module Day02
  ( day02_1,
    day02_2,
  )
where

import Data.List (isInfixOf)
import Data.List.Split (splitOn)

sumInvalid :: [Int] -> Int
sumInvalid = foldl addInvalid 0
  where
    addInvalid acc n
      | odd (length (show n)) = acc
      | let l2 = length (show n) `div` 2, take l2 (show n) == drop l2 (show n) = acc + n
      | otherwise = acc

sumInvalid' :: [Int] -> Int
sumInvalid' = foldl addInvalid 0
  where
    addInvalid acc n
      | let s = drop 1 $ show n ++ show n, show n `isInfixOf` take (length s - 1) s = acc + n
      | otherwise = acc

getRange :: String -> [Int]
getRange r = [read (takeWhile (/= '-') r) .. read $ drop 1 (dropWhile (/= '-') r)]

parseInput :: IO [Int]
parseInput = do
  concatMap getRange . splitOn "," <$> readFile "input/day2.txt"

day02_1 :: IO ()
day02_1 = do
  values <- parseInput
  let result = sumInvalid values
  putStrLn $
    "Day 2, Puzzle 1 solution: "
      ++ show result

day02_2 :: IO ()
day02_2 = do
  values <- parseInput
  let result = sumInvalid' values
  putStrLn $
    "Day 2, Puzzle 1 solution: "
      ++ show result