module Main where

import Intcode
import Data.List.Split
import qualified Data.Map.Strict as M
import qualified Data.Vector as V
import Linear.V2
import Debug.Trace

data RoboState =
  RoboState
    { hull :: M.Map (V2 Int) Integer
    , position :: V2 Int
    , direction :: V2 Int
    } deriving Show

main :: IO ()
main = do
  content <- readFile "input"
  let program = V.fromList $ concatMap (map read . splitOn ",") (lines content)
  let run x =
        runIntcode
          (TM
             { tape = tapePreprocess program
             , pointer = 0
             , pointerOffset = 0
             , output = []
             , input = Just 0
             , state = Continue
             }, RoboState {hull = M.empty, position = V2 0 0, direction = V2 0 1 })
  print "hue"
  print $ length $ hull $ snd $ run 0
    -- concat
    --   ["Part 1: " ++ show a ++ ", Part 2: " ++ show b | a <- out1, b <- out2]

runIntcode :: (TuringMachine, RoboState) -> (TuringMachine, RoboState)
runIntcode (tm,rb) =
  case state tmNew of
    Continue -> runIntcode (tmNew,rb)
    AwaitInput -> runIntcode $ updateState (tmNew,rb)
    _ -> (tmNew,rb)
  where
    tmNew = execSteps tm

updateState :: (TuringMachine, RoboState) -> (TuringMachine, RoboState)
updateState (tm, rb) = (tmNew, rbNew)
    where hullNew = M.insert (position rb) (output tm !! 1) (hull rb)
          dirNew = if output tm !! 0 == 0
                      then perp $ direction rb
                      else iterate perp (direction rb) !! 3
          posNew = (position rb + dirNew)
          floorNext = M.findWithDefault 0 posNew (hull rb)
          rbNew = rb{hull = hullNew, position = posNew, direction = dirNew}
          tmNew = tm{input = Just floorNext, output = []}