/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.commons.lang3.time;

import static org.junit.jupiter.api.Assertions.assertArrayEquals;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNotEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.lang.reflect.Constructor;
import java.lang.reflect.Modifier;
import java.time.Duration;
import java.util.Calendar;
import java.util.TimeZone;

import org.apache.commons.lang3.AbstractLangTest;
import org.apache.commons.lang3.time.DurationFormatUtils.Token;
import org.junit.jupiter.api.Test;
import org.junitpioneer.jupiter.DefaultTimeZone;

/**
 * Tests {@link DurationFormatUtils}.
 * <p>
 * NOT THREAD-SAFE.
 * </p>
 */
public class DurationFormatUtilsTest extends AbstractLangTest {

    private static final int FOUR_YEARS = 365 * 3 + 366;

    private void assertEqualDuration(final String expected, final int[] start, final int[] end, final String format) {
        assertEqualDuration(null, expected, start, end, format);
    }

    private void assertEqualDuration(final String message, final String expected, final int[] start, final int[] end, final String format) {
        final Calendar cal1 = Calendar.getInstance();
        cal1.set(start[0], start[1], start[2], start[3], start[4], start[5]);
        cal1.set(Calendar.MILLISECOND, 0);
        final Calendar cal2 = Calendar.getInstance();
        cal2.set(end[0], end[1], end[2], end[3], end[4], end[5]);
        cal2.set(Calendar.MILLISECOND, 0);
        final long milli1 = cal1.getTime().getTime();
        final long milli2 = cal2.getTime().getTime();
        final String result = DurationFormatUtils.formatPeriod(milli1, milli2, format);
        if (message == null) {
            assertEquals(expected, result);
        } else {
            assertEquals(expected, result, message);
        }
    }

    private void bruteForce(final int year, final int month, final int day, final String format, final int calendarType) {
        final String msg = year + "-" + month + "-" + day + " to ";
        final Calendar c = Calendar.getInstance();
        c.set(year, month, day, 0, 0, 0);
        final int[] array1 = { year, month, day, 0, 0, 0 };
        final int[] array2 = { year, month, day, 0, 0, 0 };
        for (int i = 0; i < FOUR_YEARS; i++) {
            array2[0] = c.get(Calendar.YEAR);
            array2[1] = c.get(Calendar.MONTH);
            array2[2] = c.get(Calendar.DAY_OF_MONTH);
            final String tmpMsg = msg + array2[0] + "-" + array2[1] + "-" + array2[2] + " at ";
            assertEqualDuration(tmpMsg + i, Integer.toString(i), array1, array2, format);
            c.add(calendarType, 1);
        }
    }

    private DurationFormatUtils.Token createTokenWithCount(final CharSequence value, final int count) {
        final DurationFormatUtils.Token token = new DurationFormatUtils.Token(value, false, -1);
        // To help debugging, toString() on a Token should never blow up.
        assertNotNull(token.toString());
        for (int i = 1; i < count; i++) {
            token.increment();
            assertNotNull(token.toString());
        }
        return token;
    }

    @Test
    public void testAlternatingLiteralOptionals() {
        final String format = "['d'dH'h'][m'm']['s's]['ms'S]";
        assertEquals("d1", DurationFormatUtils.formatDuration(Duration.ofDays(1).toMillis(), format));
        assertEquals("1h", DurationFormatUtils.formatDuration(Duration.ofHours(1).toMillis(), format));
        assertEquals("1m", DurationFormatUtils.formatDuration(Duration.ofMinutes(1).toMillis(), format));
        assertEquals("s1", DurationFormatUtils.formatDuration(Duration.ofSeconds(1).toMillis(), format));
        assertEquals("ms001", DurationFormatUtils.formatDuration(Duration.ofMillis(1).toMillis(), format));
        assertEquals("d1s1", DurationFormatUtils.formatDuration(Duration.ofDays(1).plusSeconds(1).toMillis(), format));
        assertEquals("d11h", DurationFormatUtils.formatDuration(Duration.ofDays(1).plusHours(1).toMillis(), format));
        assertEquals("d11h1m", DurationFormatUtils.formatDuration(Duration.ofDays(1).plusHours(1).plusMinutes(1).toMillis(), format));
        assertEquals("d11h1ms1", DurationFormatUtils.formatDuration(Duration.ofDays(1).plusHours(1).plusMinutes(1).plusSeconds(1).toMillis(), format));
        assertEquals("d11h1ms1ms001",
                DurationFormatUtils.formatDuration(Duration.ofDays(1).plusHours(1).plusMinutes(1).plusSeconds(1).plusMillis(1).toMillis(), format));
    }

    /** See https://issues.apache.org/bugzilla/show_bug.cgi?id=38401 */
    @Test
    public void testBugzilla38401() {
        assertEqualDuration("0000/00/30 16:00:00 000", new int[] { 2006, 0, 26, 18, 47, 34 },
                             new int[] { 2006, 1, 26, 10, 47, 34 }, "yyyy/MM/dd HH:mm:ss SSS");
    }

