extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_transporter_supply.gd
# Forgejo #19 (part 6 of #12): transporters stationed at a hub fetch ore from
# the mothership and deliver it to whichever building is waiting on it, with
# no player input at all.
#
# Verifies:
#   1. a transporter is built at the CRAFTER and takes itself to the nearest
#      hub, rather than appearing at the hub out of nowhere
#   2. a queued order the crafter cannot pay for is fulfilled end to end
#      automatically - the whole point of the ticket
#   3. ore is conserved across the entire route (bank + hold + every
#      building's stock), at every step, not just at the end
#   4. ore leaves the bank when it is LOADED, not when the order is placed -
#      the vessel is carrying something real
#   5. transporters are not ordered when there is no hub to station them at
#   6. no unbounded node accumulation: the fleet of transporters is exactly
#      what was built, however many runs they make

var game_state: Node
var scene: Node
var fleet: Node
var field: Node
var crafter_id: int = 0
var hub_id: int = 0
var stage: int = 0
var elapsed: float = 0.0
var total_at_start: int = 0
var bank_when_ordered: int = 0
var conservation_broken: bool = false
# Ore legitimately consumed by completed production. Conservation means
# "nothing vanishes in TRANSIT", not "the total never falls" - building a
# vessel spends ore, and that is the one way it is allowed to leave.
var consumed: int = 0

const MOTHERSHIP_AT: Vector2 = Vector2(0.0, 0.0)
const HUB_AT: Vector2 = Vector2(600.0, 200.0)
const CRAFTER_AT: Vector2 = Vector2(900.0, -300.0)


func _total() -> int:
	var sum: int = game_state.rocks + game_state.fleet_cargo
	for b in game_state.buildings:
		if b.type != GameState.BUILDING_MOTHERSHIP:
			sum += game_state.building_resource(int(b.id), GameState.RESOURCE_ORE)
	for t in game_state.transporters:
		sum += int(t.get("carrying", 0))
	# Ore inside a build that has STARTED but not finished (#23). It has left
	# the building's stock and has not yet been consumed by a completed
	# vessel, so without counting it the total dips for the length of every
	# build - which is a gap in this sum, not a leak in the game.
	for b in game_state.buildings:
		for o in b.get("orders", []):
			if bool(o.started):
				sum += game_state.product_cost(String(o.product))
	return sum


func _initialize() -> void:
	game_state = root.get_node("GameState")
	game_state.buildings.clear()
	game_state.extractors.clear()
	game_state.transporters.clear()
	game_state.rocks = 200
	game_state.fleet_cargo = 0
	game_state.stored_vessels.clear()
	game_state.build_time_scale = 0.02
	game_state.unlocked = ["shipyards", "logistics", "freight", "coordination", "wing", "squadron", "armada"]
	scene = load("res://Main.tscn").instantiate()
	root.add_child(scene)
	fleet = scene.get_node("Fleet")
	field = scene.get_node("BuildingField")
	game_state.order_completed.connect(_on_order_completed)


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


func _process(delta: float) -> bool:
	elapsed += delta

	# --- 3. conservation, checked EVERY tick ------------------------------
	# Ore in flight is the easy thing to lose: a leg that loads without
	# debiting, or delivers without crediting, would show up here and nowhere
	# else. Checked continuously rather than at the end, so it cannot be
	# masked by a later correction.
	if stage >= 2 and _total() + consumed != total_at_start:
		conservation_broken = true

	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()

			field.place(GameState.BUILDING_MOTHERSHIP, MOTHERSHIP_AT)
			field.place(GameState.BUILDING_SHIP_CRAFTER, CRAFTER_AT)
			crafter_id = int(game_state.buildings[-1].id)

