/** API client stub — swap BASE_URL when shared backend is live. */

export const BASE_URLS = {
  core: process.env.EXPO_PUBLIC_API_URL ?? "https://api.gishen.example/v1",
} as const;

export type ApiError = { message: string; code?: string };

export async function callEndpoint<T>(
  path: string,
  init?: RequestInit & { locale?: string }
): Promise<T> {
  const headers: Record<string, string> = {
    "Content-Type": "application/json",
    Accept: "application/json",
    ...(init?.locale ? { "Accept-Language": init.locale } : {}),
    ...(init?.headers as Record<string, string>),
  };

  // Mock mode until backend exists
  if (!process.env.EXPO_PUBLIC_API_URL) {
    throw new Error(`API not configured for ${path}`);
  }

  const res = await fetch(`${BASE_URLS.core}${path}`, {
    ...init,
    headers,
  });
  if (!res.ok) {
    const body = (await res.json().catch(() => ({}))) as ApiError;
    throw new Error(body.message || res.statusText);
  }
  return res.json() as Promise<T>;
}