extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_building_stock_queue.gd
# Forgejo #16 (part 3 of #12), updated for #23: a building produces out of
# its OWN stock, an order it cannot pay for yet is queued rather than
# refused, and building now TAKES TIME.
#
# What #23 changed here: orders no longer complete the instant the ore
# lands. The head of the queue consumes its ore, builds for build_time, and
# only then finishes - and it finishes into the mothership hangar rather
# than straight into the fleet. So a queue is something the player can watch
# and cancel, and a full fleet no longer stops a crafter working.
#
# Verifies:
#   1. ordering with an empty stock queues instead of failing, and produces
#      nothing yet
#   2. it does NOT quietly take the cost out of the bank - the whole point is
#      that the building has to be supplied
#   3. delivering enough stock starts the build, and it completes on its own
#   4. orders build ONE AT A TIME in order, not all at once the moment a big
#      delivery covers them
#   5. a part-delivery is not enough: stock below the cost leaves the order
#      queued and the ore untouched
#   6. stock and queue survive the space scene being torn down
#   7. a build completes with NO fleet in existence, into the hangar, and
#      waits there - it is not lost, and not silently crewed either

var game_state: Node
var scene: Node
var fleet: Node
var field: Node
var crafter_id: int = 0
var stage: int = 0
var elapsed: float = 0.0
var ships_at_start: int = 0
var bank_at_start: int = 0
var stored_at_start: int = 0
var ticks: int = 0

const CRAFTER_AT: Vector2 = Vector2(900.0, 0.0)


func _initialize() -> void:
	game_state = root.get_node("GameState")
	game_state.buildings.clear()
	game_state.extractors.clear()
	game_state.stored_vessels.clear()
	game_state.rocks = 500
	game_state.fleet_cargo = 0
	# Real build times are 10s+; the timed path is what matters here, not the
	# wall clock. See GameState.build_time_scale.
	game_state.build_time_scale = 0.02
	game_state.unlocked = ["shipyards", "coordination"]
	scene = load("res://world/Main.tscn").instantiate()
	root.add_child(scene)
	fleet = scene.get_node("Fleet")
	field = scene.get_node("BuildingField")


func _build_time() -> float:
	return game_state.build_time(GameState.PRODUCT_SHIP)


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			scene.get_node("AsteroidField").set_process(false)
			scene.get_node("EnemySpawner").set_process(false)
			_clear_hazards()
			fleet.spawn_ships(2, Vector2.ZERO)
			field.place(GameState.BUILDING_SHIP_CRAFTER, CRAFTER_AT)
			crafter_id = int(game_state.buildings[-1].id)
			ships_at_start = fleet.ships.size()
			bank_at_start = game_state.rocks
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < 0.2:
				return false
			# --- 1 + 2. an unaffordable order queues, and costs nothing --
			if not game_state.queue_order(crafter_id):
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (the crafter refused an order outright)")
				quit(1)
				return true
			elapsed = 0.0
			stage = 2
			return false
		2:
			if elapsed < 0.3:
				return false
			if game_state.pending_orders(crafter_id) != 1:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (order did not stay queued: %d pending)" % game_state.pending_orders(crafter_id))
				quit(1)
				return true
			if not game_state.stored_vessels.is_empty():
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (a vessel appeared with an empty stock)")
				quit(1)
				return true
			if game_state.rocks != bank_at_start:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (queueing took %d out of the bank - the building is supposed to be supplied)" % (bank_at_start - game_state.rocks))
				quit(1)
				return true
			print("empty stock -> queued=%d stored=%d bank=%d (untouched)" % [
				game_state.pending_orders(crafter_id), game_state.stored_vessels.size(), game_state.rocks
			])

			# --- 5. a part-delivery is not enough -----------------------
			game_state.deposit_to_building(crafter_id, GameState.SHIP_COST - 1)
			elapsed = 0.0
			stage = 3
			return false
		3:
			if elapsed < 0.3:
				return false
			if game_state.pending_orders(crafter_id) != 1 or not game_state.stored_vessels.is_empty():
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (produced on a part-delivery of %d against a cost of %d)" % [
					GameState.SHIP_COST - 1, GameState.SHIP_COST
				])
				quit(1)
				return true
			if game_state.building_stock(crafter_id) != GameState.SHIP_COST - 1:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (part-delivered ore was consumed anyway)")
				quit(1)
				return true
			print("part delivery (%d of %d) -> still queued, ore intact" % [
				game_state.building_stock(crafter_id), GameState.SHIP_COST
			])

