module Day4Lib
  ( Range (..),
    parseRange,
    parseRow,
    --
    processInput1,
    processInput2,
  )
where

import Data.List.Split (splitOn)

-- import Debug.Trace ()

newtype Range = Range (Int, Int) deriving (Show, Eq)

parseRange :: String -> Range
parseRange rs = let [s, e] = map read (splitOn "-" rs) in Range (s, e)

parseRow :: String -> [Range]
parseRow = map parseRange . splitOn ","

isInside :: Range -> Range -> Bool
isInside (Range (s1, e1)) (Range (s2, e2)) = s1 >= s2 && e1 <= e2

isOverlapping :: Range -> Range -> Bool
isOverlapping r1@(Range (s1, e1)) r2@(Range (s2, e2)) =
  Range (s1, s1)
    `isInside` r2
    || Range (e1, e1)
    `isInside` r2
    || Range (s2, s2)
    `isInside` r1
    || Range (e2, e2)
    `isInside` r1

-- ####################

processInput1 :: String -> Integer
processInput1 = sum . map processRow1 . lines

processRow1 :: String -> Integer
processRow1 = (\[r1, r2] -> if r1 `isInside` r2 || r2 `isInside` r1 then 1 else 0) . parseRow

processInput2 :: String -> Integer
processInput2 = sum . map processRow2 . lines

processRow2 :: String -> Integer
processRow2 = (\[r1, r2] -> if r1 `isOverlapping` r2 then 1 else 0) . parseRow