extends SceneTree

# Headless test: run with
#   godot --headless -s res://tests/test_building_health.gd
# Forgejo #99 (#97a): structures can be hurt, and can come down.
#
# Health lives on the RECORD in GameState rather than on the Building node,
# because Main.tscn is destroyed and rebuilt on every trip to a planet
# surface - damage kept on a node would heal itself the moment the player
# landed. Most of this test therefore talks to GameState directly, and only
# the last case looks at what the scene does with it.
#
# Covers:
#   A. every building definition declares a positive max_hp, and a fresh
#      record starts at full health
#   B. damage subtracts, reports survival, and enough of it destroys the
#      record outright
#   C. a record written before this existed reads as undamaged, not as
#      rubble - an existing save must not open on a field of wrecks
#   D. #159 - NOTHING is exempt from coming down, the mothership included.
#      It used to floor at 1hp to avoid a soft-lock, and a battered one sat
#      there reading as dead and never exploded. The soft-lock does not
#      exist: what is IN the mothership outlives it, and rebuilding it is
#      always reachable - so the way back is checked here rather than the
#      exemption that used to stand in for it
#   E. destroying a transport hub takes its transporters with it, and
#      nothing else keyed on the id is left pointing at a hole
#   F. the Building node follows its record out of existence, and shows
#      damage while it is still standing

var game_state: Node
var scene: Node
var stage: int = 0
var elapsed: float = 0.0
var destroyed_events: Array = []


func _initialize() -> void:
	# GameState is an autoload: a bare GameState.<instance member> does not
	# compile in a SceneTree script, so the node is fetched by name instead.
	game_state = root.get_node("GameState")
	game_state.buildings.clear()
	game_state.extractors.clear()
	game_state.transporters.clear()
	game_state.reset_progression()
	game_state.rocks = 5000


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


func _run_state_cases() -> bool:
	var definitions: Script = load("res://buildings/BuildingDefinitions.gd")

	# --- A. every structure declares what it can take -------------------
	for definition in definitions.all():
		if int(definition.max_hp) <= 0:
			return _fail("'%s' has max_hp %d - it would be rubble the moment it was placed" \
				% [definition.definition_id, definition.max_hp])
	var crafter_id: int = game_state.add_building(GameState.BUILDING_SHIP_CRAFTER, Vector2(300.0, 0.0))
	var full: int = game_state.building_max_hp(GameState.BUILDING_SHIP_CRAFTER)
	if game_state.building_hp(crafter_id) != full:
		return _fail("a new crafter opened at %d of %d hp" \
			% [game_state.building_hp(crafter_id), full])
	if not is_equal_approx(game_state.building_health_fraction(crafter_id), 1.0):
		return _fail("a new crafter is not at full health")
	print("%d definitions all declare max_hp; a new crafter starts at %d" \
		% [definitions.all().size(), full])

	# --- B. damage, then death ------------------------------------------
	game_state.building_destroyed.connect(func(id: int, type: String):
		destroyed_events.append({"id": id, "type": type}))
	if game_state.damage_building(crafter_id, full - 1):
		return _fail("one hit point short of dead reported the crafter destroyed")
	if game_state.building_hp(crafter_id) != 1:
		return _fail("hp is %d after taking max_hp - 1" % game_state.building_hp(crafter_id))
	if game_state.building_health_fraction(crafter_id) >= 0.5:
		return _fail("a crafter on its last hit point still reads as healthy")
	if not game_state.damage_building(crafter_id, 1):
		return _fail("the last hit point did not destroy the crafter")
	if not game_state.find_building(crafter_id).is_empty():
		return _fail("the destroyed crafter is still in GameState.buildings")
	if destroyed_events.size() != 1 or int(destroyed_events[0].id) != crafter_id:
		return _fail("building_destroyed did not fire once for the crafter")
	# Fired AFTER the record went, so a listener sees the world without it.
	print("a crafter takes %d damage and comes down, announcing itself" % full)

	# --- C. a record from before this existed ---------------------------
	var legacy_id: int = game_state.add_building(GameState.BUILDING_SHIP_LAB, Vector2(-300.0, 0.0))
	game_state.find_building(legacy_id).erase("hp")
	var lab_full: int = game_state.building_max_hp(GameState.BUILDING_SHIP_LAB)
	if game_state.building_hp(legacy_id) != lab_full:
		return _fail("a record with no hp field reads as %d, not the %d it should" \
			% [game_state.building_hp(legacy_id), lab_full])
	if game_state.damage_building(legacy_id, 1):
		return _fail("one point of damage levelled a building carried over from an old save")
	print("a pre-#99 record reads as undamaged (%d hp), not as rubble" % lab_full)

	# --- D. #159: the mothership comes down like anything else ----------
	var mothership_id: int = game_state.add_building(GameState.BUILDING_MOTHERSHIP, Vector2.ZERO)
	if game_state.building_is_indestructible(game_state.find_building(mothership_id)):
		return _fail("the mothership is still exempt - it would sit at 1hp reading as dead")
	# Stock the things that used to be the reason for the exemption, so
	# their survival is observed rather than assumed.
	game_state.bank_inventory.set_amount(GameState.RESOURCE_ORE, 400)
	game_state.stored_vessels.append(GameState.VESSEL_INTERCEPTOR)
	if not game_state.damage_building(mothership_id, 999999):
		return _fail("enough damage did not destroy the mothership")
	if not game_state.find_building(mothership_id).is_empty():
		return _fail("the mothership record outlived its own destruction")

