/*

 * 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

 * or visit www.oracle.com if you need additional information or have any

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 */

/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file:

 *

 * Written by Doug Lea with assistance from members of JCP JSR-166

 * Expert Group and released to the public domain, as explained at

 * http://creativecommons.org/publicdomain/zero/1.0/

 * Other contributors include Andrew Wright, Jeffrey Hayes,

 * Pat Fisher, Mike Judd.

 */

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.Iterator;

import java.util.LinkedList;

import java.util.List;

import java.util.ListIterator;

import java.util.NoSuchElementException;

import java.util.concurrent.CopyOnWriteArrayList;

import junit.framework.Test;

public class CopyOnWriteArrayListTest extends JSR166TestCase {

    public static void main(String[] args) {

        main(suite(), args);

    }

    public static Test suite() {

        class Implementation implements CollectionImplementation {

            public Class<?> klazz() { return CopyOnWriteArrayList.class; }

            public List emptyCollection() { return new CopyOnWriteArrayList(); }

            public Object makeElement(int i) { return i; }

            public boolean isConcurrent() { return true; }

            public boolean permitsNulls() { return true; }

        }

        class SubListImplementation extends Implementation {

            public List emptyCollection() {

                return super.emptyCollection().subList(0, 0);

            }

        }

        return newTestSuite(

                CopyOnWriteArrayListTest.class,

                CollectionTest.testSuite(new Implementation()),

                CollectionTest.testSuite(new SubListImplementation()));

    }

    static CopyOnWriteArrayList<Integer> populatedArray(int n) {

        CopyOnWriteArrayList<Integer> a = new CopyOnWriteArrayList<>();

        assertTrue(a.isEmpty());

        for (int i = 0; i < n; i++)

            a.add(i);

        assertFalse(a.isEmpty());

        assertEquals(n, a.size());

        return a;

    }

    static CopyOnWriteArrayList<Integer> populatedArray(Integer[] elements) {

        CopyOnWriteArrayList<Integer> a = new CopyOnWriteArrayList<>();

        assertTrue(a.isEmpty());

        for (int i = 0; i < elements.length; i++)

            a.add(elements[i]);

        assertFalse(a.isEmpty());

        assertEquals(elements.length, a.size());

        return a;

    }

    /**

     * a new list is empty

     */

    public void testConstructor() {

        CopyOnWriteArrayList a = new CopyOnWriteArrayList();

        assertTrue(a.isEmpty());

    }

    /**

     * new list contains all elements of initializing array

     */

    public void testConstructor2() {

        Integer[] ints = new Integer[SIZE];

        for (int i = 0; i < SIZE - 1; ++i)

            ints[i] = new Integer(i);

        CopyOnWriteArrayList a = new CopyOnWriteArrayList(ints);

        for (int i = 0; i < SIZE; ++i)

            assertEquals(ints[i], a.get(i));

    }

    /**

     * new list contains all elements of initializing collection

     */

    public void testConstructor3() {

        Integer[] ints = new Integer[SIZE];

        for (int i = 0; i < SIZE - 1; ++i)

            ints[i] = new Integer(i);

        CopyOnWriteArrayList a = new CopyOnWriteArrayList(Arrays.asList(ints));

        for (int i = 0; i < SIZE; ++i)

            assertEquals(ints[i], a.get(i));

    }

    /**

     * addAll adds each element from the given collection, including duplicates

     */

    public void testAddAll() {

        CopyOnWriteArrayList full = populatedArray(3);

        assertTrue(full.addAll(Arrays.asList(three, four, five)));

        assertEquals(6, full.size());

        assertTrue(full.addAll(Arrays.asList(three, four, five)));

        assertEquals(9, full.size());

    }

    /**

     * addAllAbsent adds each element from the given collection that did not

     * already exist in the List

     */

    public void testAddAllAbsent() {

        CopyOnWriteArrayList full = populatedArray(3);

