extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_planet_identity_persists.gd
# Regression test for: leaving a planet's surface and coming back
# respawned Main.tscn's PlanetField from scratch, and since planet
# name/position/shape were picked with the unseeded global RNG at spawn
# time, the "same" planet (same chunk) would come back with a different
# name, a different position within the chunk, and a different outline
# shape every single time. Fixed by seeding planet identity purely from
# the chunk's own coordinates (mirrors WorldGen's own deterministic noise
# pattern), so this loads Main.tscn twice and checks the planet at the
# same chunk is identical both times.

var target_chunk: Vector2i
var first_name: String
var first_pos: Vector2
var first_shape: PackedVector2Array
var stage: int = 0
var main_scene: Node
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

	_load_main()


func _load_main() -> void:
	# GameState (an autoload) isn't accessible as a bare global identifier
	# from a script that extends SceneTree directly - fetch it via root.
	var game_state: Node = root.get_node("GameState")
	game_state.has_return_position = true
	game_state.surviving_ship_count = 5
	game_state.return_world_position = WorldGen.chunk_origin(target_chunk) + Vector2.ONE * WorldGen.CHUNK_SIZE * 0.5
	game_state.return_camera_zoom = 1.0

	var packed: PackedScene = load("res://Main.tscn")
	main_scene = packed.instantiate()
	root.add_child(main_scene)
	main_scene.get_node("AsteroidField").set_process(false)
	main_scene.get_node("EnemySpawner").set_process(false)


func _process(_delta: float) -> bool:
	match stage:
		0:
			# Wait one tick for _ready() (and the forced synchronous
			# update_chunks() call inside it) to have actually run.
			stage = 1
			return false
		1:
			var planet_field: Node = main_scene.get_node("PlanetField")
			if not planet_field.populated_chunks.has(target_chunk):
				print("FAIL: planet never spawned in target chunk on first load")
				quit(1)
				return true
			var planet: Node2D = planet_field.populated_chunks[target_chunk][0]
			first_name = planet.planet_name
			first_pos = planet.position
			first_shape = planet.shape_points.duplicate()

			main_scene.queue_free()
			stage = 2
			return false
		2:
			# Give queue_free() a moment to actually clear the old tree
			# before loading a fresh Main.tscn on top of it.
			elapsed += 1.0
			if elapsed < 3.0:
				return false
			_load_main()
			elapsed = 0.0
			stage = 3
			return false
		3:
			stage = 4
			return false
		4:
			var planet_field: Node = main_scene.get_node("PlanetField")
			if not planet_field.populated_chunks.has(target_chunk):
				print("FAIL: planet never spawned in target chunk on second load")
				quit(1)
				return true
			var planet: Node2D = planet_field.populated_chunks[target_chunk][0]

			var name_ok: bool = planet.planet_name == first_name
			var pos_ok: bool = planet.position.distance_to(first_pos) < 0.01
			var shape_ok: bool = planet.shape_points.size() == first_shape.size()
			if shape_ok:
				for i in range(first_shape.size()):
					if planet.shape_points[i].distance_to(first_shape[i]) > 0.01:
						shape_ok = false
						break

			print("name: %s vs %s (ok=%s)" % [first_name, planet.planet_name, name_ok])
			print("pos: %s vs %s (ok=%s)" % [first_pos, planet.position, pos_ok])
			print("shape_ok=%s" % shape_ok)

			if name_ok and pos_ok and shape_ok:
				print("TEST_PLANET_IDENTITY_PERSISTS: PASS")
				quit(0)
			else:
				print("TEST_PLANET_IDENTITY_PERSISTS: FAIL")
				quit(1)
			return true
	return false