import static org.junit.Assert.*;

import org.junit.Test;

public class UTest {

  @Test
  public void testDLListconstructor()
  {
    Solution.DLList list = new Solution.DLList();
    assertEquals(0, list.size());
  }


  @Test
  public void testAddAtZero()
  {
    Solution.DLList list = new Solution.DLList();
    list.addFirst(new Solution.Node(3, null, null));
    list.addLast(new Solution.Node(2, null, null));
    list.addAtPosition(new Solution.Node(5, null, null),0);
    assertEquals(3, list.size());
    Solution.Node node = list.removeFromPosition(10);
    assertNull(node);
    assertEquals(3, list.size());
    assertEquals(5, list.removeFirst().getElement());

  }

  @Test
  public void testAddFirst() {
    Solution.DLList list = new Solution.DLList();
    Solution.Node n = new Solution.Node(3, null, null);
    Solution.Node p = new Solution.Node(5, null, null);
    list.addFirst(n);
    list.addFirst(p);
    assertEquals(2, list.size());
    assertEquals(p, list.getHead());
    assertEquals(n, list.getTail());
  }

  @Test
  public void testRemoveFirst() {
    Solution.DLList list = new Solution.DLList();
    Solution.Node n = new Solution.Node(3, null, null);
    Solution.Node p = new Solution.Node(5, null, null);
    list.addFirst(n);
    list.addFirst(p);
    Solution.Node removed = list.removeFirst();
    assertEquals(1, list.size());
    assertEquals(p, removed);
  }

 @Test
 public void testAddLast() {
   Solution.DLList list = new Solution.DLList();
   Solution.Node n = new Solution.Node(3, null, null);
   Solution.Node p = new Solution.Node(5, null, null);
   list.addFirst(n);
   list.addLast(p);
   assertEquals(p, list.getTail());
 }

 @Test
 public void testRemoveLast() {
   Solution.DLList list = new Solution.DLList();
   Solution.Node n = new Solution.Node(3, null, null);
   Solution.Node p = new Solution.Node(5, null, null);
   list.addFirst(n);
   list.addFirst(p);
   Solution.Node removed = list.removeLast();
   assertEquals(1, list.size());
   assertEquals(n, removed);
   assertEquals(p, list.getTail());
 }

 @Test
 public void testSize() {
   Solution.DLList list = new Solution.DLList();
   Solution.Node n = new Solution.Node(3, null, null);
   Solution.Node p = new Solution.Node(5, null, null);
   list.addFirst(n);
   list.addLast(p);
   assertEquals(2, list.size());
 }

 @Test
 public void testAddAtPositionLast() {
   Solution.DLList list = new Solution.DLList();
   Solution.Node n = new Solution.Node(3, null, null);
   Solution.Node p = new Solution.Node(5, null, null);
   list.addFirst(n);
   list.addLast(p);
   Solution.Node addNode = new Solution.Node(4, null, null);
   list.addAtPosition(addNode, 2);
   assertEquals(3, list.size());
   assertEquals(addNode, list.getTail());
 }

 @Test
 public void testAddAtPositionMiddle() {
   Solution.DLList list = new Solution.DLList();
   Solution.Node n = new Solution.Node(3, null, null);
   Solution.Node p = new Solution.Node(5, null, null);
   list.addFirst(n);
   list.addLast(p);
   Solution.Node addNode = new Solution.Node(4, null, null);
   list.addAtPosition(addNode, 1);
   assertEquals(3, list.size());
   assertEquals(addNode, list.getHead().getNext());
   assertEquals(n, list.getHead());
   assertEquals(p, list.getTail());
 }

 @Test
 public void testRemoveFromPositionLast() {
   Solution.DLList list = new Solution.DLList();
   Solution.Node n = new Solution.Node(3, null, null);
   Solution.Node p = new Solution.Node(5, null, null);
   Solution.Node k = new Solution.Node(4, null, null);
   list.addFirst(n);
   list.addFirst(k);
   list.addFirst(p);
   Solution.Node removed = list.removeFromPosition(2);
   assertEquals(2, list.size());
   assertEquals(n, removed);
   assertEquals(k, list.getTail());
   assertEquals(p, list.getHead());
 }

 @Test
 public void testRemoveFromPositionMiddle() {
   Solution.DLList list = new Solution.DLList();
   Solution.Node n = new Solution.Node(3, null, null);
   Solution.Node p = new Solution.Node(5, null, null);
   Solution.Node k = new Solution.Node(4, null, null);
   list.addFirst(n);
   list.addFirst(k);
   list.addFirst(p);
   Solution.Node removed = list.removeFromPosition(1);
   assertEquals(2, list.size());
   assertEquals(k, removed);
   assertEquals(n, list.getTail());
   assertEquals(p, list.getHead());
 }

 @Test
 public void testRemoveFromPositionFirst() {
   Solution.DLList list = new Solution.DLList();
   Solution.Node n = new Solution.Node(3, null, null);
   Solution.Node p = new Solution.Node(5, null, null);
   Solution.Node k = new Solution.Node(4, null, null);
   list.addFirst(n);
   list.addFirst(k);
   list.addFirst(p);
   Solution.Node removed = list.removeFromPosition(0);
   assertEquals(2, list.size());
   assertEquals(p, removed);
   assertEquals(k, list.getHead());
   assertEquals(n, list.getTail());
 }

 @Test
 public void testReverse() {
   Solution.DLList list = new Solution.DLList();
   Solution.DLList reversedList = new Solution.DLList();
   Solution.Node c = new Solution.Node(3, null, null);
   Solution.Node a = new Solution.Node(5, null, null);
   Solution.Node b = new Solution.Node(4, null, null);
   list.addFirst(c);
   list.addFirst(b);
   list.addFirst(a);
   Solution.Node x = new Solution.Node(3, null, null);
   Solution.Node z = new Solution.Node(5, null, null);
   Solution.Node y = new Solution.Node(4, null, null);
   reversedList.addFirst(x);
   reversedList.addFirst(y);
   reversedList.addFirst(z);
   assertEquals(reversedList.getHead().getElement(), list.reverse().getTail().getElement());
   assertEquals(reversedList.getHead().getNext().getElement(), list.reverse().getTail().getPrevious().getElement());
   assertEquals(reversedList.getHead().getNext().getNext().getElement(), list.reverse().getTail().getPrevious().getPrevious().getElement());
 }

}
//