/*

 * Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

 */

/*

 * @test

 * @bug 4533691 7129185

 * @summary Unit test for Collections.emptyNavigableSet

 * @run testng EmptyNavigableSet

 */

import org.testng.Assert;

import org.testng.Assert.ThrowingRunnable;

import org.testng.annotations.DataProvider;

import org.testng.annotations.Test;

import java.math.BigInteger;

import java.util.Arrays;

import java.util.Collection;

import java.util.Collections;

import java.util.Comparator;

import java.util.Iterator;

import java.util.NavigableSet;

import java.util.NoSuchElementException;

import java.util.SortedSet;

import java.util.TreeSet;

import static org.testng.Assert.assertFalse;

import static org.testng.Assert.assertSame;

import static org.testng.Assert.assertTrue;

public class EmptyNavigableSet {

    public static <T> void assertInstance(T actual, Class<? extends T> expected) {

        assertInstance(actual, expected, null);

    }

    public static <T> void assertInstance(T actual, Class<? extends T> expected, String message) {

        assertTrue(expected.isInstance(actual), ((null != message) ? message : "")

            + " " + (actual == null ? "<null>" : actual.getClass().getSimpleName()) + " != " + expected.getSimpleName() + ". ");

    }

    public static <T extends Throwable> void assertEmptyNavigableSet(Object obj) {

        assertInstance(obj, NavigableSet.class);

        assertTrue(((NavigableSet)obj).isEmpty() && (((NavigableSet)obj).size() == 0));

    }

    public static <T extends Throwable> void assertEmptyNavigableSet(Object obj, String message) {

        assertInstance(obj, NavigableSet.class, message);

        assertTrue(((NavigableSet)obj).isEmpty() && (((NavigableSet)obj).size() == 0),

            ((null != message) ? message : "") + " Not empty. ");

    }

    private <T extends Throwable> void assertThrows(Class<T> throwableClass,

                                                    ThrowingRunnable runnable,

                                                    String message) {

        try {

            Assert.assertThrows(throwableClass, runnable);

        } catch (AssertionError e) {

            throw new AssertionError(String.format("%s%n%s",

                    ((null != message) ? message : ""), e.getMessage()), e);

        }

    }

    private void assertThrowsCCE(ThrowingRunnable r, String s) {

        assertThrows(ClassCastException.class, r, s);

    }

    private void assertThrowsNPE(ThrowingRunnable r, String s) {

        assertThrows(NullPointerException.class, r, s);

    }

    private void assertThrowsIAE(ThrowingRunnable r, String s) {

        assertThrows(IllegalArgumentException.class, r, s);

    }

    private void assertThrowsNSEE(ThrowingRunnable r, String s) {

        assertThrows(NoSuchElementException.class, r, s);

    }

    public static final boolean isDescending(SortedSet<?> set) {

        if (null == set.comparator()) {

            // natural order

            return false;

        }

        if (Collections.reverseOrder() == set.comparator()) {

            // reverse natural order.

            return true;

        }

        if (set.comparator().equals(Collections.reverseOrder(Collections.reverseOrder(set.comparator())))) {

            // it's a Collections.reverseOrder(Comparator).

            return true;

        }

        throw new IllegalStateException("can't determine ordering for " + set);

    }

    /**

     * Tests that the comparator is {@code null}.

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testComparatorIsNull(String description, NavigableSet<?> navigableSet) {

        Comparator comparator = navigableSet.comparator();

        assertTrue(comparator == null || comparator == Collections.reverseOrder(), description + ": Comparator (" + comparator + ") is not null.");

    }

    /**

     * Tests that contains requires Comparable

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testContainsRequiresComparable(String description, NavigableSet<?> navigableSet) {

        assertThrowsCCE(

            () -> navigableSet.contains(new Object()),

            description + ": Comparable should be required");

    }

    /**

     * Tests that the contains method returns {@code false}.

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testContains(String description, NavigableSet<?> navigableSet) {

        assertFalse(navigableSet.contains(new Integer(1)),

            description + ": Should not contain any elements.");

    }

    /**

     * Tests that the containsAll method returns {@code false}.

