using System;
using System.Collections.Generic;
using System.Linq;

namespace project
{
    class Program
    {
        public static void Main(string[] args)
        {
            BinarySearchTree<int> bst = new BinarySearchTree<int>();
            bst.Insert(1);
            bst.Insert(3);
            bst.Insert(5);
            bst.Insert(2);
            bst.Insert(21);
            bst.Insert(4, bst.root);
            System.Console.WriteLine(bst.FindByValue(4,bst.root).data);
        }
    }

    public class BinNode<T> where T:IComparable
    {
        //constructors
        public BinNode(T data)
        {
            this.data = data;
        }
        public BinNode() { }
        //properties
        public BinNode<T> right {get; set;} = null;
        public BinNode<T> left {get; set;} = null;
        public T data {get;set;}
    }


    public class BinarySearchTree<T> where T:IComparable
    {
        public BinNode<T> root {get; set;} = null;

        //recursively insert new node into the bst instance with T data
        public void Insert(T data, BinNode<T> node)
        {

            if (data.CompareTo(node.data) > 0)
            {
                if (node.right == null)
                {
                    node.right = new BinNode<T>(data);
                    return;
                }
                Insert(data, node.right);
                System.Console.WriteLine("right");
            }

            else if (data.CompareTo(node.data) < 0)
            {
                if (node.left == null)
                {
                    node.left = new BinNode<T>(data);
                    return;
                }
                Insert(data, node.left);
                System.Console.WriteLine("left");
            }
        }

        //normal insertion method (inserts T data into a bst instance)
        public void Insert(T data)
        {
            if (root == null)
            {
                root = new BinNode<T>(data);
            }

            BinNode<T> current = root;

            while (current != null)
            {
                if (data.CompareTo(current.data) > 0)
                {
                    if (current.right != null)
                    {
                        current = current.right;
                        continue;
                    }
                    current.right = new BinNode<T>(data);
                }

                else if (data.CompareTo(current.data) < 0)
                {
                    if (current.left != null)
                    {
                        current = current.left;
                        continue;
                    }
                    current.left = new BinNode<T>(data);
                }

                else
                {
                    return;
                }

            }
        }

        //insert all elements from an array
        public void InsertFromArray(T[] array)
        {
            foreach(T t in array)
            {
                this.Insert(t);
            }
        }
        //get the last level in the bst instance
        public int GetLevel(BinNode<T> node, int current=1)
        {
            int right = 0 ;
            int left = 0 ;

            if (node.right != null)
            {
                right =  GetLevel(node.right, current+1);
            }

            if (node.left != null)
            {
                left = GetLevel(node.right, current+1);
            }

            if (right == 0 && left == 0) return current; //this is readable in my opinion but according to best practices (microsoft), only one operation per line is good, so should this be changed or is it okay

            else
            {
                return right > left ? right : left; //is this acceptable?
            }

        }
        //get a queue of all the values in a given level
        public void GetOnLevel(BinNode<T> node, int curLevel, int trgLevel, Queue<T> result)
        {
            if (curLevel == trgLevel)
            {
                result.Enqueue(node.data);
            }
            else
            {
                if (node.left != null)
                {
                    GetOnLevel(node.left, curLevel+1, trgLevel, result);
                }

                if(node.right != null)
                {
                     GetOnLevel(node.right, curLevel+1, trgLevel, result);
                }
            }
        }

        //returns the node that holds data equivalent to T data
        public BinNode<T> FindByValue(T data, BinNode<T> node)
        {
            if (node == null) return null;

            if (data.Equals(node.data))
            {
                return node;
            }

            if (data.CompareTo(node.data) > 0)
            {
                return FindByValue(data, node.right);
            }
            else if (data.CompareTo(node.data) < 0)
            {
                return FindByValue(data, node.left);
            }

            else return null;
        }

    }
}

if (right == 0 && left == 0) return current;

return right > left ? right : left;