TicTacToe -TizzyT

using System;

namespace TicTacToe
{
    internal static class Program
    {
        private static void Main(string[] args)
        {
            if (args == null)
            {
                throw new ArgumentNullException(nameof(args));
            }

            Game ttt = new Game();
            while (true)
            {
                ttt = new Game();
                ttt.Play();
                Console.WriteLine("    Press Enter To Start A New Game ...");
                Console.ReadLine();
            }
        }

        public class Game
        {
            private enum Player : sbyte
            {
                None = 0,
                X = 10, //Human Player
                O = -10 //AI Player
            }

            private readonly sbyte[][] board;
            private readonly Random rnd;
            private Player turn;

            //Creates a new game instance
            public Game()
            {
                //Clears the screen of any previous games
                Console.Clear();

                //Choose who goes first
                rnd = new Random();
                turn = Player.X;
                if (rnd.Next(0, 2) == 1) turn = Player.O;

                //Initializes the game board
                board = new sbyte[][] { new sbyte[]{ 7, 8, 9},
                                        new sbyte[]{ 4, 5, 6},
                                        new sbyte[]{ 1, 2, 3} };
            }

            //Starts the game
            public void Play()
            {
                PrintBoard();
                int i = 0;
                for (; i < 9 && !CheckWinner(); i++)
                {
                    PlayMove();
                }
                if (i == 9 && !CheckWinner()) DisplayWinner(Player.None);
            }

            //Prints the entire board
            public void PrintBoard()
            {
                Console.SetCursorPosition(0, 0);
                Console.CursorVisible = false;
                Console.ForegroundColor = ConsoleColor.Blue;
                Console.WriteLine();

                //Draws first row
                Console.Write("   "); DrawPiece(board[0][0]); Console.Write(" "); DrawBoard(BoardTypes.Vertical); Console.Write(" "); DrawPiece(board[0][1]); Console.Write(" "); DrawBoard(BoardTypes.Vertical); Console.Write(" "); DrawPiece(board[0][2]);
                Console.WriteLine();
                Console.Write("  "); DrawBoard(BoardTypes.Horizontal); DrawBoard(BoardTypes.Intersection); DrawBoard(BoardTypes.Horizontal); DrawBoard(BoardTypes.Intersection); DrawBoard(BoardTypes.Horizontal);
                Console.WriteLine();

                //Draws second row
                Console.Write("   "); DrawPiece(board[1][0]); Console.Write(" "); DrawBoard(BoardTypes.Vertical); Console.Write(" "); DrawPiece(board[1][1]); Console.Write(" "); DrawBoard(BoardTypes.Vertical); Console.Write(" "); DrawPiece(board[1][2]);
                Console.WriteLine();
                Console.Write("  "); DrawBoard(BoardTypes.Horizontal); DrawBoard(BoardTypes.Intersection); DrawBoard(BoardTypes.Horizontal); DrawBoard(BoardTypes.Intersection); DrawBoard(BoardTypes.Horizontal);
                Console.WriteLine();

                //Draws third row
                Console.Write("   "); DrawPiece(board[2][0]); Console.Write(" "); DrawBoard(BoardTypes.Vertical); Console.Write(" "); DrawPiece(board[2][1]); Console.Write(" "); DrawBoard(BoardTypes.Vertical); Console.Write(" "); DrawPiece(board[2][2]);
                Console.WriteLine();
                Console.WriteLine();
            }

            //Prints a message after the board
            private void PrintMessage(string msg)
            {
                ConsoleColor PrevColor = Console.ForegroundColor;
                Console.ForegroundColor = ConsoleColor.DarkMagenta;
                Console.WriteLine(msg);
                Console.ForegroundColor = PrevColor;
            }

            //Has the player make a move or the AI pick a move
            private void PlayMove()
            {
                if (turn == Player.X)
                {
                    PrintMessage(" Pick a position:");
                    while (!SetPiece(turn, Console.ReadKey().KeyChar)) ;
                    turn = Player.O;
                }
                else
                {
                    //Dumb AI (random non-calculated move)
                    while (!SetPiece(turn, char.Parse(rnd.Next(1, 10).ToString()))) ;
                    turn = Player.X;
                }
                PrintBoard();
            }

