {
                    if (i < noOfObjects) {
                        returnList.add(list.get(i));
                    }
                }
            }

            StaticHibernateUtil.closeSession();
        } catch (Exception e) {
            throw new HibernateSearchException(HibernateConstants.SEARCH_FAILED, e);
        }

        return returnList;
    }

    /**
     * Returns the records valid for the query
     */
    @Override
    public int getSize() throws HibernateSearchException {
        Session session = null;
        try {
            session = StaticHibernateUtil.getSessionTL();
            if (this.queryInputs == null) {
                throw new HibernateSearchException(HibernateConstants.SEARCH_INPUTNULL);
            }
            Query query = prepareQuery(session, queryInputs.getQueryStrings()[0]);
            Integer resultSetCount = ((Number) query.uniqueResult()).intValue();
            logger.debug("\n\nInside get of QueryResultSearchDTOImpl.java . size of count query=" + resultSetCount);
            this.queryInputs.setTypes(query.getReturnTypes());
            dtoBuilder.setInputs(queryInputs);
            if (resultSetCount != null && resultSetCount > 0) {
                size = resultSetCount;
            }
            StaticHibernateUtil.closeSession();
        } catch (Exception e) {
            throw new HibernateSearchException(HibernateConstants.SEARCH_FAILED, e);
        }
        return size;
    }

    public Query prepareQuery(Session session, String namedQuery) throws HibernateSearchException {
        if (this.queryInputs == null) {
            throw new HibernateSearchException(HibernateConstants.SEARCH_INPUTNULL);
        }
        List<Param> paramList = queryInputs.getParamList();
        Query query = null;
        query = session.getNamedQuery(namedQuery);
        if (paramList != null) {
            for (int i = 0; i < paramList.size(); i++) {
                if (paramList.get(i) != null) {
                    if (paramList.get(i).getValue() instanceof List) {
                        query.setParameterList(paramList.get(i).getName(), (List) paramList.get(i).getValue());
                    } else {
                        query.setParameter(paramList.get(i).getName(), paramList.get(i).getValue());
                    }
                }
            }
        }
        return query;
    }

}