extends SceneTree

# Forgejo #216: a transport hub used to conjure its own transporters, free and
# permanent. They are built at a ship crafter now, flown out from the
# mothership hangar to whichever hub asked for them, and worn out by the runs
# they make.
#
# Covers:
#   A. a new hub stands empty - nothing is provisioned with the structure
#   B. the crafter accepts a transporter order, which it used to refuse
#   C. one assigned and one in the hangar puts it at the hub, and a hub that
#      was asked for nothing stays empty however many are sitting there
#   D. the transporter then does the job the old free ones did: it supplies a
#      queued order, without ore being created or destroyed
#   E. it wears out, and the spent vessel is gone rather than returned

var state: Node
var crafter_id: int
var hub_id: int
var total_at_start: int
var consumed: int = 0
var elapsed: float = 0.0
var stage: int = 0
var conservation_broken: bool = false


func _initialize() -> void:
	state = root.get_node("GameState")
	state.buildings.clear()
	state.extractors.clear()
	state.transporters.clear()
	state.stored_vessels.clear()
	state.vessel_deliveries.clear()
	state.reset_progression()
	state.rocks = 400
	state.build_time_scale = 0.02
	state.unlocked = ["shipyards", "logistics", "freight"]
	state.add_building(state.BUILDING_MOTHERSHIP, Vector2.ZERO)
	crafter_id = state.add_building(state.BUILDING_SHIP_CRAFTER, Vector2(900, -300))
	hub_id = state.add_building(state.BUILDING_TRANSPORT_HUB, Vector2(600, 200))


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			# --- A. nothing comes with the structure ---------------------
			if not state.transporters.is_empty():
				return _fail("a new hub arrived with %d transporters" % state.transporters.size())
			if state.station_desired(hub_id) != 0:
				return _fail("a new hub already had a crew ordered")
			print("a new hub stands empty")

			# --- B. the crafter takes the order --------------------------
			if not state.queue_order(crafter_id, state.VESSEL_TRANSPORTER):
				return _fail("the crafter refused a transporter order")
			state.find_building(crafter_id).orders.clear()

			# --- C. assigned, and only then sent -------------------------
			# One in the hangar and nothing asked for: it must stay there.
			state.stored_vessels.append(state.VESSEL_TRANSPORTER)
			state._advance_station_dispatch()
			if not state.transporters.is_empty():
				return _fail("a hub that asked for nothing took a transporter anyway")
			if state.set_station_desired(hub_id, 1) != 1:
				return _fail("the hub refused an order for one transporter")
			state._advance_station_dispatch()
			if state.stored_vessels.has(state.VESSEL_TRANSPORTER):
				return _fail("the assigned transporter never left the hangar")
			if state.vessel_deliveries.is_empty():
				return _fail("nothing was sent to the hub")
			elapsed = 0.0
			stage = 1
			return false
		1:
			if state.station_crew(hub_id) < 1:
				if elapsed > 25.0:
					return _fail("the transporter never reached the hub")
				return false
			var condition: Array = state.station_condition(hub_id)
			if condition.size() != 1 or int(condition[0]) != GameState.TRANSPORTER_TRIPS:
				return _fail("the arrived transporter reports %s trips, expected [%d]" \
					% [condition, GameState.TRANSPORTER_TRIPS])
			print("ordered, built and flown out: 1 at the hub with %d runs in it" \
				% GameState.TRANSPORTER_TRIPS)

			# --- D. and it does the work ---------------------------------
			if not state.queue_order(crafter_id, state.PRODUCT_SHIP):
				return _fail("crafter refused the combat-vessel order")
			state.order_completed.connect(_on_order_completed)
			total_at_start = _total()
			elapsed = 0.0
			stage = 2
			return false
		2:
			if _total() + consumed != total_at_start:
				conservation_broken = true
			if state.pending_orders(crafter_id) > 0:
				if elapsed > 25.0:
					return _fail("the hub's transporter never supplied the queued order")
				return false
			if conservation_broken:
				return _fail("ore was created or destroyed on the automatic route")
			print("the hub's own transporter supplied the crafter")

			elapsed = 0.0
			stage = 3
			return false
		3:
			# --- E. and it is used up by doing so ------------------------
			# The run is spent when it gets HOME, not when the cargo lands, so
			# this waits for the transporter to be idle at its hub again -
			# which is also the rule that stops a vessel retiring with its
			# cargo still in the air.
			if state.transporters.is_empty():
				return _fail("the transporter vanished before completing its run")
			if String(state.transporters[0].state) != state.TRANSPORTER_IDLE:
				if elapsed > 25.0:
					return _fail("the transporter never got home")
				return false
			var worn: Array = state.station_condition(hub_id)
			if worn.is_empty() or int(worn[0]) >= GameState.TRANSPORTER_TRIPS:
				return _fail("a transporter that ran a supply route is still unworn (%s)" % [worn])
			print("a completed run wore it to %d" % int(worn[0]))
			# Wound down to its last run, so the next arrival home retires it.
			state.transporters[0].trips_left = 1
			elapsed = 0.0
			stage = 4
			return false
		4:
			if not state.transporters.is_empty():
				if elapsed > 30.0:
					return _fail("a transporter on its last run was never retired")
				# Keep it working: an idle one at its hub never completes
				# another leg, and it is the arrival home that spends the run.
				state.deposit_resource_to_building(crafter_id, GameState.RESOURCE_ORE, 0)
				state.queue_order(crafter_id, state.PRODUCT_SHIP)
				return false
			if state.stored_vessels.has(state.VESSEL_TRANSPORTER):
				return _fail("a spent transporter went back to the hangar instead of being used up")
			if state.station_crew(hub_id) != 0:
				return _fail("the hub still counts a retired transporter")
			print("spent after its last run: gone, and the hub is short again")
			print("TEST_TRANSPORTER_SUPPLY: PASS")
			quit(0)
			return true
	return false


func _on_order_completed(_building_id: int, product: String) -> void:
	consumed += state.product_cost(product)


# Every place a rock can be while the route runs: the bank (the mothership's
# own store IS state.rocks, so counting the building too would double it), a
# building's local store, an order that has started and taken its cost, and a
# transporter's hold in mid-flight.
func _total() -> int:
	var sum: int = state.rocks + state.fleet_cargo
	for building in state.buildings:
		if building.type != state.BUILDING_MOTHERSHIP:
			sum += state.building_resource(int(building.id), state.RESOURCE_ORE)
		for order in building.get("orders", []):
			if bool(order.started):
				sum += state.product_cost(String(order.product))
	for transporter in state.transporters:
		sum += int(transporter.get("carrying", 0))
	return sum


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