namespace Battleship
{
    using System;
    using System.Collections.Generic;
    using System.Drawing;
    using System.Linq;
 
    public class BP7 : IBattleshipOpponent
    {
        public string Name { get { return "BP7"; } }
        public Version Version { get { return this.version; } }
 
        Random rand = new Random();
        Version version = new Version(0, 7);
        Size gameSize;
        List<Point> scanShots;
        List<NextShot> nextShots;
        int wins, losses;
        int totalWins = 0;
        int totalLosses = 0;
        int maxWins = 0;
        int maxLosses = 0;
        int matchWins = 0;
        int matchLosses = 0;
 
        public enum Direction { VERTICAL = -1, UNKNOWN = 0, HORIZONTAL = 1 };
        Direction hitDirection, lastShotDirection;
 
        enum ShotResult { UNKNOWN, MISS, HIT };
        ShotResult[,] board;
 
        public struct NextShot
        {
            public Point point;
            public Direction direction;
            public NextShot(Point p, Direction d)
            {
                point = p;
                direction = d;
            }
        }
 
        public struct ScanShot
        {
            public Point point;
            public int openSpaces;
            public ScanShot(Point p, int o)
            {
                point = p;
                openSpaces = o;
            }
        }
 
        public void NewGame(Size size, TimeSpan timeSpan)
        {
            this.gameSize = size;
            scanShots = new List<Point>();
            nextShots = new List<NextShot>();
            fillScanShots();
            hitDirection = Direction.UNKNOWN;
            board = new ShotResult[size.Width, size.Height];
        }
 
        private void fillScanShots()
        {
            int x;
            for (x = 0; x < gameSize.Width - 1; x++)
            {
                scanShots.Add(new Point(x, x));
            }
 
            if (gameSize.Width == 10)
            {
                for (x = 0; x < 3; x++)
                {
                    scanShots.Add(new Point(9 - x, x));
                    scanShots.Add(new Point(x, 9 - x));
                }
            }
        }
 
        public void PlaceShips(System.Collections.ObjectModel.ReadOnlyCollection<Ship> ships)
        {
            foreach (Ship s in ships)
            {
                s.Place(
                    new Point(
                        rand.Next(this.gameSize.Width),
                        rand.Next(this.gameSize.Height)),
                    (ShipOrientation)rand.Next(2));
            }
        }
 
        public Point GetShot()
        {
            Point shot;
 
            if (this.nextShots.Count > 0)
            {
                if (hitDirection != Direction.UNKNOWN)
                {
                    if (hitDirection == Direction.HORIZONTAL)
                    {
                        this.nextShots = this.nextShots.OrderByDescending(x => x.direction).ToList();
                    }
                    else
                    {
                        this.nextShots = this.nextShots.OrderBy(x => x.direction).ToList();
                    }
                }
 
                shot = this.nextShots.First().point;
                lastShotDirection = this.nextShots.First().direction;
                this.nextShots.RemoveAt(0);
                return shot;
            }
 
            List<ScanShot> scanShots = new List<ScanShot>();
            for (int x = 0; x < gameSize.Width; x++)
            {
                for (int y = 0; y < gameSize.Height; y++)
                {
                    if (board[x, y] == ShotResult.UNKNOWN)
                    {
                        scanShots.Add(new ScanShot(new Point(x, y), OpenSpaces(x, y)));
                    }
                }
            }
            scanShots = scanShots.OrderByDescending(x => x.openSpaces).ToList();
            int maxOpenSpaces = scanShots.FirstOrDefault().openSpaces;
 
            List<ScanShot> scanShots2 = new List<ScanShot>();
            scanShots2 = scanShots.Where(x => x.openSpaces == maxOpenSpaces).ToList();
            shot = scanShots2[rand.Next(scanShots2.Count())].point;
 
            return shot;
        }
 
        int OpenSpaces(int x, int y)
        {
            int ctr = 0;
            Point p;
 