    @SuppressWarnings("deprecation")
    @Test
    public void testConstructor() {
        assertNotNull(new DurationFormatUtils());
        final Constructor<?>[] cons = DurationFormatUtils.class.getDeclaredConstructors();
        assertEquals(1, cons.length);
        assertTrue(Modifier.isPublic(cons[0].getModifiers()));
        assertTrue(Modifier.isPublic(DurationFormatUtils.class.getModifiers()));
        assertFalse(Modifier.isFinal(DurationFormatUtils.class.getModifiers()));
    }

    @Test
    public void testDurationsByBruteForce() {
        bruteForce(2006, 0, 1, "d", Calendar.DAY_OF_MONTH);
        bruteForce(2006, 0, 2, "d", Calendar.DAY_OF_MONTH);
        bruteForce(2007, 1, 2, "d", Calendar.DAY_OF_MONTH);
        bruteForce(2004, 1, 29, "d", Calendar.DAY_OF_MONTH);
        bruteForce(1996, 1, 29, "d", Calendar.DAY_OF_MONTH);

        bruteForce(1969, 1, 28, "M", Calendar.MONTH);  // tests for 48 years
        //bruteForce(1996, 1, 29, "M", Calendar.MONTH);  // this will fail
    }

    /** Attempting to test edge cases in DurationFormatUtils.formatPeriod. */
    @Test
    @DefaultTimeZone(TimeZones.GMT_ID)
    public void testEdgeDurations() {
        // This test case must use a time zone without DST
        TimeZone.setDefault(FastTimeZone.getGmtTimeZone());
        assertEqualDuration("01", new int[] { 2006, 0, 15, 0, 0, 0 }, new int[] { 2006, 2, 10, 0, 0, 0 }, "MM");
        assertEqualDuration("12", new int[] { 2005, 0, 15, 0, 0, 0 }, new int[] { 2006, 0, 15, 0, 0, 0 }, "MM");
        assertEqualDuration("12", new int[] { 2005, 0, 15, 0, 0, 0 }, new int[] { 2006, 0, 16, 0, 0, 0 }, "MM");
        assertEqualDuration("11", new int[] { 2005, 0, 15, 0, 0, 0 }, new int[] { 2006, 0, 14, 0, 0, 0 }, "MM");

        assertEqualDuration("01 26", new int[] { 2006, 0, 15, 0, 0, 0 }, new int[] { 2006, 2, 10, 0, 0, 0 }, "MM dd");
        assertEqualDuration("54", new int[] { 2006, 0, 15, 0, 0, 0 }, new int[] { 2006, 2, 10, 0, 0, 0 }, "dd");

        assertEqualDuration("09 12", new int[] { 2006, 1, 20, 0, 0, 0 }, new int[] { 2006, 11, 4, 0, 0, 0 }, "MM dd");
        assertEqualDuration("287", new int[] { 2006, 1, 20, 0, 0, 0 }, new int[] { 2006, 11, 4, 0, 0, 0 }, "dd");

        assertEqualDuration("11 30", new int[] { 2006, 0, 2, 0, 0, 0 }, new int[] { 2007, 0, 1, 0, 0, 0 }, "MM dd");
        assertEqualDuration("364", new int[] { 2006, 0, 2, 0, 0, 0 }, new int[] { 2007, 0, 1, 0, 0, 0 }, "dd");

        assertEqualDuration("12 00", new int[] { 2006, 0, 1, 0, 0, 0 }, new int[] { 2007, 0, 1, 0, 0, 0 }, "MM dd");
        assertEqualDuration("365", new int[] { 2006, 0, 1, 0, 0, 0 }, new int[] { 2007, 0, 1, 0, 0, 0 }, "dd");

        assertEqualDuration("31", new int[] { 2006, 0, 1, 0, 0, 0 }, new int[] { 2006, 1, 1, 0, 0, 0 }, "dd");

        assertEqualDuration("92", new int[] { 2005, 9, 1, 0, 0, 0 }, new int[] { 2006, 0, 1, 0, 0, 0 }, "dd");
        assertEqualDuration("77", new int[] { 2005, 9, 16, 0, 0, 0 }, new int[] { 2006, 0, 1, 0, 0, 0 }, "dd");

        // test month larger in start than end
        assertEqualDuration("136", new int[] { 2005, 9, 16, 0, 0, 0 }, new int[] { 2006, 2, 1, 0, 0, 0 }, "dd");
        // test when start in leap year
        assertEqualDuration("136", new int[] { 2004, 9, 16, 0, 0, 0 }, new int[] { 2005, 2, 1, 0, 0, 0 }, "dd");
        // test when end in leap year
        assertEqualDuration("137", new int[] { 2003, 9, 16, 0, 0, 0 }, new int[] { 2004, 2, 1, 0, 0, 0 }, "dd");
        // test when end in leap year but less than end of feb
        assertEqualDuration("135", new int[] { 2003, 9, 16, 0, 0, 0 }, new int[] { 2004, 1, 28, 0, 0, 0 }, "dd");

        assertEqualDuration("364", new int[] { 2007, 0, 2, 0, 0, 0 }, new int[] { 2008, 0, 1, 0, 0, 0 }, "dd");
        assertEqualDuration("729", new int[] { 2006, 0, 2, 0, 0, 0 }, new int[] { 2008, 0, 1, 0, 0, 0 }, "dd");