			# --- 3. topping it up starts the build ----------------------
			game_state.deposit_to_building(crafter_id, 1)
			elapsed = 0.0
			stage = 4
			return false
		4:
			# One tick: the build must have STARTED (ore taken) but not yet
			# finished, or "takes time" means nothing.
			ticks += 1
			if ticks < 2:
				return false
			var queue: Array = game_state.order_list(crafter_id)
			if queue.is_empty() or not bool(queue[0].started):
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (a fully funded order never started building)")
				quit(1)
				return true
			if game_state.building_stock(crafter_id) != 0:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (starting the build did not consume the ore)")
				quit(1)
				return true
			if not game_state.stored_vessels.is_empty():
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (the vessel appeared instantly - builds are supposed to take time)")
				quit(1)
				return true
			print("funded -> building started, ore consumed, nothing delivered yet")
			elapsed = 0.0
			stage = 5
			return false
		5:
			if elapsed < _build_time() * 2.0:
				return false
			if game_state.pending_orders(crafter_id) != 0:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (build never finished)")
				quit(1)
				return true
			if game_state.stored_vessels.size() != 1:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (finished build did not reach the hangar: %d stored)" % game_state.stored_vessels.size())
				quit(1)
				return true
			if fleet.ships.size() != ships_at_start:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (the vessel crewed itself - the player is supposed to pick it up)")
				quit(1)
				return true
			print("built -> 1 vessel waiting in the hangar, fleet untouched at %d" % fleet.ships.size())

			# --- 4. one at a time, in order -----------------------------
			stored_at_start = game_state.stored_vessels.size()
			game_state.queue_order(crafter_id)
			game_state.queue_order(crafter_id)
			game_state.queue_order(crafter_id)
			game_state.deposit_to_building(crafter_id, GameState.SHIP_COST * 3)
			elapsed = 0.0
			stage = 6
			return false
		6:
			# Enough time for exactly one build, and no more. Funding all
			# three at once must NOT finish all three at once - that is the
			# behaviour #23 replaced.
			if elapsed < _build_time() * 1.4:
				return false
			var done: int = game_state.stored_vessels.size() - stored_at_start
			if done != 1:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (after one build time, %d of 3 orders finished - they are not building one at a time)" % done)
				quit(1)
				return true
			if game_state.pending_orders(crafter_id) != 2:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (%d orders left, expected 2 still queued)" % game_state.pending_orders(crafter_id))
				quit(1)
				return true
			print("one build time -> 1 of 3 done, 2 still queued (sequential)")
			elapsed = 0.0
			stage = 7
			return false
		7:
			if elapsed < _build_time() * 4.0:
				return false
			if game_state.stored_vessels.size() - stored_at_start != 3:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (the rest of the queue never drained: %d of 3)" % (game_state.stored_vessels.size() - stored_at_start))
				quit(1)
				return true
			print("queue drained in order -> 3 vessels waiting")

			# --- 6 + 7. no scene, no fleet ------------------------------
			stored_at_start = game_state.stored_vessels.size()
			scene.queue_free()
			elapsed = 0.0
			stage = 8
			return false
		8:
			if elapsed < 0.3:
				return false
			if is_instance_valid(fleet):
				return false
			game_state.queue_order(crafter_id)
			game_state.deposit_to_building(crafter_id, GameState.SHIP_COST)
			elapsed = 0.0
			stage = 9
			return false
		9:
			if elapsed < _build_time() * 3.0:
				return false
			# The queue, the stock and the hangar live in the autoload, so
			# tearing the space scene down must not touch them.
			if game_state.pending_orders(crafter_id) != 0:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (build stalled once the space scene was gone)")
				quit(1)
				return true
			if game_state.stored_vessels.size() != stored_at_start + 1:
				print("TEST_BUILDING_STOCK_QUEUE: FAIL (a vessel built with no fleet present was lost)")
				quit(1)
				return true
			print("no scene at all -> build completed into the hangar (%d waiting)" % game_state.stored_vessels.size())
			print("TEST_BUILDING_STOCK_QUEUE: PASS")
			quit(0)
			return true
	return false


func _clear_hazards() -> void:
	for a in get_nodes_in_group("asteroids"):
		if is_instance_valid(a):
			a.queue_free()
	for e in get_nodes_in_group("enemies"):
		if is_instance_valid(e):
			e.queue_free()