extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_enemy_projectile_damage.gd
# Verifies the ranged damage path #44 adds: an EnemyProjectile destroys an
# unshielded ship on contact, and is absorbed by a shielded ship, removing
# exactly one charge rather than destroying it.

var game_state: Node
var scene: Node
var fleet: Node
var interceptor: Node
var shield_ship: Node
var stage: int = 0
var elapsed: float = 0.0


func _initialize() -> void:
	game_state = root.get_node("GameState")
	game_state.buildings.clear()
	game_state.extractors.clear()
	game_state.transporters.clear()
	game_state.stored_vessels.clear()
	game_state.build_time_scale = 0.02
	game_state.reset_progression()
	game_state.rocks = 2000
	scene = load("res://world/Main.tscn").instantiate()
	root.add_child(scene)
	fleet = scene.get_node("Fleet")


func _fire_at(ship: Node) -> void:
	var projectile: Area2D = load("res://enemies/EnemyProjectile.tscn").instantiate()
	projectile.global_position = ship.global_position
	projectile.launch(Vector2.ZERO)   # already on top of the target
	scene.add_child(projectile)


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			scene.get_node("AsteroidField").set_process(false)
			scene.get_node("EnemySpawner").set_process(false)
			# set_process(false) only stops NEW asteroids; the ones already
			# placed keep drifting under their own _physics_process, and they
			# are placed at random. One of them wandering into the shield
			# vessel parked out at (2000, 0) spends its single charge, and
			# the projectile fired at it a moment later then kills it - which
			# presented as "a shielded ship was destroyed by an enemy
			# projectile" on roughly one parallel suite run in thirty, and
			# never in isolation. Clearing them is what the other combat
			# tests already do (see test_sniper_enemy.gd).
			for asteroid in get_nodes_in_group("asteroids"):
				if is_instance_valid(asteroid):
					asteroid.queue_free()
			fleet.spawn_ships(1, Vector2.ZERO)
			interceptor = fleet.ships[0]
			fleet.add_ship(GameState.VESSEL_SHIELD)
			shield_ship = fleet.ships[1]
			shield_ship.position = Vector2(2000.0, 0.0)
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < 0.2:
				return false
			if not shield_ship.has_shield():
				return _fail("a fresh shield vessel has no shield")
			_fire_at(interceptor)
			elapsed = 0.0
			stage = 2
			return false
		2:
			if elapsed < 0.4:
				return false
			if is_instance_valid(interceptor):
				return _fail("an unshielded ship survived an enemy projectile")
			print("unshielded interceptor destroyed by an enemy projectile")

			_fire_at(shield_ship)
			elapsed = 0.0
			stage = 3
			return false
		3:
			if elapsed < 0.4:
				return false
			if not is_instance_valid(shield_ship):
				return _fail("a shielded ship was destroyed by an enemy projectile")
			if shield_ship.shield_charges != 0:
				return _fail("shield charges did not drop to 0 after absorbing one hit (charges=%d)" %
					shield_ship.shield_charges)
			print("shielded ship absorbed the hit and lost exactly one charge")
			print("TEST_ENEMY_PROJECTILE_DAMAGE: PASS")
			quit(0)
			return true
	return false


func _fail(message: String) -> bool:
	print("TEST_ENEMY_PROJECTILE_DAMAGE: FAIL (%s)" % message)
	quit(1)
	return true