			# --- 5. no hub yet: a transporter cannot be ordered ----------
			if game_state.queue_order(crafter_id, GameState.PRODUCT_TRANSPORTER):
				print("TEST_TRANSPORTER_SUPPLY: FAIL (ordered a transporter with no hub to station it at)")
				quit(1)
				return true
			print("no hub -> transporter order refused")

			field.place(GameState.BUILDING_TRANSPORT_HUB, HUB_AT)
			hub_id = int(game_state.buildings[-1].id)
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < 0.2:
				return false
			# --- 1. build a transporter at the crafter ------------------
			if not game_state.queue_order(crafter_id, GameState.PRODUCT_TRANSPORTER):
				print("TEST_TRANSPORTER_SUPPLY: FAIL (could not order a transporter with a hub built)")
				quit(1)
				return true
			game_state.deposit_to_building(crafter_id, GameState.TRANSPORTER_COST)
			elapsed = 0.0
			stage = 2
			total_at_start = _total()
			return false
		2:
			if elapsed < game_state.build_time(GameState.PRODUCT_TRANSPORTER) * 3.0:
				return false
			if game_state.transporters.size() != 1:
				print("TEST_TRANSPORTER_SUPPLY: FAIL (built %d transporters from one order)" % game_state.transporters.size())
				quit(1)
				return true
			var t: Dictionary = game_state.transporters[0]
			if int(t.hub_id) != hub_id:
				print("TEST_TRANSPORTER_SUPPLY: FAIL (transporter did not take the nearest hub)")
				quit(1)
				return true
			# It must fly FROM the crafter TO the hub, not appear at the hub.
			# Checked on the leg's endpoints rather than its current position,
			# which is already partway there by now - and being partway is
			# the correct behaviour.
			if (t.from as Vector2).distance_to(CRAFTER_AT) > 1.0:
				print("TEST_TRANSPORTER_SUPPLY: FAIL (transporter's first leg starts at %s, not at the crafter that built it)" % t.from)
				quit(1)
				return true
			if (t.to as Vector2).distance_to(HUB_AT) > 1.0:
				print("TEST_TRANSPORTER_SUPPLY: FAIL (transporter's first leg does not end at the hub: %s)" % t.to)
				quit(1)
				return true
			print("transporter built at the crafter, heading for hub %d" % hub_id)
			elapsed = 0.0
			stage = 3
			return false
		3:
			# Give it time to reach the hub and go idle.
			if elapsed < 4.0:
				return false
			if game_state.transporters[0].state != GameState.TRANSPORTER_IDLE:
				print("TEST_TRANSPORTER_SUPPLY: FAIL (never settled at its hub: state=%s)" % game_state.transporters[0].state)
				quit(1)
				return true
			print("stationed at the hub, idle")

			# --- 2 + 4. an order it cannot pay for ----------------------
			game_state.queue_order(crafter_id, GameState.PRODUCT_SHIP)
			bank_when_ordered = game_state.rocks
			elapsed = 0.0
			stage = 4
			return false
		4:
			# One tick: placing the order must not touch the bank.
			if elapsed < 0.1:
				return false
			if game_state.rocks != bank_when_ordered:
				print("TEST_TRANSPORTER_SUPPLY: FAIL (bank moved on placing the order, before anything was loaded)")
				quit(1)
				return true
			print("order placed, bank untouched at %d" % game_state.rocks)
			elapsed = 0.0
			stage = 5
			return false
		5:
			# --- 2. the whole run, with no player input -----------------
			if game_state.pending_orders(crafter_id) > 0:
				if elapsed > 25.0:
					print("TEST_TRANSPORTER_SUPPLY: FAIL (order never fulfilled: transporter state=%s carrying=%d crafter stock=%d)" % [
						game_state.transporters[0].state,
						int(game_state.transporters[0].carrying),
						game_state.building_stock(crafter_id),
					])
					quit(1)
					return true
				return false
			if conservation_broken:
				print("TEST_TRANSPORTER_SUPPLY: FAIL (ore created or destroyed somewhere along the route)")
				quit(1)
				return true
			print("order fulfilled automatically in %.1fs, no player input" % elapsed)

			# --- 6. no vessel accumulation ------------------------------
			if game_state.transporters.size() != 1:
				print("TEST_TRANSPORTER_SUPPLY: FAIL (%d transporters exist after the run, one was built)" % game_state.transporters.size())
				quit(1)
				return true
			print("still exactly 1 transporter after a full round trip")
			print("bank=%d crafter stock=%d total=%d + %d consumed = %d (started %d)" % [
				game_state.rocks, game_state.building_stock(crafter_id), _total(),
				consumed, _total() + consumed, total_at_start
			])
			print("TEST_TRANSPORTER_SUPPLY: PASS")
			quit(0)
			return true
	return false