/*
 * 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.platform.persistence.support;

import org.hibernate.Query;
import org.mifos.platform.persistence.GenericDao;
import org.mifos.platform.persistence.QueryExecutor;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import java.io.Serializable;
import java.util.Collection;
import java.util.List;

public class GenericDaoHibernateImpl<T, ID extends Serializable>
    extends HibernateDaoSupport implements GenericDao<T, ID>, QueryExecutor<T> {

    private final Class<T> type;

    public GenericDaoHibernateImpl(Class<T> type) {
        super();
        this.type = type;
    }

    @Override
    public void add(T newInstance) {
        getHibernateTemplate().save(newInstance);
    }

    @Override
    public ID create(T newInstance) {
        return (ID) getHibernateTemplate().save(newInstance);
    }

    @Override
    public void delete(T persistentObject) {
        getHibernateTemplate().delete(persistentObject);
    }

    @Override
    public T getDetails(ID id) {
        return getHibernateTemplate().get(type, id);
    }

    @Override
    public List<T> getDetailsAll() {
        return getHibernateTemplate().find("from " + type.getName());
    }

    @Override
    public void saveOrUpdateAll(Collection<T> c) {
        getHibernateTemplate().saveOrUpdateAll(c);
    }

    @Override
    public void saveOrUpdate(T entity) {
        getHibernateTemplate().saveOrUpdate(entity);
    }

    @Override
    public void update(T transientObject) {
        getHibernateTemplate().update(transientObject);
    }

    @Override
    public List<T> execFindQuery(String qryMethodName, Object[] queryArgs) {
        Query namedQuery = getSession().getNamedQuery(type.getSimpleName() + "." + qryMethodName);
        if (namedQuery.getNamedParameters().length == 0) {
            setParamsOnNamedQuery(queryArgs, namedQuery);
        } else {
            setArgsOnNamedQuery(queryArgs, namedQuery);
        }
        return namedQuery.list();
    }

    private void setParamsOnNamedQuery(Object[] queryArgs, Query namedQuery) {
        if(queryArgs != null) {
            for(int i = 0; i < queryArgs.length; i++) {
                namedQuery.setParameter(i, queryArgs[i]);
            }
        }
    }

    private void setArgsOnNamedQuery(Object[] queryArgs, Query namedQuery) {
        if(queryArgs != null) {
            String[] namedParameters = namedQuery.getNamedParameters();
            for(int i = 0; i < queryArgs.length; i++) {
                Object arg = queryArgs[i];
                if(arg instanceof Collection) {
                    namedQuery.setParameterList(namedParameters[i], (Collection) arg);
                } else {
                    namedQuery.setParameter(namedParameters[i], arg);
                }
            }
        }
    }

}