        assertEqualDuration("365", new int[] { 2007, 2, 2, 0, 0, 0 }, new int[] { 2008, 2, 1, 0, 0, 0 }, "dd");
        assertEqualDuration("333", new int[] { 2007, 1, 2, 0, 0, 0 }, new int[] { 2008, 0, 1, 0, 0, 0 }, "dd");

        assertEqualDuration("28", new int[] { 2008, 1, 2, 0, 0, 0 }, new int[] { 2008, 2, 1, 0, 0, 0 }, "dd");
        assertEqualDuration("393", new int[] { 2007, 1, 2, 0, 0, 0 }, new int[] { 2008, 2, 1, 0, 0, 0 }, "dd");

        assertEqualDuration("369", new int[] { 2004, 0, 29, 0, 0, 0 }, new int[] { 2005, 1, 1, 0, 0, 0 }, "dd");

        assertEqualDuration("338", new int[] { 2004, 1, 29, 0, 0, 0 }, new int[] { 2005, 1, 1, 0, 0, 0 }, "dd");

        assertEqualDuration("28", new int[] { 2004, 2, 8, 0, 0, 0 }, new int[] { 2004, 3, 5, 0, 0, 0 }, "dd");

        assertEqualDuration("48", new int[] { 1992, 1, 29, 0, 0, 0 }, new int[] { 1996, 1, 29, 0, 0, 0 }, "M");

        // this seems odd - and will fail if I throw it in as a brute force
        // below as it expects the answer to be 12. It's a tricky edge case
        assertEqualDuration("11", new int[] { 1996, 1, 29, 0, 0, 0 }, new int[] { 1997, 1, 28, 0, 0, 0 }, "M");
        // again - this seems odd
        assertEqualDuration("11 28", new int[] { 1996, 1, 29, 0, 0, 0 }, new int[] { 1997, 1, 28, 0, 0, 0 }, "M d");

    }

    @Test
    public void testEmptyOptionals() {
        assertEquals("", DurationFormatUtils.formatDuration(0L, "[d'd'][H'h'][m'm'][s's']"));
        assertEquals("", DurationFormatUtils.formatDuration(0L, "['d''h''m''s's]"));
    }

    @Test
    public void testFormatDuration() {
        long duration = 0;
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "y"));
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "M"));
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "d"));
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "H"));
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "m"));
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "s"));
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "S"));
        assertEquals("0000", DurationFormatUtils.formatDuration(duration, "SSSS"));
        assertEquals("0000", DurationFormatUtils.formatDuration(duration, "yyyy"));
        assertEquals("0000", DurationFormatUtils.formatDuration(duration, "yyMM"));

        duration = 60 * 1000;
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "y"));
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "M"));
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "d"));
        assertEquals("0", DurationFormatUtils.formatDuration(duration, "H"));
        assertEquals("1", DurationFormatUtils.formatDuration(duration, "m"));
        assertEquals("60", DurationFormatUtils.formatDuration(duration, "s"));
        assertEquals("60000", DurationFormatUtils.formatDuration(duration, "S"));
        assertEquals("01:00", DurationFormatUtils.formatDuration(duration, "mm:ss"));

        final Calendar base = Calendar.getInstance();
        base.set(2000, Calendar.JANUARY, 1, 0, 0, 0);
        base.set(Calendar.MILLISECOND, 0);

        final Calendar cal = Calendar.getInstance();
        cal.set(2003, Calendar.FEBRUARY, 1, 0, 0, 0);
        cal.set(Calendar.MILLISECOND, 0);
        duration = cal.getTime().getTime() - base.getTime().getTime(); // duration from 2000-01-01 to cal
        // don't use 1970 in test as time zones were less reliable in 1970 than now
        // remember that duration formatting ignores time zones, working on strict hour lengths
        final int days = 366 + 365 + 365 + 31;
        assertEquals("0 0 " + days, DurationFormatUtils.formatDuration(duration, "y M d"));
    }

    @Test
    public void testFormatDurationHMS() {
        long time = 0;
        assertEquals("00:00:00.000", DurationFormatUtils.formatDurationHMS(time));

        time = 1;
        assertEquals("00:00:00.001", DurationFormatUtils.formatDurationHMS(time));

        time = 15;
        assertEquals("00:00:00.015", DurationFormatUtils.formatDurationHMS(time));

        time = 165;
        assertEquals("00:00:00.165", DurationFormatUtils.formatDurationHMS(time));

        time = 1675;
        assertEquals("00:00:01.675", DurationFormatUtils.formatDurationHMS(time));

        time = 13465;
        assertEquals("00:00:13.465", DurationFormatUtils.formatDurationHMS(time));

        time = 72789;
        assertEquals("00:01:12.789", DurationFormatUtils.formatDurationHMS(time));

        time = 12789 + 32 * 60000;
        assertEquals("00:32:12.789", DurationFormatUtils.formatDurationHMS(time));

        time = 12789 + 62 * 60000;
        assertEquals("01:02:12.789", DurationFormatUtils.formatDurationHMS(time));
    }

