export function getAuthHeaders(): HeadersInit {
  let token: string | null = null;
  let userRaw: string | null = null;

  if (typeof window !== "undefined") {
    token = sessionStorage.getItem("rentx_auth_token");
    userRaw = sessionStorage.getItem("rentx_user");
  }

  // Tenant ID: usa o companyId do usuário logado ou "default" para SUPERADMIN/fallback
  let tenantId = "default";
  if (userRaw) {
    try {
      const user = JSON.parse(userRaw);
      // companyId salvo diretamente no login (UUID da empresa)
      if (user?.companyId && user.companyId !== "default") {
        tenantId = user.companyId;
      }
    } catch {
      // mantém "default"
    }
  }

  const headers: Record<string, string> = {
    "Content-Type": "application/json",
    "x-tenant-id": tenantId,
  };

  if (token) {
    headers["Authorization"] = `Bearer ${token}`;
  }

  return headers;
}