(ns aphorisms.fourty-one
  (:require [thi.ng.geom.core :as g]
            [thi.ng.geom.vector :as v]
            [quil.core :as q]
            [quil.middleware :as qm]
            [thi.ng.geom.rect :as r]
            [aphorisms.utils.middleware :refer [screenshottable]]

            [thi.ng.geom.line :as l]
            [thi.ng.math.core :as m]
            [thi.ng.geom.utils.intersect :as isec]))

;; More practice to get a feeling for the `thi.ng` API again
;; Resizing cells in the grid, generating random lines and playing with intersections

(def height 500 #_(int (* width (Math/sqrt 2))))
(def width #_500 (int (* height (Math/sqrt 2))))
(def padding (* height 0.1))
(def canvas (r/rect width height))

(defn center-in
  "Centers `r2` in or around `r1`."
  [r1 r2]
  (g/translate (assoc r2 :p (:p r1))
               (v/vec2 (* 0.5 (- (g/width r1) (g/width r2)))
                       (* 0.5 (- (g/height r1) (g/height r2))))))

(def bounds (center-in canvas (r/rect (- width (* 2 padding)) (- height (* 2 padding)))))

(defn as-grid [rect cell-size]
  (let [n-x (int (/ (g/width rect) cell-size))
        n-y (int (/ (g/height rect) cell-size))
        t (v/vec2 (* (mod (g/width rect) n-x) 0.5)
                  (* (mod (g/height rect) n-x) 0.5))]
    (for [x (range n-x)
          y (range n-y)]
      (-> (r/rect (* x cell-size) (* y cell-size) cell-size)
          (g/translate (:p rect))
          (g/translate t )))))

(def grid (map #(g/scale-size % 0.92) (as-grid bounds 50)))

(defn line-inside [rect]
  (l/line2 (g/random-point-inside rect) (g/random-point-inside rect)))

;; below is the rendering logic

(defn setup []
  (q/frame-rate 30)
  (q/color-mode :hsb 360 100 100)
  (q/rect-mode :center)
  (q/ellipse-mode :center)
  (q/background 350)
  {:lines (repeatedly 5 #(line-inside bounds))})

(defn update-state [state]
  state)

(defn mouse-pressed [state _]
  (assoc state :lines (repeatedly 20 #(line-inside bounds))))

(let [l (l/line2 50 50 200 210)]
  (g/intersect-line l (first (g/edges (first grid)))))

(defn draw-state [state]
  (q/translate -0.5 -0.5)
  (q/background 180 0 98)
  (q/stroke-weight 0.5)
  (q/no-fill)
  (q/stroke 320 100 70)
  (doseq [line (:lines state)
          :let [[a b] (g/vertices line)]]
    (q/line a b))
  (doseq [cell grid
          [a b] (g/edges cell)]
    (q/line a b))
  (q/no-stroke)
  (q/fill 320 100 70)
  (doseq [cell grid
          line (:lines state)
          isecs (->>
                 (map #(g/intersect-line line %) (g/edges cell))
                 (keep #(when (= (:type %) :intersect) (:p %))))
          :let [[i1 i2] isecs]]
    (q/ellipse i1 i2 5 5)))

#_:clj-kondo/ignore
(q/defsketch fourty-one
  :title "Fourty One"
  :size [width height]
  :settings (fn []
              (q/smooth 2)
              (q/pixel-density (q/display-density)))
  :setup setup
  :update #'update-state
  :mouse-pressed #'mouse-pressed
  :draw #'draw-state
  :features [:keep-on-top :no-bind-output]
  :middleware [qm/pause-on-error qm/fun-mode (screenshottable)])