    @Test
    public void testFormatDurationISO() {
        assertEquals("P0Y0M0DT0H0M0.000S", DurationFormatUtils.formatDurationISO(0L));
        assertEquals("P0Y0M0DT0H0M0.001S", DurationFormatUtils.formatDurationISO(1L));
        assertEquals("P0Y0M0DT0H0M0.010S", DurationFormatUtils.formatDurationISO(10L));
        assertEquals("P0Y0M0DT0H0M0.100S", DurationFormatUtils.formatDurationISO(100L));
        assertEquals("P0Y0M0DT0H1M15.321S", DurationFormatUtils.formatDurationISO(75321L));
    }

    /**
     * Tests that "1 &lt;unit&gt;s" gets converted to "1 &lt;unit&gt;" but that "11 &lt;unit&gt;s" is left alone.
     */
    @Test
    public void testFormatDurationPluralWords() {
        final long oneSecond = 1000;
        final long oneMinute = oneSecond * 60;
        final long oneHour = oneMinute * 60;
        final long oneDay = oneHour * 24;
        String text;

        text = DurationFormatUtils.formatDurationWords(oneSecond, false, false);
        assertEquals("0 days 0 hours 0 minutes 1 second", text);
        text = DurationFormatUtils.formatDurationWords(oneSecond * 2, false, false);
        assertEquals("0 days 0 hours 0 minutes 2 seconds", text);
        text = DurationFormatUtils.formatDurationWords(oneSecond * 11, false, false);
        assertEquals("0 days 0 hours 0 minutes 11 seconds", text);

        text = DurationFormatUtils.formatDurationWords(oneMinute, false, false);
        assertEquals("0 days 0 hours 1 minute 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(oneMinute * 2, false, false);
        assertEquals("0 days 0 hours 2 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(oneMinute * 11, false, false);
        assertEquals("0 days 0 hours 11 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(oneMinute + oneSecond, false, false);
        assertEquals("0 days 0 hours 1 minute 1 second", text);

        text = DurationFormatUtils.formatDurationWords(oneHour, false, false);
        assertEquals("0 days 1 hour 0 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(oneHour * 2, false, false);
        assertEquals("0 days 2 hours 0 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(oneHour * 11, false, false);
        assertEquals("0 days 11 hours 0 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(oneHour + oneMinute + oneSecond, false, false);
        assertEquals("0 days 1 hour 1 minute 1 second", text);

        text = DurationFormatUtils.formatDurationWords(oneDay, false, false);
        assertEquals("1 day 0 hours 0 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(oneDay * 2, false, false);
        assertEquals("2 days 0 hours 0 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(oneDay * 11, false, false);
        assertEquals("11 days 0 hours 0 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(oneDay + oneHour + oneMinute + oneSecond, false, false);
        assertEquals("1 day 1 hour 1 minute 1 second", text);
    }

    @Test
    public void testFormatDurationWords() {
        String text;

        text = DurationFormatUtils.formatDurationWords(50 * 1000, true, false);
        assertEquals("50 seconds", text);
        text = DurationFormatUtils.formatDurationWords(65 * 1000, true, false);
        assertEquals("1 minute 5 seconds", text);
        text = DurationFormatUtils.formatDurationWords(120 * 1000, true, false);
        assertEquals("2 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(121 * 1000, true, false);
        assertEquals("2 minutes 1 second", text);
        text = DurationFormatUtils.formatDurationWords(72 * 60 * 1000, true, false);
        assertEquals("1 hour 12 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(24 * 60 * 60 * 1000, true, false);
        assertEquals("1 day 0 hours 0 minutes 0 seconds", text);

        text = DurationFormatUtils.formatDurationWords(50 * 1000, true, true);
        assertEquals("50 seconds", text);
        text = DurationFormatUtils.formatDurationWords(65 * 1000, true, true);
        assertEquals("1 minute 5 seconds", text);
        text = DurationFormatUtils.formatDurationWords(120 * 1000, true, true);
        assertEquals("2 minutes", text);
        text = DurationFormatUtils.formatDurationWords(121 * 1000, true, true);
        assertEquals("2 minutes 1 second", text);
        text = DurationFormatUtils.formatDurationWords(72 * 60 * 1000, true, true);
        assertEquals("1 hour 12 minutes", text);
        text = DurationFormatUtils.formatDurationWords(24 * 60 * 60 * 1000, true, true);
        assertEquals("1 day", text);

        text = DurationFormatUtils.formatDurationWords(50 * 1000, false, true);
        assertEquals("0 days 0 hours 0 minutes 50 seconds", text);
        text = DurationFormatUtils.formatDurationWords(65 * 1000, false, true);
        assertEquals("0 days 0 hours 1 minute 5 seconds", text);
        text = DurationFormatUtils.formatDurationWords(120 * 1000, false, true);
        assertEquals("0 days 0 hours 2 minutes", text);
        text = DurationFormatUtils.formatDurationWords(121 * 1000, false, true);
        assertEquals("0 days 0 hours 2 minutes 1 second", text);
        text = DurationFormatUtils.formatDurationWords(72 * 60 * 1000, false, true);
        assertEquals("0 days 1 hour 12 minutes", text);
        text = DurationFormatUtils.formatDurationWords(24 * 60 * 60 * 1000, false, true);
        assertEquals("1 day", text);

