/*
* Copyright 2001-2005 Stephen Colebourne
*
* 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 org.joda.time.chrono;
import org.joda.time.DateTimeConstants;
import org.joda.time.DateTimeFieldType;
import org.joda.time.DurationField;
import org.joda.time.field.FieldUtils;
import org.joda.time.field.ImpreciseDateTimeField;
/**
* Provides time calculations for the week of the weekyear component of time.
*
* @author Guy Allard
* @author Stephen Colebourne
* @author Brian S O'Neill
* @since 1.1, refactored from GJWeekyearDateTimeField
*/
final class BasicWeekyearDateTimeField extends ImpreciseDateTimeField {
private static final long serialVersionUID = 6215066916806820644L;
private static final long WEEK_53 = (53L - 1) * DateTimeConstants.MILLIS_PER_WEEK;
private final BasicChronology iChronology;
/**
* Restricted constructor
*/
BasicWeekyearDateTimeField(BasicChronology chronology) {
super(DateTimeFieldType.weekyear(), chronology.getAverageMillisPerYear());
iChronology = chronology;
}
public boolean isLenient() {
return false;
}
/**
* Get the Year of a week based year component of the specified time instant.
*
* @see org.joda.time.DateTimeField#get
* @param instant the time instant in millis to query.
* @return the year extracted from the input.
*/
public int get(long instant) {
return iChronology.getWeekyear(instant);
}
/**
* Add the specified years to the specified time instant.
*
* @see org.joda.time.DateTimeField#add
* @param instant the time instant in millis to update.
* @param years the years to add (can be negative).
* @return the updated time instant.
*/
public long add(long instant, int years) {
if (years == 0) {
return instant;
}
return set(instant, get(instant) + years);
}
public long add(long instant, long value) {
return add(instant, FieldUtils.safeToInt(value));
}
/**
* Add to the year component of the specified time instant
* wrapping around within that component if necessary.
*
* @see org.joda.time.DateTimeField#addWrapField
* @param instant the time instant in millis to update.
* @param years the years to add (can be negative).
* @return the updated time instant.
*/
public long addWrapField(long instant, int years) {
return add(instant, years);
}
public long getDifferenceAsLong(long minuendInstant, long subtrahendInstant) {
if (minuendInstant < subtrahendInstant) {
return -getDifference(subtrahendInstant, minuendInstant);
}
int minuendWeekyear = get(minuendInstant);
int subtrahendWeekyear = get(subtrahendInstant);
long minuendRem = remainder(minuendInstant);
long subtrahendRem = remainder(subtrahendInstant);
// Balance leap weekyear differences on remainders.
if (subtrahendRem >= WEEK_53 && iChronology.getWeeksInYear(minuendWeekyear) <= 52) {
subtrahendRem -= DateTimeConstants.MILLIS_PER_WEEK;
}
int difference = minuendWeekyear - subtrahendWeekyear;
if (minuendRem < subtrahendRem) {
difference--;
}
return difference;
}
/**
* Set the Year of a week based year component of the specified time instant.
*
* @see org.joda.time.DateTimeField#set
* @param instant the time instant in millis to update.
* @param year the year (-9999,9999) to set the date to.
* @return the updated DateTime.
* @throws IllegalArgumentException if year is invalid.
*/
public long set(long instant, int year) {
FieldUtils.verifyValueBounds(this, Math.abs(year),
iChronology.getMinYear(), iChronology.getMaxYear());
//
// Do nothing if no real change is requested.
//
int thisWeekyear = get( instant );
if ( thisWeekyear == year ) {
return instant;
}
//
// Calculate the DayOfWeek (to be preserved).
//
int thisDow = iChronology.getDayOfWeek(instant);
//
// Calculate the maximum weeks in the target year.
//
int weeksInFromYear = iChronology.getWeeksInYear( thisWeekyear );
int weeksInToYear = iChronology.getWeeksInYear( year );
int maxOutWeeks = (weeksInToYear < weeksInFromYear) ?
weeksInToYear : weeksInFromYear;
//
// Get the current week of the year. This will be preserved in
// the output unless it is greater than the maximum possible
// for the target weekyear. In that case it is adjusted
// to the maximum possible.
//
int setToWeek = iChronology.getWeekOfWeekyear(instant);
if ( setToWeek > maxOutWeeks ) {
setToWeek = maxOutWeeks;
}
//
// Get a wroking copy of the current date-time.
// This can be a convenience for debugging.
//
long workInstant = instant; // Get a copy
//
// Attempt to get close to the proper weekyear.
// Note - we cannot currently call ourself, so we just call
// set for the year. This at least gets us close.
//
workInstant = iChronology.setYear( workInstant, year );
//
// Calculate the weekyear number for the get close to value
// (which might not be equal to the year just set).
//
int workWoyYear = get( workInstant );
//
// At most we are off by one year, which can be "fixed" by
// adding/subtracting a week.
//
if ( workWoyYear < year ) {
workInstant += DateTimeConstants.MILLIS_PER_WEEK;
} else if ( workWoyYear > year ) {
workInstant -= DateTimeConstants.MILLIS_PER_WEEK;
}
//
// Set the proper week in the current weekyear.
//
// BEGIN: possible set WeekOfWeekyear logic.
int currentWoyWeek = iChronology.getWeekOfWeekyear(workInstant);
// No range check required (we already know it is OK).
workInstant = workInstant + (setToWeek - currentWoyWeek)
* (long)DateTimeConstants.MILLIS_PER_WEEK;
// END: possible set WeekOfWeekyear logic.
//
// Reset DayOfWeek to previous value.
//
// Note: This works fine, but it ideally shouldn't invoke other
// fields from within a field.
workInstant = iChronology.dayOfWeek().set( workInstant, thisDow );
//
// Return result.
//
return workInstant;
}
public DurationField getRangeDurationField() {
return null;
}
public boolean isLeap(long instant) {
return iChronology.getWeeksInYear(iChronology.getWeekyear(instant)) > 52;
}
public int getLeapAmount(long instant) {
return iChronology.getWeeksInYear(iChronology.getWeekyear(instant)) - 52;
}
public DurationField getLeapDurationField() {
return iChronology.weeks();
}
public int getMinimumValue() {
return iChronology.getMinYear();
}
public int getMaximumValue() {
return iChronology.getMaxYear();
}
public long roundFloor(long instant) {
// Note: This works fine, but it ideally shouldn't invoke other
// fields from within a field.
instant = iChronology.weekOfWeekyear().roundFloor(instant);
int wow = iChronology.getWeekOfWeekyear(instant);
if (wow > 1) {
instant -= ((long) DateTimeConstants.MILLIS_PER_WEEK) * (wow - 1);
}
return instant;
}
public long remainder(long instant) {
return instant - roundFloor(instant);
}
/**
* Serialization singleton
*/
private Object readResolve() {
return iChronology.weekyear();
}
}