// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html#License
/*
 ********************************************************************************
 * Copyright (C) 2007-2016, Google, International Business Machines Corporation
 * and others. All Rights Reserved.
 ********************************************************************************
 */

package com.ibm.icu.dev.test.format;

import java.text.FieldPosition;
import java.text.ParseException;
import java.text.ParsePosition;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Date;
import java.util.EnumSet;
import java.util.List;
import java.util.Locale;
import java.util.Random;
import java.util.Set;
import java.util.TreeSet;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.regex.Pattern;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

import com.ibm.icu.dev.test.TestFmwk;
import com.ibm.icu.impl.TZDBTimeZoneNames;
import com.ibm.icu.impl.ZoneMeta;
import com.ibm.icu.lang.UCharacter;
import com.ibm.icu.text.DateFormat;
import com.ibm.icu.text.SimpleDateFormat;
import com.ibm.icu.text.TimeZoneFormat;
import com.ibm.icu.text.TimeZoneFormat.GMTOffsetPatternType;
import com.ibm.icu.text.TimeZoneFormat.ParseOption;
import com.ibm.icu.text.TimeZoneFormat.Style;
import com.ibm.icu.text.TimeZoneFormat.TimeType;
import com.ibm.icu.text.TimeZoneNames;
import com.ibm.icu.text.TimeZoneNames.Factory;
import com.ibm.icu.text.TimeZoneNames.NameType;
import com.ibm.icu.util.BasicTimeZone;
import com.ibm.icu.util.Calendar;
import com.ibm.icu.util.Output;
import com.ibm.icu.util.SimpleTimeZone;
import com.ibm.icu.util.TimeZone;
import com.ibm.icu.util.TimeZone.SystemTimeZoneType;
import com.ibm.icu.util.TimeZoneTransition;
import com.ibm.icu.util.ULocale;

@RunWith(JUnit4.class)
public class TimeZoneFormatTest extends TestFmwk {

    private static boolean JDKTZ = (TimeZone.getDefaultTimeZoneType() == TimeZone.TIMEZONE_JDK);
    private static final Pattern EXCL_TZ_PATTERN = Pattern.compile(".*/Riyadh8[7-9]");

    private static final String[] PATTERNS = {
        "z",
        "zzzz",
        "Z",        // equivalent to "xxxx"
        "ZZZZ",     // equivalent to "OOOO"
        "v",
        "vvvv",
        "O",
        "OOOO",
        "X",
        "XX",
        "XXX",
        "XXXX",
        "XXXXX",
        "x",
        "xx",
        "xxx",
        "xxxx",
        "xxxxx",
        "V",
        "VV",
        "VVV",
        "VVVV"
    };
    boolean REALLY_VERBOSE_LOG = false;

    /*
     * Test case for checking if a TimeZone is properly set in the result calendar
     * and if the result TimeZone has the expected behavior.
     */
    @Test
    public void TestTimeZoneRoundTrip() {
        boolean TEST_ALL = getBooleanProperty("TimeZoneRoundTripAll", false);

        TimeZone unknownZone = new SimpleTimeZone(-31415, "Etc/Unknown");
        int badDstOffset = -1234;
        int badZoneOffset = -2345;

        int[][] testDateData = {
            {2007, 1, 15},
            {2007, 6, 15},
            {1990, 1, 15},
            {1990, 6, 15},
            {1960, 1, 15},
            {1960, 6, 15},
        };

        Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
        cal.clear();

        // Set up rule equivalency test range
        long low, high;
        cal.set(1900, 0, 1);
        low = cal.getTimeInMillis();
        cal.set(2040, 0, 1);
        high = cal.getTimeInMillis();

        // Set up test dates
        Date[] DATES = new Date[testDateData.length];
        cal.clear();
        for (int i = 0; i < DATES.length; i++) {
            cal.set(testDateData[i][0], testDateData[i][1], testDateData[i][2]);
            DATES[i] = cal.getTime();
        }

        // Set up test locales
        ULocale[] LOCALES = null;
        if (TEST_ALL || TestFmwk.getExhaustiveness() > 5) {
            LOCALES = ULocale.getAvailableLocales();
        } else {
            LOCALES = new ULocale[] {new ULocale("en"), new ULocale("en_CA"), new ULocale("fr"),
                    new ULocale("zh_Hant"), new ULocale("fa"), new ULocale("ccp")};
        }

        String[] tzids;
        if (JDKTZ) {
            tzids = java.util.TimeZone.getAvailableIDs();
        } else {
            tzids = TimeZone.getAvailableIDs();
        }
        int[] inOffsets = new int[2];
        int[] outOffsets = new int[2];

        // Run the roundtrip test
        for (int locidx = 0; locidx < LOCALES.length; locidx++) {
            logln("Locale: " + LOCALES[locidx].toString());

            String localGMTString = TimeZoneFormat.getInstance(LOCALES[locidx]).formatOffsetLocalizedGMT(0);

            for (int patidx = 0; patidx < PATTERNS.length; patidx++) {
                logln("    pattern: " + PATTERNS[patidx]);
                SimpleDateFormat sdf = new SimpleDateFormat(PATTERNS[patidx], LOCALES[locidx]);

                for (int tzidx = 0; tzidx < tzids.length; tzidx++) {
                    if (EXCL_TZ_PATTERN.matcher(tzids[tzidx]).matches()) {
                        continue;
                    }
                    TimeZone tz = TimeZone.getTimeZone(tzids[tzidx]);

                    for (int datidx = 0; datidx < DATES.length; datidx++) {
                        // Format
                        sdf.setTimeZone(tz);
                        String tzstr = sdf.format(DATES[datidx]);

                        // Before parse, set unknown zone to SimpleDateFormat instance
                        // just for making sure that it does not depends on the time zone
                        // originally set.
                        sdf.setTimeZone(unknownZone);

                        // Parse
                        ParsePosition pos = new ParsePosition(0);
                        Calendar outcal = Calendar.getInstance(unknownZone);
                        outcal.set(Calendar.DST_OFFSET, badDstOffset);
                        outcal.set(Calendar.ZONE_OFFSET, badZoneOffset);

                        sdf.parse(tzstr, outcal, pos);

                        // Check the result
                        TimeZone outtz = outcal.getTimeZone();

                        tz.getOffset(DATES[datidx].getTime(), false, inOffsets);
                        outtz.getOffset(DATES[datidx].getTime(), false, outOffsets);

