extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_prompt_debounce.gd
# Verifies the enter-atmosphere prompt is debounced: rapid flicker in the
# underlying landing-detection (planet_field.get_planet_fleet_is_on())
# must NOT cause the prompt to flicker on/off - only a raw signal that
# stays consistent for prompt_debounce_time in a row should commit a
# visible change. Simulates the worst-case flicker by teleporting the
# whole fleet back and forth across the planet's landing_radius boundary
# every single frame (bypassing actual ship steering, for a fully
# deterministic repro).

var main_scene: Node
var fleet: Node
var planet_field: Node
var enter_button: IconButton
var target_chunk: Vector2i
var planet_pos: Vector2
var landing_radius: float
var flicker_frames: int = 0
var visible_toggle_count: int = 0
var last_visible_state: bool = false
var stage: int = 0
var elapsed: float = 0.0


func _initialize() -> void:
	var found: bool = false
	for x in range(-15, 15):
		for y in range(-15, 15):
			var chunk: Vector2i = Vector2i(x, y)
			if WorldGen.has_planet_at_chunk(chunk):
				target_chunk = chunk
				found = true
				break
		if found:
			break

	if not found:
		print("FAIL: could not find any chunk with a planet to test with")
		quit(1)
		return

	var packed: PackedScene = load("res://Main.tscn")
	main_scene = packed.instantiate()
	root.add_child(main_scene)
	fleet = main_scene.get_node("Fleet")
	planet_field = main_scene.get_node("PlanetField")
	enter_button = main_scene.get_node("UI/BuildActionButton")
	main_scene.get_node("AsteroidField").set_process(false)
	main_scene.get_node("EnemySpawner").set_process(false)


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			var vicinity_pos: Vector2 = WorldGen.chunk_origin(target_chunk) + Vector2.ONE * WorldGen.CHUNK_SIZE * 0.5
			for ship in fleet.ships:
				ship.position = vicinity_pos
			fleet.move_to(vicinity_pos)
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < planet_field.check_interval + 0.1:
				return false
			if not planet_field.populated_chunks.has(target_chunk):
				print("TEST_PROMPT_DEBOUNCE: FAIL (planet never spawned)")
				quit(1)
				return true
			var planet: Node2D = planet_field.populated_chunks[target_chunk][0]
			planet_pos = planet.position
			landing_radius = planet.landing_radius
			last_visible_state = enter_button.visible
			elapsed = 0.0
			stage = 2
			return false
		2:
			# Teleport the fleet's centroid just inside, then just outside,
			# the landing radius every single frame - the raw detection
			# flips every frame, so the debounced prompt must never react
			# to this at all.
			var inside_pos: Vector2 = planet_pos + Vector2(landing_radius - 5.0, 0.0)
			var outside_pos: Vector2 = planet_pos + Vector2(landing_radius + 5.0, 0.0)
			var target_pos: Vector2 = inside_pos if (flicker_frames % 2 == 0) else outside_pos
			for ship in fleet.ships:
				ship.position = target_pos
			flicker_frames += 1

			if enter_button.visible != last_visible_state:
				visible_toggle_count += 1
				last_visible_state = enter_button.visible

			if flicker_frames < 20:
				return false

			print("visible_toggle_count=%d (should be 0)" % visible_toggle_count)
			if visible_toggle_count == 0:
				print("TEST_PROMPT_DEBOUNCE: PASS")
				quit(0)
			else:
				print("TEST_PROMPT_DEBOUNCE: FAIL (prompt flickered despite debounce)")
				quit(1)
			return true
	return false