using System;
using System.Web;
using System.Collections;
using System.Web.Services;
using System.Web.Services.Protocols;

using System.ComponentModel;
using System.Data;
using System.Diagnostics;


namespace ttt
{
    /// <summary>
    /// Provides methods for playing the tic-tac-toe boardgame
    /// </summary>
    /// 
    [WebService(Namespace = "http://harbormist.com/",
          Description = "A web service which provides a TicTacToe game. " +
         "[Programmers: Charlie Chambers, Jay Patel.]")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class TicTacToe : System.Web.Services.WebService
    {
        private ArrayList triplets = new ArrayList();

        public const char USER_PIECE = 'X';
        public const char COMP_PIECE = 'O';
        public const char EMPT_PIECE = '_';

        static public int NUM_CELLS = 9;


        public TicTacToe()
        {
            InitializeComponent();
            triplets = new ArrayList();

            triplets.Add(new Triplet(0, 1, 2));
            triplets.Add(new Triplet(3, 4, 5));
            triplets.Add(new Triplet(6, 7, 8));
            triplets.Add(new Triplet(0, 3, 6));
            triplets.Add(new Triplet(1, 4, 7));
            triplets.Add(new Triplet(2, 5, 8));
            triplets.Add(new Triplet(0, 4, 8));
            triplets.Add(new Triplet(2, 4, 6));
        }

        #region Component Designer generated code

        //Required by the Web Services Designer 
        private IContainer components = null;

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
        }

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose(bool disposing)
        {
            if (disposing && components != null)
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #endregion


        [WebMethod(Description = "Given a string of 9 characters representing the state of the board, each of which is one of: \n" +
             " TicTacToe.USER_PIECE, TicTacToe.COMP_PIECE, or TicTacToe.EMPT_PIECE," +
             " and an integer index from 0 to 8, representing the user move from the given board, " +
             " This returns a similar string with a new 'O' move in place"
             )]
        public string respondToUserMove(String boardState, int userMoveIndex)
        {
            //first put in user move, if allowed
            if (boardState[userMoveIndex] != EMPT_PIECE) return boardState; //can't move there, so return same board
            if (boardState.Length != NUM_CELLS) return "" + EMPT_PIECE + EMPT_PIECE + EMPT_PIECE + EMPT_PIECE + EMPT_PIECE + EMPT_PIECE + EMPT_PIECE + EMPT_PIECE + EMPT_PIECE;
            if (userMoveIndex >= NUM_CELLS || userMoveIndex < 0) return boardState;

            //don't let the user move if the game is won or lost
            foreach (Triplet t in triplets)
            {
                if (t.isWon(boardState) || t.isLost(boardState)) return boardState;
            }

            // user move is legal, so add it
            String afterUser = boardState.Substring(0, userMoveIndex);
            afterUser += USER_PIECE;
            if (afterUser.Length < NUM_CELLS) afterUser += boardState.Substring(userMoveIndex + 1);

            //has the user just won? if so, computer gets no move
            foreach (Triplet t in triplets)
            {
                if (t.isWon(afterUser)) return afterUser;
            }

            //are there no spaces for the computer to move?
            if (afterUser.IndexOf(EMPT_PIECE) == -1) return afterUser;


            //now to find the computer move...


            //first, two explicit conditions that we are fudging.
            if (afterUser.Equals(
                TicTacToe.USER_PIECE + TicTacToe.EMPT_PIECE + TicTacToe.EMPT_PIECE +
                TicTacToe.EMPT_PIECE + TicTacToe.COMP_PIECE + TicTacToe.EMPT_PIECE +
                TicTacToe.EMPT_PIECE + TicTacToe.EMPT_PIECE + TicTacToe.USER_PIECE
                ))
            {
                return ("" +
                    TicTacToe.USER_PIECE + TicTacToe.COMP_PIECE + TicTacToe.EMPT_PIECE +
                    TicTacToe.EMPT_PIECE + TicTacToe.COMP_PIECE + TicTacToe.EMPT_PIECE +
                    TicTacToe.EMPT_PIECE + TicTacToe.EMPT_PIECE + TicTacToe.USER_PIECE
                    );
            }
            if (afterUser.Equals(
                TicTacToe.EMPT_PIECE + TicTacToe.EMPT_PIECE + TicTacToe.USER_PIECE +
                TicTacToe.EMPT_PIECE + TicTacToe.COMP_PIECE + TicTacToe.EMPT_PIECE +
                TicTacToe.USER_PIECE + TicTacToe.EMPT_PIECE + TicTacToe.EMPT_PIECE
                ))
            {
                return ("" +
                    TicTacToe.EMPT_PIECE + TicTacToe.COMP_PIECE + TicTacToe.USER_PIECE +
                    TicTacToe.EMPT_PIECE + TicTacToe.COMP_PIECE + TicTacToe.EMPT_PIECE +
                    TicTacToe.USER_PIECE + TicTacToe.EMPT_PIECE + TicTacToe.EMPT_PIECE
                    );
            }

            int[] weights = new int[NUM_CELLS];
            for (int i = 0; i < NUM_CELLS; i++) weights[i] = 0; //initialize weights to 0 expicitly

            foreach (Triplet t in triplets)
            {
                weights = t.addWeight(afterUser, weights); // add the influence of each triplet 
            }


            //find the highest weight value that is a legal move
            int heighestWeight = -1;
            int bestMoveCell = 0;
            for (int i = 0; i < NUM_CELLS; i++)
            {
                if (weights[i] > heighestWeight && afterUser.Substring(i, 1) == ("" + EMPT_PIECE))
                {//upgrade to better, empty-cell moves
                    bestMoveCell = i;
                    heighestWeight = weights[i];
                }
            }

            String afterComputer = afterUser.Substring(0, bestMoveCell);
            afterComputer += COMP_PIECE;
            if (afterComputer.Length < NUM_CELLS) afterComputer += afterUser.Substring(bestMoveCell + 1);

            return afterComputer;
        }






        [WebMethod(Description = "Given a string of 9 characters representing the state of the board, " +
             " each of which is one of: \n" +
             " TicTacToe.USER_PIECE, TicTacToe.COMP_PIECE, or TicTacToe.EMPT_PIECE," +
             " This returns a status line (e.g. 'You lose', or 'You win') to explain " +
             " the status of the game to the user."
             )]
        public string getStatus(String boardState)
        {
            foreach (Triplet t in triplets)  //we will check every "way" of winning
            {
                if (t.isWon(boardState)) return "You win.";
                if (t.isLost(boardState)) return "You lose.";
            }

            if (boardState.IndexOf(EMPT_PIECE) == -1) return "Stalemate.";     //no empty squares
            return "Your turn"; //barring everything else, we are waiting for the user
        }



    }
}