                        if (PATTERNS[patidx].equals("V")) {
                            // Short zone ID - should support roundtrip for canonical CLDR IDs
                            String canonicalID = TimeZone.getCanonicalID(tzids[tzidx]);
                            if (!outtz.getID().equals(canonicalID)) {
                                if (outtz.getID().equals("Etc/Unknown")) {
                                    // Note that some zones like Asia/Riyadh87 does not have
                                    // short zone ID and "unk" is used as the fallback
                                    if (REALLY_VERBOSE_LOG) {
                                        logln("Canonical round trip failed (probably as expected); tz=" + tzids[tzidx]
                                            + ", locale=" + LOCALES[locidx] + ", pattern=" + PATTERNS[patidx]
                                            + ", time=" + DATES[datidx].getTime() + ", str=" + tzstr
                                            + ", outtz=" + outtz.getID());
                                    }
                                } else {
                                    errln("Canonical round trip failed; tz=" + tzids[tzidx]
                                        + ", locale=" + LOCALES[locidx] + ", pattern=" + PATTERNS[patidx]
                                        + ", time=" + DATES[datidx].getTime() + ", str=" + tzstr
                                        + ", outtz=" + outtz.getID());
                                }
                            }
                        } else if (PATTERNS[patidx].equals("VV")) {
                            // Zone ID - full roundtrip support
                            if (!outtz.getID().equals(tzids[tzidx])) {
                                errln("Zone ID round trip failed; tz=" + tzids[tzidx]
                                        + ", locale=" + LOCALES[locidx] + ", pattern=" + PATTERNS[patidx]
                                        + ", time=" + DATES[datidx].getTime() + ", str=" + tzstr
                                        + ", outtz=" + outtz.getID());
                            }
                        } else if (PATTERNS[patidx].equals("VVV") || PATTERNS[patidx].equals("VVVV")) {
                            // Location: time zone rule must be preserved except
                            // zones not actually associated with a specific location.
                            String canonicalID = TimeZone.getCanonicalID(tzids[tzidx]);
                            if (canonicalID != null && !outtz.getID().equals(canonicalID)) {
                                // Canonical ID did not match - check the rules
                                boolean bFailure = false;
                                if ((tz instanceof BasicTimeZone) && (outtz instanceof BasicTimeZone)) {
                                    boolean hasNoLocation = TimeZone.getRegion(tzids[tzidx]).equals("001");
                                    bFailure = !hasNoLocation
                                                && !((BasicTimeZone)outtz).hasEquivalentTransitions(tz, low, high);
                                }
                                if (bFailure) {
                                    errln("Canonical round trip failed; tz=" + tzids[tzidx]
                                            + ", locale=" + LOCALES[locidx] + ", pattern=" + PATTERNS[patidx]
                                            + ", time=" + DATES[datidx].getTime() + ", str=" + tzstr
                                            + ", outtz=" + outtz.getID());
                                } else if (REALLY_VERBOSE_LOG) {
                                    logln("Canonical round trip failed (as expected); tz=" + tzids[tzidx]
                                            + ", locale=" + LOCALES[locidx] + ", pattern=" + PATTERNS[patidx]
                                            + ", time=" + DATES[datidx].getTime() + ", str=" + tzstr
                                            + ", outtz=" + outtz.getID());
                                }
                            }
                        } else {
                            boolean isOffsetFormat = (PATTERNS[patidx].charAt(0) == 'Z'
                                    || PATTERNS[patidx].charAt(0) == 'O'
                                    || PATTERNS[patidx].charAt(0) == 'X'
                                    || PATTERNS[patidx].charAt(0) == 'x');
                            boolean minutesOffset = false;
                            if (PATTERNS[patidx].charAt(0) == 'X' || PATTERNS[patidx].charAt(0) == 'x') {
                                minutesOffset = PATTERNS[patidx].length() <= 3;
                            }

                            if (!isOffsetFormat) {
                                // Check if localized GMT format is used as a fallback of name styles
                                int numDigits = 0;
                                int idx = 0;
                                while (idx < tzstr.length()) {
                                    int cp = tzstr.codePointAt(idx);
                                    if (UCharacter.isDigit(cp)) {
                                        numDigits++;
                                    }
                                    idx += UCharacter.charCount(cp);
                                }
                                isOffsetFormat = (numDigits > 0);
                            }

                            if (isOffsetFormat || tzstr.equals(localGMTString)) {
                                // Localized GMT or ISO: total offset (raw + dst) must be preserved.
                                int inOffset = inOffsets[0] + inOffsets[1];
                                int outOffset = outOffsets[0] + outOffsets[1];
                                int diff = outOffset - inOffset;
                                if (minutesOffset) {
                                    diff = (diff / 60000) * 60000;
                                }
                                if (diff != 0) {
                                    errln("Offset round trip failed; tz=" + tzids[tzidx]
                                        + ", locale=" + LOCALES[locidx] + ", pattern=" + PATTERNS[patidx]
                                        + ", time=" + DATES[datidx].getTime() + ", str=" + tzstr
                                        + ", inOffset=" + inOffset + ", outOffset=" + outOffset);
                                }
                            } else {
                                // Specific or generic: raw offset must be preserved.
                                if (inOffsets[0] != outOffsets[0]) {
                                    if (JDKTZ && tzids[tzidx].startsWith("SystemV/")) {
                                        // JDK uses rule SystemV for these zones while
                                        // ICU handles these zones as aliases of existing time zones
                                        if (REALLY_VERBOSE_LOG) {
                                            logln("Raw offset round trip failed; tz=" + tzids[tzidx]
                                                + ", locale=" + LOCALES[locidx] + ", pattern=" + PATTERNS[patidx]
                                                + ", time=" + DATES[datidx].getTime() + ", str=" + tzstr
                                                + ", inRawOffset=" + inOffsets[0] + ", outRawOffset=" + outOffsets[0]);
                                        }

                                    } else {
                                        errln("Raw offset round trip failed; tz=" + tzids[tzidx]
                                            + ", locale=" + LOCALES[locidx] + ", pattern=" + PATTERNS[patidx]
                                            + ", time=" + DATES[datidx].getTime() + ", str=" + tzstr
                                            + ", inRawOffset=" + inOffsets[0] + ", outRawOffset=" + outOffsets[0]);
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }

    }

    /*
     * Test case of round trip time and text.  This test case detects every canonical TimeZone's
     * rule transition since 1900 until 2020, then check if time around each transition can
     * round trip as expected.
     */
    @Test
    public void TestTimeRoundTrip() {

        boolean TEST_ALL = getBooleanProperty("TimeZoneRoundTripAll", false);

        int startYear, endYear;

        if (TEST_ALL || TestFmwk.getExhaustiveness() > 5) {
            startYear = 1900;
        } else {
            startYear = 1990;
        }

        Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
        endYear = cal.get(Calendar.YEAR) + 3;

        cal.set(startYear, Calendar.JANUARY, 1);
        final long START_TIME = cal.getTimeInMillis();

        cal.set(endYear, Calendar.JANUARY, 1);
        final long END_TIME = cal.getTimeInMillis();

        // These patterns are ambiguous at DST->STD local time overlap
        List<String> AMBIGUOUS_DST_DECESSION = Arrays.asList("v", "vvvv", "V", "VV", "VVV", "VVVV");

        // These patterns are ambiguous at STD->STD/DST->DST local time overlap
        List<String> AMBIGUOUS_NEGATIVE_SHIFT = Arrays.asList("z", "zzzz", "v", "vvvv", "V", "VV", "VVV", "VVVV");

