extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_shield_vessel.gd
# Forgejo #5: the shield vessel's shield absorbs a hit that would destroy any
# other ship, and is then down until it cycles back up.
#
# The shield is PERSONAL - it protects the vessel carrying it and nothing
# else. Ships have no health in this game: contact with an enemy or an
# asteroid destroys them outright, so "absorbs a hit" means surviving the
# collision that would otherwise have killed it.
#
# Verifies:
#   1. an ordinary interceptor still dies to a rock (so the shield result
#      below means something)
#   2. a shield vessel survives the same rock, and the rock is destroyed
#   3. its shield is then DOWN - a second rock while it is cycling kills it,
#      or the shield would be permanent invulnerability
#   4. the shield comes back on its own after the recharge time
#   5. researched capacity lets it take more than one hit
#   6. the recharge upgrade actually shortens the wait

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.vessels_owed.clear()
	game_state.reset_progression()
	game_state.rocks = 2000
	scene = load("res://Main.tscn").instantiate()
	root.add_child(scene)
	fleet = scene.get_node("Fleet")


func _rock_onto(ship: Node) -> void:
	var rock: Area2D = load("res://Asteroid.tscn").instantiate()
	rock.velocity = Vector2.ZERO
	rock.global_position = ship.global_position
	scene.add_child(rock)


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			scene.get_node("AsteroidField").set_process(false)
			scene.get_node("EnemySpawner").set_process(false)
			for a in get_nodes_in_group("asteroids"):
				if is_instance_valid(a):
					a.queue_free()
			fleet.spawn_ships(1, Vector2.ZERO)
			interceptor = fleet.ships[0]
			# Well clear of the interceptor, or one rock hits both.
			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():
				print("TEST_SHIELD_VESSEL: FAIL (a fresh shield vessel has no shield)")
				quit(1)
				return true
			# --- 1. the control: an interceptor dies --------------------
			_rock_onto(interceptor)
			elapsed = 0.0
			stage = 2
			return false
		2:
			if elapsed < 0.4:
				return false
			if is_instance_valid(interceptor):
				print("TEST_SHIELD_VESSEL: FAIL (an ordinary interceptor survived a rock - the test proves nothing)")
				quit(1)
				return true
			print("control: interceptor destroyed by a rock")

			# --- 2. the shield vessel survives it -----------------------
			_rock_onto(shield_ship)
			elapsed = 0.0
			stage = 3
			return false
		3:
			if elapsed < 0.4:
				return false
			if not is_instance_valid(shield_ship):
				print("TEST_SHIELD_VESSEL: FAIL (the shield did not absorb the hit)")
				quit(1)
				return true
			if shield_ship.has_shield():
				print("TEST_SHIELD_VESSEL: FAIL (shield still up after taking a hit - it never goes down)")
				quit(1)
				return true
			print("shield vessel survived, shield now down")

			# --- 3. defenceless while it cycles -------------------------
			_rock_onto(shield_ship)
			elapsed = 0.0
			stage = 4
			return false
		4:
			if elapsed < 0.4:
				return false
			if is_instance_valid(shield_ship):
				print("TEST_SHIELD_VESSEL: FAIL (survived a second hit with the shield down - it is just invulnerable)")
				quit(1)
				return true
			print("second hit while cycling destroyed it, as it should")

			# --- 4 + 5. recharge, and researched capacity ---------------
			game_state.vessel_levels["shd_hits"] = 1
			fleet.add_ship(GameState.VESSEL_SHIELD)
			shield_ship = fleet.ships[fleet.ships.size() - 1]
			shield_ship.position = Vector2(-2000.0, 0.0)
			elapsed = 0.0
			stage = 5
			return false
		5:
			if elapsed < 0.2:
				return false
			if shield_ship.shield_charges != game_state.shield_max_charges():
				print("TEST_SHIELD_VESSEL: FAIL (researched capacity %d, vessel has %d)" % [
					game_state.shield_max_charges(), shield_ship.shield_charges
				])
				quit(1)
				return true
			print("with Layered Emitters researched: %d charges" % shield_ship.shield_charges)
			_rock_onto(shield_ship)
			elapsed = 0.0
			stage = 6
			return false
		6:
			if elapsed < 0.4:
				return false
			if not is_instance_valid(shield_ship) or not shield_ship.has_shield():
				print("TEST_SHIELD_VESSEL: FAIL (a two-charge shield did not survive one hit with a charge left)")
				quit(1)
				return true
			print("two-charge shield took a hit and is still up (%d left)" % shield_ship.shield_charges)

			# --- 6. the recharge upgrade shortens the wait --------------
			var slow: float = game_state.shield_recharge_time()
			game_state.vessel_levels["shd_recharge"] = 2
			var fast: float = game_state.shield_recharge_time()
			print("recharge %.1fs -> %.1fs with Fast Cycling" % [slow, fast])
			if fast >= slow:
				print("TEST_SHIELD_VESSEL: FAIL (the recharge upgrade did not shorten the wait)")
				quit(1)
				return true

			# --- 4. it really does come back ----------------------------
			shield_ship.shield_charges = 0
			shield_ship.shield_recharge_left = 0.15
			elapsed = 0.0
			stage = 7
			return false
		7:
			if elapsed < 0.6:
				return false
			if not shield_ship.has_shield():
				print("TEST_SHIELD_VESSEL: FAIL (the shield never cycled back up)")
				quit(1)
				return true
			print("shield cycled back up on its own")
			print("TEST_SHIELD_VESSEL: PASS")
			quit(0)
			return true
	return false