#lang curly-fn racket

(require "scripts/aoc.rkt" parser-tools/lex parser-tools/yacc (prefix-in : parser-tools/lex-sre))

;; solution for day 18

(define-tokens nums [number])
(define-empty-tokens syms [+ * lp rp eof])

(define the-lexer
  (lexer
    [whitespace (the-lexer input-port)]
    ["+" (token-+)]
    ["*" (token-*)]
    ["(" (token-lp)]
    [")" (token-rp)]
    [(:+ (char-set "0123456789")) (token-number (string->number lexeme))]
    [(eof) (token-eof)]))

(define the-parser
  (parser
    [start exp]
    [end eof]
    [error (lambda args (error "meow" args))]
    [tokens nums syms]
    [precs (left *)(left +)
           (left lp rp)]
    [grammar
      (exp [(lp exp rp) $2]
           [(exp + exp) (+ $1 $3)]
           [(exp * exp) (* $1 $3)]
           [(number) $1])]))

(define (parse/string str)
  (let ([input (open-input-string str)])
    (the-parser (lambda () (the-lexer input)))))

;; broken!
(define (part1 input)
  (for/sum ([line (in-list input)])
    (parse/string line)))

(define (part2 input)
  (for/sum ([line (in-list input)])
    (parse/string line)))

;; parse input file
(define (parse fname)
  (define input (file->lines fname))
  input)

(module+ test
  (require rackunit)
  ;; tests here
  (displayln "no tests :("))

(module+ main
  (define input (parse "inputs/18"))
  (answer 18 1 (time (part1 input)))
  (answer 18 2 (time (part2 input)))
  (displayln "meow"))