        // These patterns only support integer minutes offset
        List<String> MINUTES_OFFSET = Arrays.asList("X", "XX", "XXX", "x", "xx", "xxx");

        // Regex pattern used for filtering zone IDs without exemplar location
        final Pattern LOC_EXCLUSION_PATTERN = Pattern.compile("Etc/.*|SystemV/.*|.*/Riyadh8[7-9]");

        final String BASEPATTERN = "yyyy-MM-dd'T'HH:mm:ss.SSS";

        ULocale[] LOCALES = null;

        // timer for performance analysis
        long[] times = new long[PATTERNS.length];
        long timer;

        if (TEST_ALL) {
            // It may take about an hour for testing all locales
            LOCALES = ULocale.getAvailableLocales();
        } else if (TestFmwk.getExhaustiveness() > 5) {
            LOCALES = new ULocale[] {
                new ULocale("ar_EG"), new ULocale("bg_BG"), new ULocale("ca_ES"), new ULocale("da_DK"), new ULocale("de"),
                new ULocale("de_DE"), new ULocale("el_GR"), new ULocale("en"), new ULocale("en_AU"), new ULocale("en_CA"),
                new ULocale("en_US"), new ULocale("es"), new ULocale("es_ES"), new ULocale("es_MX"), new ULocale("fi_FI"),
                new ULocale("fr"), new ULocale("fr_CA"), new ULocale("fr_FR"), new ULocale("he_IL"), new ULocale("hu_HU"),
                new ULocale("it"), new ULocale("it_IT"), new ULocale("ja"), new ULocale("ja_JP"), new ULocale("ko"),
                new ULocale("ko_KR"), new ULocale("nb_NO"), new ULocale("nl_NL"), new ULocale("nn_NO"), new ULocale("pl_PL"),
                new ULocale("pt"), new ULocale("pt_BR"), new ULocale("pt_PT"), new ULocale("ru_RU"), new ULocale("sv_SE"),
                new ULocale("th_TH"), new ULocale("tr_TR"), new ULocale("zh"), new ULocale("zh_Hans"), new ULocale("zh_Hans_CN"),
                new ULocale("zh_Hant"), new ULocale("zh_Hant_HK"), new ULocale("zh_Hant_TW"), new ULocale("ccp"), new ULocale("fa")
            };
        } else {
            LOCALES = new ULocale[] {
                new ULocale("en"),
            };
        }

        SimpleDateFormat sdfGMT = new SimpleDateFormat(BASEPATTERN);
        sdfGMT.setTimeZone(TimeZone.getTimeZone("Etc/GMT"));

        long testCounts = 0;
        long[] testTimes = new long[4];
        boolean[] expectedRoundTrip = new boolean[4];
        int testLen = 0;
        for (int locidx = 0; locidx < LOCALES.length; locidx++) {
            logln("Locale: " + LOCALES[locidx].toString());
            for (int patidx = 0; patidx < PATTERNS.length; patidx++) {
                logln("    pattern: " + PATTERNS[patidx]);
                String pattern = BASEPATTERN + " " + PATTERNS[patidx];
                SimpleDateFormat sdf = new SimpleDateFormat(pattern, LOCALES[locidx]);
                boolean minutesOffset = MINUTES_OFFSET.contains(PATTERNS[patidx]);

                Set<String> ids = null;
                if (JDKTZ) {
                    ids = new TreeSet<String>();
                    String[] jdkIDs = java.util.TimeZone.getAvailableIDs();
                    for (String jdkID : jdkIDs) {
                        if (EXCL_TZ_PATTERN.matcher(jdkID).matches()) {
                            continue;
                        }
                        String tmpID = TimeZone.getCanonicalID(jdkID);
                        if (tmpID != null) {
                            ids.add(tmpID);
                        }
                    }
                } else {
                    ids = TimeZone.getAvailableIDs(SystemTimeZoneType.CANONICAL, null, null);
                }

                for (String id : ids) {
                    if (PATTERNS[patidx].equals("V")) {
                        // Some zones do not have short ID assigned, such as Asia/Riyadh87.
                        // The time roundtrip will fail for such zones with pattern "V" (short zone ID).
                        // This is expected behavior.
                        String shortZoneID = ZoneMeta.getShortID(id);
                        if (shortZoneID == null) {
                            continue;
                        }
                    } else if (PATTERNS[patidx].equals("VVV")) {
                        // Some zones are not associated with any region, such as Etc/GMT+8.
                        // The time roundtrip will fail for such zones with pattern "VVV" (exemplar location).
                        // This is expected behavior.
                        if (id.indexOf('/') < 0 || LOC_EXCLUSION_PATTERN.matcher(id).matches()) {
                            continue;
                        }
                    }

                    if ((id.equals("Pacific/Apia") || id.equals("Pacific/Midway") || id.equals("Pacific/Pago_Pago"))
                            && PATTERNS[patidx].equals("vvvv")
                            && logKnownIssue("11052", "Ambiguous zone name - Samoa Time")) {
                        continue;
                    }

                    BasicTimeZone btz = (BasicTimeZone)TimeZone.getTimeZone(id, TimeZone.TIMEZONE_ICU);
                    TimeZone tz = TimeZone.getTimeZone(id);
                    sdf.setTimeZone(tz);

                    long t = START_TIME;
                    TimeZoneTransition tzt = null;
                    boolean middle = true;
                    boolean last = false;
                    while (t < END_TIME) {
                        if (tzt == null) {
                            testTimes[0] = t;
                            expectedRoundTrip[0] = true;
                            testLen = 1;
                        } else {
                            int fromOffset = tzt.getFrom().getRawOffset() + tzt.getFrom().getDSTSavings();
                            int toOffset = tzt.getTo().getRawOffset() + tzt.getTo().getDSTSavings();
                            int delta = toOffset - fromOffset;
                            if (delta < 0) {
                                boolean isDstDecession = tzt.getFrom().getDSTSavings() > 0 && tzt.getTo().getDSTSavings() == 0;
                                testTimes[0] = t + delta - 1;
                                expectedRoundTrip[0] = true;
                                testTimes[1] = t + delta;
                                expectedRoundTrip[1] = isDstDecession ?
                                        !AMBIGUOUS_DST_DECESSION.contains(PATTERNS[patidx]) :
                                        !AMBIGUOUS_NEGATIVE_SHIFT.contains(PATTERNS[patidx]);
                                testTimes[2] = t - 1;
                                expectedRoundTrip[2] = isDstDecession ?
                                        !AMBIGUOUS_DST_DECESSION.contains(PATTERNS[patidx]) :
                                        !AMBIGUOUS_NEGATIVE_SHIFT.contains(PATTERNS[patidx]);
                                testTimes[3] = t;
                                expectedRoundTrip[3] = true;
                                testLen = 4;
                            } else {
                                testTimes[0] = t - 1;
                                expectedRoundTrip[0] = true;
                                testTimes[1] = t;
                                expectedRoundTrip[1] = true;
                                testLen = 2;
                            }
                        }
                        for (int testidx = 0; testidx < testLen; testidx++) {
                            testCounts++;
                            timer = System.currentTimeMillis();
                            String text = sdf.format(new Date(testTimes[testidx]));
                            try {
                                Date parsedDate = sdf.parse(text);
                                long restime = parsedDate.getTime();
                                long timeDiff = restime - testTimes[testidx];
                                boolean bTimeMatch = minutesOffset ?
                                        (timeDiff/60000)*60000 == 0 : timeDiff == 0;
                                if (!bTimeMatch) {
                                    StringBuffer msg = new StringBuffer();
                                    msg.append("Time round trip failed for ")
                                        .append("tzid=").append(id)
                                        .append(", locale=").append(LOCALES[locidx])
                                        .append(", pattern=").append(PATTERNS[patidx])
                                        .append(", text=").append(text)
                                        .append(", gmt=").append(sdfGMT.format(new Date(testTimes[testidx])))
                                        .append(", time=").append(testTimes[testidx])
                                        .append(", restime=").append(restime)
                                        .append(", diff=").append(timeDiff);
                                    if (expectedRoundTrip[testidx]
                                            && !isSpecialTimeRoundTripCase(LOCALES[locidx], id, PATTERNS[patidx], testTimes[testidx])) {
                                        errln("FAIL: " + msg.toString());
                                    } else if (REALLY_VERBOSE_LOG) {
                                        logln(msg.toString());
                                    }
                                }
                            } catch (ParseException pe) {
                                errln("FAIL: " + pe.getMessage() + " tzid=" + id + ", locale=" + LOCALES[locidx] +
                                        ", pattern=" + PATTERNS[patidx] + ", text=" + text);
                            }
                            times[patidx] += System.currentTimeMillis() - timer;
                        }

