using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        private int index;
        private int players;
        private int level;

        // Buttons table for indexed button handling
        Button[] mButtons = new Button[9];

        // Used Class definitions
        CheckWinner winnerClass;
        ArtificialIntelligence aiClass;

        public Form1()
        {
            InitializeComponent();

            // Request player mode (1 or 2 players)
            if (MessageBox.Show( "Select 2 player mode?", "Game mode:", 
                    MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
            {
                players = 2;
            }
            else
            {
                players = 1;

                // Request inteligence mode (Artificial- inteligence/Nonsense)
                if (MessageBox.Show("Select Artificial inteligence?",
                        "Game Difficulty Level:", MessageBoxButtons.YesNo,
                        MessageBoxIcon.Question) == DialogResult.Yes)
                {
                    level = 2; //Artificial Intelligence
                }
                else
                {
                    level = 1; //Artificial Nonsense
                }
            }

            // Initialize Form for game start
            intialize();

            // Initialize used classes
            winnerClass = new CheckWinner();
            winnerClass.Initialize(mButtons);

            aiClass = new ArtificialIntelligence();
            aiClass.Initialize(mButtons);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            int status;
            Button b = sender as Button;

            // Button already used
            if ( 0 == b.Text.Length )
            {
                if ( 0 == index % 2)
                {
                    b.Text = "X";
                }
                else
                {
                    b.Text = "O";
                }

                index++;

                status = checkWinner();

                if (0 == status && 1 == players)
                {

                    // set computer move
                    if ( 1 == level){
                        artificialNonsense();
                    }
                    else{
                        artificialIntelligence();
                    }

                    status = checkWinner();
                }
            }
        }

        private void intialize()
        {
            index=1;

            // Set real buttons to button table
            mButtons[0] = button1;
            mButtons[1] = button2;
            mButtons[2] = button3;
            mButtons[3] = button4;
            mButtons[4] = button5;
            mButtons[5] = button6;
            mButtons[6] = button7;
            mButtons[7] = button8;
            mButtons[8] = button9;
            
            // Clear button name used for X and O (player)
            CleanScreen();

            // Select X as first player
            label7.Text = "Turn: Player X";
        }

        public void artificialIntelligence()
        {
            // Use real logic
            // Find 2 pair lines -> no -> set random -> otherwise block
            // check rows

            index++; // next turn is human player

            aiClass.CreateMove();
        }

        public void artificialNonsense()
        {
            int button;

            button = aiClass.CreateRandomMove();

            index++; // next turn is human player
        }

        public int checkWinner()
        {
            int ret = 0;

            ret = winnerClass.getWinnerStatus();
              
            // Check game state
            if(1 == ret){
                   HandleRetryExit("Winner is X.");    
            }
            else if(2 == ret) {
                HandleRetryExit("Winner is O.");               
            }
            else if (10 == index){
                HandleRetryExit("The game is draw.");
                ret = 3;
            }
                     
            return ret;
        }

        public void HandleRetryExit(String caption)
        {
            // Create Dialog, add text and image, associate a sound
            var result = MessageBox.Show( "Try again ?", caption,  MessageBoxButtons.YesNo,
                             MessageBoxIcon.Question );

            if(result == DialogResult.No)
            {
                Application.Exit(); // Close program
            }
            else
            {
                // Start again
                CleanScreen();       
            }
        }

        public void CleanScreen()
        {
            for (int i = 0; i < 9; i++)
            {
                mButtons[i].Text = "";
            }
            index=1;
       }

    }

/* AI CLASS */
    public class ArtificialIntelligence
    {
        private Button[] btnTable;
        private Random rnd;
        private bool classInitialized = false;

        public void Initialize( Button[] table )
        {
            btnTable = table;
            // initialize random class
            rnd = new Random();
            classInitialized = true;
        }

        public int CreateMove()
        {
            int ret = 0;

            if (classInitialized != true)
            {
                throw new Exception("Class Init is missing");
            }
            else
            {
                ret = CheckRows(btnTable);

                if (0 == ret)
                {
                    ret = CheckColumns(btnTable);
                }

                if (0 == ret)
                {
                    ret = CheckCrossLines(btnTable);
                }

