## VERTICAL SLICE - NOT FOR PRODUCTION
## 系统级设置独立存储（一安装一份、不进存档与生涯数据）：音量（master bus）/全屏/减动效三件最小面，入口与持久化在此。
## 探针/冒烟必须经 path 注入隔离——禁碰真实 user://settings.cfg。
class_name SettingsStore
extends RefCounted

const DEFAULT_PATH := "user://settings.cfg"

var path: String = DEFAULT_PATH
var volume_linear := 1.0     # master bus 线性 0-1（0=静音）
var fullscreen := false
var reduced_motion := false


func _init(path_override: String = "") -> void:
	if path_override != "":
		path = path_override


func load_settings() -> void:
	var cf := ConfigFile.new()
	if cf.load(path) != OK:
		return   # 缺文件 = 出厂默认（合法态——非损坏不兜底）
	volume_linear = clampf(float(cf.get_value("audio", "volume_linear", 1.0)), 0.0, 1.0)
	fullscreen = bool(cf.get_value("display", "fullscreen", false))
	reduced_motion = bool(cf.get_value("motion", "reduced", false))


func save_settings() -> bool:
	var cf := ConfigFile.new()
	cf.set_value("audio", "volume_linear", volume_linear)
	cf.set_value("display", "fullscreen", fullscreen)
	cf.set_value("motion", "reduced", reduced_motion)
	return cf.save(path) == OK


# 应用到引擎态（启动恢复与实时调节同一口——headless 下窗口面跳过）
func apply() -> void:
	var master := AudioServer.get_bus_index("Master")
	AudioServer.set_bus_mute(master, volume_linear <= 0.001)
	AudioServer.set_bus_volume_db(master, linear_to_db(maxf(volume_linear, 0.001)))
	UiKit.motion_scale = 0.5 if reduced_motion else 1.0
	if DisplayServer.get_name() != "headless":
		DisplayServer.window_set_mode(
			DisplayServer.WINDOW_MODE_FULLSCREEN if fullscreen else DisplayServer.WINDOW_MODE_WINDOWED)