                        if (last) {
                            break;
                        }

                        tzt = btz.getNextTransition(t, false);
                        if (tzt == null) {
                            last = true;
                            t = END_TIME - 1;
                        } else if (middle) {
                            // Test the date in the middle of two transitions.
                            t += (tzt.getTime() - t)/2;
                            middle = false;
                            tzt = null;
                        } else {
                            t = tzt.getTime();
                        }
                    }
                }
            }
        }

        long total = 0;
        logln("### Elapsed time by patterns ###");
        for (int i = 0; i < PATTERNS.length; i++) {
            logln(times[i] + "ms (" + PATTERNS[i] + ")");
            total += times[i];
        }
        logln("Total: " + total + "ms");
        logln("Iteration: " + testCounts);
    }

    // Special exclusions in TestTimeZoneRoundTrip.
    // These special cases do not round trip time as designed.
    private boolean isSpecialTimeRoundTripCase(ULocale loc, String id, String pattern, long time) {
        final Object[][] EXCLUSIONS = {
            {null, "Asia/Chita", "zzzz", Long.valueOf(1414252800000L)},
            {null, "Asia/Chita", "vvvv", Long.valueOf(1414252800000L)},
            {null, "Asia/Srednekolymsk", "zzzz", Long.valueOf(1414241999999L)},
            {null, "Asia/Srednekolymsk", "vvvv", Long.valueOf(1414241999999L)},
        };
        boolean isExcluded = false;
        for (Object[] excl : EXCLUSIONS) {
            if (excl[0] == null || loc.equals(excl[0])) {
                if (id.equals(excl[1])) {
                    if (excl[2] == null || pattern.equals(excl[2])) {
                        if (excl[3] == null || ((Long)excl[3]).compareTo(time) == 0) {
                            isExcluded = true;
                            break;
                        }
                    }
                }
            }
        }
        return isExcluded;
    }

    @Test
    public void TestParse() {
        final Object[][] DATA = {
        //   text                   inpos       locale      style
        //      parseOptions            expected            outpos      time type
            {"Z",                   0,          "en_US",    Style.ISO_EXTENDED_FULL,
                null,                   "Etc/GMT",          1,          TimeType.UNKNOWN},

            {"Z",                   0,          "en_US",    Style.SPECIFIC_LONG,
                null,                   "Etc/GMT",          1,          TimeType.UNKNOWN},

            {"Zambia time",         0,          "en_US",    Style.ISO_EXTENDED_FULL,
                EnumSet.of(ParseOption.ALL_STYLES), "Etc/GMT",  1,      TimeType.UNKNOWN},

            {"Zambia time",         0,          "en_US",    Style.GENERIC_LOCATION,
                null,                   "Africa/Lusaka",    11,         TimeType.UNKNOWN},

            {"Zambia time",         0,          "en_US",    Style.ISO_BASIC_LOCAL_FULL,
                EnumSet.of(ParseOption.ALL_STYLES), "Africa/Lusaka",    11, TimeType.UNKNOWN},

            {"+00:00",              0,          "en_US",    Style.ISO_EXTENDED_FULL,
                null,                   "Etc/GMT",          6,          TimeType.UNKNOWN},

            {"-01:30:45",           0,          "en_US",    Style.ISO_EXTENDED_FULL,
                null,                   "GMT-01:30:45",     9,          TimeType.UNKNOWN},

            {"-7",                  0,          "en_US",    Style.ISO_BASIC_LOCAL_FULL,
                null,                   "GMT-07:00",        2,          TimeType.UNKNOWN},

            {"-2222",               0,          "en_US",    Style.ISO_BASIC_LOCAL_FULL,
                null,                   "GMT-22:22",        5,          TimeType.UNKNOWN},

            {"-3333",               0,          "en_US",    Style.ISO_BASIC_LOCAL_FULL,
                null,                   "GMT-03:33",        4,          TimeType.UNKNOWN},

            {"XXX+01:30YYY",        3,          "en_US",    Style.LOCALIZED_GMT,
                null,                   "GMT+01:30",        9,          TimeType.UNKNOWN},

            {"GMT0",                0,          "en_US",    Style.SPECIFIC_SHORT,
                null,                   "Etc/GMT",          3,          TimeType.UNKNOWN},

            {"EST",                 0,          "en_US",    Style.SPECIFIC_SHORT,
                null,                   "America/New_York", 3,          TimeType.STANDARD},

            {"ESTx",                0,          "en_US",    Style.SPECIFIC_SHORT,
                null,                   "America/New_York", 3,          TimeType.STANDARD},

            {"EDTx",                0,          "en_US",    Style.SPECIFIC_SHORT,
                null,                   "America/New_York", 3,          TimeType.DAYLIGHT},

            {"EST",                 0,          "en_US",    Style.SPECIFIC_LONG,
                null,                   null,               0,          TimeType.UNKNOWN},

            {"EST",                 0,          "en_US",    Style.SPECIFIC_LONG,
                EnumSet.of(ParseOption.ALL_STYLES), "America/New_York", 3,  TimeType.STANDARD},

            {"EST",                 0,          "en_CA",    Style.SPECIFIC_SHORT,
                null,                   "America/Toronto",  3,          TimeType.STANDARD},

