(import scheme
        (chicken base)
        (prefix sdl2 "sdl2:")
        (prefix sdl2-ttf "ttf:")
        (prefix sdl2-image "img:")
        downstroke-engine
        downstroke-world
        downstroke-tilemap
        downstroke-renderer
        downstroke-input
        downstroke-physics
        downstroke-assets
        downstroke-entity
        downstroke-sound
        downstroke-scene-loader)

(define *game*
  (make-game
    title: "Demo: Platformer" width: 600 height: 400

    preload: (lambda (game)
      (init-audio!)
      (load-sounds! '((jump . "demo/assets/jump.wav"))))

    create: (lambda (game)
      (let* ((scene  (game-load-scene! game "demo/assets/level-0.tmx"))
             (player (list #:type 'player
                           #:x 100 #:y 50
                           #:width 16 #:height 16
                           #:vx 0 #:vy 0
                           #:gravity? #t
                           #:on-ground? #f
                           #:tile-id 1
                           #:tags '(player)))
             (_ (scene-add-entity scene player)))
        (scene-camera-target-set! scene 'player)))

    update: (lambda (game dt)
      (let* ((input  (game-input game))
             (scene  (game-scene game))
             (tm     (scene-tilemap scene))
             (player (car (scene-entities scene)))
             (player (entity-set player #:vx
                       (cond
                         ((input-held? input 'left)  -3)
                         ((input-held? input 'right)  3)
                         (else 0))))
             (_ (when (and (input-pressed? input 'a)
                           (entity-ref player #:on-ground? #f))
                  (play-sound 'jump)))
             (player (apply-jump        player (input-pressed? input 'a)))
             (player (apply-acceleration player))
             (player (apply-gravity      player))
             (player (apply-velocity-x   player))
             (player (resolve-tile-collisions-x player tm))
             (player (apply-velocity-y   player))
             (player (resolve-tile-collisions-y player tm))
             (player (detect-ground      player tm)))
        (scene-entities-set! scene (list player))))))

(game-run! *game*)