extends SceneTree

var failures: Array[String] = []


func _initialize() -> void:
	call_deferred("_run")


func _run() -> void:
	var clock := SimulationClock.new(1.0)
	_check(clock.advance(0.4) == 0, "Clock should not tick before its interval")
	_check(clock.advance(0.6) == 1, "Clock should emit one tick at its interval")
	_check(clock.advance(2.4) == 2, "Clock should preserve remainder across multiple ticks")
	_check(clock.elapsed_ticks == 3, "Clock should track elapsed simulation ticks")

	var first := _run_scenario(424242)
	var second := _run_scenario(424242)
	var different := _run_scenario(424243)

	_check(first == second, "The same seed and commands should produce the same checksum")
	_check(first != different, "A different seed should change the scenario checksum")

	if failures.is_empty():
		print("[TEST] Deterministic simulation passed | checksum=", first)
		quit(0)
		return

	for failure in failures:
		push_error("[TEST] " + failure)
	quit(1)


func _run_scenario(seed_value: int) -> String:
	var manager: Node = load("res://simulation/SimulationManager.gd").new()
	manager.simulation_seed = seed_value
	manager.debug_logs = false
	root.add_child(manager)
	manager.set_process(false)

	for step in 24:
		manager.simulate_tick()
		for npc in manager.npcs:
			if npc.task_state == SimNPC.TASK_STATE_TRAVELING:
				manager.notify_npc_arrived(npc.id)

	var snapshot: Dictionary = manager.get_state_snapshot()
	snapshot.erase("seed")
	var checksum := JSON.stringify(snapshot).sha256_text()
	manager.free()
	return checksum


func _check(condition: bool, message: String) -> void:
	if not condition:
		failures.append(message)