            {"CST",                 0,          "en_US",    Style.SPECIFIC_SHORT,
                null,                   "America/Chicago",  3,          TimeType.STANDARD},

            {"CST",                 0,          "en_GB",    Style.SPECIFIC_SHORT,
                null,                   null,               0,          TimeType.UNKNOWN},

            {"CST",                 0,          "en_GB",    Style.SPECIFIC_SHORT,
                EnumSet.of(ParseOption.TZ_DATABASE_ABBREVIATIONS),  "America/Chicago",  3,  TimeType.STANDARD},

            {"--CST--",             2,          "en_GB",    Style.SPECIFIC_SHORT,
                EnumSet.of(ParseOption.TZ_DATABASE_ABBREVIATIONS),  "America/Chicago",  5,  TimeType.STANDARD},

            {"CST",                 0,          "zh_CN",    Style.SPECIFIC_SHORT,
                EnumSet.of(ParseOption.TZ_DATABASE_ABBREVIATIONS),  "Asia/Shanghai",    3,  TimeType.STANDARD},

            {"AEST",                0,          "en_AU",    Style.SPECIFIC_SHORT,
                EnumSet.of(ParseOption.TZ_DATABASE_ABBREVIATIONS),  "Australia/Sydney", 4,  TimeType.STANDARD},

            {"AST",                 0,          "ar_SA",    Style.SPECIFIC_SHORT,
                EnumSet.of(ParseOption.TZ_DATABASE_ABBREVIATIONS),  "Asia/Riyadh",      3,  TimeType.STANDARD},

            {"AQTST",               0,          "en",       Style.SPECIFIC_LONG,
                null,                       null,           0,          TimeType.UNKNOWN},

            {"AQTST",           0,      "en",       Style.SPECIFIC_LONG,
                EnumSet.of(ParseOption.ALL_STYLES), null,   0,          TimeType.UNKNOWN},

            {"AQTST",           0,      "en",       Style.SPECIFIC_LONG,
                EnumSet.of(ParseOption.ALL_STYLES, ParseOption.TZ_DATABASE_ABBREVIATIONS),  "Asia/Aqtobe",  5,  TimeType.DAYLIGHT},

            {"hora de verano británica", 0,     "es",       Style.SPECIFIC_LONG,
                null,                   "Europe/London",    24,         TimeType.DAYLIGHT},
        };

        for (Object[] test : DATA) {
            String text = (String)test[0];
            int inPos = (Integer)test[1];
            ULocale loc = new ULocale((String)test[2]);
            Style style = (Style)test[3];
            EnumSet<ParseOption> options = (EnumSet<ParseOption>)test[4];
            String expID = (String)test[5];
            int expPos = (Integer)test[6];
            TimeType expType = (TimeType)test[7];

            TimeZoneFormat tzfmt = TimeZoneFormat.getInstance(loc);
            Output<TimeType> timeType = new Output<TimeType>(TimeType.UNKNOWN);
            ParsePosition pos = new ParsePosition(inPos);
            TimeZone tz = tzfmt.parse(style, text, pos, options, timeType);

            String errMsg = null;
            if (tz == null) {
                if (expID != null) {
                    errMsg = "Parse failure - expected: " + expID;
                }
            } else if (!tz.getID().equals(expID)) {
                errMsg = "Time zone ID: " + tz.getID() + " - expected: " + expID;
            } else if (pos.getIndex() != expPos) {
                errMsg = "Parsed pos: " + pos.getIndex() + " - expected: " + expPos;
            } else if (timeType.value != expType) {
                errMsg = "Time type: " + timeType + " - expected: " + expType;
            }

            if (errMsg != null) {
                errln("Fail: " + errMsg +
                        " [text=" + text + ", pos=" + inPos +
                        ", locale=" + loc + ", style=" + style + "]");
            }
        }
    }

    // Coverage tests for other versions of the parse() method. All of them end up
    // calling the full parse() method tested on the TestParse() test.
    @Test
    public void TestParseCoverage() {
        TimeZone expectedTZ = TimeZone.getTimeZone("America/Los_Angeles");
        TimeZoneFormat fmt = TimeZoneFormat.getInstance(ULocale.ENGLISH);

        // Test parse(String)
        try {
            TimeZone tz1 = fmt.parse("America/Los_Angeles");
            if (tz1 == null) {
                errln("Parse failure using parse(String) - expected: " + expectedTZ.getID());
            } else if (!expectedTZ.equals(tz1)) {
                errln("Parsed TimeZone: '" + tz1.getID()  + "' using parse(String) - expected: "
                        + expectedTZ.getID());
            }
        } catch (ParseException e) {
            errln("Parse failure using parse(String) - expected: " + expectedTZ.getID()
                    + " exception: " + e.getMessage());
        }

        // Test parse(String, ParsePosition)
        TimeZone tz2 = fmt.parse("++America/Los_Angeles", new ParsePosition(2));
        if (tz2 == null) {
            errln("Parse failure using parse(String, ParsePosition) - expected: "
                    + expectedTZ.getID());
        } else if (!expectedTZ.equals(tz2)) {
            errln("Parsed TimeZone: '" + tz2.getID()  + "' using parse(String, ParsePosition) - expected: "
                    + expectedTZ.getID());
        }

        // Test parseObject(String, ParsePosition)
        Object tz3 = fmt.parseObject("++America/Los_Angeles", new ParsePosition(2));
        if (tz3 == null) {
            errln("Parse failure using parseObject(String, ParsePosition) - expected: "
                    + expectedTZ.getID());
        } else if (!expectedTZ.equals(tz3)) {
            errln("Parsed TimeZone: '" + ((TimeZone)tz3).getID()
                    + "' using parseObject(String, ParsePosition) - expected: "
                    + expectedTZ.getID());
        }
    }

    @Test
    public void TestISOFormat() {
        final int[] OFFSET = {
            0,          // 0
            999,        // 0.999s
            -59999,     // -59.999s
            60000,      // 1m
            -77777,     // -1m 17.777s
            1800000,    // 30m
            -3600000,   // -1h
            36000000,   // 10h
            -37800000,  // -10h 30m
            -37845000,  // -10h 30m 45s
            108000000,  // 30h
        };