        text = DurationFormatUtils.formatDurationWords(50 * 1000, false, false);
        assertEquals("0 days 0 hours 0 minutes 50 seconds", text);
        text = DurationFormatUtils.formatDurationWords(65 * 1000, false, false);
        assertEquals("0 days 0 hours 1 minute 5 seconds", text);
        text = DurationFormatUtils.formatDurationWords(120 * 1000, false, false);
        assertEquals("0 days 0 hours 2 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(121 * 1000, false, false);
        assertEquals("0 days 0 hours 2 minutes 1 second", text);
        text = DurationFormatUtils.formatDurationWords(72 * 60 * 1000, false, false);
        assertEquals("0 days 1 hour 12 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(24 * 60 * 60 * 1000 + 72 * 60 * 1000, false, false);
        assertEquals("1 day 1 hour 12 minutes 0 seconds", text);
        text = DurationFormatUtils.formatDurationWords(2 * 24 * 60 * 60 * 1000 + 72 * 60 * 1000, false, false);
        assertEquals("2 days 1 hour 12 minutes 0 seconds", text);
        for (int i = 2; i < 31; i++) {
            text = DurationFormatUtils.formatDurationWords(i * 24 * 60 * 60 * 1000L, false, false);
            assertEquals(i + " days 0 hours 0 minutes 0 seconds", text);
        }
    }

    @Test
    public void testFormatNegativeDuration() {
        assertThrows(IllegalArgumentException.class, () -> DurationFormatUtils.formatDuration(-5000, "S", true));
    }

    @Test
    public void testFormatNegativeDurationHMS() {
        assertThrows(IllegalArgumentException.class, () -> DurationFormatUtils.formatDurationHMS(-5000));
    }

    @Test
    public void testFormatNegativeDurationISO() {
        assertThrows(IllegalArgumentException.class, () -> DurationFormatUtils.formatDurationISO(-5000));
    }

    @Test
    public void testFormatNegativeDurationWords() {
        assertThrows(IllegalArgumentException.class, () -> DurationFormatUtils.formatDurationWords(-5000, true, true));
    }

    @Test
    public void testFormatPeriod() {
        final Calendar cal1970 = Calendar.getInstance();
        cal1970.set(1970, Calendar.JANUARY, 1, 0, 0, 0);
        cal1970.set(Calendar.MILLISECOND, 0);
        final long time1970 = cal1970.getTime().getTime();

        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time1970, "y"));
        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time1970, "M"));
        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time1970, "d"));
        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time1970, "H"));
        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time1970, "m"));
        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time1970, "s"));
        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time1970, "S"));
        assertEquals("0000", DurationFormatUtils.formatPeriod(time1970, time1970, "SSSS"));
        assertEquals("0000", DurationFormatUtils.formatPeriod(time1970, time1970, "yyyy"));
        assertEquals("0000", DurationFormatUtils.formatPeriod(time1970, time1970, "yyMM"));

        long time = time1970 + 60 * 1000;
        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time, "y"));
        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time, "M"));
        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time, "d"));
        assertEquals("0", DurationFormatUtils.formatPeriod(time1970, time, "H"));
        assertEquals("1", DurationFormatUtils.formatPeriod(time1970, time, "m"));
        assertEquals("60", DurationFormatUtils.formatPeriod(time1970, time, "s"));
        assertEquals("60000", DurationFormatUtils.formatPeriod(time1970, time, "S"));
        assertEquals("01:00", DurationFormatUtils.formatPeriod(time1970, time, "mm:ss"));

        final Calendar cal = Calendar.getInstance();
        cal.set(1973, Calendar.JULY, 1, 0, 0, 0);
        cal.set(Calendar.MILLISECOND, 0);
        time = cal.getTime().getTime();
        assertEquals("36", DurationFormatUtils.formatPeriod(time1970, time, "yM"));
        assertEquals("3 years 6 months", DurationFormatUtils.formatPeriod(time1970, time, "y' years 'M' months'"));
        assertEquals("03/06", DurationFormatUtils.formatPeriod(time1970, time, "yy/MM"));

        cal.set(1973, Calendar.NOVEMBER, 1, 0, 0, 0);
        cal.set(Calendar.MILLISECOND, 0);
        time = cal.getTime().getTime();
        assertEquals("310", DurationFormatUtils.formatPeriod(time1970, time, "yM"));
        assertEquals("3 years 10 months", DurationFormatUtils.formatPeriod(time1970, time, "y' years 'M' months'"));
        assertEquals("03/10", DurationFormatUtils.formatPeriod(time1970, time, "yy/MM"));

