/*
 * WP: the test-class is adapted so that it can be run without the
 * original parent class JSR166TestCase, and can be run from 
 * Junit runner. This makes it convenient for the benchmark tool.
 * 
 * The class JSR166TestCase is kept in the directory just for reader's
 * reference.
 * 
 * Original:
 * 
 * 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.
 * 
 * Some note copied from JSR166TestCase:
 * 
 * Usually, there is one testcase method per JSR166 method
 * covering "normal" operation, and then as many exception-testing
 * methods as there are exceptions the method can throw. Sometimes
 * there are multiple tests per JSR166 method when the different
 * "normal" behaviors differ significantly. And sometimes testcases
 * cover multiple methods when they cannot be tested in
 * isolation.
 */

package Examples ;

import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
//import java.util.LinkedList;
import java.util.NoSuchElementException;

import org.junit.* ;

import static org.junit.Assert.* ;

public class TestJavaLinkedList {
	
	
    /**
     * The number of elements to place in collections, arrays, etc.
     */
    public static final int SIZE = 20;

    // Some convenient Integer constants

    public static final Integer zero  = new Integer(0);
    public static final Integer one   = new Integer(1);
    public static final Integer two   = new Integer(2);
    public static final Integer three = new Integer(3);
    public static final Integer four  = new Integer(4);
    public static final Integer five  = new Integer(5);
    public static final Integer six   = new Integer(6);
    public static final Integer seven = new Integer(7);
    public static final Integer eight = new Integer(8);
    public static final Integer nine  = new Integer(9);
    public static final Integer m1  = new Integer(-1);
    public static final Integer m2  = new Integer(-2);
    public static final Integer m3  = new Integer(-3);
    public static final Integer m4  = new Integer(-4);
    public static final Integer m5  = new Integer(-5);
    public static final Integer m6  = new Integer(-6);
    public static final Integer m10 = new Integer(-10);
	
    /**
     * Returns a new queue of given size containing consecutive
     * Integers 0 ... n.
     */
    private JavaLinkedList<Integer> populatedQueue(int n) {
        JavaLinkedList<Integer> q = new JavaLinkedList<Integer>();
        assertTrue(q.isEmpty());
        for (int i = 0; i < n; ++i)
            assertTrue(q.offer(new Integer(i)));
        assertFalse(q.isEmpty());
        assertEquals(n, q.size());
        return q;
    }

    /**
     * new queue is empty
     */
    @Test
    public void testConstructor1() {
        assertEquals(0, new JavaLinkedList().size());
    }

    /**
     * Initializing from null Collection throws NPE
     */
    @Test
    public void testConstructor3() {
        try {
            JavaLinkedList q = new JavaLinkedList((Collection)null);
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (NullPointerException success) {}
    }

    /**
     * Queue contains all elements of collection used to initialize
     */
    @Test
    public void testConstructor6() {
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE; ++i)
            ints[i] = i;
        JavaLinkedList q = new JavaLinkedList(Arrays.asList(ints));
        for (int i = 0; i < SIZE; ++i)
            assertEquals(ints[i], q.poll());
    }

    /**
     * isEmpty is true before add, false after
     */
    @Test
    public void testEmpty() {
        JavaLinkedList q = new JavaLinkedList();
        assertTrue(q.isEmpty());
        q.add(new Integer(1));
        assertFalse(q.isEmpty());
        q.add(new Integer(2));
        q.remove();
        q.remove();
        assertTrue(q.isEmpty());
    }

    /**
     * size changes when elements added and removed
     */
    @Test
    public void testSize() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(SIZE-i, q.size());
            q.remove();
        }
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.size());
            q.add(new Integer(i));
        }
    }

    /**
     * offer(null) succeeds
     */
    @Test
    public void testOfferNull() {
        JavaLinkedList q = new JavaLinkedList();
        q.offer(null);
    }

    /**
     * Offer succeeds
     */
    @Test
    public void testOffer() {
        JavaLinkedList q = new JavaLinkedList();
        assertTrue(q.offer(new Integer(0)));
        assertTrue(q.offer(new Integer(1)));
    }

    /**
     * add succeeds
     */
    @Test
    public void testAdd() {
        JavaLinkedList q = new JavaLinkedList();
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.size());
            assertTrue(q.add(new Integer(i)));
        }
    }

