03.clj

(ns advent-of-code.day03
  (:require [clojure.string :as str]
            [clojure.java.io :as io]))

(defn read-input [file]
  (str/trim (slurp file)))

(defn find-correct-mule [text] (
  re-seq #"mul\(\d+,\d+\)" text
  ))

(defn cleanup-mule [text] 
  (str/replace text #"mul\((\d+),(\d+)\)" "$1,$2")
  )

(defn calculate-mule [mule]
  (let [nums (map #(Integer/parseInt %) (str/split mule #","))]
    (* (first nums) (second nums))
    ))

(defn part1 [input] (reduce + (map calculate-mule (map cleanup-mule (find-correct-mule input)))))

(defn find-command [text] (
  re-seq #"(do\(\)|don't\(\)|mul\(\d+,\d+\))" text
  ))

;; acc - :state - active/inactive, :mule - current sum
(defn calculate-activated-mule [acc mule]
  (println acc)
  (println (first mule))
  (cond
   (= (first mule) "do()" ) (assoc acc :state 1)
   (= (first mule) "don't()" ) (assoc acc :state 0)
   (and (= (:state acc) 1) (= (subs (first mule) 0 3) "mul")) (assoc acc :mule (+ (:mule acc) (calculate-mule (cleanup-mule (first mule)))))
   :else acc)
)

(defn part2 [input] (:mule (reduce calculate-activated-mule {:state 1 :mule 0} (find-command input))))

(def answer1example (part1 (read-input "03-example.txt")))
(assert (= answer1example 161) answer1example)
(def answer1 (part1 (read-input "03.txt")))
(assert (= answer1 183788984) answer1)

(def answer2example (part2 (read-input "03-example2.txt")))
(assert (= answer2example 48) answer2example)

(def answer2 (part2 (read-input "03.txt")))
(assert (= answer2 0) answer2)