001package biweekly.util;
002
003import java.util.regex.Matcher;
004import java.util.regex.Pattern;
005
006/*
007 Copyright (c) 2013, Michael Angstadt
008 All rights reserved.
009
010 Redistribution and use in source and binary forms, with or without
011 modification, are permitted provided that the following conditions are met: 
012
013 1. Redistributions of source code must retain the above copyright notice, this
014 list of conditions and the following disclaimer. 
015 2. Redistributions in binary form must reproduce the above copyright notice,
016 this list of conditions and the following disclaimer in the documentation
017 and/or other materials provided with the distribution. 
018
019 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
026 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030
031/**
032 * Represents a UTC offset.
033 * @author Michael Angstadt
034 */
035public final class UtcOffset {
036        private final int hour;
037        private final int minute;
038
039        /**
040         * Creates a new UTC offset.
041         * @param hour the hour component (may be negative)
042         * @param minute the minute component (must be between 0 and 59)
043         */
044        public UtcOffset(int hour, int minute) {
045                this.hour = hour;
046                this.minute = minute;
047        }
048
049        /**
050         * Parses a UTC offset from a string.
051         * @param text the text to parse (e.g. "-0500")
052         * @return the parsed UTC offset
053         * @throws IllegalArgumentException if the text cannot be parsed
054         */
055        public static UtcOffset parse(String text) {
056                Pattern timeZoneRegex = Pattern.compile("^([-\\+])?(\\d{1,2})(:?(\\d{2}))?$");
057                Matcher m = timeZoneRegex.matcher(text);
058
059                if (!m.find()) {
060                        throw new IllegalArgumentException("Offset string is not in ISO8610 format: " + text);
061                }
062
063                String sign = m.group(1);
064                boolean positive;
065                if ("-".equals(sign)) {
066                        positive = false;
067                } else {
068                        positive = true;
069                }
070
071                String hourStr = m.group(2);
072                int hourOffset = Integer.parseInt(hourStr);
073                if (!positive) {
074                        hourOffset *= -1;
075                }
076
077                String minuteStr = m.group(4);
078                int minuteOffset = (minuteStr == null) ? 0 : Integer.parseInt(minuteStr);
079
080                return new UtcOffset(hourOffset, minuteOffset);
081        }
082
083        /**
084         * Gets the hour component.
085         * @return the hour component
086         */
087        public int getHour() {
088                return hour;
089        }
090
091        /**
092         * Gets the minute component.
093         * @return the minute component
094         */
095        public int getMinute() {
096                return minute;
097        }
098
099        /**
100         * Converts this offset to its ISO string representation using "basic"
101         * format.
102         * @return the ISO string representation (e.g. "-0500")
103         */
104        @Override
105        public String toString() {
106                return toString(false);
107        }
108
109        /**
110         * Converts this offset to its ISO string representation.
111         * @param extended true to use extended format (e.g. "-05:00"), false to use
112         * basic format (e.g. "-0500")
113         * @return the ISO string representation
114         */
115        public String toString(boolean extended) {
116                StringBuilder sb = new StringBuilder();
117
118                boolean positive = hour >= 0;
119                sb.append(positive ? '+' : '-');
120
121                int hour = Math.abs(this.hour);
122                if (hour < 10) {
123                        sb.append('0');
124                }
125                sb.append(hour);
126
127                if (extended) {
128                        sb.append(':');
129                }
130
131                if (minute < 10) {
132                        sb.append('0');
133                }
134                sb.append(minute);
135
136                return sb.toString();
137        }
138
139        @Override
140        public int hashCode() {
141                final int prime = 31;
142                int result = 1;
143                result = prime * result + hour;
144                result = prime * result + minute;
145                return result;
146        }
147
148        @Override
149        public boolean equals(Object obj) {
150                if (this == obj)
151                        return true;
152                if (obj == null)
153                        return false;
154                if (getClass() != obj.getClass())
155                        return false;
156                UtcOffset other = (UtcOffset) obj;
157                if (hour != other.hour)
158                        return false;
159                if (minute != other.minute)
160                        return false;
161                return true;
162        }
163}