export async function proxyToBackend(
  endpoint: string,
  payload: any,
  baseUrl?: string,
  apiKey?: string
) {
  if (!baseUrl) throw new Error("API_BASE_URL is not configured.");
  
  const url = `${baseUrl.replace(/\/$/, "")}${endpoint}`;
  
  const response = await fetch(url, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "Authorization": `Bearer ${apiKey || ""}`,
    },
    body: JSON.stringify(payload),
  });

  if (!response.ok) {
    const text = await response.text();
    throw new Error(`Backend error (${response.status}): ${text}`);
  }

  return response.json();
}