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/**
 * Copyright (c) 2012, Ben Fortuna
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  o Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 *  o Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 *  o Neither the name of Ben Fortuna nor the names of any other contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package net.fortuna.ical4j.model;

import net.fortuna.ical4j.util.CompatibilityHints;
import net.fortuna.ical4j.util.Dates;
import net.fortuna.ical4j.util.TimeZones;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.TimeZone;


/**
 * A representation of the DATE object defined in RFC5445.
 * 
 * NOTE: iCal4j calculates the timezone of Date objects by default. In the iCalendar specification a
 * DATE object doesn't really have a timezone associated with it, but in the ical4j implementation it does (as it is
 * based on a java.util.Date object). An unfortunate side effect of this is that a Date object can be affected by
 * daylight savings rules for the associated timezone. So currently ical4j offers two approaches to setting the
 * timezone:
 * 

 * 

 *     Use UTC time (no DST rules, but depending on how the Date is constructed it may change the displayed value
 *     Use local timezone (in rare cases the DST rules may affect the displayed value).
 * 
 * 
 * By default option 1 is used, but you can override this with the following flag in the ical4j.properties file:
 * net.fortuna.ical4j.timezone.date.floating=true
 * 

 * Alternatively you can avoid using the constructor that accepts a java.util.Date object, and instead provide a date
 * string value. This should always display the correct value, however when the local timezone is used any calculations
 * (recurrences, etc.) may still be affect by DST rules.
 * 

 * Extract from RFC5545:
 * 

 * 
 * 3.3.4.  Date
 * 
 * Value Name:  DATE
 * 
 * Purpose:  This value type is used to identify values that contain a
 * calendar date.
 * 
 * Format Definition:  This value type is defined by the following
 * notation:
 * 
 * date               = date-value
 * 
 * date-value         = date-fullyear date-month date-mday
 * date-fullyear      = 4DIGIT
 * date-month         = 2DIGIT        ;01-12
 * date-mday          = 2DIGIT        ;01-28, 01-29, 01-30, 01-31
 * ;based on month/year
 * 
 * Description:  If the property permits, multiple "date" values are
 * specified as a COMMA-separated list of values.  The format for the
 * value type is based on the [ISO.8601.2004] complete
 * representation, basic format for a calendar date.  The textual
 * format specifies a four-digit year, two-digit month, and two-digit
 * day of the month.  There are no separator characters between the
 * year, month, and day component text.
 * 
 * No additional content value encoding (i.e., BACKSLASH character
 * encoding, see Section 3.3.11) is defined for this value type.
 * 
 * Example:  The following represents July 14, 1997:
 * 
 * 19970714
 * 
 * 
 * 
 * @author Ben Fortuna
 * @version 2.0
 */
public class Date extends Iso8601 {

    private static final long serialVersionUID = 7136072363141363141L;

    private static final String DEFAULT_PATTERN = "yyyyMMdd";
    
    private static final String VCARD_PATTERN = "yyyy'-'MM'-'dd";

    /**
     * Default constructor.
     */
    public Date() {
        super(DEFAULT_PATTERN, Dates.PRECISION_DAY, TimeZones.getDateTimeZone());
    }
    
    /**
     * Creates a new date instance with the specified precision. This
     * constructor is only intended for use by sub-classes.
     * @param precision the date precision
     * @param tz the timezone
     * @see Dates#PRECISION_DAY
     * @see Dates#PRECISION_SECOND
     */
    protected Date(final int precision, TimeZone tz) {
        super(DEFAULT_PATTERN, precision, tz);
    }

    /**
     * @param time a date value in milliseconds
     */
    public Date(final long time) {
        super(time, DEFAULT_PATTERN, Dates.PRECISION_DAY, TimeZones.getDateTimeZone());
    }
    
    /**
     * Creates a new date instance with the specified precision. This
     * constructor is only intended for use by sub-classes.
     * @param time a date value in milliseconds
     * @param precision the date precision
     * @param tz the timezone
     * @see Dates#PRECISION_DAY
     * @see Dates#PRECISION_SECOND
     */
    protected Date(final long time, final int precision, TimeZone tz) {
        super(time, DEFAULT_PATTERN, precision, tz);
    }
    
    /**
     * @param calendar a calendar value
     */
    public Date(final java.util.Calendar calendar) {
        this(calendar.getTimeInMillis(), Dates.PRECISION_DAY, TimeZones.getDateTimeZone());
    }

    /**
     * @param date a date value
     */
    public Date(final java.util.Date date) {
//        this();
        this(date.getTime(), Dates.PRECISION_DAY, TimeZones.getDateTimeZone());
//        setTime(date.getTime());
    }

    /**
     * @param value a string representation of a date
     * @throws ParseException where the specified string is not a valid date
     */
    public Date(final String value) throws ParseException {
        this();
        try {
        	setTime(getFormat().parse(value).getTime());
        } catch (ParseException pe) {
        	if (CompatibilityHints.isHintEnabled(CompatibilityHints.KEY_VCARD_COMPATIBILITY)) {
                final DateFormat parseFormat = new SimpleDateFormat(VCARD_PATTERN);
                parseFormat.setTimeZone(TimeZones.getDateTimeZone());
                setTime(parseFormat.parse(value).getTime());
        	}
        	else {
        		throw pe;
        	}
        }
    }
    
    /**
     * @param value a string representation of a date
     * @param pattern a date pattern to apply when parsing
     * @throws ParseException where the specified string is not a valid date
     */
    public Date(String value, String pattern) throws ParseException {
        super(DEFAULT_PATTERN, Dates.PRECISION_DAY, TimeZones.getDateTimeZone());
        final DateFormat parseFormat = new SimpleDateFormat(pattern);
        parseFormat.setTimeZone(TimeZones.getDateTimeZone());
        setTime(parseFormat.parse(value).getTime());
    }
}