import Data.Map as Map
import Data.Maybe

data Coordinates = Coordinates Int Int deriving Eq

instance Ord Coordinates where
    compare (Coordinates a b) (Coordinates c d)
        |(b == d) = a `compare` c
        |otherwise = b `compare` d

data Color = White | Black deriving Eq

instance Show Color where
   show White = "o"
   show Black = "x"

data Board = Board (Map Coordinates Color)

instance Show Board where
    show = toString

negateColor color
    | (color==White) = Black
    | otherwise = White

toString (Board map) =
    iterate([Coordinates x y | y <- [1..19], x <- [1..19]])
        where
            iterate [element] = (mapToCharacter element) ++ (newLine element)
            iterate (element:listOfCoordinates) = (mapToCharacter element) ++ (newLine element) ++ iterate(listOfCoordinates)
            mapToCharacter coordinates
                | (member coordinates map) = show(fromJust (Map.lookup coordinates map))
                | otherwise = " "
            newLine (Coordinates x y)
                | (x == 19) = "\n"
                | otherwise = ""

rateVerticalNeighbors (Coordinates x y) listOfCoordinates
    | ((Coordinates x (y-1)) `elem` listOfCoordinates) || ((Coordinates x (y+1)) `elem` listOfCoordinates) = 1
    | otherwise = 0

rateHorizontalNeighbors (Coordinates x y) listOfCoordinates
    | ((Coordinates (x-1) y) `elem` listOfCoordinates) || ((Coordinates (x+1) y) `elem` listOfCoordinates) = 1
    | otherwise = 0

rateRightDiagonalNeighbors (Coordinates x y) listOfCoordinates
    | ((Coordinates (x-1) (y-1)) `elem` listOfCoordinates) || ((Coordinates (x+1) (y+1)) `elem` listOfCoordinates) = 1
    | otherwise = 0

rateLeftDiagonalNeighbors (Coordinates x y) listOfCoordinates
    | ((Coordinates (x-1) (y+1)) `elem` listOfCoordinates) || ((Coordinates (x+1) (y-1)) `elem` listOfCoordinates) = 1
    | otherwise = 0



rateBoard (Board map) color =
    rate 0 [x | x <- Map.keys map, fromJust (Map.lookup coordinates map) == color] - rate 0 [x | x <- Map.keys map, fromJust (Map.lookup coordinates map) == negate color]
        where
            rate:: Int->[Coordinates]->Int
            rate index listOfCoordinates =
                if index == (length listOfCoordinates - 1)
                    then 0
                    else rateVerticalNeighbors ((listOfCoordinates !! index) listOfCoordinates) + rateHorizontalNeighbors ((listOfCoordinates !! index) listOfCoordinates) +rateRightDiagonalNeighbors ((listOfCoordinates !! index) listOfCoordinates) + rateLeftDiagonalNeighbors ((listOfCoordinates !! index) listOfCoordinates) + rateIterating (index+1 listOfCoordinates)