(ns adventofcode2019.day08
    [:require [adventofcode2019.lib :refer :all]
              [clojure.string :as str]
              [clojure.core.match :refer [match]]])

(defn day08 []
  (let [input (map parse-int (get-list-from-file (input-file) #""))
        [image-x image-y] [25 6]
        layer-size (* image-x image-y)

        count-num #(count (filter (hash-set %1) %2))
        combine-layers #(match [%1 %2] [0 _] 0
                                       [1 _] 1
                                       [2 p] p)
        to-text #(match % 0 \u0020 ; 0s are spaces, 1s are full-block
                          1 \u2588)
        layers (partition layer-size input)

        fewest-zeroes (apply (partial min-key (partial count-num 0)) layers)
        layered-image (reduce #(map combine-layers %1 %2) layers)] 
    (part1 (* (count-num 1 fewest-zeroes)
              (count-num 2 fewest-zeroes)))
    (part2 "see below")
    (run! println (->> layered-image
                       (map to-text)
                       (partition image-x)
                       (map str/join)))))