extends SceneTree

# Forgejo #227: a resumed run comes back at its own mothership.
#
# Loading a save used to fall through to the brand-new-game branch in
# PlanetAtmosphereController, which spawns STARTING_SHIP_COUNT interceptors
# at the world origin. So a resume stranded the player in empty space with
# the wrong ships, while their base sat wherever they had left it - which on
# a charted map is thousands of units away.
#
# Covers:
#   A. resuming puts the fleet at the mothership, not at the origin
#   B. and crews it with the ships the save actually had
#   C. with no mothership standing, it falls back to where the save was made
#   D. a NEW game is untouched - still the starting fleet at the origin

const HOME: Vector2 = Vector2(7400.0, -3100.0)
const AWAY: Vector2 = Vector2(-5200.0, 900.0)

var game_state: Node
var scene: Node
var elapsed: float = 0.0
var stage: int = 0
var expected_crew: int = 0


func _initialize() -> void:
	game_state = root.get_node("GameState")
	SaveGame.clear()


func _fresh_state() -> void:
	game_state.buildings.clear()
	game_state.extractors.clear()
	game_state.reset_progression()
	game_state.reset_new_game()
	game_state.reset_quests()
	game_state.intro_active = false


func _load_scene() -> void:
	if scene != null and is_instance_valid(scene):
		scene.free()
	scene = load("res://world/Main.tscn").instantiate()
	root.add_child(scene)
	current_scene = scene


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			if elapsed < 0.3:
				return false
			# A run with a base at HOME and the fleet parked far from it.
			_fresh_state()
			game_state.add_building(GameState.BUILDING_MOTHERSHIP, HOME)
			# Capacity for the crew below. Since #219 the fleet holds
			# BASE_FLEET_SIZE (1) plus one berth per supplied fleet office,
			# so a save with three ships flying is a save that had two
			# offices standing - without them spawn_ships clamps to 1 and
			# this would assert nothing.
			game_state.add_building(GameState.BUILDING_FLEET_OFFICE, HOME + Vector2(400.0, 0.0))
			game_state.add_building(GameState.BUILDING_FLEET_OFFICE, HOME + Vector2(800.0, 0.0))
			game_state.fleet_vessel_types = PackedStringArray([
				GameState.VESSEL_INTERCEPTOR, GameState.VESSEL_INTERCEPTOR,
				GameState.VESSEL_INTERCEPTOR])
			game_state.fleet_position = AWAY
			expected_crew = game_state.fleet_vessel_types.size()
			if game_state.max_fleet_size() < expected_crew:
				return _fail("the fleet cannot hold %d, so a resumed crew would prove nothing (cap %d)" \
					% [expected_crew, game_state.max_fleet_size()])
			if not SaveGame.save(game_state):
				return _fail("could not write the save this test resumes from")
			_fresh_state()
			var result: Dictionary = SaveGame.load_into(game_state)
			if not bool(result.get("ok", false)):
				return _fail("the save would not load: %s" % result.get("reason", ""))
			game_state.resumed_from_save = true
			_load_scene()
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < 0.6:
				return false
			var fleet: Node2D = scene.get_node("Fleet")
			# --- A. at the mothership, not the origin -------------------
			var at: Vector2 = fleet.get_centroid()
			if at.distance_to(HOME) > 400.0:
				return _fail("resumed at %s, but the mothership is at %s" % [at, HOME])
			if at.distance_to(Vector2.ZERO) < 400.0:
				return _fail("resumed at the world origin, which is the new-game behaviour")
			print("resumed at the mothership (%.0f units from it)" % at.distance_to(HOME))

			# --- B. with the crew the save had --------------------------
			if fleet.ships.size() != expected_crew:
				return _fail("resumed with %d ships, the save had %d" \
					% [fleet.ships.size(), expected_crew])
			print("resumed with the saved crew of %d" % fleet.ships.size())
			if game_state.resumed_from_save:
				return _fail("the resume flag was left raised, so the next scene would re-use it")

			# --- C. no mothership: fall back to where the save was made --
			_fresh_state()
			game_state.fleet_vessel_types = PackedStringArray([GameState.VESSEL_INTERCEPTOR])
			game_state.fleet_position = AWAY
			game_state.resumed_from_save = true
			_load_scene()
			elapsed = 0.0
			stage = 2
			return false
		2:
			if elapsed < 0.6:
				return false
			var fleet2: Node2D = scene.get_node("Fleet")
			var at2: Vector2 = fleet2.get_centroid()
			if at2.distance_to(AWAY) > 400.0:
				return _fail("with no mothership, resumed at %s rather than the saved %s" % [at2, AWAY])
			print("with no mothership, resumed where the save was written")

			# --- D. a new game is untouched -----------------------------
			_fresh_state()
			game_state.resumed_from_save = false
			_load_scene()
			elapsed = 0.0
			stage = 3
			return false
		3:
			if elapsed < 0.6:
				return false
			var fleet3: Node2D = scene.get_node("Fleet")
			if fleet3.get_centroid().distance_to(Vector2.ZERO) > 400.0:
				return _fail("a new game no longer starts at the origin (%s)" % fleet3.get_centroid())
			if fleet3.ships.size() != GameState.STARTING_SHIP_COUNT:
				return _fail("a new game starts with %d ships, expected %d" \
					% [fleet3.ships.size(), GameState.STARTING_SHIP_COUNT])
			print("a new game still starts with %d ships at the origin" % fleet3.ships.size())

			SaveGame.clear()
			print("TEST_RESUME_SPAWN: PASS")
			quit(0)
			return true
	return false


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