/* ============================================================
   NAV CONFIG — 按设备 MAC 下发的导航入口隐藏配置
   - 连接设备拿到 deviceState.mac 后请求 /audio/getNavConfig
   - localStorage 缓存(30min)：首屏/离线即时生效，后台再刷新
   - fail-open：接口失败或无 mac 时隐藏集为空，默认全部显示，
     绝不因后端异常导致导航不可用
   ============================================================ */
import {
  createContext,
  useContext,
  useEffect,
  useMemo,
  useState,
  type ReactNode,
} from "react";
import { useDevice } from "@/contexts/DeviceContext";
import { getNavConfig } from "@/lib/luxsinApi";

/** nav key ↔ 路由 path 映射；隐藏入口时据此同步拦截路由。 */
export const NAV_KEY_TO_PATH: Record<string, string> = {
  community: "/community",
  hpEq: "/eq",
  home: "/",
  effects: "/effects",
  myAi: "/ai",
};

const CACHE_PREFIX = "luxsin:navConfig:";
const CACHE_TTL_MS = 30 * 60 * 1000;

type NavConfigContextValue = {
  /** 需要隐藏的 nav key 集合 */
  hiddenKeys: Set<string>;
  /** 某个 nav key 是否被隐藏 */
  isNavHidden: (key: string) => boolean;
  /** 某个路由 path 是否因入口隐藏而被拦截 */
  isPathHidden: (path: string) => boolean;
};

const NavConfigContext = createContext<NavConfigContextValue | null>(null);

function cacheKey(mac: string): string {
  return CACHE_PREFIX + mac.toUpperCase();
}

function readCache(mac: string): string[] | null {
  try {
    const raw = localStorage.getItem(cacheKey(mac));
    if (!raw) return null;
    const parsed = JSON.parse(raw) as { at?: number; hidden?: string[] };
    if (!parsed || typeof parsed.at !== "number" || !Array.isArray(parsed.hidden)) {
      return null;
    }
    if (Date.now() - parsed.at > CACHE_TTL_MS) {
      localStorage.removeItem(cacheKey(mac));
      return null;
    }
    return parsed.hidden;
  } catch {
    return null;
  }
}

function writeCache(mac: string, hidden: string[]): void {
  try {
    localStorage.setItem(cacheKey(mac), JSON.stringify({ at: Date.now(), hidden }));
  } catch {
    /* ignore — 隐私模式/配额不足时静默降级 */
  }
}

export function NavConfigProvider({ children }: { children: ReactNode }) {
  const { deviceState } = useDevice();
  const mac = (deviceState?.mac ?? "").trim();
  const [hidden, setHidden] = useState<string[]>([]);

  useEffect(() => {
    if (!mac) {
      setHidden([]);
      return;
    }
    // 先用本地缓存立即生效（避免首屏闪烁 / 离线可用），再后台刷新
    const cached = readCache(mac);
    if (cached) setHidden(cached);

    let cancelled = false;
    (async () => {
      try {
        const res = await getNavConfig(mac);
        const list = Array.isArray(res.data?.hidden) ? res.data!.hidden! : [];
        if (!cancelled) {
          setHidden(list);
          writeCache(mac, list);
        }
      } catch {
        // fail-open：保留缓存或空数组，默认全部显示
      }
    })();

    return () => {
      cancelled = true;
    };
  }, [mac]);

  const value = useMemo<NavConfigContextValue>(() => {
    const keySet = new Set(hidden);
    const pathSet = new Set(
      hidden.map((k) => NAV_KEY_TO_PATH[k]).filter((p): p is string => !!p),
    );
    return {
      hiddenKeys: keySet,
      isNavHidden: (key: string) => keySet.has(key),
      isPathHidden: (path: string) => pathSet.has(path),
    };
  }, [hidden]);

  return (
    <NavConfigContext.Provider value={value}>{children}</NavConfigContext.Provider>
  );
}

export function useNavConfig(): NavConfigContextValue {
  const ctx = useContext(NavConfigContext);
  if (!ctx) {
    throw new Error("useNavConfig must be used within NavConfigProvider");
  }
  return ctx;
}