const BASE = import.meta.env.VITE_BACKEND_URL ?? "http://localhost:8787";

export async function apiFetch<T>(path: string, init?: RequestInit): Promise<T> {
  // Only declare a JSON content-type when we actually send a body. Body-less
  // POSTs (resume, close) would otherwise make Fastify reject the empty body
  // with FST_ERR_CTP_EMPTY_JSON_BODY (400).
  const headers: Record<string, string> = {
    ...(init?.headers as Record<string, string> | undefined),
  };
  if (init?.body != null && !("content-type" in headers) && !("Content-Type" in headers)) {
    headers["content-type"] = "application/json";
  }
  const res = await fetch(`${BASE}${path}`, { ...init, headers });
  if (!res.ok) throw new Error(`${res.status} ${await res.text().catch(() => "")}`);
  return res.status === 204 ? (undefined as T) : ((await res.json()) as T);
}

export { BASE };