        final String[][] ISO_STR = {
            // 0
            {
                "Z", "Z", "Z", "Z", "Z",
                "+00", "+0000", "+00:00", "+0000", "+00:00",
                "+0000"
            },
            // 999
            {
                "Z", "Z", "Z", "Z", "Z",
                "+00", "+0000", "+00:00", "+0000", "+00:00",
                "+0000"
            },
            // -59999
            {
                "Z", "Z", "Z", "-000059", "-00:00:59",
                "+00", "+0000", "+00:00", "-000059", "-00:00:59",
                "-000059"
            },
            // 60000
            {
                "+0001", "+0001", "+00:01", "+0001", "+00:01",
                "+0001", "+0001", "+00:01", "+0001", "+00:01",
                "+0001"
            },
            // -77777
            {
                "-0001", "-0001", "-00:01", "-000117", "-00:01:17",
                "-0001", "-0001", "-00:01", "-000117", "-00:01:17",
                "-000117"
            },
            // 1800000
            {
                "+0030", "+0030", "+00:30", "+0030", "+00:30",
                "+0030", "+0030", "+00:30", "+0030", "+00:30",
                "+0030"
            },
            // -3600000
            {
                "-01", "-0100", "-01:00", "-0100", "-01:00",
                "-01", "-0100", "-01:00", "-0100", "-01:00",
                "-0100"
            },
            // 36000000
            {
                "+10", "+1000", "+10:00", "+1000", "+10:00",
                "+10", "+1000", "+10:00", "+1000", "+10:00",
                "+1000"
            },
            // -37800000
            {
                "-1030", "-1030", "-10:30", "-1030", "-10:30",
                "-1030", "-1030", "-10:30", "-1030", "-10:30",
                "-1030"
            },
            // -37845000
            {
                "-1030", "-1030", "-10:30", "-103045", "-10:30:45",
                "-1030", "-1030", "-10:30", "-103045", "-10:30:45",
                "-103045"
            },
            // 108000000
            {
                null, null, null, null, null,
                null, null, null, null, null,
                null
            }
        };

        final String[] PATTERN = {
            "X", "XX", "XXX", "XXXX", "XXXXX", "x", "xx", "xxx", "xxxx", "xxxxx",
            "Z", // equivalent to "xxxx"
        };

        final int[] MIN_OFFSET_UNIT = {
            60000, 60000, 60000, 1000, 1000, 60000, 60000, 60000, 1000, 1000,
            1000,
        };

        // Formatting
        SimpleDateFormat sdf = new SimpleDateFormat();
        Date d = new Date();

        for (int i = 0; i < OFFSET.length; i++) {
            SimpleTimeZone tz = new SimpleTimeZone(OFFSET[i], "Zone Offset:" + String.valueOf(OFFSET[i]) + "ms");
            sdf.setTimeZone(tz);
            for (int j = 0; j < PATTERN.length; j++) {
                sdf.applyPattern(PATTERN[j]);
                try {
                    String result = sdf.format(d);
                    if (!result.equals(ISO_STR[i][j])) {
                        errln("FAIL: pattern=" + PATTERN[j] + ", offset=" + OFFSET[i] + " -> "
                            + result + " (expected: " + ISO_STR[i][j] + ")");
                    }
                } catch (IllegalArgumentException e) {
                    if (ISO_STR[i][j] != null) {
                        errln("FAIL: IAE thrown for pattern=" + PATTERN[j] + ", offset=" + OFFSET[i]
                                + " (expected: " + ISO_STR[i][j] + ")");
                    }
                }
            }
        }

        // Parsing
        SimpleTimeZone bogusTZ = new SimpleTimeZone(-1, "Zone Offset: -1ms");
        for (int i = 0; i < ISO_STR.length; i++) {
            for (int j = 0; j < ISO_STR[i].length; j++) {
                if (ISO_STR[i][j] == null) {
                    continue;
                }
                ParsePosition pos = new ParsePosition(0);
                Calendar outcal = Calendar.getInstance(bogusTZ);
                sdf.applyPattern(PATTERN[j]);

                sdf.parse(ISO_STR[i][j], outcal, pos);

                if (pos.getIndex() != ISO_STR[i][j].length()) {
                    errln("FAIL: Failed to parse the entire input string: " + ISO_STR[i][j]);
                    continue;
                }

                TimeZone outtz = outcal.getTimeZone();
                int outOffset = outtz.getRawOffset();
                int adjustedOffset = OFFSET[i] / MIN_OFFSET_UNIT[j] * MIN_OFFSET_UNIT[j];

                if (outOffset != adjustedOffset) {
                    errln("FAIL: Incorrect offset:" + outOffset + "ms for input string: " + ISO_STR[i][j]
                            + " (expected:" + adjustedOffset + "ms)");
                }
            }
        }
    }

    @Test
    public void TestFormat() {
        final Date dateJan = new Date(1358208000000L);  // 2013-01-15T00:00:00Z
        final Date dateJul = new Date(1373846400000L);  // 2013-07-15T00:00:00Z

        final Object[][] TESTDATA = {
            {
                "en",
                "America/Los_Angeles",
                dateJan,
                Style.GENERIC_LOCATION,
                "Los Angeles Time",
                TimeType.UNKNOWN
            },
            {
                "en",
                "America/Los_Angeles",
                dateJan,
                Style.GENERIC_LONG,
                "Pacific Time",
                TimeType.UNKNOWN
            },
            {
                "en",
                "America/Los_Angeles",
                dateJan,
                Style.SPECIFIC_LONG,
                "Pacific Standard Time",
                TimeType.STANDARD
            },
            {
                "en",
                "America/Los_Angeles",
                dateJul,
                Style.SPECIFIC_LONG,
                "Pacific Daylight Time",
                TimeType.DAYLIGHT
            },
            {
                "ja",
                "America/Los_Angeles",
                dateJan,
                Style.ZONE_ID,
                "America/Los_Angeles",
                TimeType.UNKNOWN
            },
            {
                "fr",
                "America/Los_Angeles",
                dateJul,
                Style.ZONE_ID_SHORT,
                "uslax",
                TimeType.UNKNOWN
            },
            {
                "en",
                "America/Los_Angeles",
                dateJan,
                Style.EXEMPLAR_LOCATION,
                "Los Angeles",
                TimeType.UNKNOWN
            },
            {
                "ja",
                "Asia/Tokyo",
                dateJan,
                Style.GENERIC_LONG,
                "\u65E5\u672C\u6A19\u6E96\u6642",   // "日本標準時"
                TimeType.UNKNOWN
            },
        };

        for (Object[] testCase : TESTDATA) {
            TimeZone tz = TimeZone.getTimeZone((String)testCase[1]);
            Output<TimeType> timeType = new Output<TimeType>();

            ULocale uloc = new ULocale((String)testCase[0]);
            TimeZoneFormat tzfmt = TimeZoneFormat.getInstance(uloc);
            String out = tzfmt.format((Style)testCase[3], tz, ((Date)testCase[2]).getTime(), timeType);

            if (!out.equals(testCase[4]) || timeType.value != testCase[5]) {
                errln("Format result for [locale=" + testCase[0] + ",tzid=" + testCase[1] + ",date=" + testCase[2]
                        + ",style=" + testCase[3] + "]: expected [output=" + testCase[4] + ",type=" + testCase[5]
                        + "]; actual [output=" + out + ",type=" + timeType.value + "]");
            }

            // with equivalent Java Locale
            Locale loc = uloc.toLocale();
            tzfmt = TimeZoneFormat.getInstance(loc);
            out = tzfmt.format((Style)testCase[3], tz, ((Date)testCase[2]).getTime(), timeType);

            if (!out.equals(testCase[4]) || timeType.value != testCase[5]) {
                errln("Format result for [locale(Java)=" + testCase[0] + ",tzid=" + testCase[1] + ",date=" + testCase[2]
                        + ",style=" + testCase[3] + "]: expected [output=" + testCase[4] + ",type=" + testCase[5]
                        + "]; actual [output=" + out + ",type=" + timeType.value + "]");
            }
        }
    }