    /**
     * addAll(null) throws NPE
     */
    @Test
    public void testAddAll1() {
        try {
            JavaLinkedList q = new JavaLinkedList();
            q.addAll(null);
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (NullPointerException success) {}
    }

    /**
     * Queue contains all elements, in traversal order, of successful addAll
     */
    @Test
    public void testAddAll5() {
        Integer[] empty = new Integer[0];
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE; ++i)
            ints[i] = i;
        JavaLinkedList q = new JavaLinkedList();
        assertFalse(q.addAll(Arrays.asList(empty)));
        assertTrue(q.addAll(Arrays.asList(ints)));
        for (int i = 0; i < SIZE; ++i)
            assertEquals(ints[i], q.poll());
    }

    /**
     * addAll with too large an index throws IOOBE
     */
    @Test
    public void testAddAll2_IndexOutOfBoundsException() {
        JavaLinkedList l = new JavaLinkedList();
        l.add(new Object());
        JavaLinkedList m = new JavaLinkedList();
        m.add(new Object());
        try {
            l.addAll(4,m);
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (IndexOutOfBoundsException success) {}
    }

    /**
     * addAll with negative index throws IOOBE
     */
    @Test
    public void testAddAll4_BadIndex() {
        JavaLinkedList l = new JavaLinkedList();
        l.add(new Object());
        JavaLinkedList m = new JavaLinkedList();
        m.add(new Object());
        try {
            l.addAll(-1,m);
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (IndexOutOfBoundsException success) {}
    }

    /**
     * poll succeeds unless empty
     */
    @Test
    public void testPoll() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.poll());
        }
        assertNull(q.poll());
    }

    /**
     * peek returns next element, or null if empty
     */
    @Test
    public void testPeek() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.peek());
            assertEquals(i, q.poll());
            assertTrue(q.peek() == null ||
                       !q.peek().equals(i));
        }
        assertNull(q.peek());
    }

    /**
     * element returns next element, or throws NSEE if empty
     */
    @Test
    public void testElement() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.element());
            assertEquals(i, q.poll());
        }
        try {
            q.element();
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (NoSuchElementException success) {}
    }

    /**
     * remove removes next element, or throws NSEE if empty
     */
    @Test
    public void testRemove() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.remove());
        }
        try {
            q.remove();
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (NoSuchElementException success) {}
    }

    /**
     * remove(x) removes x and returns true if present
     */
    @Test
    public void testRemoveElement() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 1; i < SIZE; i+=2) {
            assertTrue(q.contains(i));
            assertTrue(q.remove((Integer)i));
            assertFalse(q.contains(i));
            assertTrue(q.contains(i-1));
        }
        for (int i = 0; i < SIZE; i+=2) {
            assertTrue(q.contains(i));
            assertTrue(q.remove((Integer)i));
            assertFalse(q.contains(i));
            assertFalse(q.remove((Integer)(i+1)));
            assertFalse(q.contains(i+1));
        }
        assertTrue(q.isEmpty());
    }

    /**
     * contains(x) reports true when elements added but not yet removed
     */
    @Test
    public void testContains() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.contains(new Integer(i)));
            q.poll();
            assertFalse(q.contains(new Integer(i)));
        }
    }

    /**
     * clear removes all elements
     */
    @Test
    public void testClear() {
        JavaLinkedList q = populatedQueue(SIZE);
        q.clear();
        assertTrue(q.isEmpty());
        assertEquals(0, q.size());
        assertTrue(q.add(new Integer(1)));
        assertFalse(q.isEmpty());
        q.clear();
        assertTrue(q.isEmpty());
    }

    /**
     * containsAll(c) is true when c contains a subset of elements
     */
    @Test
    public void testContainsAll() {
        JavaLinkedList q = populatedQueue(SIZE);
        JavaLinkedList p = new JavaLinkedList();
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.containsAll(p));
            assertFalse(p.containsAll(q));
            assertTrue(p.add(new Integer(i)));
        }
        assertTrue(p.containsAll(q));
    }

    /**
     * retainAll(c) retains only those elements of c and reports true if changed
     */
    @Test
    public void testRetainAll() {
        JavaLinkedList q = populatedQueue(SIZE);
        JavaLinkedList p = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            boolean changed = q.retainAll(p);
            if (i == 0)
                assertFalse(changed);
            else
                assertTrue(changed);

            assertTrue(q.containsAll(p));
            assertEquals(SIZE-i, q.size());
            p.remove();
        }
    }

