data Position = Pos {x::Int, y::Int}
data PositionRotated = PosR {xR::Int, yR::Int}

instance Show Position where
  show (Pos x y) = show (x,y)

instance Show PositionRotated where
  show (PosR x y) = show (x,y) ++ "'"
  

data Sensor = Sensor { position :: Position, beacon::Position } deriving Show
data SensorRotated = SensorRotated { positionR :: PositionRotated, beaconR :: PositionRotated } deriving Show

maxX (Sensor (Pos x _) (Pos x' _)) = maximum [x,x']
maxY (Sensor (Pos _ y) (Pos _ y')) = maximum [y,y']

class RotatePair a b where
  rotateS :: Int -> a -> b

instance RotatePair Sensor SensorRotated where
  rotateS = rotateSensor

instance RotatePair SensorRotated Sensor where
  rotateS = rotateSensor'

rotate :: Int -> Position -> PositionRotated
rotate width (Pos x y) = PosR (x+y) (width - x + y)

rotate' :: Int -> PositionRotated -> Position
rotate' width (PosR a b) = let y = ((b+a-width) `div` 2) in Pos (a-y) y

-- parseLine :: String -> Sensor
parseLine l = Sensor (Pos (read sx) (read sy)) (Pos (read bx) (read by))
      where (sx,(_:_:_:_:ys)) = span(/=',') (drop (length "Sensor at x=") l)
            (sy,beaconLine) = span(/=':') ys
            (bx,(_:_:_:_:by)) = span(/=',') (drop (length ": closest beacon is at x=") beaconLine)

parseInput = map parseLine.lines

short = readFile "day15short" >>= pure.parseInput

rotateSensor :: Int -> Sensor -> SensorRotated
rotateSensor width (Sensor p b) = SensorRotated (rotate width p) (rotate width b)

rotateSensor' :: Int -> SensorRotated -> Sensor
rotateSensor' width (SensorRotated p b) = Sensor (rotate' width p) (rotate' width b)

oneBeacon :: SensorRotated -> ((Int,Int),(Int, Int))
oneBeacon (SensorRotated (PosR x y) (PosR bx by)) = ((x-distance, y-distance),(x+distance, y+distance))
        where distance = max (abs (x-bx)) (abs (y-by))

puzzle1 = do
  input <- short
  let (height, width) = (maximum $ map maxX input,maximum $ map maxY input)
  print (width, height)
  let rotatedSensors = map (rotateS width) input
  -- let relevantSensors = filter (relevant 10) rotatedSensors
  print rotatedSensors