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testContainsAll(String description, NavigableSet<?> navigableSet) {

        TreeSet treeSet = new TreeSet();

        treeSet.add("1");

        treeSet.add("2");

        treeSet.add("3");

        assertFalse(navigableSet.containsAll(treeSet), "Should not contain any elements.");

    }

    /**

     * Tests that the iterator is empty.

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testEmptyIterator(String description, NavigableSet<?> navigableSet) {

    }

    /**

     * Tests that the set is empty.

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testIsEmpty(String description, NavigableSet<?> navigableSet) {

        assertTrue(navigableSet.isEmpty(), "The set is not empty.");

    }

    /**

     * Tests that the first() method throws NoSuchElementException

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testFirst(String description, NavigableSet<?> navigableSet) {

        assertThrowsNSEE(navigableSet::first, description);

    }

    /**

     * Tests the headSet() method.

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testHeadSet(String description, NavigableSet navigableSet) {

        assertThrowsNPE(

            () -> { NavigableSet ns = navigableSet.headSet(null, false); },

            description + ": Must throw NullPointerException for null element");

        assertThrowsCCE(

            () -> { NavigableSet ns = navigableSet.headSet(new Object(), true); },

            description + ": Must throw ClassCastException for non-Comparable element");

        NavigableSet ns = navigableSet.headSet("1", false);

        assertEmptyNavigableSet(ns, description + ": Returned value is not empty navigable set.");

    }

    /**

     * Tests that the last() method throws NoSuchElementException

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testLast(String description, NavigableSet<?> navigableSet) {

        assertThrowsNSEE(navigableSet::last, description);

    }

    /**

     * Tests that the size is 0.

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testSizeIsZero(String description, NavigableSet<?> navigableSet) {

        assertTrue(0 == navigableSet.size(), "The size of the set is not 0.");

    }

    /**

     * Tests the subSet() method.

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testSubSet(String description, NavigableSet navigableSet) {

        assertThrowsNPE(

            () -> {

                SortedSet ss = navigableSet.subSet(null, BigInteger.TEN);

            },

            description + ": Must throw NullPointerException for null element");

        assertThrowsNPE(

            () -> {

                SortedSet ss = navigableSet.subSet(BigInteger.ZERO, null);

            },

            description + ": Must throw NullPointerException for null element");

        assertThrowsNPE(

            () -> {

                SortedSet ss = navigableSet.subSet(null, null);

            },

            description + ": Must throw NullPointerException for null element");

        Object obj1 = new Object();

        Object obj2 = new Object();

        assertThrowsCCE(

            () -> {

                SortedSet ss = navigableSet.subSet(obj1, BigInteger.TEN);

            },

            description + ": Must throw ClassCastException for parameter which is not Comparable.");

        assertThrowsCCE(

            () -> {

                SortedSet ss = navigableSet.subSet(BigInteger.ZERO, obj2);

            },

            description + ": Must throw ClassCastException for parameter which is not Comparable.");

        assertThrowsCCE(

            () -> {

                SortedSet ss = navigableSet.subSet(obj1, obj2);

            },

            description + ": Must throw ClassCastException for parameter which is not Comparable.");

        // minimal range

        navigableSet.subSet(BigInteger.ZERO, false, BigInteger.ZERO, false);

        navigableSet.subSet(BigInteger.ZERO, false, BigInteger.ZERO, true);

        navigableSet.subSet(BigInteger.ZERO, true, BigInteger.ZERO, false);

        navigableSet.subSet(BigInteger.ZERO, true, BigInteger.ZERO, true);

        Object first = isDescending(navigableSet) ? BigInteger.TEN : BigInteger.ZERO;

        Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;

            assertThrowsIAE(

                () -> navigableSet.subSet(last, true, first, false),

                description

                + ": Must throw IllegalArgumentException when fromElement is not less than toElement.");

        navigableSet.subSet(first, true, last, false);

