/**
 * 移动端底栏配置的单一事实源：
 * 与后端 service.MobileTabKeys 保持一致；管理面板、MobileTabBar、公共设置 normalize 共用。
 * 配置为有序数组，数组顺序即前台底栏展示顺序；配置为空/非法回落默认全量。
 */

export const MOBILE_TABS = ["home", "library", "compose", "messages", "me"] as const;

export type MobileTabKey = (typeof MOBILE_TABS)[number];

/** 底栏默认全量配置 */
export const DEFAULT_MOBILE_TABS: MobileTabKey[] = [...MOBILE_TABS];

/** 配置子集解析：去空白、去重、只留白名单内元素；结果为空视为非法，回落默认全量 */
export function normalizeMobileTabs(raw: unknown): MobileTabKey[] {
  if (!Array.isArray(raw)) return [...DEFAULT_MOBILE_TABS];
  const seen = new Set<string>();
  const out: MobileTabKey[] = [];
  for (const item of raw) {
    const key = String(item ?? "")
      .trim()
      .toLowerCase();
    if (!key || seen.has(key)) continue;
    if (!(MOBILE_TABS as readonly string[]).includes(key)) continue;
    seen.add(key);
    out.push(key as MobileTabKey);
  }
  return out.length > 0 ? out : [...DEFAULT_MOBILE_TABS];
}