        cal.set(1974, Calendar.JANUARY, 1, 0, 0, 0);
        cal.set(Calendar.MILLISECOND, 0);
        time = cal.getTime().getTime();
        assertEquals("40", DurationFormatUtils.formatPeriod(time1970, time, "yM"));
        assertEquals("4 years 0 months", DurationFormatUtils.formatPeriod(time1970, time, "y' ''years' M 'months'"));
        assertEquals("4 years 0 months", DurationFormatUtils.formatPeriod(time1970, time, "y' years 'M' months'"));
        assertEquals("4years 0months", DurationFormatUtils.formatPeriod(time1970, time, "y'years 'M'months'"));
        assertEquals("04/00", DurationFormatUtils.formatPeriod(time1970, time, "yy/MM"));
        assertEquals("48", DurationFormatUtils.formatPeriod(time1970, time, "M"));
        assertEquals("48", DurationFormatUtils.formatPeriod(time1970, time, "MM"));
        assertEquals("048", DurationFormatUtils.formatPeriod(time1970, time, "MMM"));
        // no date in result
        assertEquals("hello", DurationFormatUtils.formatPeriod(time1970, time, "'hello'"));
        assertEquals("helloworld", DurationFormatUtils.formatPeriod(time1970, time, "'hello''world'"));
    }

    @Test
    public void testFormatPeriodeStartGreaterEnd() {
        assertThrows(IllegalArgumentException.class, () -> DurationFormatUtils.formatPeriod(5000, 2500, "yy/MM"));
    }

    @SuppressWarnings("deprecation")
    @Test
    public void testFormatPeriodISO() {
        final TimeZone timeZone = TimeZone.getTimeZone("GMT-3");
        final Calendar base = Calendar.getInstance(timeZone);
        base.set(1970, Calendar.JANUARY, 1, 0, 0, 0);
        base.set(Calendar.MILLISECOND, 0);

        final Calendar cal = Calendar.getInstance(timeZone);
        cal.set(2002, Calendar.FEBRUARY, 23, 9, 11, 12);
        cal.set(Calendar.MILLISECOND, 1);
        String text;
        // repeat a test from testDateTimeISO to compare extended and not extended.
        text = DateFormatUtils.format(cal, DateFormatUtils.ISO_DATETIME_TIME_ZONE_FORMAT.getPattern(), timeZone);
        assertEquals("2002-02-23T09:11:12-03:00", text);
        // test fixture is the same as above, but now with extended format.
        text = DurationFormatUtils.formatPeriod(base.getTime().getTime(), cal.getTime().getTime(),
                DurationFormatUtils.ISO_EXTENDED_FORMAT_PATTERN, false, timeZone);
        assertEquals("P32Y1M22DT9H11M12.001S", text);
        // test fixture from example in https://www.w3.org/TR/xmlschema-2/#duration
        cal.set(1971, Calendar.FEBRUARY, 3, 10, 30, 0);
        cal.set(Calendar.MILLISECOND, 0);
        text = DurationFormatUtils.formatPeriod(base.getTime().getTime(), cal.getTime().getTime(),
                DurationFormatUtils.ISO_EXTENDED_FORMAT_PATTERN, false, timeZone);
        assertEquals("P1Y1M2DT10H30M0.000S", text);
        // want a way to say 'don't print the seconds in format()' or other fields for that matter:
        // assertEquals("P1Y2M3DT10H30M", text);
        //
        // TODO Jacoco shows missing coverage for internal negative days
    }

    @Test
    public void testFormatPeriodISOMethod() {
        assertEquals("P0Y0M0DT0H0M0.000S", DurationFormatUtils.formatPeriodISO(0L, 0L));
        assertEquals("P0Y0M0DT0H0M1.000S", DurationFormatUtils.formatPeriodISO(0L, 1000L));
        assertEquals("P0Y0M0DT0H1M1.000S", DurationFormatUtils.formatPeriodISO(0L, 61000L));
    }

    @Test
    public void testFormatPeriodISOStartGreaterEnd() {
        assertThrows(IllegalArgumentException.class, () -> DurationFormatUtils.formatPeriodISO(5000, 2000));
    }

    // https://issues.apache.org/jira/browse/LANG-281
    @Test
    public void testJiraLang281() {
        assertEqualDuration("09", new int[] { 2005, 11, 31, 0, 0, 0 }, new int[] { 2006, 9, 6, 0, 0, 0 }, "MM");
    }

    /**
     * Takes 8 seconds to run.
     */
    @Test
    public void testFourYears() {
        Calendar c = Calendar.getInstance();
        c.set(2004, 0, 1, 0, 0, 0);
        for (int i = 0; i < FOUR_YEARS; i++) {
            bruteForce(c.get(Calendar.YEAR), c.get(Calendar.MONTH), c.get(Calendar.DAY_OF_MONTH), "d", Calendar.DAY_OF_MONTH);
            c.add(Calendar.DAY_OF_MONTH, 1);
        }
    }

    @Test
    public void testLANG815() {
        final Calendar calendar = Calendar.getInstance();
        calendar.set(2012, Calendar.JULY, 30, 0, 0, 0);
        final long startMillis = calendar.getTimeInMillis();

        calendar.set(2012, Calendar.SEPTEMBER, 8);
        final long endMillis = calendar.getTimeInMillis();

        assertEquals("1 9", DurationFormatUtils.formatPeriod(startMillis, endMillis, "M d"));
    }

