(ns advent.core
  (:require [play-clj.core :refer :all]
            [play-clj.ui :refer :all]
            [play-clj.utils :refer :all]
            [play-clj.g2d :refer :all]
            [clojure.pprint])
  (:import [com.badlogic.gdx.graphics Pixmap Pixmap$Filter]))

(def scale 4)
(def +screen-width+ 320)
(def +screen-height+ 240)
(def +num-cursors+ 4)
(def +next-cursor+ (into {} (map vector (range +num-cursors+) (drop 1 (cycle (range +num-cursors+))))))

(defn +next-cursor+ [x]
  (first (drop 1 (drop-while #(not= x %) (cycle (range +num-cursors+))))))

(defn cursor [filename index]
  (let [base-cursor (pixmap filename)
        target-width (* 16 scale)
        target-height (* 16 scale)
        resized (Pixmap. target-width target-height (.getFormat base-cursor))]
    (Pixmap/setFilter Pixmap$Filter/NearestNeighbour)
    (pixmap! resized :draw-pixmap base-cursor (* index 16) 0 16 16
             0 0 target-width target-height)
    resized ))

(defn right-click [screen entities]
  (let [entities (update-in entities [:cursor] #(assoc % :cursor-index (+next-cursor+ (:cursor-index %))))]
    (input! :set-cursor-image (cursor "cursor.png" (get-in entities [:cursor :cursor-index])) 0 0 )
    entities))

(defn left-click [screen entities]
  (let [{:keys [x y]} (input->screen screen {:x (:input-x screen) :y (:input-y screen)})]
    (assoc-in entities [:ego :target] {:x x :y y})))

(defn get-ego [screen]
  (let [player-sheet (texture! (texture "player.png") :split 18 36)
        ego {:right  (animation 0.075 (for [i (range 8)]
                                          (texture  (aget player-sheet 0 i))))
               :left (animation 0.075 (for [i (range 8)]
                                        (texture  (aget player-sheet 1 i))))
               :anim (animation 0.075 (for [i (range 8)]
                                        (texture  (aget player-sheet 0 i))))
               :x 100 :y 75  :x-velocity 1
             :id "ego"}]
    (merge (animation->texture screen (:anim ego)) ego)))

(defn update-ego [screen entities ego]
  
  (let [ego (merge ego (animation->texture screen (:anim ego)))
        target (:target ego)]
    (if target
      (let [delta-x (- (:x target) (:x ego))
            delta-y (- (:y target) (:y ego))
            mag (Math/sqrt (+ (* delta-x delta-x) (* delta-y delta-y)))
            vector-x (* 2 (/ delta-x mag))
            vector-y (* 2 (/ delta-y mag))]
        (if (< mag 1)
          (dissoc ego :target)
          (-> ego 
              (update-in [:x] #(+ % vector-x))
              (update-in [:y] #(+ % vector-y)))))
      
      ego)))
(defscreen main-screen
  :on-show
  (fn [screen entities]
    (update! screen :renderer (stage) :camera (orthographic))
    (let [
          _ (input! :set-cursor-image (cursor "cursor.png" 0) 0 0)
          background (texture "bg5.png")]
      {:cursor {:id "cursor" :cursor-index 0}
        :background (assoc background :origin-y 0 :origin-x 0 :id "background" :x 0 :y 0 :scale-x 1 :scale-y 1)
        :ego (get-ego screen)}))
  
  :on-render
  (fn [screen [entities]]
    (clear!)
    (let [entities (assoc entities :ego (update-ego screen entities (:ego entities)))]
      (render! screen (vals entities))
      entities))
  :on-resize (fn [screen entities]
               (size! screen 320 240))


  :on-touch-down (fn [screen [entities]]
                   (if (= (button-code :right) (:button screen))
                     (right-click screen entities)
                     (left-click screen entities)))) 

(defgame advent
  :on-create
  (fn [this]
    (set-screen! this main-screen)
    #_(input! :set-cursor-catched true)))