/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.log4j.helpers;

import org.apache.log4j.Layout;
import org.apache.log4j.spi.LoggingEvent;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
import java.text.FieldPosition;

/**
 * This abstract layout takes care of all the date related options and
 * formatting work.
 * 
 * 
 * @author Ceki G&uuml;lc&uuml;
 */
abstract public class DateLayout extends Layout {

    /**
     * String constant designating no time information. Current value of this
     * constant is <b>NULL</b>.
     * 
     */
    public final static String NULL_DATE_FORMAT = "NULL";

    /**
     * String constant designating relative time. Current value of this constant is
     * <b>RELATIVE</b>.
     */
    public final static String RELATIVE_TIME_DATE_FORMAT = "RELATIVE";

    protected FieldPosition pos = new FieldPosition(0);

    /**
     * @deprecated Options are now handled using the JavaBeans paradigm. This
     *             constant is not longer needed and will be removed in the
     *             <em>near</em> term.
     */
    final static public String DATE_FORMAT_OPTION = "DateFormat";

    /**
     * @deprecated Options are now handled using the JavaBeans paradigm. This
     *             constant is not longer needed and will be removed in the
     *             <em>near</em> term.
     */
    final static public String TIMEZONE_OPTION = "TimeZone";

    private String timeZoneID;
    private String dateFormatOption;

    protected DateFormat dateFormat;
    protected Date date = new Date();

    /**
     * @deprecated Use the setter method for the option directly instead of the
     *             generic <code>setOption</code> method.
     */
    public String[] getOptionStrings() {
	return new String[] { DATE_FORMAT_OPTION, TIMEZONE_OPTION };
    }

    /**
     * @deprecated Use the setter method for the option directly instead of the
     *             generic <code>setOption</code> method.
     */
    public void setOption(String option, String value) {
	if (option.equalsIgnoreCase(DATE_FORMAT_OPTION)) {
	    dateFormatOption = value.toUpperCase();
	} else if (option.equalsIgnoreCase(TIMEZONE_OPTION)) {
	    timeZoneID = value;
	}
    }

    /**
     * The value of the <b>DateFormat</b> option should be either an argument to the
     * constructor of {@link SimpleDateFormat} or one of the srings "NULL",
     * "RELATIVE", "ABSOLUTE", "DATE" or "ISO8601.
     */
    public void setDateFormat(String dateFormat) {
	if (dateFormat != null) {
	    dateFormatOption = dateFormat;
	}
	setDateFormat(dateFormatOption, TimeZone.getDefault());
    }

    /**
     * Returns value of the <b>DateFormat</b> option.
     */
    public String getDateFormat() {
	return dateFormatOption;
    }

    /**
     * The <b>TimeZoneID</b> option is a time zone ID string in the format expected
     * by the {@link TimeZone#getTimeZone} method.
     */
    public void setTimeZone(String timeZone) {
	this.timeZoneID = timeZone;
    }

    /**
     * Returns value of the <b>TimeZone</b> option.
     */
    public String getTimeZone() {
	return timeZoneID;
    }

    public void activateOptions() {
	setDateFormat(dateFormatOption);
	if (timeZoneID != null && dateFormat != null) {
	    dateFormat.setTimeZone(TimeZone.getTimeZone(timeZoneID));
	}
    }

    public void dateFormat(StringBuffer buf, LoggingEvent event) {
	if (dateFormat != null) {
	    date.setTime(event.timeStamp);
	    dateFormat.format(date, buf, this.pos);
	    buf.append(' ');
	}
    }

    /**
     * Sets the {@link DateFormat} used to format time and date in the zone
     * determined by <code>timeZone</code>.
     */
    public void setDateFormat(DateFormat dateFormat, TimeZone timeZone) {
	this.dateFormat = dateFormat;
	this.dateFormat.setTimeZone(timeZone);
    }

    /**
     * Sets the DateFormat used to format date and time in the time zone determined
     * by <code>timeZone</code> parameter. The {@link DateFormat} used will depend
     * on the <code>dateFormatType</code>.
     * 
     * <p>
     * The recognized types are {@link #NULL_DATE_FORMAT},
     * {@link #RELATIVE_TIME_DATE_FORMAT}
     * {@link AbsoluteTimeDateFormat#ABS_TIME_DATE_FORMAT},
     * {@link AbsoluteTimeDateFormat#DATE_AND_TIME_DATE_FORMAT} and
     * {@link AbsoluteTimeDateFormat#ISO8601_DATE_FORMAT}. If the
     * <code>dateFormatType</code> is not one of the above, then the argument is
     * assumed to be a date pattern for {@link SimpleDateFormat}.
     */
    public void setDateFormat(String dateFormatType, TimeZone timeZone) {
	if (dateFormatType == null) {
	    this.dateFormat = null;
	    return;
	}

	if (dateFormatType.equalsIgnoreCase(NULL_DATE_FORMAT)) {
	    this.dateFormat = null;
	} else if (dateFormatType.equalsIgnoreCase(RELATIVE_TIME_DATE_FORMAT)) {
	    this.dateFormat = new RelativeTimeDateFormat();
	} else if (dateFormatType.equalsIgnoreCase(AbsoluteTimeDateFormat.ABS_TIME_DATE_FORMAT)) {
	    this.dateFormat = new AbsoluteTimeDateFormat(timeZone);
	} else if (dateFormatType.equalsIgnoreCase(AbsoluteTimeDateFormat.DATE_AND_TIME_DATE_FORMAT)) {
	    this.dateFormat = new DateTimeDateFormat(timeZone);
	} else if (dateFormatType.equalsIgnoreCase(AbsoluteTimeDateFormat.ISO8601_DATE_FORMAT)) {
	    this.dateFormat = new ISO8601DateFormat(timeZone);
	} else {
	    this.dateFormat = new SimpleDateFormat(dateFormatType);
	    this.dateFormat.setTimeZone(timeZone);
	}
    }
}
