extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_building_redraw_cost.gd
# Animated buildings must not re-run _draw() to animate (Forgejo issues #6
# and #10).
#
# Every NeonDraw call expands into four antialiased polylines, so redrawing
# a whole shipyard each frame to advance a crane re-tessellates all of it.
# The moving elements are now separate NeonPiece children, rasterised once
# and thereafter only moved, scaled, faded or hidden - operations that reuse
# the cached geometry. Ship.gd and Asteroid.gd already worked this way.
#
# Verifies:
#   1. an animated building's geometry is rasterised exactly ONCE, however
#      long it animates
#   2. it is genuinely still animating (so this cannot be "passed" by
#      freezing the animation)
#   3. the moving parts really do move - the crane travels and the
#      mothership's satellites orbit - proving the animation reaches the
#      nodes rather than being silently dropped
#   4. the static command centre needs no per-frame work either

var scene: Node
var field: Node
var crafter: Node2D
var mothership: Node2D
var command: Node2D
var stage: int = 0
var elapsed: float = 0.0
var crane_x_start: float = 0.0
var satellite_rotation_start: float = 0.0


func _initialize() -> void:
	var game_state: Node = root.get_node("GameState")
	game_state.buildings.clear()
	game_state.extractors.clear()
	scene = load("res://Main.tscn").instantiate()
	root.add_child(scene)
	field = scene.get_node("BuildingField")


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			scene.get_node("AsteroidField").set_process(false)
			scene.get_node("EnemySpawner").set_process(false)
			field.place(GameState.BUILDING_SHIP_CRAFTER, Vector2(600.0, 0.0))
			field.place(GameState.BUILDING_MOTHERSHIP, Vector2(-600.0, 0.0))
			field.place(GameState.BUILDING_COMMAND_CENTER, Vector2(0.0, 600.0))
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < 0.3:
				return false
			for b in field.spawned:
				if not is_instance_valid(b):
					continue
				match b.building_type:
					GameState.BUILDING_SHIP_CRAFTER:
						crafter = b.visual
					GameState.BUILDING_MOTHERSHIP:
						mothership = b.visual
					GameState.BUILDING_COMMAND_CENTER:
						command = b.visual
			if crafter == null or mothership == null or command == null:
				print("TEST_BUILDING_REDRAW_COST: FAIL (buildings never spawned)")
				quit(1)
				return true

			crane_x_start = crafter._crane.position.x
			satellite_rotation_start = mothership._satellites.rotation
			elapsed = 0.0
			stage = 2
			return false
		2:
			# Long enough to cross several assembly phases and a good arc of
			# the satellites' orbit.
			if elapsed < 2.5:
				return false

			print("rasterisations after %.1fs of animation - crafter:%d mothership:%d command:%d" % [
				elapsed, crafter.draw_count, mothership.draw_count, command.draw_count
			])
			for b in [crafter, mothership, command]:
				if b.draw_count != 1:
					print("TEST_BUILDING_REDRAW_COST: FAIL (%s redrew its geometry %d times)" % [
						b.name, b.draw_count
					])
					quit(1)
					return true

			var animating: bool = crafter.anim_time > 0.0 and mothership.phase_time > 0.0
			var crane_moved: bool = absf(crafter._crane.position.x - crane_x_start) > 1.0
			var orbit_moved: bool = absf(mothership._satellites.rotation - satellite_rotation_start) > 0.05
			print("still animating=%s crane travelled=%s satellites orbited=%s" % [
				animating, crane_moved, orbit_moved
			])
			if not (animating and crane_moved and orbit_moved):
				print("TEST_BUILDING_REDRAW_COST: FAIL (nothing actually moved - not a fix)")
				quit(1)
				return true

			print("TEST_BUILDING_REDRAW_COST: PASS")
			quit(0)
			return true
	return false