import Control.Lens
import Data.List.Split
import qualified Data.Map as M

type Valves = M.Map String Node

type Node = (Int, [String])

main :: IO ()
main = do
  input <- map words . lines <$> readFile "testinput"
  print $ parse input
  print $ walk 5 "AA" $ parse input

parse :: [[String]] -> Valves
parse = M.fromList . concatMap parse'
  where
    parse' (_:name:_:_:rate:_:_:_:_:ts) =
      [(name, (0, ("open" ++ name) : nexts)), ("open" ++ name, (r, nexts))]
      where
        r = read $ init $ last $ splitOn "=" rate
        nexts = map (\(x:y:_) -> [x, y]) ts

-- value multiplicator: 28, 25, etc
-- delete opened nodes (both)

walk :: Int -> String -> Valves -> Int
walk n start valves
  | n == 0 = 0
  | otherwise = n * rate + maximum [walk (pred n) x valves | x<-nextNodes]
  where rate = valves M.! start ^._1
        nextNodes = valves M.! start ^._2