(ns adventofcode2019.day11
    [:require [adventofcode2019.lib :refer :all]
              [adventofcode2019.intcode :as i]
              [clojure.string :as str]
              [clojure.core.match :refer [match]]])

(defn painterbot-9000 [program]
  (let [stop-on-output #(= (count (:output %)) 2)
        get-next-ic-output (partial i/intcode-until stop-on-output)
        rotate (fn [heading turning]
                 (match [heading turning]
                        [:up    0] :left
                        [:down  0] :right
                        [:left  0] :down
                        [:right 0] :up
                        [:up    1] :right
                        [:down  1] :left
                        [:left  1] :down
                        [:right 1] :up))
        travel (fn [[x y] heading]
                 (case heading
                   :up    [x (inc y)]
                   :down  [x (dec y)]
                   :left  [(dec x) y]
                   :right [(inc x) y]))]
    (loop [program-state (i/build-state program {:input [0]})
           tileset {}
           position [0 0]
           heading :up]
      (if (:exit program-state)
        tileset
        (let [next-state (get-next-ic-output program-state)
              [color direction] (:output next-state)
              new-heading (rotate heading direction)]
          (recur (assoc next-state :output []) (assoc tileset position color)
                 (travel position new-heading) new-heading))))))

(defn day11 []
  (let [input (mapv parse-int (get-list-from-file (input-file) #","))
        painted-tiles (painterbot-9000 input)] 
    (part1 (count painted-tiles))
    #_(part2)))