/**
* 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.component;
import java.io.IOException;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Collections;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;
import net.fortuna.ical4j.model.Component;
import net.fortuna.ical4j.model.Date;
import net.fortuna.ical4j.model.DateList;
import net.fortuna.ical4j.model.DateTime;
import net.fortuna.ical4j.model.Property;
import net.fortuna.ical4j.model.PropertyList;
import net.fortuna.ical4j.model.ValidationException;
import net.fortuna.ical4j.model.parameter.Value;
import net.fortuna.ical4j.model.property.DtStart;
import net.fortuna.ical4j.model.property.RDate;
import net.fortuna.ical4j.model.property.RRule;
import net.fortuna.ical4j.model.property.TzOffsetFrom;
import net.fortuna.ical4j.model.property.TzOffsetTo;
import net.fortuna.ical4j.util.Dates;
import net.fortuna.ical4j.util.PropertyValidator;
import net.fortuna.ical4j.util.TimeZones;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* $Id$ [05-Apr-2004]
*
* Defines an iCalendar sub-component representing a timezone observance. Class made abstract such that only Standard
* and Daylight instances are valid.
* @author Ben Fortuna
*/
public abstract class Observance extends Component {
/**
*
*/
private static final long serialVersionUID = 2523330383042085994L;
/**
* one of 'standardc' or 'daylightc' MUST occur and each MAY occur more than once.
*/
public static final String STANDARD = "STANDARD";
/**
* Token for daylight observance.
*/
public static final String DAYLIGHT = "DAYLIGHT";
// TODO: clear cache when observance definition changes (??)
private long[] onsetsMillisec;
private DateTime[] onsetsDates;
private Map onsets = new TreeMap();
private Date initialOnset = null;
/**
* Used for parsing times in a UTC date-time representation.
*/
private static final String UTC_PATTERN = "yyyyMMdd'T'HHmmss";
private static final DateFormat UTC_FORMAT = new SimpleDateFormat(
UTC_PATTERN);
static {
UTC_FORMAT.setTimeZone(TimeZones.getUtcTimeZone());
UTC_FORMAT.setLenient(false);
}
/* If this is set we have rrules. If we get a date after this rebuild onsets */
private Date onsetLimit;
/**
* Constructs a timezone observance with the specified name and no properties.
* @param name the name of this observance component
*/
protected Observance(final String name) {
super(name);
}
/**
* Constructor protected to enforce use of sub-classes from this library.
* @param name the name of the time type
* @param properties a list of properties
*/
protected Observance(final String name, final PropertyList properties) {
super(name, properties);
}
/**
* {@inheritDoc}
*/
public final void validate(final boolean recurse) throws ValidationException {
// From "4.8.3.3 Time Zone Offset From":
// Conformance: This property MUST be specified in a "VTIMEZONE"
// calendar component.
PropertyValidator.getInstance().assertOne(Property.TZOFFSETFROM,
getProperties());
// From "4.8.3.4 Time Zone Offset To":
// Conformance: This property MUST be specified in a "VTIMEZONE"
// calendar component.
PropertyValidator.getInstance().assertOne(Property.TZOFFSETTO,
getProperties());
/*
* ; the following are each REQUIRED, ; but MUST NOT occur more than once dtstart / tzoffsetto / tzoffsetfrom /
*/
PropertyValidator.getInstance().assertOne(Property.DTSTART,
getProperties());
/*
* ; the following are optional, ; and MAY occur more than once comment / rdate / rrule / tzname / x-prop
*/
if (recurse) {
validateProperties();
}
}
/**
* Returns the latest applicable onset of this observance for the specified date.
* @param date the latest date that an observance onset may occur
* @return the latest applicable observance date or null if there is no applicable observance onset for the
* specified date
*/
public final Date getLatestOnset(final Date date) {
if (initialOnset == null) {
try {
initialOnset = applyOffsetFrom(calculateOnset(((DtStart) getProperty(Property.DTSTART)).getDate()));
} catch (ParseException e) {
Log log = LogFactory.getLog(Observance.class);
log.error("Unexpected error calculating initial onset", e);
// XXX: is this correct?
return null;
}
}
// observance not applicable if date is before the effective date of this observance..
if (date.before(initialOnset)) {
return null;
}
if ((onsetsMillisec != null) && (onsetLimit == null || date.before(onsetLimit))) {
return getCachedOnset(date);
}
Date onset = initialOnset;
Date initialOnsetUTC;
// get first onset without adding TZFROM as this may lead to a day boundary
// change which would be incompatible with BYDAY RRULES
// we will have to add the offset to all cacheable onsets
try {
initialOnsetUTC = calculateOnset(((DtStart) getProperty(Property.DTSTART)).getDate());
} catch (ParseException e) {
Log log = LogFactory.getLog(Observance.class);
log.error("Unexpected error calculating initial onset", e);
// XXX: is this correct?