        // "one" is duplicate and will not be added

        assertEquals(2, full.addAllAbsent(Arrays.asList(three, four, one)));

        assertEquals(5, full.size());

        assertEquals(0, full.addAllAbsent(Arrays.asList(three, four, one)));

        assertEquals(5, full.size());

    }

    /**

     * addIfAbsent will not add the element if it already exists in the list

     */

    public void testAddIfAbsent() {

        CopyOnWriteArrayList full = populatedArray(SIZE);

        full.addIfAbsent(one);

        assertEquals(SIZE, full.size());

    }

    /**

     * addIfAbsent adds the element when it does not exist in the list

     */

    public void testAddIfAbsent2() {

        CopyOnWriteArrayList full = populatedArray(SIZE);

        full.addIfAbsent(three);

        assertTrue(full.contains(three));

    }

    /**

     * clear removes all elements from the list

     */

    public void testClear() {

        CopyOnWriteArrayList full = populatedArray(SIZE);

        full.clear();

        assertEquals(0, full.size());

    }

    /**

     * Cloned list is equal

     */

    public void testClone() {

        CopyOnWriteArrayList l1 = populatedArray(SIZE);

        CopyOnWriteArrayList l2 = (CopyOnWriteArrayList)(l1.clone());

        assertEquals(l1, l2);

        l1.clear();

        assertFalse(l1.equals(l2));

    }

    /**

     * contains is true for added elements

     */

    public void testContains() {

        CopyOnWriteArrayList full = populatedArray(3);

        assertTrue(full.contains(one));

        assertFalse(full.contains(five));

    }

    /**

     * adding at an index places it in the indicated index

     */

    public void testAddIndex() {

        CopyOnWriteArrayList full = populatedArray(3);

        full.add(0, m1);

        assertEquals(4, full.size());

        assertEquals(m1, full.get(0));

        assertEquals(zero, full.get(1));

        full.add(2, m2);

        assertEquals(5, full.size());

        assertEquals(m2, full.get(2));

        assertEquals(two, full.get(4));

    }

    /**

     * lists with same elements are equal and have same hashCode

     */

    public void testEquals() {

        CopyOnWriteArrayList a = populatedArray(3);

        CopyOnWriteArrayList b = populatedArray(3);

        assertTrue(a.equals(b));

        assertTrue(b.equals(a));

        assertTrue(a.containsAll(b));

        assertTrue(b.containsAll(a));

        assertEquals(a.hashCode(), b.hashCode());

        a.add(m1);

        assertFalse(a.equals(b));

        assertFalse(b.equals(a));

        assertTrue(a.containsAll(b));

        assertFalse(b.containsAll(a));

        b.add(m1);

        assertTrue(a.equals(b));

        assertTrue(b.equals(a));

        assertTrue(a.containsAll(b));

        assertTrue(b.containsAll(a));

        assertEquals(a.hashCode(), b.hashCode());

        assertFalse(a.equals(null));

    }

    /**

     * containsAll returns true for collections with subset of elements

     */

    public void testContainsAll() {

        CopyOnWriteArrayList full = populatedArray(3);

        assertTrue(full.containsAll(Arrays.asList()));

        assertTrue(full.containsAll(Arrays.asList(one)));

        assertTrue(full.containsAll(Arrays.asList(one, two)));

        assertFalse(full.containsAll(Arrays.asList(one, two, six)));

        assertFalse(full.containsAll(Arrays.asList(six)));

        try {

            full.containsAll(null);

            shouldThrow();

        } catch (NullPointerException success) {}

    }

    /**

     * get returns the value at the given index

     */

    public void testGet() {

        CopyOnWriteArrayList full = populatedArray(3);

        assertEquals(0, full.get(0));

    }

    /**

     * indexOf gives the index for the given object

     */

    public void testIndexOf() {

        CopyOnWriteArrayList full = populatedArray(3);

        assertEquals(1, full.indexOf(one));

        assertEquals(-1, full.indexOf("puppies"));