            //Checks for valid position input and sets the move on the board
            private bool SetPiece(Player player, char pos)
            {
                switch (pos)
                {
                    case '1':
                        if (board[2][0] == 1)
                        {
                            board[2][0] = (sbyte)player;
                            return true;
                        }
                        break;
                    case '2':
                        if (board[2][1] == 2)
                        {
                            board[2][1] = (sbyte)player;
                            return true;
                        }
                        break;
                    case '3':
                        if (board[2][2] == 3)
                        {
                            board[2][2] = (sbyte)player;
                            return true;
                        }
                        break;
                    case '4':
                        if (board[1][0] == 4)
                        {
                            board[1][0] = (sbyte)player;
                            return true;
                        }
                        break;
                    case '5':
                        if (board[1][1] == 5)
                        {
                            board[1][1] = (sbyte)player;
                            return true;
                        }
                        break;
                    case '6':
                        if (board[1][2] == 6)
                        {
                            board[1][2] = (sbyte)player;
                            return true;
                        }
                        break;
                    case '7':
                        if (board[0][0] == 7)
                        {
                            board[0][0] = (sbyte)player;
                            return true;
                        }
                        break;
                    case '8':
                        if (board[0][1] == 8)
                        {
                            board[0][1] = (sbyte)player;
                            return true;
                        }
                        break;
                    case '9':
                        if (board[0][2] == 9)
                        {
                            board[0][2] = (sbyte)player;
                            return true;
                        }
                        break;
                }
                return false;
            }

            //Draws the player piece with color
            private void DrawPiece(sbyte value)
            {
                ConsoleColor prevColor = Console.ForegroundColor;
                if (value == 10)
                {
                    Console.ForegroundColor = ConsoleColor.Red;
                    Console.Write('X');
                    Console.ForegroundColor = prevColor;
                }
                else if (value == -10)
                {
                    Console.ForegroundColor = ConsoleColor.Green;
                    Console.Write('O');
                    Console.ForegroundColor = prevColor;
                }
                else
                {
                    Console.ForegroundColor = ConsoleColor.DarkGray;
                    Console.Write(value.ToString());
                    Console.ForegroundColor = prevColor;
                }
            }

            //Specifies the 3 parts of a board
            private enum BoardTypes
            {
                Vertical,
                Horizontal,
                Intersection
            }

            //Draws parts of the board
            private void DrawBoard(BoardTypes type)
            {
                switch (type)
                {
                    case BoardTypes.Vertical:
                        Console.Write('║');
                        break;
                    case BoardTypes.Horizontal:
                        Console.Write("═══");
                        break;

                    case BoardTypes.Intersection:
                        Console.Write('╬');
                        break;
                }
            }

            //Checks the board for winning pattern
            private bool CheckWinner()
            {
                //Check Rows for winner
                for (int y = 0; y < board.Length; y++)
                {
                    int total = 0;
                    for (int x = 0; x < board[y].Length; x++)
                    {
                        total += board[y][x];
                    }
                    if (total == 30)
                    {
                        DisplayWinner(Player.X);
                        return true;
                    }
                    if (total == -30)
                    {
                        DisplayWinner(Player.O);
                        return true;
                    }
                }

                //Check Columns for winner
                for (int x = 0; x < board.Length; x++)
                {
                    int total = 0;
                    for (int y = 0; y < board[x].Length; y++)
                        total += board[y][x];
                    if (total == 30)
                    {
                        DisplayWinner(Player.X);
                        return true;
                    }
                    if (total == -30)
                    {
                        DisplayWinner(Player.O);
                        return true;
                    }
                }

                //Check diagonals
                int d1 = 0, d2 = 0;
                for (int i1 = 0, i2 = 2; i1 < board.Length; i1++, i2--)
                {
                    d1 += board[i1][i1];
                    d2 += board[i1][i2];
                }
                if (d1 == 30 || d2 == 30)
                {
                    DisplayWinner(Player.X);
                    return true;
                }
                if (d1 == -30 || d2 == -30)
                {
                    DisplayWinner(Player.O);
                    return true;
                }
                return false;
            }

            //Displays the Win/Lose/Draw message
            private void DisplayWinner(Player player)
            {
                ConsoleColor PrevColor = Console.ForegroundColor;
                Console.ForegroundColor = ConsoleColor.Cyan;
                if (player == Player.X)
                    Console.WriteLine("  Congrats, You've Won !!!");
                else if (player == Player.O)
                    Console.WriteLine("  Sorry, You've Lost !!!");
                else
                    Console.WriteLine("  Game Ended In A Draw !!!");
                Console.ForegroundColor = PrevColor;
            }
        }
    }
}