return null;
}
// collect all onsets for the purposes of caching..
final DateList cacheableOnsets = new DateList();
cacheableOnsets.setUtc(true);
cacheableOnsets.add(initialOnset);
// check rdates for latest applicable onset..
final PropertyList rdates = getProperties(Property.RDATE);
for (final Iterator i = rdates.iterator(); i.hasNext();) {
final RDate rdate = (RDate) i.next();
for (final Iterator j = rdate.getDates().iterator(); j.hasNext();) {
try {
final DateTime rdateOnset = applyOffsetFrom(calculateOnset((Date) j.next()));
if (!rdateOnset.after(date) && rdateOnset.after(onset)) {
onset = rdateOnset;
}
/*
* else if (rdateOnset.after(date) && rdateOnset.after(onset) && (nextOnset == null ||
* rdateOnset.before(nextOnset))) { nextOnset = rdateOnset; }
*/
cacheableOnsets.add(rdateOnset);
} catch (ParseException e) {
Log log = LogFactory.getLog(Observance.class);
log.error("Unexpected error calculating onset", e);
}
}
}
// check recurrence rules for latest applicable onset..
final PropertyList rrules = getProperties(Property.RRULE);
for (final Iterator i = rrules.iterator(); i.hasNext();) {
final RRule rrule = (RRule) i.next();
// include future onsets to determine onset period..
final Calendar cal = Dates.getCalendarInstance(date);
cal.setTime(date);
cal.add(Calendar.YEAR, 10);
onsetLimit = Dates.getInstance(cal.getTime(), Value.DATE_TIME);
final DateList recurrenceDates = rrule.getRecur().getDates(initialOnsetUTC,
onsetLimit, Value.DATE_TIME);
for (final Iterator j = recurrenceDates.iterator(); j.hasNext();) {
final DateTime rruleOnset = applyOffsetFrom((DateTime) j.next());
if (!rruleOnset.after(date) && rruleOnset.after(onset)) {
onset = rruleOnset;
}
/*
* else if (rruleOnset.after(date) && rruleOnset.after(onset) && (nextOnset == null ||
* rruleOnset.before(nextOnset))) { nextOnset = rruleOnset; }
*/
cacheableOnsets.add(rruleOnset);
}
}
// cache onsets..
Collections.sort(cacheableOnsets);
DateTime cacheableOnset = null;
this.onsetsMillisec = new long[cacheableOnsets.size()];
this.onsetsDates = new DateTime[onsetsMillisec.length];
for (int i = 0; i < onsetsMillisec.length; i++) {
cacheableOnset = (DateTime)cacheableOnsets.get(i);
onsetsMillisec[i] = cacheableOnset.getTime();
onsetsDates[i] = cacheableOnset;
}
return onset;
}
/**
* Returns a cached onset for the specified date.
* @param date
* @return a cached onset date or null if no cached onset is applicable for the specified date
*/
private DateTime getCachedOnset(final Date date) {
int index = Arrays.binarySearch(onsetsMillisec, date.getTime());
if (index >= 0) {
return onsetsDates[index];
} else {
int insertionIndex = -index -1;
return onsetsDates[insertionIndex -1];
}
}
/**
* Returns the mandatory dtstart property.
* @return the DTSTART property or null if not specified
*/
public final DtStart getStartDate() {
return (DtStart) getProperty(Property.DTSTART);
}
/**
* Returns the mandatory tzoffsetfrom property.
* @return the TZOFFSETFROM property or null if not specified
*/
public final TzOffsetFrom getOffsetFrom() {
return (TzOffsetFrom) getProperty(Property.TZOFFSETFROM);
}
/**
* Returns the mandatory tzoffsetto property.
* @return the TZOFFSETTO property or null if not specified
*/
public final TzOffsetTo getOffsetTo() {
return (TzOffsetTo) getProperty(Property.TZOFFSETTO);
}
// private Date calculateOnset(DateProperty dateProperty) {
// return calculateOnset(dateProperty.getValue());
// }
//
private DateTime calculateOnset(Date date) throws ParseException {
return calculateOnset(date.toString());
}
private DateTime calculateOnset(String dateStr) throws ParseException {
// Translate local onset into UTC time by parsing local time
// as GMT and adjusting by TZOFFSETFROM if required
long utcOnset;
synchronized (UTC_FORMAT) {
utcOnset = UTC_FORMAT.parse(dateStr).getTime();
}
// return a UTC
DateTime onset = new DateTime(true);
onset.setTime(utcOnset);
return onset;
}
private DateTime applyOffsetFrom(DateTime orig) {
DateTime withOffset = new DateTime(true);
withOffset.setTime(orig.getTime() - getOffsetFrom().getOffset().getOffset());
return withOffset;
}
}