    /**
     * removeAll(c) removes only those elements of c and reports true if changed
     */
    @Test
    public void testRemoveAll() {
        for (int i = 1; i < SIZE; ++i) {
            JavaLinkedList q = populatedQueue(SIZE);
            JavaLinkedList p = populatedQueue(i);
            assertTrue(q.removeAll(p));
            assertEquals(SIZE-i, q.size());
            for (int j = 0; j < i; ++j) {
                Integer I = (Integer)(p.remove());
                assertFalse(q.contains(I));
            }
        }
    }

    /**
     * toArray contains all elements in FIFO order
     */
    @Test
    public void testToArray() {
        JavaLinkedList q = populatedQueue(SIZE);
        Object[] o = q.toArray();
        for (int i = 0; i < o.length; i++)
            assertSame(o[i], q.poll());
    }

    /**
     * toArray(a) contains all elements in FIFO order
     */
    @Test
    public void testToArray2() {
        JavaLinkedList<Integer> q = populatedQueue(SIZE);
        Integer[] ints = new Integer[SIZE];
        Integer[] array = q.toArray(ints);
        assertSame(ints, array);
        for (int i = 0; i < ints.length; i++)
            assertSame(ints[i], q.poll());
    }

    /**
     * toArray(null) throws NullPointerException
     */
    @Test
    public void testToArray_NullArg() {
        JavaLinkedList l = new JavaLinkedList();
        l.add(new Object());
        try {
            l.toArray(null);
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (NullPointerException success) {}
    }

    /**
     * toArray(incompatible array type) throws ArrayStoreException
     */
    @Test
    public void testToArray1_BadArg() {
        JavaLinkedList l = new JavaLinkedList();
        l.add(new Integer(5));
        try {
            l.toArray(new String[10]);
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (ArrayStoreException success) {}
    }

    /**
     * iterator iterates through all elements
     */
    @Test
    public void testIterator() {
        JavaLinkedList q = populatedQueue(SIZE);
        int i = 0;
        Iterator it = q.iterator();
        while (it.hasNext()) {
            assertTrue(q.contains(it.next()));
            ++i;
        }
        assertEquals(i, SIZE);
    }

    /**
     * iterator ordering is FIFO
     */
    @Test
    public void testIteratorOrdering() {
        final JavaLinkedList q = new JavaLinkedList();
        q.add(new Integer(1));
        q.add(new Integer(2));
        q.add(new Integer(3));
        int k = 0;
        for (Iterator it = q.iterator(); it.hasNext();) {
            assertEquals(++k, it.next());
        }

        assertEquals(3, k);
    }

    /**
     * iterator.remove removes current element
     */
    @Test
    public void testIteratorRemove() {
        final JavaLinkedList q = new JavaLinkedList();
        q.add(new Integer(1));
        q.add(new Integer(2));
        q.add(new Integer(3));
        Iterator it = q.iterator();
        assertEquals(1, it.next());
        it.remove();
        it = q.iterator();
        assertEquals(2, it.next());
        assertEquals(3, it.next());
        assertFalse(it.hasNext());
    }

    /**
     * Descending iterator iterates through all elements
     */
    @Test
    public void testDescendingIterator() {
        JavaLinkedList q = populatedQueue(SIZE);
        int i = 0;
        Iterator it = q.descendingIterator();
        while (it.hasNext()) {
            assertTrue(q.contains(it.next()));
            ++i;
        }
        assertEquals(i, SIZE);
        assertFalse(it.hasNext());
        try {
            it.next();
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (NoSuchElementException success) {}
    }

    /**
     * Descending iterator ordering is reverse FIFO
     */
    @Test
    public void testDescendingIteratorOrdering() {
        final JavaLinkedList q = new JavaLinkedList();
        q.add(new Integer(3));
        q.add(new Integer(2));
        q.add(new Integer(1));
        int k = 0;
        for (Iterator it = q.descendingIterator(); it.hasNext();) {
            assertEquals(++k, it.next());
        }

        assertEquals(3, k);
    }

    /**
     * descendingIterator.remove removes current element
     */
    @Test
    public void testDescendingIteratorRemove() {
        final JavaLinkedList q = new JavaLinkedList();
        q.add(three);
        q.add(two);
        q.add(one);
        Iterator it = q.descendingIterator();
        it.next();
        it.remove();
        it = q.descendingIterator();
        assertSame(it.next(), two);
        assertSame(it.next(), three);
        assertFalse(it.hasNext());
    }

