(import srfi-64)
(include "entity.scm")
(include "tilemap.scm")
(include "world.scm")
(include "animation.scm")
(import downstroke-entity downstroke-world downstroke-animation)

(test-begin "animation")

(test-group "frame->tile-id"
  (test-group "tile IDs only"
    (test-equal "first frame, frames (0)" 0 (frame->tile-id '(0) 0))
    (test-equal "wraps around" 0 (frame->tile-id '(0 1) 2))
    (test-equal "frame 1 of (27 28)" 28 (frame->tile-id '(27 28) 1)))
  (test-group "tile IDs and durations"
    (test-equal "first frame, frames (0)" 0 (frame->tile-id '((0 10)) 0))
    (test-equal "wraps around" 0 (frame->tile-id '((0 10) (1 10)) 2))
    (test-equal "frame 1 of (27 28)" 28 (frame->tile-id '((27 10) (28 10)) 1))))

(test-group "frame->duration"
  (test-equal "first frame, frames (0)" 100 (frame->duration '((0 100)) 0))
  (test-equal "wraps around" 100 (frame->duration '((0 100) (1 200)) 2))
  (test-equal "frame 1 of (27 28)" 200 (frame->duration '((27 100) (28 200)) 1)))

(test-group "set-animation"
  (let ((entity (list #:type 'player #:anim-name 'idle #:anim-frame 5 #:anim-tick 8)))
    (test-equal "no-op if already active" entity (set-animation entity 'idle))
    (let ((switched (set-animation entity 'walk)))
      (test-equal "switches anim-name" 'walk (entity-ref switched #:anim-name))
      (test-equal "resets frame" 0 (entity-ref switched #:anim-frame))
      (test-equal "resets tick" 0 (entity-ref switched #:anim-tick)))))

(test-group "animate-entity"
  (test-group "Single frames"
    (let* ((anims '((#:name walk #:frames (2 3) #:duration 4)))
           (entity (list #:type 'player #:anim-name 'walk #:anim-frame 0 #:anim-tick 0))
           (stepped (animate-entity entity anims)))
      (test-equal "increments tick" 1 (entity-ref stepped #:anim-tick))
      (test-equal "sets tile-id on first tick" 2 (entity-ref stepped #:tile-id)))
    (let* ((anims '((#:name walk #:frames (0 1) #:duration 2)))
           (entity (list #:type 'player #:anim-name 'walk #:anim-frame 0 #:anim-tick 1))
           (advanced (animate-entity entity anims)))
      (test-equal "advances frame when tick reaches duration" 1 (entity-ref advanced #:anim-frame))
      (test-equal "resets tick on frame advance" 0 (entity-ref advanced #:anim-tick))))
  (test-group "Frames with duration"
    (let* ((anims '((#:name walk #:frames ((0 10) (1 20)) #:duration 4)))
           (entity (list #:type 'player #:anim-name 'walk #:anim-frame 0 #:anim-tick 9))
           (stepped (animate-entity entity anims)))
      (test-equal "ticks resets on frame switch" 0 (entity-ref stepped #:anim-tick))
      (test-equal "sets tile-id on 10th tick" 1 (entity-ref stepped #:tile-id))
      (test-equal "sets duration to frame duration" 20 (entity-ref stepped #:duration))))
  (test-group "Empty"
    (let* ((entity (list #:type 'player)))
      (test-equal "unchanged entity without anim-name" entity (animate-entity entity '())))))

(test-group "animation pipeline"
  (test-group "animated entity"
    (let* ((anims '((#:name walk #:frames (2 3) #:duration 4)))
           (entity (list #:type 'player #:anim-name 'walk #:anim-frame 0 #:anim-tick 0 #:animations anims))
	   (stepped-entity (apply-animation entity #f 10)))
      (test-equal "Updated animated entity" 1 (entity-ref stepped-entity #:anim-tick)))
    (let* ((entity (list #:type 'static))
	   (stepped-entity (apply-animation entity #f 10)))
      (test-equal "unchanged static entity" #f (entity-ref stepped-entity #:anim-tick)))))

(test-end "animation")