    }

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testSubSetRanges(String description, NavigableSet navigableSet) {

        Object first = isDescending(navigableSet) ? BigInteger.TEN : BigInteger.ZERO;

        Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;

        NavigableSet subSet = navigableSet.subSet(first, true, last, true);

        // same subset

        subSet.subSet(first, true, last, true);

        // slightly smaller

        NavigableSet ns = subSet.subSet(first, false, last, false);

        // slight expansion

        assertThrowsIAE(

            () -> ns.subSet(first, true, last, true),

            description + ": Expansion should not be allowed");

        // much smaller

        subSet.subSet(first, false, BigInteger.ONE, false);

    }

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testheadSetRanges(String description, NavigableSet navigableSet) {

        NavigableSet subSet = navigableSet.headSet(BigInteger.ONE, true);

        // same subset

        subSet.headSet(BigInteger.ONE, true);

        // slightly smaller

        NavigableSet ns = subSet.headSet(BigInteger.ONE, false);

        // slight expansion

        assertThrowsIAE(

            () -> ns.headSet(BigInteger.ONE, true),

            description + ": Expansion should not be allowed");

        // much smaller

        subSet.headSet(isDescending(subSet) ? BigInteger.TEN : BigInteger.ZERO, true);

    }

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testTailSetRanges(String description, NavigableSet navigableSet) {

        NavigableSet subSet = navigableSet.tailSet(BigInteger.ONE, true);

        // same subset

        subSet.tailSet(BigInteger.ONE, true);

        // slightly smaller

        NavigableSet ns = subSet.tailSet(BigInteger.ONE, false);

        // slight expansion

        assertThrowsIAE(

            () -> ns.tailSet(BigInteger.ONE, true),

            description + ": Expansion should not be allowed");

        // much smaller

        subSet.tailSet(isDescending(subSet) ? BigInteger.ZERO : BigInteger.TEN, false);

    }

    /**

     * Tests the tailSet() method.

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testTailSet(String description, NavigableSet navigableSet) {

        assertThrowsNPE(

            () -> navigableSet.tailSet(null),

            description + ": Must throw NullPointerException for null element");

        assertThrowsCCE(

            () -> navigableSet.tailSet(new Object()),

            description);

        NavigableSet ss = navigableSet.tailSet("1", true);

        assertEmptyNavigableSet(ss, description + ": Returned value is not empty navigable set.");

    }

    /**

     * Tests that the array has a size of 0.

     */

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)

    public void testToArray(String description, NavigableSet<?> navigableSet) {

        Object[] emptyNavigableSetArray = navigableSet.toArray();

        assertTrue(emptyNavigableSetArray.length == 0, "Returned non-empty Array.");

        emptyNavigableSetArray = new Object[20];

        Object[] result = navigableSet.toArray(emptyNavigableSetArray);

        assertSame(emptyNavigableSetArray, result);

        assertTrue(result[0] == null);

    }

    @DataProvider(name = "NavigableSet<?>", parallel = true)

    public static Iterator<Object[]> navigableSetsProvider() {

        return makeNavigableSets().iterator();

    }

    public static Collection<Object[]> makeNavigableSets() {

        return Arrays.asList(

            new Object[]{"UnmodifiableNavigableSet(TreeSet)", Collections.unmodifiableNavigableSet(new TreeSet())},

            new Object[]{"UnmodifiableNavigableSet(TreeSet.descendingSet()", Collections.unmodifiableNavigableSet(new TreeSet().descendingSet())},

            new Object[]{"UnmodifiableNavigableSet(TreeSet.descendingSet().descendingSet()", Collections.unmodifiableNavigableSet(new TreeSet().descendingSet().descendingSet())},

            new Object[]{"emptyNavigableSet()", Collections.emptyNavigableSet()},

            new Object[]{"emptyNavigableSet().descendingSet()", Collections.emptyNavigableSet().descendingSet()},

            new Object[]{"emptyNavigableSet().descendingSet().descendingSet()", Collections.emptyNavigableSet().descendingSet().descendingSet()}

        );

    }

}