    /**
     * toString contains toStrings of elements
     */
    @Test
    public void testToString() {
        JavaLinkedList q = populatedQueue(SIZE);
        String s = q.toString();
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(s.contains(String.valueOf(i)));
        }
    }

    /**
     * peek returns element inserted with addFirst
     */
    @Test
    public void testAddFirst() {
        JavaLinkedList q = populatedQueue(3);
        q.addFirst(four);
        assertSame(four, q.peek());
    }

    /**
     * peekFirst returns element inserted with push
     */
    @Test
    public void testPush() {
        JavaLinkedList q = populatedQueue(3);
        q.push(four);
        assertSame(four, q.peekFirst());
    }

    /**
     * pop removes next element, or throws NSEE if empty
     */
    @Test
    public void testPop() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.pop());
        }
        try {
            q.pop();
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (NoSuchElementException success) {}
    }

    /**
     * OfferFirst succeeds
     */
    @Test
    public void testOfferFirst() {
        JavaLinkedList q = new JavaLinkedList();
        assertTrue(q.offerFirst(new Integer(0)));
        assertTrue(q.offerFirst(new Integer(1)));
    }

    /**
     * OfferLast succeeds
     */
    @Test
    public void testOfferLast() {
        JavaLinkedList q = new JavaLinkedList();
        assertTrue(q.offerLast(new Integer(0)));
        assertTrue(q.offerLast(new Integer(1)));
    }

    /**
     * pollLast succeeds unless empty
     */
    @Test
    public void testPollLast() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = SIZE-1; i >= 0; --i) {
            assertEquals(i, q.pollLast());
        }
        assertNull(q.pollLast());
    }

    /**
     * peekFirst returns next element, or null if empty
     */
    @Test
    public void testPeekFirst() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.peekFirst());
            assertEquals(i, q.pollFirst());
            assertTrue(q.peekFirst() == null ||
                       !q.peekFirst().equals(i));
        }
        assertNull(q.peekFirst());
    }

    /**
     * peekLast returns next element, or null if empty
     */
    @Test
    public void testPeekLast() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = SIZE-1; i >= 0; --i) {
            assertEquals(i, q.peekLast());
            assertEquals(i, q.pollLast());
            assertTrue(q.peekLast() == null ||
                       !q.peekLast().equals(i));
        }
        assertNull(q.peekLast());
    }
    
    @Test
    public void testFirstElement() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.getFirst());
            assertEquals(i, q.pollFirst());
        }
        try {
            q.getFirst();
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (NoSuchElementException success) {}
    }

    /**
     * getLast returns next element, or throws NSEE if empty
     */
    @Test
    public void testLastElement() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = SIZE-1; i >= 0; --i) {
            assertEquals(i, q.getLast());
            assertEquals(i, q.pollLast());
        }
        try {
            q.getLast();
            fail("should have thrown an exception")  /* shouldThrow() */;
        } catch (NoSuchElementException success) {}
        assertNull(q.peekLast());
    }

    /**
     * removeFirstOccurrence(x) removes x and returns true if present
     */
    @Test
    public void testRemoveFirstOccurrence() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 1; i < SIZE; i+=2) {
            assertTrue(q.removeFirstOccurrence(new Integer(i)));
        }
        for (int i = 0; i < SIZE; i+=2) {
            assertTrue(q.removeFirstOccurrence(new Integer(i)));
            assertFalse(q.removeFirstOccurrence(new Integer(i+1)));
        }
        assertTrue(q.isEmpty());
    }

    /**
     * removeLastOccurrence(x) removes x and returns true if present
     */
    @Test
    public void testRemoveLastOccurrence() {
        JavaLinkedList q = populatedQueue(SIZE);
        for (int i = 1; i < SIZE; i+=2) {
            assertTrue(q.removeLastOccurrence(new Integer(i)));
        }
        for (int i = 0; i < SIZE; i+=2) {
            assertTrue(q.removeLastOccurrence(new Integer(i)));
            assertFalse(q.removeLastOccurrence(new Integer(i+1)));
        }
        assertTrue(q.isEmpty());
    }

}