(ns aoc2025
  (:require [clojure.string :as str]))

(defn get-input [day] (slurp (str "2025/day" day "-input.txt")))

(defn remove-index
  "Removes an item at the specified position in a vector"
  [coll ^long index]
  (-> (into (subvec coll 0 index)
            (subvec coll (inc index)))
      (with-meta (meta coll))))

;;  _____                __ 
;; |  __ \              /_ |
;; | |  | | __ _ _   _   | |
;; | |  | |/ _` | | | |  | |
;; | |__| | (_| | |_| |  | |
;; |_____/ \__,_|\__, |  |_|
;;                __/ |     
;;               |___/      

(def day1-input-test
  "L68
L30
R48
L5
R60
L55
L1
L99
R14
L82")

(defn day1 [input zero-count-fn]
  (let [sequence (map (fn [line]
                        [(if (= "R" (str (first line)))
                           #'+
                           #'-)
                         (parse-long (str/join (rest line)))])
                      (str/split-lines input))]
    (loop [s sequence
           curr 50
           zero-count 0]
      (if (not (seq s))
        zero-count
        (let [[f amount] (first s)
              new-dial-pos (mod (f curr amount) 100)
              spins (zero-count-fn curr (f amount) new-dial-pos)]
          (println curr new-dial-pos amount spins)
          (recur (rest s) new-dial-pos (+ zero-count spins)))))))

(defn day1-p1 [input]
  (day1 input (fn [_ _ new-dial-pos] (if (zero? new-dial-pos) 1 0))))

(defn day1-p2 [input]
  (day1 input (fn [curr rotation _]
                (let [amount (abs rotation)]
                  (if (and (neg? rotation)
                           (not (zero? curr)))
                    (quot (+ (- 100 curr) (abs amount)) 100)
                    (quot (+ curr amount) 100))))))

(comment
  (day1-p1 day1-input-test)
  (day1-p1 (get-input 1))
  (day1-p2 day1-input-test)
  (day1-p2 (get-input 1))
  :-)

;;  _____                ___  
;; |  __ \              |__ \ 
;; | |  | | __ _ _   _     ) |
;; | |  | |/ _` | | | |   / / 
;; | |__| | (_| | |_| |  / /_ 
;; |_____/ \__,_|\__, | |____|
;;                __/ |       
;;               |___/        

(def day2-input-test
  "11-22,95-115,998-1012,1188511880-1188511890,222220-222224,1698522-1698528,446443-446449,38593856-38593862,565653-565659,824824821-824824827,2121212118-2121212124")

(defn day2-parse-input [input]
  (->> (str/split (str/trim input) #",")
       (map #(str/split % #"-"))
       (map #(mapv parse-long %))
       (map (fn [[lo hi]] (range lo (inc hi))))
       flatten))

(defn day2-p1 [input]
  (->> input
       (keep #(let [num-str (str %)
                    length (count num-str)
                    half (/ length 2)]
                (when (and (even? length)
                           (= (subs num-str 0 half)
                              (subs num-str half length)))
                  %)))
       (reduce +)))

(defn day2-p2 [input]
  (->> input
       (keep #(let [num-str (str %)
                    length (count num-str)]
                (loop [p-size (quot length 2)]
                  (cond
                    (zero? p-size)
                    nil
                    (apply = (partition-all p-size num-str))
                    %
                    :else
                    (recur (dec p-size))))))
       (reduce +)))

(comment
  (day2-p1 (day2-parse-input day2-input-test))
  (day2-p1 (day2-parse-input (get-input 2)))

  (day2-p2 (day2-parse-input day2-input-test))
  (day2-p2 (day2-parse-input (get-input 2)))
  :-)

;;  _____                ____  
;; |  __ \              |___ \ 
;; | |  | | __ _ _   _    __) |
;; | |  | |/ _` | | | |  |__ < 
;; | |__| | (_| | |_| |  ___) |
;; |_____/ \__,_|\__, | |____/ 
;;                __/ |        
;;               |___/         

(def day3-input-test
  "987654321111111
811111111111119
234234234234278
818181911112111")

(defn day3-get-max-battery [total-digits bank]
  (loop [remaining (dec total-digits)
         curr-idx 0
         nums []]
    (if (= (count nums) total-digits)
      (reduce (fn [acc digit] (+ (* acc 10) digit)) 0 nums)
      (let [subbank (subvec bank curr-idx (- (count bank) remaining))
            [idx max-num] (->> (map-indexed vector subbank)
                               (reduce (fn [[idx max] [i n]]
                                         (if (> n max)
                                           [i n]
                                           [idx max]))
                                       [-1 -1]))]
        (recur (dec remaining) (+ curr-idx idx 1) (conj nums max-num))))))

(defn day3 [total-digits input]
  (->> (str/split-lines input)
       (mapv #(mapv (fn [c] (Character/digit c 10)) (vec %)))
       (map (partial day3-get-max-battery total-digits))
       taptap
       (reduce +)))

(comment
  (day3 2  day3-input-test)
  (day3 2  (get-input 3))
  (day3 12 day3-input-test)
  (day3 12 (get-input 3))
  :-)