#lang racket

(require "scripts/aoc.rkt")

;; solution for day 2

(define (password-valid-part1? lmin lmax char password)
  (<= lmin (count (curry char=? char) (string->list password)) lmax))

(define (password-valid-part2? a b char password)
  (define pwd-chars (string->list password))
  (xor (char=? (string-ref password (sub1 a)) char)
       (char=? (string-ref password (sub1 b)) char)))

(define (calculate valid-proc input)
  (for/sum ([line (in-list input)])
    (match line
      [(pregexp #px"^([0-9]+)\\-([0-9]+) (.): (.*?)$" (list _ lmin lmax char password))
       (if (valid-proc (string->number lmin) (string->number lmax)
                       (string-ref char 0) password) 1 0)]
      [_ (error "failed to parse" line)])))

(module+ main
  (define input (file->lines "inputs/2"))
  ;; part 1
  (answer 2 1 (calculate password-valid-part1? input))

  ;; part 2
  (answer 2 2 (calculate password-valid-part2? input))

  (displayln "meow"))