    }

    /**

     * indexOf gives the index based on the given index

     * at which to start searching

     */

    public void testIndexOf2() {

        CopyOnWriteArrayList full = populatedArray(3);

        assertEquals(1, full.indexOf(one, 0));

        assertEquals(-1, full.indexOf(one, 2));

    }

    /**

     * isEmpty returns true when empty, else false

     */

    public void testIsEmpty() {

        CopyOnWriteArrayList empty = new CopyOnWriteArrayList();

        CopyOnWriteArrayList full = populatedArray(SIZE);

        assertTrue(empty.isEmpty());

        assertFalse(full.isEmpty());

    }

    /**

     * iterator() returns an iterator containing the elements of the

     * list in insertion order

     */

    public void testIterator() {

        Collection empty = new CopyOnWriteArrayList();

        assertFalse(empty.iterator().hasNext());

        try {

            empty.iterator().next();

            shouldThrow();

        } catch (NoSuchElementException success) {}

        Integer[] elements = new Integer[SIZE];

        for (int i = 0; i < SIZE; i++)

            elements[i] = i;

        shuffle(elements);

        Collection<Integer> full = populatedArray(elements);

        Iterator it = full.iterator();

        for (int j = 0; j < SIZE; j++) {

            assertTrue(it.hasNext());

            assertEquals(elements[j], it.next());

        }

        assertIteratorExhausted(it);

    }

    /**

     * iterator of empty collection has no elements

     */

    public void testEmptyIterator() {

        Collection c = new CopyOnWriteArrayList();

        assertIteratorExhausted(c.iterator());

    }

    /**

     * iterator.remove throws UnsupportedOperationException

     */

    public void testIteratorRemove() {

        CopyOnWriteArrayList full = populatedArray(SIZE);

        Iterator it = full.iterator();

        it.next();

        try {

            it.remove();

            shouldThrow();

        } catch (UnsupportedOperationException success) {}

    }

    /**

     * toString contains toString of elements

     */

    public void testToString() {

        assertEquals("[]", new CopyOnWriteArrayList().toString());

        CopyOnWriteArrayList full = populatedArray(3);

        String s = full.toString();

        for (int i = 0; i < 3; ++i)

            assertTrue(s.contains(String.valueOf(i)));

        assertEquals(new ArrayList(full).toString(),

                     full.toString());

    }

    /**

     * lastIndexOf returns the index for the given object

     */

    public void testLastIndexOf1() {

        CopyOnWriteArrayList full = populatedArray(3);

        full.add(one);

        full.add(three);

        assertEquals(3, full.lastIndexOf(one));

        assertEquals(-1, full.lastIndexOf(six));

    }

    /**

     * lastIndexOf returns the index from the given starting point

     */

    public void testLastIndexOf2() {

        CopyOnWriteArrayList full = populatedArray(3);

        full.add(one);

        full.add(three);

        assertEquals(3, full.lastIndexOf(one, 4));

        assertEquals(-1, full.lastIndexOf(three, 3));

    }

    /**

     * listIterator traverses all elements

     */

    public void testListIterator1() {

        CopyOnWriteArrayList full = populatedArray(SIZE);

        ListIterator i = full.listIterator();

        int j;

        for (j = 0; i.hasNext(); j++)

            assertEquals(j, i.next());

        assertEquals(SIZE, j);

    }

    /**

     * listIterator only returns those elements after the given index

     */

    public void testListIterator2() {

        CopyOnWriteArrayList full = populatedArray(3);

        ListIterator i = full.listIterator(1);

        int j;

        for (j = 0; i.hasNext(); j++)

            assertEquals(j + 1, i.next());

        assertEquals(2, j);

    }

    /**

     * remove(int) removes and returns the object at the given index

     */

    public void testRemove_int() {

        int SIZE = 3;

        for (int i = 0; i < SIZE; i++) {

            CopyOnWriteArrayList full = populatedArray(SIZE);

            assertEquals(i, full.remove(i));

            assertEquals(SIZE - 1, full.size());

            assertFalse(full.contains(new Integer(i)));