    @Test
    public void TestFormatTZDBNames() {
        final Date dateJan = new Date(1358208000000L);  // 2013-01-15T00:00:00Z
        final Date dateJul = new Date(1373846400000L);  // 2013-07-15T00:00:00Z

        final Object[][] TESTDATA = {
            {
                "en",
                "America/Chicago",
                dateJan,
                Style.SPECIFIC_SHORT,
                "CST",
                TimeType.STANDARD
            },
            {
                "en",
                "Asia/Shanghai",
                dateJan,
                Style.SPECIFIC_SHORT,
                "CST",
                TimeType.STANDARD
            },
            {
                "zh_Hans",
                "Asia/Shanghai",
                dateJan,
                Style.SPECIFIC_SHORT,
                "CST",
                TimeType.STANDARD
            },
            {
                "en",
                "America/Los_Angeles",
                dateJul,
                Style.SPECIFIC_LONG,
                "GMT-07:00",    // No long display names
                TimeType.DAYLIGHT
            },
            {
                "ja",
                "America/Los_Angeles",
                dateJul,
                Style.SPECIFIC_SHORT,
                "PDT",
                TimeType.DAYLIGHT
            },
            {
                "en",
                "Australia/Sydney",
                dateJan,
                Style.SPECIFIC_SHORT,
                "AEDT",
                TimeType.DAYLIGHT
            },
            {
                "en",
                "Australia/Sydney",
                dateJul,
                Style.SPECIFIC_SHORT,
                "AEST",
                TimeType.STANDARD
            },
        };

        for (Object[] testCase : TESTDATA) {
            ULocale loc = new ULocale((String)testCase[0]);
            TimeZoneFormat tzfmt = TimeZoneFormat.getInstance(loc).cloneAsThawed();
            TimeZoneNames tzdbNames = TimeZoneNames.getTZDBInstance(loc);
            tzfmt.setTimeZoneNames(tzdbNames);

            TimeZone tz = TimeZone.getTimeZone((String)testCase[1]);
            Output<TimeType> timeType = new Output<TimeType>();
            String out = tzfmt.format((Style)testCase[3], tz, ((Date)testCase[2]).getTime(), timeType);

            if (!out.equals(testCase[4]) || timeType.value != testCase[5]) {
                errln("Format result for [locale=" + testCase[0] + ",tzid=" + testCase[1] + ",date=" + testCase[2]
                        + ",style=" + testCase[3] + "]: expected [output=" + testCase[4] + ",type=" + testCase[5]
                        + "]; actual [output=" + out + ",type=" + timeType.value + "]");
            }
        }
    }

    // Tests format(Object, StringBuffer, FieldPosition):StringBuffer method
    // inherited from Format class
    @Test
    public void TestInheritedFormat() {
        TimeZone tz = TimeZone.getTimeZone("America/Los_Angeles");
        Calendar cal = Calendar.getInstance(tz);
        cal.setTimeInMillis(1459187377690L); // Mar 28, 2016

        StringBuffer sb = new StringBuffer();
        FieldPosition fp = new FieldPosition(DateFormat.Field.TIME_ZONE);

        TimeZoneFormat fmt = TimeZoneFormat.getInstance(ULocale.ENGLISH);

        // Test formatting a non-timezone related object
        try {
            fmt.format(new Object(), sb, fp);
            errln("ERROR: format non-timezone related object failed");
        } catch (IllegalArgumentException e) { /* Expected */ }

        // Test formatting a TimeZone object
        sb = new StringBuffer();
        fmt.format(tz, sb, fp);
        // When formatting a TimeZone object the formatter uses the current date.
        String fmtOutput = tz.inDaylightTime(new Date()) ? "GMT-07:00" : "GMT-08:00";
        if (!sb.toString().equals(fmtOutput)) {
            errln("ERROR: format TimerZone object failed. Expected: " + fmtOutput + ", actual: " + sb);
        }

        // Test formatting a Calendar object
        sb = new StringBuffer();
        fmt.format(cal, sb, fp);
        if (!sb.toString().equals("GMT-07:00")) {
            errln("ERROR: format Calendar object failed. Expected: GMT-07:00, actual: " + sb);
        }
    }

    // This is a test case of Ticket#11487.
    // Because the problem is reproduced for the very first time,
    // the reported problem cannot be reproduced with regular test
    // execution. Run this test alone reproduced the problem before
    // the fix was merged.
    @Test
    public void TestTZDBNamesThreading() {
        final TZDBTimeZoneNames names = new TZDBTimeZoneNames(ULocale.ENGLISH);
        final AtomicInteger found = new AtomicInteger();
        List<Thread> threads = new ArrayList<Thread>();
        final int numIteration = 1000;

        try {
            for (int i = 0; i < numIteration; i++) {
                Thread thread = new Thread() {
                    @Override
                    public void run() {
                        int resultSize = names.find("GMT", 0, EnumSet.allOf(NameType.class)).size();
                        if (resultSize > 0) {
                            found.incrementAndGet();
                        }
                    }
                };
                thread.start();
                threads.add(thread);
            }

            for(Thread thread: threads) {
                thread.join();
            }
        } catch (Throwable t) {
            errln(t.toString());
        }

        if (found.intValue() != numIteration) {
            errln("Incorrect count: " + found.toString() + ", expected: " + numIteration);
        }
    }

    @Test
    public void TestGetDisplayNames() {
        long date = System.currentTimeMillis();
        NameType[] types = new NameType[]{
                NameType.LONG_STANDARD, NameType.LONG_DAYLIGHT,
                NameType.SHORT_STANDARD, NameType.SHORT_DAYLIGHT
        };
        Set<String> zones = ZoneMeta.getAvailableIDs(SystemTimeZoneType.ANY, null, null);

        int casesTested = 0;
        Random rnd = new Random(2016);
        for (ULocale uloc : ULocale.getAvailableLocales()) {
            if (rnd.nextDouble() > 0.01) { continue; }
            for (String zone : zones) {
                if (rnd.nextDouble() > 0.01) { continue; }
                casesTested++;

                // Test default TimeZoneNames (uses an overridden getDisplayNames)
                {
                    TimeZoneNames tznames = TimeZoneNames.getInstance(uloc);
                    tznames.loadAllDisplayNames();
                    String[] result = new String[types.length];
                    tznames.getDisplayNames(zone, types, date, result, 0);
                    for (int i=0; i<types.length; i++) {
                        NameType type = types[i];
                        String expected = result[i];
                        String actual = tznames.getDisplayName(zone, type, date);
                        assertEquals("TimeZoneNames: getDisplayNames() returns different result than getDisplayName()"
                                + " for " + zone + " in locale " + uloc, expected, actual);
                    }
                    // Coverage for empty call to getDisplayNames
                    tznames.getDisplayNames(null, null, 0, null, 0);
                }

