(ns adventofcode2019.day10
    [:require [adventofcode2019.lib :refer :all]
              [clojure.string :as str]
              [clojure.core.match :refer [match]]
              [clojure.math.combinatorics :as combo]])

(defn day10 []
  (let [input (get-list-from-file (input-file))
        to-points (fn [j l] 
                    (map-indexed (fn [i m] 
                                   (if (= \# m) [i j] nil)) l))
        asteroids (->> input
                       (map-indexed to-points)
                       (reduce concat)
                       (filter some?)
                       (set))
        to-slope (fn [[a-x a-y] [b-x b-y]] 
                   (if (= a-x b-x) 
                       :inf
                       (rationalize 
                        (/ (- a-y b-y)
                           (- a-x b-x)))))
        find-visible (fn [ast]
                       (count (set (map (partial to-slope ast) 
                                        (disj asteroids ast)))))
        visible-count (map #(vector % (find-visible %)) asteroids)] 
    (part1 (reduce (partial max-key second) visible-count))
    #_(part2)))