import { createServerClient } from "@supabase/ssr";
import { NextResponse, type NextRequest } from "next/server";

export async function updateSession(request: NextRequest) {
  let supabaseResponse = NextResponse.next({
    request,
  });

  const supabase = createServerClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
    {
      cookies: {
        getAll() {
          return request.cookies.getAll();
        },
        setAll(cookiesToSet: { name: string; value: string; options?: Record<string, unknown> }[]) {
          cookiesToSet.forEach(({ name, value }) =>
            request.cookies.set(name, value)
          );
          supabaseResponse = NextResponse.next({
            request,
          });
          cookiesToSet.forEach(({ name, value, options }) =>
            supabaseResponse.cookies.set(name, value, options)
          );
        },
      },
    }
  );

  // IMPORTANT: Avoid writing any logic between createServerClient and
  // supabase.auth.getUser(). A simple mistake could make it very hard to debug
  // issues with users being randomly logged out.
  const {
    data: { user },
  } = await supabase.auth.getUser();

  const pathname = request.nextUrl.pathname;
  const isLoginPage = pathname === "/login";
  const isAdminRoute = pathname.startsWith("/admin");
  const isPublicRoute = isLoginPage;

  // Redirect unauthenticated users to login
  if (!user && !isPublicRoute) {
    const url = request.nextUrl.clone();
    url.pathname = "/login";
    return NextResponse.redirect(url);
  }

  // For authenticated users, check admin status for admin routes and redirects
  if (user) {
    // Redirect from login page
    if (isLoginPage) {
      // Check if user is admin to redirect to correct page
      const { data: profile } = await supabase
        .from("profiles")
        .select("is_admin")
        .eq("id", user.id)
        .single();

      const url = request.nextUrl.clone();
      url.pathname = profile?.is_admin ? "/admin" : "/";
      return NextResponse.redirect(url);
    }

    // Protect admin routes - only allow admins
    if (isAdminRoute) {
      const { data: profile } = await supabase
        .from("profiles")
        .select("is_admin")
        .eq("id", user.id)
        .single();

      if (!profile?.is_admin) {
        const url = request.nextUrl.clone();
        url.pathname = "/";
        return NextResponse.redirect(url);
      }
    }

    // Redirect admins from home page to admin dashboard
    if (pathname === "/") {
      const { data: profile } = await supabase
        .from("profiles")
        .select("is_admin")
        .eq("id", user.id)
        .single();

      if (profile?.is_admin) {
        const url = request.nextUrl.clone();
        url.pathname = "/admin";
        return NextResponse.redirect(url);
      }
    }
  }

  return supabaseResponse;
}