                // Test TZDBTimeZoneNames (uses getDisplayNames from abstract class)
                {
                    TimeZoneNames tznames = new TZDBTimeZoneNames(uloc);
                    tznames.loadAllDisplayNames();
                    String[] result = new String[types.length];
                    tznames.getDisplayNames(zone, types, date, result, 0);
                    for (int i=0; i<types.length; i++) {
                        NameType type = types[i];
                        String expected = result[i];
                        String actual = tznames.getDisplayName(zone, type, date);
                        assertEquals("TZDBTimeZoneNames: getDisplayNames() returns different result than getDisplayName()"
                                + " for " + zone + " in locale " + uloc, expected, actual);
                    }
                    // Coverage for empty call to getDisplayNames
                    tznames.getDisplayNames(null, null, 0, null, 0);
                }
            }
        }

        assertTrue("No cases were tested", casesTested > 0);
    }

    class TimeZoneNamesInheriter extends TimeZoneNames {
        private static final long serialVersionUID = 1L;

        @Override
        public Set<String> getAvailableMetaZoneIDs() {
            return null;
        }

        @Override
        public Set<String> getAvailableMetaZoneIDs(String tzID) {
            return null;
        }

        @Override
        public String getMetaZoneID(String tzID, long date) {
            return null;
        }

        @Override
        public String getReferenceZoneID(String mzID, String region) {
            return null;
        }

        @Override
        public String getMetaZoneDisplayName(String mzID, NameType type) {
            return null;
        }

        @Override
        public String getTimeZoneDisplayName(String tzID, NameType type) {
            return null;
        }
    }

    // Coverage for default implementation and abstract methods in base class.
    @Test
    public void TestDefaultTimeZoneNames() {
        long date = System.currentTimeMillis();
        TimeZoneNames.Factory factory;
        try {
            Class cls = Class.forName("com.ibm.icu.text.TimeZoneNames$DefaultTimeZoneNames$FactoryImpl");
            factory = (Factory) cls.newInstance();
        } catch (Exception e) {
            errln("Could not create class DefaultTimeZoneNames.FactoryImpl: " + e.getClass() + ": " + e.getMessage());
            return;
        }
        TimeZoneNames tzn = factory.getTimeZoneNames(ULocale.ENGLISH);
        assertEquals("Abstract: getAvailableMetaZoneIDs()",
                tzn.getAvailableMetaZoneIDs(), Collections.emptySet());
        assertEquals("Abstract: getAvailableMetaZoneIDs(String tzID)",
                tzn.getAvailableMetaZoneIDs("America/Chicago"), Collections.emptySet());
        assertEquals("Abstract: getMetaZoneID(String tzID, long date)",
                tzn.getMetaZoneID("America/Chicago", date), null);
        assertEquals("Abstract: getReferenceZoneID(String mzID, String region)",
                tzn.getReferenceZoneID("America_Central", "IT"), null);
        assertEquals("Abstract: getMetaZoneDisplayName(String mzID, NameType type)",
                tzn.getMetaZoneDisplayName("America_Central", NameType.LONG_DAYLIGHT), null);
        assertEquals("Abstract: getTimeZoneDisplayName(String mzID, NameType type)",
                tzn.getTimeZoneDisplayName("America/Chicago", NameType.LONG_DAYLIGHT), null);
        assertEquals("Abstract: find(CharSequence text, int start, EnumSet<NameType> nameTypes)",
                tzn.find("foo", 0, EnumSet.noneOf(NameType.class)), Collections.emptyList());

        // Other abstract-class methods that aren't covered
        tzn = new TimeZoneNamesInheriter();
        try {
            tzn.find(null, 0, null);
        } catch (UnsupportedOperationException e) {
            assertEquals("find() exception", "The method is not implemented in TimeZoneNames base class.", e.getMessage());
        }
    }

    // Basic get/set test for methods not being called otherwise.
    @Test
    public void TestAPI() {
        TimeZoneFormat tzfmtEn = TimeZoneFormat.getInstance(ULocale.ENGLISH);
        TimeZoneFormat tzfmtAr = TimeZoneFormat.getInstance(new ULocale("ar")).cloneAsThawed();
        TimeZoneNames tzn = TimeZoneNames.getInstance(Locale.ENGLISH);

        String digits = tzfmtEn.getGMTOffsetDigits();
        tzfmtAr.setGMTOffsetDigits(digits);
        if (!digits.equals(tzfmtAr.getGMTOffsetDigits())) {
            errln("ERROR: get/set GMTOffsetDigits failed");
        }

        String pattern = tzfmtEn.getGMTOffsetPattern(GMTOffsetPatternType.POSITIVE_H);
        tzfmtAr.setGMTOffsetPattern(GMTOffsetPatternType.POSITIVE_H, pattern);
        if (!pattern.equals(tzfmtAr.getGMTOffsetPattern(GMTOffsetPatternType.POSITIVE_H))) {
            errln("ERROR: get/set GMTOffsetPattern failed");
        }

        String zeroFmt = tzfmtEn.getGMTZeroFormat();
        tzfmtAr.setGMTZeroFormat(zeroFmt);
        if (!zeroFmt.equals(tzfmtAr.getGMTZeroFormat())) {
            errln("ERROR: get/set GMTZeroFormat failed");
        }

        Set<String> allAvailableMZIDs = tzn.getAvailableMetaZoneIDs();
        if (allAvailableMZIDs.size() < 150 || !allAvailableMZIDs.contains("America_Central")) {
            errln("ERROR: getAvailableMetaZoneIDs() did not return expected value");
        }

        Set<String> kinshasaAvailableMZIDs = tzn.getAvailableMetaZoneIDs("Africa/Kinshasa");
        if (!kinshasaAvailableMZIDs.contains("Africa_Western") || kinshasaAvailableMZIDs.contains("America_Central")) {
            errln("ERROR: getAvailableMetaZoneIDs('Africa/Kinshasa') did not return expected value");
        }

        try {
            new TimeZoneNames.MatchInfo(null, null, null, -1);
            assertTrue("MatchInfo doesn't throw IllegalArgumentException", false);
        } catch (IllegalArgumentException e) {
            assertEquals("MatchInfo constructor exception", "nameType is null", e.getMessage());
        }

        try {
            new TimeZoneNames.MatchInfo(NameType.LONG_GENERIC, null, null, -1);
            assertTrue("MatchInfo doesn't throw IllegalArgumentException", false);
        } catch (IllegalArgumentException e) {
            assertEquals("MatchInfo constructor exception", "Either tzID or mzID must be available", e.getMessage());
        }

        try {
            new TimeZoneNames.MatchInfo(NameType.LONG_GENERIC, "America/Chicago", null, -1);
            assertTrue("MatchInfo doesn't throw IllegalArgumentException", false);
        } catch (IllegalArgumentException e) {
            assertEquals("MatchInfo constructor exception", "matchLength must be positive value", e.getMessage());
        }
    }
}