	# ...and the way back. This is what the exemption was protecting, so it
	# is what has to be true without it.
	if game_state.banked_resource(GameState.RESOURCE_ORE) != 400:
		return _fail("the bank died with the building - it holds %d" \
			% game_state.banked_resource(GameState.RESOURCE_ORE))
	if game_state.stored_vessels.is_empty():
		return _fail("the hangar died with the building")
	if game_state.research_for_building(GameState.BUILDING_MOTHERSHIP) != "":
		return _fail("rebuilding the mothership needs research, which needs a mothership")
	var rebuild: int = int(game_state.building_costs(GameState.BUILDING_MOTHERSHIP).get(
		GameState.RESOURCE_ORE, 0))
	var one_hold: int = game_state.fleet_cargo_capacity(
		PackedStringArray([GameState.VESSEL_INTERCEPTOR]))
	if rebuild > one_hold:
		return _fail("a rebuild costs %d ore and one surviving hull carries %d - unreachable with the bank gone" \
			% [rebuild, one_hold])
	print("the mothership comes down; bank, hangar and an ungated %d-ore rebuild all survive it" \
		% rebuild)
	# Repair, on a fresh one - the last was destroyed on purpose above.
	var rebuilt_id: int = game_state.add_building(GameState.BUILDING_MOTHERSHIP, Vector2.ZERO)
	var at_full: int = game_state.building_max_hp(GameState.BUILDING_MOTHERSHIP)
	if game_state.damage_building(rebuilt_id, at_full - 5):
		return _fail("damage short of the last few points still destroyed it")
	if game_state.building_hp(rebuilt_id) != 5:
		return _fail("a battered mothership sits at %d hp, expected 5" \
			% game_state.building_hp(rebuilt_id))
	if game_state.repair_building(rebuilt_id, 999999) <= 0:
		return _fail("a battered mothership could not be repaired")
	if game_state.building_hp(rebuilt_id) != at_full:
		return _fail("repair did not take the mothership back to full")
	print("a rebuilt one takes damage down to %d and repairs back to %d" % [5, at_full])

	# --- E. a hub takes its transporters with it ------------------------
	var hub_id: int = game_state.add_building(GameState.BUILDING_TRANSPORT_HUB, Vector2(800.0, 0.0))
	var hub_transporters: int = 0
	for transporter in game_state.transporters:
		if int(transporter.get("hub_id", 0)) == hub_id:
			hub_transporters += 1
	if hub_transporters <= 0:
		return _fail("the hub provisioned no transporters, so this case proves nothing")
	var others: int = game_state.transporters.size() - hub_transporters
	if not game_state.destroy_building(hub_id):
		return _fail("the hub could not be destroyed")
	for transporter in game_state.transporters:
		if int(transporter.get("hub_id", 0)) == hub_id:
			return _fail("a transporter is still flying for a hub that no longer exists")
	if game_state.transporters.size() != others:
		return _fail("destroying the hub took %d unrelated transporters with it" \
			% (others - game_state.transporters.size()))
	print("destroying a hub retires its %d transporters and no others" % hub_transporters)
	return false


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			if _run_state_cases():
				return true
			# --- F. what the scene does with it -------------------------
			game_state.buildings.clear()
			game_state.transporters.clear()
			scene = load("res://world/Main.tscn").instantiate()
			root.add_child(scene)
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < 0.3:
				return false
			scene.get_node("AsteroidField").set_process(false)
			scene.get_node("EnemySpawner").set_process(false)
			var field: Node = scene.get_node("BuildingField")
			field.place(GameState.BUILDING_SHIP_CRAFTER, Vector2(600.0, 0.0))
			elapsed = 0.0
			stage = 2
			return false
		2:
			if elapsed < 0.2:
				return false
			var field: Node = scene.get_node("BuildingField")
			var node: Node2D = null
			for b in field.spawned:
				if is_instance_valid(b) and b.building_type == GameState.BUILDING_SHIP_CRAFTER:
					node = b
			if node == null:
				return _fail("no crafter node was spawned")
			if node.is_damaged():
				return _fail("a freshly placed crafter already shows damage")
			game_state.damage_building(node.building_id, game_state.building_max_hp(
				GameState.BUILDING_SHIP_CRAFTER) / 2)
			node._process(0.0)
			if not node.is_damaged():
				return _fail("a crafter at half health does not show it")
			print("a half-wrecked crafter reads %.0f%%" % (node.health_fraction() * 100.0))
			game_state.damage_building(node.building_id, 999999)
			elapsed = 0.0
			stage = 3
			return false
		3:
			if elapsed < 0.2:
				return false
			var field: Node = scene.get_node("BuildingField")
			for b in field.spawned:
				if is_instance_valid(b) and b.building_type == GameState.BUILDING_SHIP_CRAFTER:
					return _fail("the crafter node outlived the record it was built from")
			print("the node follows its record out of existence")

			print("TEST_BUILDING_HEALTH: PASS")
			quit(0)
			return true
	return false