#!/usr/bin/env -S guile -s
!#
(use-modules (ice-9 regex)
             (ice-9 textual-ports)
             (srfi srfi-1))

(define red-max 12)
(define green-max 13)
(define blue-max 14)

(define (read-lines port)
  (letrec ((loop (lambda (l ls)
                   (if (eof-object? l)
                       ls
                       (loop (get-line port) (cons l ls))))))
    (reverse (loop (get-line port) '()))))

(define (valid-triplet? triplet)
  (let* ((zero (string-match "(.)" "0"))
         (red (string->number (match:substring (or (string-match "([0-9]+) red" triplet) zero) 1)))
         (green (string->number (match:substring (or (string-match "([0-9]+) green" triplet) zero) 1)))
         (blue (string->number (match:substring (or (string-match "([0-9]+) blue" triplet) zero) 1))))
    (and (<= red red-max) (<= green green-max) (<= blue blue-max))))

(define (line-value line)
  (let* ((id-split (string-match "^Game ([0-9]+):(.*)$" line))
         (id (string->number (match:substring id-split 1)))
         (rest (string-split (match:substring id-split 2) #\;))
         (valid? (fold (lambda (x y) (and x y)) #t (map valid-triplet? rest))))
    (if valid? id 0)))

(line-value "Game 38: 2 blue, 4 green, 11 red; 7 green, 6 red, 2 blue; 1 green, 3 red, 1 blue; 4 blue, 4 green, 4 red; 2 red, 5 blue, 2 green")

(let* ((port (open-input-file "2.txt"))
       (lines (read-lines port)))
  (close-port port)
  (display (fold + 0 (map line-value lines))))