            // spaces to the left
            p = new Point(x - 1, y);
            while (p.X >= 0 && board[p.X, p.Y] == ShotResult.UNKNOWN)
            {
                ctr++;
                p.X--;
            }
 
            // spaces to the right
            p = new Point(x + 1, y);
            while (p.X < gameSize.Width && board[p.X, p.Y] == ShotResult.UNKNOWN)
            {
                ctr++;
                p.X++;
            }
 
            // spaces to the top
            p = new Point(x, y - 1);
            while (p.Y >= 0 && board[p.X, p.Y] == ShotResult.UNKNOWN)
            {
                ctr++;
                p.Y--;
            }
 
            // spaces to the bottom
            p = new Point(x, y + 1);
            while (p.Y < gameSize.Height && board[p.X, p.Y] == ShotResult.UNKNOWN)
            {
                ctr++;
                p.Y++;
            }
 
            return ctr;
        }
 
        public void NewMatch(string opponenet)
        {
            wins = 0;
            losses = 0;
        }
 
        public void OpponentShot(Point shot) { }
 
        public void ShotHit(Point shot, bool sunk)
        {
            board[shot.X, shot.Y] = ShotResult.HIT;
 
            if (!sunk)
            {
                hitDirection = lastShotDirection;
                if (shot.X != 0)
                {
                    this.nextShots.Add(new NextShot(new Point(shot.X - 1, shot.Y), Direction.HORIZONTAL));
                }
 
                if (shot.Y != 0)
                {
                    this.nextShots.Add(new NextShot(new Point(shot.X, shot.Y - 1), Direction.VERTICAL));
                }
 
                if (shot.X != this.gameSize.Width - 1)
                {
                    this.nextShots.Add(new NextShot(new Point(shot.X + 1, shot.Y), Direction.HORIZONTAL));
                }
 
                if (shot.Y != this.gameSize.Height - 1)
                {
                    this.nextShots.Add(new NextShot(new Point(shot.X, shot.Y + 1), Direction.VERTICAL));
                }
            }
            else
            {
                hitDirection = Direction.UNKNOWN;
                this.nextShots.Clear();     // so now this works like gangbusters ?!?!?!?!?!?!?!?!?
            }
        }
 
        public void ShotMiss(Point shot)
        {
            board[shot.X, shot.Y] = ShotResult.MISS;
        }
 
        public void GameWon()
        {
            wins++;
        }
 
        public void GameLost()
        {
            losses++;
        }
 
        public void MatchOver()
        {
            if (wins > maxWins)
            {
                maxWins = wins;
            }
 
            if (losses > maxLosses)
            {
                maxLosses = losses;
            }
 
            totalWins += wins;
            totalLosses += losses;
 
            if (wins >= losses)
            {
                matchWins++;
            }
            else
            {
                matchLosses++;
            }
        }
 
        public void FinalStats()
        {
            Console.WriteLine("Games won: " + totalWins.ToString());
            Console.WriteLine("Games lost: " + totalLosses.ToString());
            Console.WriteLine("Game winning percentage: " + (totalWins * 1.0 / (totalWins + totalLosses)).ToString("P"));
            Console.WriteLine("Game losing percentage: " + (totalLosses * 1.0 / (totalWins + totalLosses)).ToString("P"));
            Console.WriteLine();
            Console.WriteLine("Matches won: " + matchWins.ToString());
            Console.WriteLine("Matches lost: " + matchLosses.ToString());
            Console.WriteLine("Match winning percentage: " + (matchWins * 1.0 / (matchWins + matchLosses)).ToString("P"));
            Console.WriteLine("Match losing percentage: " + (matchLosses * 1.0 / (matchWins + matchLosses)).ToString("P"));
            Console.WriteLine("Match games won high: " + maxWins.ToString());
            Console.WriteLine("Match games lost high: " + maxLosses.ToString());
            Console.WriteLine();
        }
    }
}