extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_gas_burner.gd
# Forgejo #54: gas burner building + the energy resource, stored/moved
# exactly like ore and gas.
#
# Modeled on tests/test_extractor_income.gd's shape: pure GameState state,
# no scene loaded, poking buildings/inventories directly and waiting out
# real production/transporter timing with generous margins rather than
# fixed frame counts (SceneTree physics can run ahead of _process(), trap 5
# in the repo notes).
#
# Covers:
#   A. energy is fully generic - in resource_types(), has its own
#      ResourceDefinition/glyph/colour - with no per-resource code anywhere
#      (ResourceBar/ResourceTransferList already iterate resource_types())
#   B. a burner with local gas converts it to energy, into its OWN
#      inventory, at the configured rate; with no gas it stalls and never
#      touches the bank
#   C. the building is gated behind its own research node
#   D. a hub transporter both delivers gas to a burner and collects its
#      energy, following the existing supply/pickup dispatch paths

var game_state: Node
var stage: int = 0
var elapsed: float = 0.0
var mothership_id: int = 0
var hub_id: int = 0
var burner_id: int = 0
var load_limit: int = 0
var energy_before_stall: int = 0
var conversion_rate: float = 0.0
var conversion_yield: int = 0

const MOTHERSHIP_AT := Vector2.ZERO
const HUB_AT := Vector2(150.0, 0.0)
const BURNER_AT := Vector2(400.0, 0.0)


func _initialize() -> void:
	game_state = root.get_node("GameState")
	game_state.rocks = 0
	game_state.gas = 0
	game_state.buildings.clear()
	game_state.extractors.clear()
	game_state.transporters.clear()
	game_state.reset_progression()

	mothership_id = game_state.add_building(GameState.BUILDING_MOTHERSHIP, MOTHERSHIP_AT)
	burner_id = game_state.add_building(GameState.BUILDING_GAS_BURNER, BURNER_AT)
	game_state.deposit_resource_to_building(burner_id, GameState.RESOURCE_GAS, 20)
	var logistics: Resource = game_state.building_logistics_profile(game_state.find_building(burner_id))
	conversion_rate = logistics.conversion_rate
	conversion_yield = logistics.conversion_yield


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			# --- A. energy is fully generic -------------------------------
			if not game_state.resource_types().has(GameState.RESOURCE_ENERGY):
				return _fail("energy is not in resource_types() - the HUD/transfer list would never show it")
			var definition: Resource = game_state.resource_definition(GameState.RESOURCE_ENERGY)
			if definition == null or definition.glyph_scene == null:
				return _fail("energy has no ResourceDefinition or glyph_scene")
			var energy_color: Color = game_state.resource_color(GameState.RESOURCE_ENERGY)
			if energy_color == game_state.resource_color(GameState.RESOURCE_ORE) \
					or energy_color == game_state.resource_color(GameState.RESOURCE_GAS):
				return _fail("energy shares a colour with ore or gas")
			print("energy is generic: in resource_types(), own definition, own colour %s" % energy_color)

			# --- B. produces energy from local gas at the configured rate -
			if elapsed < 2.5:
				return false
			var gas_left: int = game_state.building_resource(burner_id, GameState.RESOURCE_GAS)
			var energy_made: int = game_state.building_resource(burner_id, GameState.RESOURCE_ENERGY)
			var gas_burned: int = 20 - gas_left
			if gas_burned < 2:
				return _fail("burner only burned %d gas in 2.5s at rate %.1f/s" % [gas_burned, conversion_rate])
			if energy_made != gas_burned * conversion_yield:
				return _fail("burner made %d energy for %d gas burned, expected %dx" % [
					energy_made, gas_burned, conversion_yield
				])
			if game_state.rocks != 0 or game_state.gas != 0:
				return _fail("conversion touched the bank (rocks=%d gas=%d) - it must only use local stock" % [
					game_state.rocks, game_state.gas
				])
			print("burner converted %d gas -> %d energy locally, bank untouched" % [gas_burned, energy_made])

			# --- stall with no gas -----------------------------------------
			var burner_inventory: RefCounted = game_state.building_inventory(burner_id)
			burner_inventory.withdraw(GameState.RESOURCE_GAS, burner_inventory.amount(GameState.RESOURCE_GAS))
			energy_before_stall = game_state.building_resource(burner_id, GameState.RESOURCE_ENERGY)
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < 1.5:
				return false
			var energy_now: int = game_state.building_resource(burner_id, GameState.RESOURCE_ENERGY)
			if energy_now != energy_before_stall:
				return _fail("burner made energy with no local gas (energy %d -> %d) - it must stall" % [
					energy_before_stall, energy_now
				])
			print("stalled with no gas: energy held at %d" % energy_now)

			# --- C. gated behind research -----------------------------------
			if game_state.is_building_unlocked(GameState.BUILDING_GAS_BURNER):
				return _fail("gas_burner is buildable with no research at all")
			var gate: String = game_state.research_for_building(GameState.BUILDING_GAS_BURNER)
			if gate == "":
				return _fail("no research node gates gas_burner")
			game_state.unlocked = ["shipyards", "logistics", "freight", "power_systems"]
			if not game_state.is_building_unlocked(GameState.BUILDING_GAS_BURNER):
				return _fail("still locked after researching '%s'" % gate)
			print("locked behind research '%s', unlockable" % gate)

			# --- D. logistics: reset for a fresh delivery/pickup test -----
			game_state.buildings.clear()
			game_state.transporters.clear()
			game_state.gas = 200
			mothership_id = game_state.add_building(GameState.BUILDING_MOTHERSHIP, MOTHERSHIP_AT)
			hub_id = game_state.add_building(GameState.BUILDING_TRANSPORT_HUB, HUB_AT)
			burner_id = game_state.add_building(GameState.BUILDING_GAS_BURNER, BURNER_AT)
			if game_state.transporters.size() != game_state.hub_capacity():
				return _fail("hub did not provision its transporters")
			load_limit = game_state.transporter_load_limit()
			elapsed = 0.0
			stage = 2
			return false
		2:
			# --- a transporter delivers gas to the burner ------------------
			if game_state.building_resource(burner_id, GameState.RESOURCE_GAS) > 0:
				print("transporter delivered gas to the burner: %d" % [
					game_state.building_resource(burner_id, GameState.RESOURCE_GAS)
				])
				# Force the burner's local energy up to a full load so pickup
				# dispatch fires immediately, rather than waiting out the
				# genuinely slow conversion rate for a second, separate check.
				game_state.building_inventory(burner_id).set_amount(GameState.RESOURCE_ENERGY, load_limit)
				elapsed = 0.0
				stage = 3
				return false
			if elapsed > 10.0:
				return _fail("no gas was ever delivered to the burner")
			return false
		3:
			# --- a transporter collects the burner's energy to the bank ---
			if game_state.banked_resource(GameState.RESOURCE_ENERGY) >= load_limit:
				print("transporter collected %d energy to the bank" % game_state.banked_resource(GameState.RESOURCE_ENERGY))
				print("TEST_GAS_BURNER: PASS")
				quit(0)
				return true
			if elapsed > 10.0:
				return _fail("burner's energy was never collected (bank=%d burner=%d)" % [
					game_state.banked_resource(GameState.RESOURCE_ENERGY),
					game_state.building_resource(burner_id, GameState.RESOURCE_ENERGY),
				])
			return false
	return false


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