"use client";

import { usePathname } from "next/navigation";
import { useEffect, useState, type ReactNode } from "react";
import { authFetch, getApiBase, getToken } from "../lib/auth";
import { canAccess, featureForPath, type FeatureAccess } from "../lib/features";
import { useEffectiveRole } from "../lib/viewMode";
import { isAdminPage } from "../lib/user-view-policy";

export function useFeatureUser() {
  const pathname = usePathname();
  const [state, setState] = useState<{
    path: string;
    user: { role?: string; features?: FeatureAccess; invite_management_enabled?: boolean } | null;
  }>({ path: "", user: null });
  const role = useEffectiveRole(state.user?.role);
  useEffect(() => {
    let active = true;
    const load = async () => {
      if (!getToken()) {
        if (active) setState({ path: pathname, user: null });
        return;
      }
      try {
        const response = await authFetch(`${getApiBase()}/auth/me`);
        const user = response.ok ? await response.json() : null;
        if (active) setState({ path: pathname, user });
      } catch {
        if (active) setState({ path: pathname, user: null });
      }
    };
    void load();
    window.addEventListener("focus", load);
    return () => {
      active = false;
      window.removeEventListener("focus", load);
    };
  }, [pathname]);
  return { user: state.user ? { ...state.user, role: role ?? undefined } : null, ready: state.path === pathname };
}

export default function FeatureGate({ children }: { children: ReactNode }) {
  const pathname = usePathname();
  const { user, ready } = useFeatureUser();
  const feature = featureForPath(pathname);
  if (isAdminPage(pathname, false)) {
    if (!ready) return <main className="card">Checking administrator access...</main>;
    if (user?.role !== "admin") {
      return (
        <main className="card">
          <h1>Administrator access required</h1>
          <p>Sign in with an administrator account to use configuration and administration tools.</p>
          <a href="/login">Sign in</a>
        </main>
      );
    }
    return children;
  }
  if (!feature) return children;
  if (!ready) return <main className="card">Loading account access...</main>;
  if (!getToken()) return children;
  if (!canAccess(user, feature))
    return (
      <main className="card">
        <h1>Feature unavailable</h1>
        <p>Your account does not have access to this feature. Ask an administrator if you need it enabled.</p>
        <a href="/profile">Go to my profile</a>
      </main>
    );
  return children;
}