import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.CoreMatchers.nullValue;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.core.IsNull.notNullValue;

import java.util.List;

import org.junit.Test;

public class BinaryTreeTest {

  BinaryTree tree = new BinaryTree();


  @Test
  public void treeShouldReceiveOnlyNodeValueAsInput() {
    tree.insert(5);
    assertThat("If no root defined, new node should become root", tree.getRoot().getValue(), is(notNullValue()));
  }

  @Test
  public void inputValueMustBeNumeric() {
    tree.insert(5);
  }

  @Test
  public void testTreeInsertion() {
    tree.insert(5);
    tree.insert(3);
    tree.insert(6);

    Node node = tree.find(5);

    assertThat("root node should contains second node as left children", node.getLeft().getValue(), is(3));

    assertThat("root node should contains second node as right children", node.getRight().getValue(), is(6));
  }


  @Test
  public void treeMustInsertNodesNoToRootOnly() {
    tree.insert(5);
    tree.insert(3);
    tree.insert(6);
    tree.insert(12);

    Node node = tree.find(6);

    assertThat("root node should contains second node as right children", node.getRight().getValue(), is(12));

  }


  @Test
  public void treeMustReturnNullIfThereIsNoSuchNode() {
    tree.insert(5);
    tree.insert(3);
    tree.insert(6);
    tree.insert(12);

    Node node = tree.find(24);

    assertThat("node should be null", node, is(nullValue()));
  }

  @Test
  public void treeMustHaveFindMaxMethod() {

    assertThat("in empty tree it should be zero",  tree.findMax() , is(0));

    tree.insert(5);
    tree.insert(3);
    tree.insert(6);
    tree.insert(12);

    assertThat("should be 12",  tree.findMax() , is(12));

  }

  @Test
  public void treeMustHaveMinimumMethod() {
    assertThat("in empty tree it should be zero",  tree.findMin() , is(0));

    tree.insert(5);
    tree.insert(3);
    tree.insert(6);
    tree.insert(12);

    assertThat("should be 3",  tree.findMin() , is(3));
  }

  @Test
  public void traverseTree() {

    tree.insert(5);
    tree.insert(3);
    tree.insert(6);

    List<Node> inOrderNodes = tree.traverseInOrder();
    List<Node> preOrderNodes = tree.traversePreOrder();
    List<Node> postOrderNodes = tree.traverPostOrder();

    assertThat("in order nodes", inOrderNodes.get(0).getValue(), is(5));
    assertThat("in order nodes", inOrderNodes.get(1).getValue(), is(3));
    assertThat("in order nodes", inOrderNodes.get(2).getValue(), is(6));

    assertThat("pre order nodes", preOrderNodes.get(0).getValue(), is(3));
    assertThat("pre order nodes", preOrderNodes.get(1).getValue(), is(6));
    assertThat("pre order nodes", preOrderNodes.get(2).getValue(), is(5));



  }


  @Test
  public void treeShouldSupportDelete() {

  }
}