/*
 * 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 junit.framework.*;
import java.util.Arrays;
import java.util.Iterator;
import java.util.Set;
import java.util.Vector;
import java.util.concurrent.CopyOnWriteArraySet;

public class CopyOnWriteArraySetTest extends JSR166TestCase {
    public static void main(String[] args) {
        junit.textui.TestRunner.run(suite());
    }
    public static Test suite() {
        return new TestSuite(CopyOnWriteArraySetTest.class);
    }

    static CopyOnWriteArraySet populatedSet(int n) {
        CopyOnWriteArraySet a = new CopyOnWriteArraySet();
        assertTrue(a.isEmpty());
        for (int i = 0; i < n; ++i)
            a.add(new Integer(i));
        assertFalse(a.isEmpty());
        assertEquals(n, a.size());
        return a;
    }

    /**
     * Default-constructed set is empty
     */
    public void testConstructor() {
        CopyOnWriteArraySet a = new CopyOnWriteArraySet();
        assertTrue(a.isEmpty());
    }

    /**
     * Collection-constructed set holds all of its elements
     */
    public void testConstructor3() {
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE-1; ++i)
            ints[i] = new Integer(i);
        CopyOnWriteArraySet a = new CopyOnWriteArraySet(Arrays.asList(ints));
        for (int i = 0; i < SIZE; ++i)
            assertTrue(a.contains(ints[i]));
    }

    /**
     * addAll adds each element from the given collection
     */
    public void testAddAll() {
        CopyOnWriteArraySet full = populatedSet(3);
        Vector v = new Vector();
        v.add(three);
        v.add(four);
        v.add(five);
        full.addAll(v);
        assertEquals(6, full.size());
    }

    /**
     * addAll adds each element from the given collection that did not
     * already exist in the set
     */
    public void testAddAll2() {
        CopyOnWriteArraySet full = populatedSet(3);
        Vector v = new Vector();
        v.add(three);
        v.add(four);
        v.add(one); // will not add this element
        full.addAll(v);
        assertEquals(5, full.size());
    }

    /**
     * add will not add the element if it already exists in the set
     */
    public void testAdd2() {
        CopyOnWriteArraySet full = populatedSet(3);
        full.add(one);
        assertEquals(3, full.size());
    }

    /**
     * add adds the element when it does not exist in the set
     */
    public void testAdd3() {
        CopyOnWriteArraySet full = populatedSet(3);
        full.add(three);
        assertTrue(full.contains(three));
    }

    /**
     * clear removes all elements from the set
     */
    public void testClear() {
        CopyOnWriteArraySet full = populatedSet(3);
        full.clear();
        assertEquals(0, full.size());
    }

    /**
     * contains returns true for added elements
     */
    public void testContains() {
        CopyOnWriteArraySet full = populatedSet(3);
        assertTrue(full.contains(one));
        assertFalse(full.contains(five));
    }

    /**
     * Sets with equal elements are equal
     */
    public void testEquals() {
        CopyOnWriteArraySet a = populatedSet(3);
        CopyOnWriteArraySet b = populatedSet(3);
        assertTrue(a.equals(b));
        assertTrue(b.equals(a));
        assertEquals(a.hashCode(), b.hashCode());
        a.add(m1);
        assertFalse(a.equals(b));
        assertFalse(b.equals(a));
        b.add(m1);
        assertTrue(a.equals(b));
        assertTrue(b.equals(a));
        assertEquals(a.hashCode(), b.hashCode());
    }

    /**
     * containsAll returns true for collections with subset of elements
     */
    public void testContainsAll() {
        CopyOnWriteArraySet full = populatedSet(3);
        Vector v = new Vector();
        v.add(one);
        v.add(two);
        assertTrue(full.containsAll(v));
        v.add(six);
        assertFalse(full.containsAll(v));
    }

    /**
     * isEmpty is true when empty, else false
     */
    public void testIsEmpty() {
        CopyOnWriteArraySet empty = new CopyOnWriteArraySet();
        CopyOnWriteArraySet full = populatedSet(3);
        assertTrue(empty.isEmpty());
        assertFalse(full.isEmpty());
    }

    /**
     * iterator() returns an iterator containing the elements of the set
     */
    public void testIterator() {
        CopyOnWriteArraySet full = populatedSet(3);
        Iterator i = full.iterator();
        int j;
        for (j = 0; i.hasNext(); j++)
            assertEquals(j, i.next());
        assertEquals(3, j);
    }

    /**
     * iterator remove is unsupported
     */
    public void testIteratorRemove() {
        CopyOnWriteArraySet full = populatedSet(3);
        Iterator it = full.iterator();
        it.next();
        try {
            it.remove();
            shouldThrow();
        } catch (UnsupportedOperationException success) {}
    }

    /**
     * toString holds toString of elements
     */
    public void testToString() {
        CopyOnWriteArraySet full = populatedSet(3);
        String s = full.toString();
        for (int i = 0; i < 3; ++i) {
            assertTrue(s.contains(String.valueOf(i)));
        }
    }

    /**
     * removeAll removes all elements from the given collection
     */
    public void testRemoveAll() {
        CopyOnWriteArraySet full = populatedSet(3);
        Vector v = new Vector();
        v.add(one);
        v.add(two);
        full.removeAll(v);
        assertEquals(1, full.size());
    }

    /**
     * remove removes an element
     */
    public void testRemove() {
        CopyOnWriteArraySet full = populatedSet(3);
        full.remove(one);
        assertFalse(full.contains(one));
        assertEquals(2, full.size());
    }

    /**
     * size returns the number of elements
     */
    public void testSize() {
        CopyOnWriteArraySet empty = new CopyOnWriteArraySet();
        CopyOnWriteArraySet full = populatedSet(3);
        assertEquals(3, full.size());
        assertEquals(0, empty.size());
    }

    /**
     * toArray returns an Object array containing all elements from the set
     */
    public void testToArray() {
        CopyOnWriteArraySet<Integer> full = populatedSet(SIZE);
        Object[] array = full.toArray();
        Iterator<Integer> it = full.iterator();
        for (int i = 0; i < SIZE; i++)
            assertSame(array[i], it.next());
        assertFalse(it.hasNext());
    }

    /**
     * toArray returns an Integer array containing all elements from
     * the set
     */
    public void testToArray2() {
        CopyOnWriteArraySet<Integer> full = populatedSet(SIZE);
        Integer[] ints = new Integer[SIZE];
        assertSame(ints, full.toArray(ints));
        Iterator<Integer> it = full.iterator();
        for (int i = 0; i < SIZE; i++)
            assertSame(ints[i], it.next());
        assertFalse(it.hasNext());
    }

    /**
     * toArray throws an ArrayStoreException when the given array can
     * not store the objects inside the set
     */
    public void testToArray_ArrayStoreException() {
        try {
            CopyOnWriteArraySet c = new CopyOnWriteArraySet();
            c.add("zfasdfsdf");
            c.add("asdadasd");
            c.toArray(new Long[5]);
            shouldThrow();
        } catch (ArrayStoreException success) {}
    }

    /**
     * A deserialized serialized set is equal
     */
    public void testSerialization() throws Exception {
        Set x = populatedSet(SIZE);
        Set y = serialClone(x);

        assertTrue(x != y);
        assertEquals(x.size(), y.size());
        assertEquals(x, y);
        assertEquals(y, x);
    }

}