extends SceneTree

# Forgejo #217: transporters crawl by default, and a Burn Drive lets them
# carry energy and spend it to go far faster. The energy is theirs to find -
# they fetch it from the nearest store that has any - and it runs out, so the
# speed is something the player's energy supply pays for continuously rather
# than a one-off purchase.
#
# Covers:
#   A. unresearched, a transporter never detours for fuel however much energy
#      is lying about, and makes the base speed
#   B. researched and empty, an idle one goes for the NEAREST store with
#      energy in it, and takes what is there
#   C. a fuelled transporter is measurably faster than an unfuelled one
#   D. a leg burns a unit, and an empty tank drops it back to the crawl
#   E. the leg it flies to collect fuel is not itself charged

const HUB_AT: Vector2 = Vector2(0.0, 0.0)
const NEAR_ENERGY_AT: Vector2 = Vector2(400.0, 0.0)
const FAR_ENERGY_AT: Vector2 = Vector2(-3000.0, 0.0)

var state: Node
var hub_id: int
var near_id: int
var far_id: int


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 = 500
	state.unlocked = ["shipyards", "logistics", "freight"]
	state.add_building(state.BUILDING_MOTHERSHIP, Vector2(0.0, 4000.0))
	hub_id = state.add_building(state.BUILDING_TRANSPORT_HUB, HUB_AT)
	near_id = state.add_building(state.BUILDING_SHIP_CRAFTER, NEAR_ENERGY_AT)
	far_id = state.add_building(state.BUILDING_SHIP_LAB, FAR_ENERGY_AT)
	load("res://tests/_staff.gd").staff(state, hub_id, 1)


func _initialize_done() -> void:
	pass


func _process(_delta: float) -> bool:
	# The bank is deliberately empty of energy, so the only sources are the
	# two structures below and "nearest" is a real choice.
	state.bank_inventory.set_amount(GameState.RESOURCE_ENERGY, 0)
	state.deposit_resource_to_building(near_id, GameState.RESOURCE_ENERGY, 4)
	state.deposit_resource_to_building(far_id, GameState.RESOURCE_ENERGY, 50)

	var t: Dictionary = state.transporters[0]

	# --- A. unresearched: no tank, no detour, base speed ----------------
	if state.transporter_burns_energy():
		return _fail("an unresearched transporter already burns energy")
	var crawl: float = state.transporter_leg_speed(t)
	if not is_equal_approx(crawl, state.transporter_speed()):
		return _fail("an unfuelled transporter makes %.1f, expected the base %.1f" \
			% [crawl, state.transporter_speed()])
	state._refuel_idle_transporters()
	if String(t.state) != state.TRANSPORTER_IDLE:
		return _fail("an unresearched transporter went looking for fuel")
	print("unresearched: no detour, %.0f base speed" % crawl)

	# --- B. researched and empty: to the NEAREST store ------------------
	state.vessel_levels["trn_burn"] = 1
	if not state.transporter_burns_energy():
		return _fail("a researched Burn Drive did not enable energy burning")
	state._refuel_idle_transporters()
	if String(t.state) != state.TRANSPORTER_TO_FUEL:
		return _fail("an empty transporter did not go for fuel (state %s)" % t.state)
	if not Vector2(t.to).is_equal_approx(NEAR_ENERGY_AT):
		return _fail("it flew to %s, not the nearer store at %s" % [t.to, NEAR_ENERGY_AT])
	print("researched and empty: flies to the nearest store, not the fullest")

	# --- E. and the trip to collect is not itself charged ---------------
	var before_fuel: int = int(t.get("fuel", 0))
	state._advance_transporters(600.0)
	if int(t.get("fuel", 0)) <= before_fuel:
		return _fail("the transporter came back from the fuel store with nothing")
	# The near store held 4, which is under the tank, so it took all of it.
	if int(t.fuel) != 4:
		return _fail("it drew %d energy, expected the 4 that were there" % int(t.fuel))
	if state.building_resource(near_id, GameState.RESOURCE_ENERGY) != 0:
		return _fail("the store it drew from still holds energy")
	print("collected 4 - all the near store had - and was not charged for the trip")

	# --- C. fuelled is faster -------------------------------------------
	var boosted: float = state.transporter_leg_speed(t)
	if boosted <= crawl:
		return _fail("a fuelled transporter makes %.1f, no better than the crawl %.1f" \
			% [boosted, crawl])
	if not is_equal_approx(boosted, crawl * state.transporter_fuel_boost()):
		return _fail("a fuelled transporter makes %.1f, expected %.1f" \
			% [boosted, crawl * state.transporter_fuel_boost()])
	print("fuelled: %.0f against %.0f, a %.1fx difference" \
		% [boosted, crawl, state.transporter_fuel_boost()])

	# --- D. and it burns down to the crawl ------------------------------
	var tank: int = int(t.fuel)
	for leg in range(tank):
		t.state = state.TRANSPORTER_RETURNING
		t.progress = 0.0
		t.from = HUB_AT
		t.to = NEAR_ENERGY_AT
		state._advance_transporters(600.0)
	if int(t.get("fuel", 0)) != 0:
		return _fail("%d legs left %d energy aboard, expected an empty tank" \
			% [tank, int(t.fuel)])
	if not is_equal_approx(state.transporter_leg_speed(t), crawl):
		return _fail("an emptied transporter did not drop back to the crawl")
	print("%d legs emptied the tank and it is back to %.0f" % [tank, crawl])

	print("TEST_TRANSPORTER_BURN: PASS")
	quit(0)
	return true


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