        }

    }

    /**

     * remove(Object) removes the object if found and returns true

     */

    public void testRemove_Object() {

        int SIZE = 3;

        for (int i = 0; i < SIZE; i++) {

            CopyOnWriteArrayList full = populatedArray(SIZE);

            assertFalse(full.remove(new Integer(-42)));

            assertTrue(full.remove(new Integer(i)));

            assertEquals(SIZE - 1, full.size());

            assertFalse(full.contains(new Integer(i)));

        }

        CopyOnWriteArrayList x = new CopyOnWriteArrayList(Arrays.asList(4, 5, 6));

        assertTrue(x.remove(new Integer(6)));

        assertEquals(x, Arrays.asList(4, 5));

        assertTrue(x.remove(new Integer(4)));

        assertEquals(x, Arrays.asList(5));

        assertTrue(x.remove(new Integer(5)));

        assertEquals(x, Arrays.asList());

        assertFalse(x.remove(new Integer(5)));

    }

    /**

     * removeAll removes all elements from the given collection

     */

    public void testRemoveAll() {

        CopyOnWriteArrayList full = populatedArray(3);

        assertTrue(full.removeAll(Arrays.asList(one, two)));

        assertEquals(1, full.size());

        assertFalse(full.removeAll(Arrays.asList(one, two)));

        assertEquals(1, full.size());

    }

    /**

     * set changes the element at the given index

     */

    public void testSet() {

        CopyOnWriteArrayList full = populatedArray(3);

        assertEquals(2, full.set(2, four));

        assertEquals(4, full.get(2));

    }

    /**

     * size returns the number of elements

     */

    public void testSize() {

        CopyOnWriteArrayList empty = new CopyOnWriteArrayList();

        CopyOnWriteArrayList full = populatedArray(SIZE);

        assertEquals(SIZE, full.size());

        assertEquals(0, empty.size());

    }

    /**

     * toArray() returns an Object array containing all elements from

     * the list in insertion order

     */

    public void testToArray() {

        Object[] a = new CopyOnWriteArrayList().toArray();

        assertTrue(Arrays.equals(new Object[0], a));

        assertSame(Object[].class, a.getClass());

        Integer[] elements = new Integer[SIZE];

        for (int i = 0; i < SIZE; i++)

            elements[i] = i;

        shuffle(elements);

        Collection<Integer> full = populatedArray(elements);

        assertTrue(Arrays.equals(elements, full.toArray()));

        assertSame(Object[].class, full.toArray().getClass());

    }

    /**

     * toArray(Integer array) returns an Integer array containing all

     * elements from the list in insertion order

     */

    public void testToArray2() {

        Collection empty = new CopyOnWriteArrayList();

        Integer[] a;

        a = new Integer[0];

        assertSame(a, empty.toArray(a));

        a = new Integer[SIZE / 2];

        Arrays.fill(a, 42);

        assertSame(a, empty.toArray(a));

        assertNull(a[0]);

        for (int i = 1; i < a.length; i++)

            assertEquals(42, (int) a[i]);

        Integer[] elements = new Integer[SIZE];

        for (int i = 0; i < SIZE; i++)

            elements[i] = i;

        shuffle(elements);

        Collection<Integer> full = populatedArray(elements);

        Arrays.fill(a, 42);

        assertTrue(Arrays.equals(elements, full.toArray(a)));

        for (int i = 0; i < a.length; i++)

            assertEquals(42, (int) a[i]);

        assertSame(Integer[].class, full.toArray(a).getClass());

        a = new Integer[SIZE];

        Arrays.fill(a, 42);

        assertSame(a, full.toArray(a));

        assertTrue(Arrays.equals(elements, a));

        a = new Integer[2 * SIZE];

        Arrays.fill(a, 42);

        assertSame(a, full.toArray(a));

        assertTrue(Arrays.equals(elements, Arrays.copyOf(a, SIZE)));

        assertNull(a[SIZE]);

        for (int i = SIZE + 1; i < a.length; i++)

            assertEquals(42, (int) a[i]);

    }

    /**