import System.Random

data CellState  = Dead | Alive deriving (Eq)
data Cell       = Cell CellState deriving (Eq)
data Row        = Row [Cell]
data Map        = Map [Row]

instance Show CellState where
    show Dead   = "_"
    show Alive  = "#"

instance Show Cell where
    show (Cell cellState)   = show cellState

instance Show Row where
    show (Row cells)        = unwords $ map show cells

instance Show Map where
    show (Map rows)         = unlines $ map show rows

getElem :: Int -> [a] -> a
getElem n xs
    | n >= length xs    = xs!!(n - length xs)
    | n < 0             = xs!!(length xs + n)
    | otherwise         = xs!!n

getNeighbours :: Int -> Int -> [[Bool]] -> [Bool]
getNeighbours x y xs = [ getElem (x-1) (getElem (y-1) xs), getElem x (getElem (y-1) xs)  , getElem (x+1) (getElem (y-1) xs)
                       , getElem (x-1) (getElem y xs)                                    , getElem (x+1) (getElem y xs)
                       , getElem (x-1) (getElem (y+1) xs), getElem x (getElem (y+1) xs)  , getElem (x+1) (getElem (y+1) xs) ]

countLivingNeighbours :: Int -> Int -> [[Bool]] -> Int
countLivingNeighbours x y xs = length [x | x <- getNeighbours x y xs, x == True]

intToCellState :: Int -> CellState -- TODO probably change to Maybe CellState one day
intToCellState n
    | n == 0    = Dead
    | n == 1    = Alive
    | otherwise = Dead

returnFixedRow :: Row
returnFixedRow = Row $ map Cell $ map intToCellState [1,0,1,0,1]

returnFixedMap :: Map
returnFixedMap = Map $ replicate 5 returnFixedRow