    @Test
    public void testLANG981() { // unmatched quote char in lexx
        assertThrows(IllegalArgumentException.class, () -> DurationFormatUtils.lexx("'yMdHms''S"));
    }
    @Test
    public void testLANG982() { // More than 3 millisecond digits following a second
        assertEquals("61.999", DurationFormatUtils.formatDuration(61999, "s.S"));
        assertEquals("1 1999", DurationFormatUtils.formatDuration(61999, "m S"));
        assertEquals("61.999", DurationFormatUtils.formatDuration(61999, "s.SSS"));
        assertEquals("1 1999", DurationFormatUtils.formatDuration(61999, "m SSS"));
        assertEquals("61.0999", DurationFormatUtils.formatDuration(61999, "s.SSSS"));
        assertEquals("1 1999", DurationFormatUtils.formatDuration(61999, "m SSSS"));
        assertEquals("61.00999", DurationFormatUtils.formatDuration(61999, "s.SSSSS"));
        assertEquals("1 01999", DurationFormatUtils.formatDuration(61999, "m SSSSS"));
    }

    @Test
    public void testLANG984() { // Long durations
        assertEquals("0", DurationFormatUtils.formatDuration(0, "S"));
        assertEquals(Integer.toString(Integer.MAX_VALUE), DurationFormatUtils.formatDuration(Integer.MAX_VALUE, "S"));
        long maxIntPlus = Integer.MAX_VALUE;
        maxIntPlus++;
        assertEquals(Long.toString(maxIntPlus), DurationFormatUtils.formatDuration(maxIntPlus, "S"));
        assertEquals(Long.toString(Long.MAX_VALUE), DurationFormatUtils.formatDuration(Long.MAX_VALUE, "S"));
    }

    @Test
    public void testLexx() {
        // tests each constant
        assertArrayEquals(new DurationFormatUtils.Token[] {
            createTokenWithCount(DurationFormatUtils.y, 1),
            createTokenWithCount(DurationFormatUtils.M, 1),
            createTokenWithCount(DurationFormatUtils.d, 1),
            createTokenWithCount(DurationFormatUtils.H, 1),
            createTokenWithCount(DurationFormatUtils.m, 1),
            createTokenWithCount(DurationFormatUtils.s, 1),
            createTokenWithCount(DurationFormatUtils.S, 1) }, DurationFormatUtils.lexx("yMdHmsS"));

        // tests the ISO 8601-like
        assertArrayEquals(new DurationFormatUtils.Token[] {
            createTokenWithCount(DurationFormatUtils.H, 2),
            createTokenWithCount(new StringBuilder(":"), 1),
            createTokenWithCount(DurationFormatUtils.m, 2),
            createTokenWithCount(new StringBuilder(":"), 1),
            createTokenWithCount(DurationFormatUtils.s, 2),
            createTokenWithCount(new StringBuilder("."), 1),
            createTokenWithCount(DurationFormatUtils.S, 3) }, DurationFormatUtils.lexx("HH:mm:ss.SSS"));

        // test the iso extended format
        assertArrayEquals(new DurationFormatUtils.Token[] {
            createTokenWithCount(new StringBuilder("P"), 1),
            createTokenWithCount(DurationFormatUtils.y, 4),
            createTokenWithCount(new StringBuilder("Y"), 1),
            createTokenWithCount(DurationFormatUtils.M, 1),
            createTokenWithCount(new StringBuilder("M"), 1),
            createTokenWithCount(DurationFormatUtils.d, 1),
            createTokenWithCount(new StringBuilder("DT"), 1),
            createTokenWithCount(DurationFormatUtils.H, 1),
            createTokenWithCount(new StringBuilder("H"), 1),
            createTokenWithCount(DurationFormatUtils.m, 1),
            createTokenWithCount(new StringBuilder("M"), 1),
            createTokenWithCount(DurationFormatUtils.s, 1),
            createTokenWithCount(new StringBuilder("."), 1),
            createTokenWithCount(DurationFormatUtils.S, 3),
            createTokenWithCount(new StringBuilder("S"), 1) }, DurationFormatUtils.lexx(DurationFormatUtils.ISO_EXTENDED_FORMAT_PATTERN));

        // test failures in equals
        final DurationFormatUtils.Token token = createTokenWithCount(DurationFormatUtils.y, 4);
        assertEquals(token, token);
        assertEquals(token.hashCode(), token.hashCode());
        assertNotEquals(token, new Object(), "Token equal to non-Token class. ");
        final Token token2 = createTokenWithCount("", 1);
        assertNotEquals(token, token2, "Token equal to Token with wrong value class. ");
        assertNotEquals(token.hashCode(), token2.hashCode());
        assertNotEquals(token, createTokenWithCount(DurationFormatUtils.y, 1), "Token equal to Token with different count. ");
        final DurationFormatUtils.Token numToken = createTokenWithCount("1", 4);
        assertEquals(numToken, numToken, "Token with Number value not equal to itself. ");
    }

