using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace GeneratForUnity
{
    class Tree
    {
        private TreeNode Root;

        public Tree()
        {
            Root = new TreeNode();
        }

        #region CreateTree(int[],int)

        private bool FindNotZero(int[] Mas)
        {
            bool result= false;
            int summa=0;
            for (var i = 0; i < Mas.Length; i++) summa += Mas[i];
            if (summa > 0) result = true;
            return result;
        }


        public TreeNode CreateTree(int[] Mas,int result)
        {
            TreeNode root=new TreeNode();
            Random rnd = new Random();
            if (FindNotZero(Mas))
            {
                bool res = false;
                int i = 0;
                int kof = 1;
                int element;

                while (res!=true)
                {
                    i = rnd.Next(0, 4);
                    if (Mas[i] != 0) res = true;
                }

                switch (i)
                {
                    case 0:
                        Mas[i]--;
                        root.Sign = '+';
                        element = rnd.Next(0, result+1);
                        root.LeftNode = new TreeNode(element);
                        root.RightNode = new TreeNode(result - element);

                        if (FindNotZero(Mas)) root.LeftNode.LeftNode = CreateTree(Mas, root.LeftNode.Figure);

                        break;

                    case 1:
                        Mas[i]--;
                        root.Sign = '-';
                        element = rnd.Next(result-1,result + result/100*20);
                        root.LeftNode = new TreeNode(element);
                        root.RightNode = new TreeNode(element - result);

                        if (FindNotZero(Mas)) root.LeftNode.LeftNode = CreateTree(Mas, root.LeftNode.Figure);

                        break;

                    case 2:
                        Mas[i]--;
                        root.Sign = '/';
                        kof = 1;
                        element = rnd.Next(result, result + 200);

                        while ((element % kof != 0) || (element / kof != result))
                        {
                            if (kof > element)
                            {
                                element = rnd.Next(result + 10, result + 200);
                                kof = 1;
                            }
                            kof++;
                        }

                        root.LeftNode = new TreeNode(element);
                        root.RightNode = new TreeNode(kof);

                        if (FindNotZero(Mas)) root.LeftNode.LeftNode = CreateTree(Mas, root.LeftNode.Figure);

                        break;

                    case 3:
                        Mas[i]--;
                        root.Sign = '*';
                        kof = 1;
                        element = rnd.Next(1, result+1);

                        while((element*kof!=result))
                        {
                            kof++;
                            if (kof * element > result)
                            {
                                element = rnd.Next(1, result+1);
                                kof = 1;
                            }
                        }

                        if (kof>element)
                        {
                            root.LeftNode = new TreeNode(kof);
                            root.RightNode = new TreeNode(element);
                        }
                        else
                        {
                            root.LeftNode = new TreeNode(element);
                            root.RightNode = new TreeNode(kof);
                        }

                        if (FindNotZero(Mas)) root.LeftNode.LeftNode = CreateTree(Mas, root.LeftNode.Figure);

                        break;
                }

            }
            else root = null;

            return root;
        }

        #endregion

        public int Calculation(string str)
        {
            int result = 0;
            StringBuilder strInt = new StringBuilder("ds");
            for (var i=0;i<str.Length;i++)
            {

            }
            return result;
        }


        private string ToString(TreeNode root)
        {
            StringBuilder str = new StringBuilder("");

            if (root.LeftNode != null) str.Insert(str.Length, "("+ToString(root.LeftNode));

            if (root.Sign != 'e') str.Insert(str.Length, root.Sign);
            else
            {
                if ((root.LeftNode != null) && (root.RightNode == null)) ;
                else str.Insert(str.Length, root.Figure);
            }

            if (root.RightNode!=null) str.Insert(str.Length, ToString(root.RightNode)+")");

            return Convert.ToString(str);
        }


        public string Generate(int pCount, int sCount, int dCount, int mCount, int result)
        {
            Root.Figure = result;
            int[] Mas = new int[4] { pCount, sCount, dCount, mCount };
            Root.LeftNode=CreateTree(Mas,result);
            string str = ToString(Root.LeftNode);

            return str;
        }

    }
}