{-# LANGUAGE LambdaCase #-}
module Main where

import Data.Functor
import Data.List
import Data.Universe.Helpers
import Text.Regex.PCRE
import Data.Function
import Debug.Trace

parse1 :: String -> [String]
parse1 a =
  let x = lines a
      x' = x <&> reverse in
  x ++ -- vertical ⇒
  x' ++ -- vertical ⇐
  transpose x ++ -- horizontal ⇓
  (transpose x <&> reverse) ++ -- horizontal ⇓
  diagonals x ++ -- diagonal ⇗
  diagonals x' ++ -- diagonal ⇖
  (diagonals x <&> reverse) ++ -- diagonal ⇙
  (diagonals x'<&> reverse)    -- diagonal ⇘

solve1 :: [String] -> Int
solve1 = sum . (length . (getAllTextMatches . (=~ "XMAS") :: String -> [String]) <$>)

pattern2 :: Int -> String
pattern2 i = let i' = i-2 in
  "M.M.{"++ show i' ++"}.A..{" ++ show i' ++ "}S.S|" ++
  "M.S.{"++ show i' ++"}.A..{" ++ show i' ++ "}M.S|" ++
  "S.M.{"++ show i' ++"}.A..{" ++ show i' ++ "}S.M|" ++
  "S.S.{"++ show i' ++"}.A..{" ++ show i' ++ "}M.M"

solve2 :: String -> Int
solve2 s =
  let l = length . head . lines $ s in
  let t = (getAllTextSubmatches . (=~ pattern2 l) :: String -> [String]) . intercalate "U" . lines <$> tails s
      t' = nub . concat $ t in
    length t'

main :: IO ()
main = readFile "inputs/4" >>= \i ->
       print (solve1 $ parse1 i) >>
       print (solve2 i)