module AoC.Y2023.D04 where

import AoC.Parser
import AoC.Riddle
import Text.Megaparsec (sepBy, (<?>))
import Text.Megaparsec.Char (char, space, string)
import Text.Megaparsec.Char.Lexer qualified as L

type Cards = [Int]

data Game = Game
  { winningCards :: Cards
  , playedCards :: Cards
  }
  deriving stock (Show)

-- | parse list of cards
--
-- >>> parseText pCards "5 6 42 23"
-- Right [5,6,42,23]
pCards :: Parser Cards
pCards = L.decimal `sepBy` ws

-- | parse a game
--
-- >>> parseText pGame "Game 1: 5 6 42 23 | 78 56 42"
pGame :: Parser Game
pGame = do
  _ <- string "Card "
  _ <- L.decimal :: Parser Int
  _ <- string ": "
  w <- many $ L.decimal <* ws
  _ <- string "|"
  h <- L.decimal `sepBy` ws
  pure $ Game w h

-- sets <- pCards `sepBy` (char '|' >> ws)
-- case sets of
--   [w, h] -> pure $ Game w h
--   _ -> fail "expected two sets of cards"

pPuzzle :: Parser [Game]
pPuzzle = linewise pGame

solve :: (MonadIO m) => Text -> m (Either Text Solution)
solve riddle = case parseText pPuzzle riddle of
  Right puzzle ->
    let
      part1 :: Integer
      part1 = 42

      part2 :: Integer
      part2 = part1
     in
      pure $ Right [part1, part2]
  Left e -> pure $ Left e