'use strict';

class BinarySearchTree {

  constructor() {
    this.root = null;
  }

  insertNode(val) {
    var node = {
      data: val,
      left: null,
      right: null
    };

    var currentNode;

    if (!this.root) {
      this.root = node;
    } else {
      currentNode = this.root;
      while (currentNode) {
        if (val < currentNode.data) {
          if (!currentNode.left) {
            currentNode.left = node;
            break;
          } else {
            currentNode = currentNode.left;
          }
        } else if (val > currentNode.data) {
          if (!currentNode.right) {
            currentNode.right = node;
            break;
          } else {
            currentNode = currentNode.right;
          }
        } else {
          console.log('Ignoring this value as the BST supposed to be a tree containing UNIQUE values');
          break;
        }
      }
    }
  }
}

var BST = new BinarySearchTree();

BST.insertNode(8);
BST.insertNode(3);
BST.insertNode(10);
BST.insertNode(1);
BST.insertNode(6);
BST.insertNode(14);
BST.insertNode(4);
BST.insertNode(7);
BST.insertNode(13);

console.log(BST);