001/*
002 *  Copyright 2001-2005 Stephen Colebourne
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.joda.time.field;
017
018import org.joda.time.DateTimeField;
019import org.joda.time.DateTimeFieldType;
020import org.joda.time.DurationField;
021
022/**
023 * Counterpart remainder datetime field to {@link DividedDateTimeField}. The
024 * field's unit duration is unchanged, but the range duration is scaled
025 * accordingly.
026 * <p>
027 * RemainderDateTimeField is thread-safe and immutable.
028 *
029 * @see DividedDateTimeField
030 *
031 * @author Brian S O'Neill
032 * @since 1.0
033 */
034public class RemainderDateTimeField extends DecoratedDateTimeField {
035
036    private static final long serialVersionUID = 5708241235177666790L;
037
038    // Shared with DividedDateTimeField.
039    final int iDivisor;
040    final DurationField iRangeField;
041
042    /**
043     * Constructor.
044     * 
045     * @param field  the field to wrap, like "year()".
046     * @param type  the field type this field actually uses
047     * @param divisor  divisor, such as 100 years in a century
048     * @throws IllegalArgumentException if divisor is less than two
049     */
050    public RemainderDateTimeField(DateTimeField field,
051                                  DateTimeFieldType type, int divisor) {
052        super(field, type);
053
054        if (divisor < 2) {
055            throw new IllegalArgumentException("The divisor must be at least 2");
056        }
057
058        DurationField rangeField = field.getDurationField();
059        if (rangeField == null) {
060            iRangeField = null;
061        } else {
062            iRangeField = new ScaledDurationField(
063                rangeField, type.getRangeDurationType(), divisor);
064        }
065
066        iDivisor = divisor;
067    }
068
069    /**
070     * Construct a RemainderDateTimeField that compliments the given
071     * DividedDateTimeField.
072     *
073     * @param dividedField  complimentary divided field, like "century()".
074     */
075    public RemainderDateTimeField(DividedDateTimeField dividedField) {
076        this(dividedField, dividedField.getType());
077    }
078
079    /**
080     * Construct a RemainderDateTimeField that compliments the given
081     * DividedDateTimeField.
082     *
083     * @param dividedField  complimentary divided field, like "century()".
084     * @param type  the field type this field actually uses
085     */
086    public RemainderDateTimeField(DividedDateTimeField dividedField, DateTimeFieldType type) {
087        super(dividedField.getWrappedField(), type);
088        iDivisor = dividedField.iDivisor;
089        iRangeField = dividedField.iDurationField;
090    }
091
092    //-----------------------------------------------------------------------
093    /**
094     * Get the remainder from the specified time instant.
095     * 
096     * @param instant  the time instant in millis to query.
097     * @return the remainder extracted from the input.
098     */
099    public int get(long instant) {
100        int value = getWrappedField().get(instant);
101        if (value >= 0) {
102            return value % iDivisor;
103        } else {
104            return (iDivisor - 1) + ((value + 1) % iDivisor);
105        }
106    }
107
108    /**
109     * Add the specified amount to the specified time instant, wrapping around
110     * within the remainder range if necessary. The amount added may be
111     * negative.
112     * 
113     * @param instant  the time instant in millis to update.
114     * @param amount  the amount to add (can be negative).
115     * @return the updated time instant.
116     */
117    public long addWrapField(long instant, int amount) {
118        return set(instant, FieldUtils.getWrappedValue(get(instant), amount, 0, iDivisor - 1));
119    }
120
121    /**
122     * Set the specified amount of remainder units to the specified time instant.
123     * 
124     * @param instant  the time instant in millis to update.
125     * @param value  value of remainder units to set.
126     * @return the updated time instant.
127     * @throws IllegalArgumentException if value is too large or too small.
128     */
129    public long set(long instant, int value) {
130        FieldUtils.verifyValueBounds(this, value, 0, iDivisor - 1);
131        int divided = getDivided(getWrappedField().get(instant));
132        return getWrappedField().set(instant, divided * iDivisor + value);
133    }
134
135    /**
136     * Returns a scaled version of the wrapped field's unit duration field.
137     */
138    public DurationField getRangeDurationField() {
139        return iRangeField;
140    }
141
142    /**
143     * Get the minimum value for the field, which is always zero.
144     * 
145     * @return the minimum value of zero.
146     */
147    public int getMinimumValue() {
148        return 0;
149    }
150
151    /**
152     * Get the maximum value for the field, which is always one less than the
153     * divisor.
154     * 
155     * @return the maximum value
156     */
157    public int getMaximumValue() {
158        return iDivisor - 1;
159    }
160
161    public long roundFloor(long instant) {
162        return getWrappedField().roundFloor(instant);
163    }
164
165    public long roundCeiling(long instant) {
166        return getWrappedField().roundCeiling(instant);
167    }
168
169    public long roundHalfFloor(long instant) {
170        return getWrappedField().roundHalfFloor(instant);
171    }
172
173    public long roundHalfCeiling(long instant) {
174        return getWrappedField().roundHalfCeiling(instant);
175    }
176
177    public long roundHalfEven(long instant) {
178        return getWrappedField().roundHalfEven(instant);
179    }
180
181    public long remainder(long instant) {
182        return getWrappedField().remainder(instant);
183    }
184
185    /**
186     * Returns the divisor applied, in the field's units.
187     * 
188     * @return the divisor
189     */
190    public int getDivisor() {
191        return iDivisor;
192    }
193
194    private int getDivided(int value) {
195        if (value >= 0) {
196            return value / iDivisor;
197        } else {
198            return ((value + 1) / iDivisor) - 1;
199        }
200    }
201
202}