/*
 * Copyright (c) 2010-2013 Evolveum
 *
 * 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.evolveum.midpoint.repo.sql.type;

import org.hibernate.HibernateException;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.type.AbstractSingleColumnStandardBasicType;
import org.hibernate.type.TimestampType;
import org.hibernate.usertype.UserType;

import javax.xml.datatype.DatatypeConfigurationException;
import javax.xml.datatype.DatatypeFactory;
import javax.xml.datatype.XMLGregorianCalendar;
import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Date;
import java.util.GregorianCalendar;

/**
 * @author lazyman
 */
public class XMLGregorianCalendarType implements UserType {

    public static final String NAME = "XMLGregorianCalendarType";

    private static final AbstractSingleColumnStandardBasicType HIBERNATE_TYPE = TimestampType.INSTANCE;
    private static DatatypeFactory df = null;

    static {
        try {
            df = DatatypeFactory.newInstance();
        } catch (DatatypeConfigurationException dce) {
            throw new IllegalStateException("Exception while obtaining Datatype Factory instance", dce);
        }
    }

    @Override
    public Object assemble(Serializable cached, Object owner) throws HibernateException {
        if (cached == null) {
            return null;
        }
        long date = (Long) cached;

        return asXMLGregorianCalendar(new Date(date));
    }

    @Override
    public int[] sqlTypes() {
        return new int[]{HIBERNATE_TYPE.sqlType()};
    }

    @Override
    public Class returnedClass() {
        return Date.class;
    }

    @Override
    public boolean equals(Object x, Object y) throws HibernateException {
        return x == null ? y == null : x.equals(y);
    }

    @Override
    public int hashCode(Object x) throws HibernateException {
        if (x == null) {
            return 0;
        }

        return x.hashCode();
    }

    @Override
    public Object nullSafeGet(ResultSet rs, String[] names, SessionImplementor session, Object owner) throws
            HibernateException, SQLException {
        Date date = (Date) HIBERNATE_TYPE.nullSafeGet(rs, names[0], session);
        if (date == null) {
            return null;
        }
        return asXMLGregorianCalendar(date);
    }

    @Override
    public void nullSafeSet(PreparedStatement st, Object value, int index, SessionImplementor session) throws
            HibernateException, SQLException {
        XMLGregorianCalendar calendar = (XMLGregorianCalendar) value;
        Date date = null;
        if (calendar != null) {
            date = asDate(calendar);
        }

        HIBERNATE_TYPE.nullSafeSet(st, date, index, session);
    }

    @Override
    public Object deepCopy(Object value) throws HibernateException {
        if (value == null) {
            return null;
        }

        XMLGregorianCalendar calendar = (XMLGregorianCalendar) value;
        return asXMLGregorianCalendar(asDate(calendar));
    }

    @Override
    public boolean isMutable() {
        return true;
    }

    @Override
    public Serializable disassemble(Object value) throws HibernateException {
        if (value == null) {
            return null;
        }

        XMLGregorianCalendar calendar = (XMLGregorianCalendar) value;
        return asDate(calendar).getTime();
    }

    @Override
    public Object replace(Object original, Object target, Object owner) throws HibernateException {
        return deepCopy(original);
    }

    /**
     * Converts a java.util.Date into an instance of XMLGregorianCalendar
     *
     * @param date Instance of java.util.Date or a null reference
     * @return XMLGregorianCalendar instance whose value is based upon the
     *         value in the date parameter. If the date parameter is null then
     *         this method will simply return null.
     */
    public static XMLGregorianCalendar asXMLGregorianCalendar(java.util.Date date) {
        if (date == null) {
            return null;
        } else {
            GregorianCalendar gc = new GregorianCalendar();
            gc.setTimeInMillis(date.getTime());
            return df.newXMLGregorianCalendar(gc);
        }
    }

    /**
     * Converts an XMLGregorianCalendar to an instance of java.util.Date
     *
     * @param xgc Instance of XMLGregorianCalendar or a null reference
     * @return java.util.Date instance whose value is based upon the
     *         value in the xgc parameter. If the xgc parameter is null then
     *         this method will simply return null.
     */
    public static java.util.Date asDate(XMLGregorianCalendar xgc) {
        if (xgc == null) {
            return null;
        } else {
            return xgc.toGregorianCalendar().getTime();
        }
    }
}