                // no need block, use random logic
                if (0 == ret)
                {
                    ret = CreateRandomMove();
                }
            }
            return ret;
        }

        public int CreateRandomMove()
        {
            int button = 0;

            if (true != classInitialized)
            {
                throw new Exception("Class Init is missing");
            }
            else
            {
                // randomize turns, select next empty randomly selected button.
                while (getButtonTextLength(btnTable[button = rnd.Next(0, 9)]) != 0)
                {
                    ;
                }
                setButtonText(btnTable[button], "X");
            }

            return button + 1;
        }

        private int CreateLineMove(Button btn1, Button btn2, Button btn3)
        {
            int ret = 0;
    
            ret = CreateLineMoveSign(btn1, btn2, btn3, "O");

            if (0 == ret)
            {
                ret = CreateLineMoveSign(btn1, btn2, btn3, "X");
            }

            return ret;
        }

        private int CreateLineMoveSign(Button btn1, Button btn2, Button btn3, String sign)
        {
            // Block Opponents attack
            if (0 == getButtonTextLength(btn1) && getButtonText(btn2) == sign)
            {
                // buttons 2 and 3 used
                if (getButtonText(btn2) == getButtonText(btn3))
                {
                    setButtonText(btn1, "X");
                    return 1;
                }
            }

            if (0 == getButtonTextLength(btn2) && getButtonText(btn1) == sign)
            {
                // buttons 1 and 3 used
                if (getButtonText(btn1) == getButtonText(btn3))
                {
                    setButtonText(btn2, "X");
                    return 2;
                }
            }

            if (0 == getButtonTextLength(btn3) && getButtonText(btn2) == sign)
            {
                // buttons 1 and 2 used
                if (getButtonText(btn2) == getButtonText(btn1))
                {
                    setButtonText(btn3, "X");
                    return 3;
                }
            }

        return 0;
        }

        private int CheckRows(Button[] table)
        {
            int ret = 0;

            // check rows
            for (int i = 0; i < 3 && 0 == ret; i++)
            {
                ret = CreateLineMove(table[0 + (i * 3)], table[1 + (i * 3)], table[2 + (i * 3)]);
            }

            return ret;
        }

        private int CheckColumns(Button[] table)
        {
            int ret = 0;

            // check columns
            for (int i = 0; i < 3 && 0 == ret; i++)
            {
                ret = CreateLineMove(table[0 + i], table[3 + i], table[6 + i]);
            }

            return ret;
        }

        private int CheckCrossLines(Button[] table)
        {
            int ret = 0;

            // check cross line \
            ret = CreateLineMove(table[0], table[4], table[8]);

            // check cross line /
            if (0 == ret)
            {
                ret = CreateLineMove(table[2], table[4], table[6]);
            }

            return ret;
        }

        private int getButtonTextLength(Button btn)
        {
            return btn.Text.Length;
        }

        private string getButtonText(Button btn)
        {
            return btn.Text;
        }

        private void setButtonText(Button btn, string text)
        {
            btn.Text = text;
        }
    }

/* CHECK WINNER CLASS */
    public class CheckWinner
    {
        private Button[] btnTable;
        private bool classInitialized = false;

        public void Initialize(Button[] table)
        {
            btnTable = table;
            classInitialized = true;
        }

        public int getWinnerStatus()
        {
            int ret = 0;

            if (true != classInitialized)
            {
                throw new Exception("Class Init is missing");
            }
            else
            {
                ret = CheckRows(btnTable);

                if (0 == ret)
                {
                    ret = CheckColumns(btnTable);
                }

                if (0 == ret)
                {
                    ret = CheckCrossLines(btnTable);
                }
            }
            return ret;
        }

        private int CheckRows(Button[] table)
        {
            int ret = 0;

            // check rows
            for (int i = 0; i < 3 && 0 == ret; i++)
            {
                ret = CheckLine(table[0 + (i * 3)], table[1 + (i * 3)], table[2 + (i * 3)]);
            }

            return ret;
        }

        private int CheckColumns(Button[] table)
        {
            int ret = 0;

            // check columns
            for (int i = 0; i < 3 && 0 == ret; i++)
            {
                ret = CheckLine(table[0 + i], table[3 + i], table[6 + i]);
            }

            return ret;
        }

        private int CheckCrossLines(Button[] table)
        {
            int ret = 0;

            // check cross line \
            ret = CheckLine(table[0], table[4], table[8]);

            // check cross line /
            if (0 == ret)
            {
                ret = CheckLine(table[2], table[4], table[6]);
            }

            return ret;
        }

        private int CheckLine(Button btn1, Button btn2, Button btn3)
        {
            int ret = 0;


            if (getButtonText(btn1) == getButtonText(btn2) &&
                getButtonText(btn1) == getButtonText(btn3) )
            {
                if (getButtonText(btn1) == "X")
                {
                    ret = 1;
                }
                else if (getButtonText(btn1) == "O")
                {
                    ret = 2;
                }
            }

            return ret;
        }

        private string getButtonText(Button btn)
        {
            return btn.Text;
        }
    }

}