    @Test
    public void testLiteralPrefixOptionalToken() {
        assertEquals(DurationFormatUtils.formatDuration(10000L, "s's'"), DurationFormatUtils.formatDuration(10000L, "['['d']']['<'H'>']['{'m'}']s's'"));
        assertEquals(DurationFormatUtils.formatDuration(10000L, "s's'"), DurationFormatUtils.formatDuration(10000L, "['{'m'}']s's'"));
    }

    // Testing the under a day range in DurationFormatUtils.formatPeriod
    @Test
    public void testLowDurations() {
        for (int hr = 0; hr < 24; hr++) {
            for (int min = 0; min < 60; min++) {
                for (int sec = 0; sec < 60; sec++) {
                    assertEqualDuration(hr + ":" + min + ":" + sec, new int[] { 2000, 0, 1, 0, 0, 0, 0 }, new int[] { 2000, 0, 1, hr, min, sec }, "H:m:s");
                }
            }
        }
    }

    @Test
    public void testMultipleOptionalBlocks() {
        assertEquals(DurationFormatUtils.formatDuration(Duration.ofHours(1).toMillis(), "'[['H']]'"),
                DurationFormatUtils.formatDuration(Duration.ofHours(1).toMillis(), "['{'d'}']['[['H']]']"));
        assertEquals(DurationFormatUtils.formatDuration(Duration.ofDays(1).toMillis(), "['{'d'}']"),
                DurationFormatUtils.formatDuration(Duration.ofDays(1).toMillis(), "['{'d'}']['['H']']"));
    }

    @Test
    public void testOptionalLiteralSpecialCharacters() {
      assertEquals(
          DurationFormatUtils.formatDuration(10000L, "s's'"),
          DurationFormatUtils.formatDuration(10000L, "['['m']']s's'"));
    }

    @Test
    public void testOptionalToken() {

        //make sure optional formats match corresponding adjusted non-optional formats
        assertEquals(
                DurationFormatUtils.formatDuration(915361000L, "d'd'H'h'm'm's's'"),
                DurationFormatUtils.formatDuration(915361000L, "[d'd'H'h'm'm']s's'"));

        assertEquals(
                DurationFormatUtils.formatDuration(9153610L, "H'h'm'm's's'"),
                DurationFormatUtils.formatDuration(9153610L, "[d'd'H'h'm'm']s's'"));

        assertEquals(
                DurationFormatUtils.formatDuration(915361L, "m'm's's'"),
                DurationFormatUtils.formatDuration(915361L, "[d'd'H'h'm'm']s's'"));

        assertEquals(
                DurationFormatUtils.formatDuration(9153L, "s's'"),
                DurationFormatUtils.formatDuration(9153L, "[d'd'H'h'm'm']s's'"));

        assertEquals(
                DurationFormatUtils.formatDuration(9153L, "s's'"),
                DurationFormatUtils.formatDuration(9153L, "[d'd'H'h'm'm']s's'"));

        assertEquals(
                DurationFormatUtils.formatPeriod(9153610L, 915361000L, "d'd'H'h'm'm's's'"),
                DurationFormatUtils.formatPeriod(9153610L, 915361000L, "[d'd'H'h'm'm']s's'"));

        assertEquals(
                DurationFormatUtils.formatPeriod(915361L, 9153610L, "H'h'm'm's's'"),
                DurationFormatUtils.formatPeriod(915361L, 9153610L, "[d'd'H'h'm'm']s's'"));

        assertEquals(
                DurationFormatUtils.formatPeriod(9153L, 915361L, "m'm's's'"),
                DurationFormatUtils.formatPeriod(9153L, 915361L, "[d'd'H'h'm'm']s's'"));

        assertEquals(
                DurationFormatUtils.formatPeriod(0L, 9153L, "s's'"),
                DurationFormatUtils.formatPeriod(0L, 9153L, "[d'd'H'h'm'm']s's'"));

        //make sure optional parts are actually omitted when zero

        assertEquals("2h32m33s610ms", DurationFormatUtils.formatDuration(9153610L, "[d'd'H'h'm'm's's']S'ms'"));

        assertEquals("15m15s361ms", DurationFormatUtils.formatDuration(915361L, "[d'd'H'h'm'm's's']S'ms'"));

        assertEquals("9s153ms", DurationFormatUtils.formatDuration(9153L, "[d'd'H'h'm'm's's']S'ms'"));

        assertEquals("915ms", DurationFormatUtils.formatDuration(915L, "[d'd'H'h'm'm's's']S'ms'"));

        //make sure we can handle omitting multiple literals after a token

        assertEquals(
                DurationFormatUtils.formatPeriod(915361L, 9153610L, "H'h''h2'm'm's's'"),
                DurationFormatUtils.formatPeriod(915361L, 9153610L, "[d'd''d2'H'h''h2'm'm']s's'"));
    }

    @Test
    public void testUnmatchedOptionalTokens() {
        assertThrows(IllegalArgumentException.class, () -> DurationFormatUtils.formatDuration(1, "[s"));
        assertThrows(IllegalArgumentException.class, () -> DurationFormatUtils.formatDuration(1, "[[s"));
        assertThrows(IllegalArgumentException.class, () -> DurationFormatUtils.formatDuration(1, "[s]]"));
    }
}
