using System.Collections;
using System.Collections.Generic;
using System.Linq;
using Chess.Data;
using Type = Chess.Data.Type;

namespace Chess.Players.Algorithms
{
    public class WeightedPlayer : Player, IPlayer
    {
        //Simple robot player class which chooses the highest weighted move
        private readonly Hashtable _hashtable = new Hashtable
        {
            {Type.King, 900},
            {Type.Queen, 90},
            {Type.Rook, 50},
            {Type.Bishop, 30},
            {Type.Knight, 30},
            {Type.Pawn, 10}
        };

        public WeightedPlayer(Colours colour) : base(colour) { }

        private List<KeyValuePair<Pos, KeyValuePair<int, Pos>>> GetValidWeightedMoves(Board board, Pos pos)
        {
            List<KeyValuePair<Pos, KeyValuePair<int, Pos>>> output = new List<KeyValuePair<Pos, KeyValuePair<int, Pos>>>();

            for (int x = 0; x < board.GetCols(); x++)
                for (int y = 0; y < board.GetRows(); y++)
                    if (board.PieceAt(pos).ValidMove(board, pos, new Pos(x, y)))
                    {
                        if (board.PieceAt(new Pos(x, y)) != null)
                            output.Add(new KeyValuePair<Pos, KeyValuePair<int, Pos>>(pos,
                                new KeyValuePair<int, Pos>((int) _hashtable[board.PieceAt(new Pos(x, y)).GetType()],
                                    new Pos(x, y))));
                        else
                            output.Add(new KeyValuePair<Pos, KeyValuePair<int, Pos>>(pos,
                                new KeyValuePair<int, Pos>(0, new Pos(x, y))));
                    }

            return output;
        }

        public MovePieceData MovePiece(Board board)
        {
            List<KeyValuePair<Pos, KeyValuePair<int, Pos>>> validMoves = new List<KeyValuePair<Pos, KeyValuePair<int, Pos>>>();

            //Loops through every cell in the board, and adds all the valid movements for each piece to a list
            for (int x = 0; x < board.GetCols(); x++)
            for (int y = 0; y < board.GetRows(); y++)
                if (board.PieceAt(new Pos(x, y)) != null && board.PieceAt(new Pos(x, y)).GetColour() == _colour)
                    validMoves.AddRange(GetValidWeightedMoves(board, new Pos(x, y)));

            //Sort list of movements by weight
            validMoves = validMoves.OrderBy(o => o.Value.Key).Reverse().ToList();

            //Fetch positional information from highest weight movement
            List<Pos> movement = new List<Pos> {validMoves[0].Key, validMoves[0].Value.Value};

            return base.MovePiece(board, movement[0], movement[1]);
        }
    }
}