const MAX_ERROR_CHARS = 300;

export function normalizeBaseUrl(baseUrl: string | undefined, fallback: string): string {
  const raw = baseUrl?.trim() || fallback;
  return raw.replace(/\/+$/, "");
}

export async function fetchWithTimeout(
  url: string,
  init: RequestInit,
  timeoutMs: number,
  fetchFn: typeof fetch,
): Promise<Response> {
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), Math.max(1, timeoutMs));
  try {
    return await fetchFn(url, { ...init, signal: controller.signal });
  } finally {
    clearTimeout(timer);
  }
}

export async function readErrorResponse(res: Response): Promise<string | undefined> {
  try {
    const text = await res.text();
    const collapsed = text.replace(/\s+/g, " ").trim();
    if (!collapsed) return undefined;
    if (collapsed.length <= MAX_ERROR_CHARS) return collapsed;
    return `${collapsed.slice(0, MAX_ERROR_CHARS)}…`;
  } catch {
    return undefined;
  }
}