import { useUiStore } from "../stores/ui";

export interface ApiError {
  error: string;
  status: number;
}

// Surface infra / unexpected failures (network, 5xx) globally. 4xx are left to
// the caller — forms and views show their own inline messages for those.
function notifyError(err: ApiError) {
  try {
    useUiStore().showToast(err.error);
  } catch {
    /* pinia not active yet (very early boot) — skip the toast */
  }
}

async function request<T>(method: string, path: string, body?: unknown): Promise<T> {
  // FormData carries its own multipart Content-Type (with boundary), so let the
  // browser set it — only JSON bodies get an explicit header + stringify.
  const isForm = body instanceof FormData;
  let resp: Response;
  try {
    resp = await fetch(path, {
      method,
      credentials: "include", // send/receive the signed session cookie
      headers: body !== undefined && !isForm ? { "Content-Type": "application/json" } : undefined,
      body: body === undefined ? undefined : isForm ? body : JSON.stringify(body),
    });
  } catch {
    const err: ApiError = { error: "Can't reach the server. Check your connection.", status: 0 };
    notifyError(err);
    throw err;
  }

  const text = await resp.text();
  let data: unknown = {};
  if (text) {
    try {
      data = JSON.parse(text);
    } catch {
      data = {}; // non-JSON body (e.g. a proxy error page) — fall through to status handling
    }
  }

  if (!resp.ok) {
    const message =
      typeof data === "object" && data !== null && "error" in data
        ? String((data as { error: unknown }).error)
        : "Something went wrong. Please try again.";
    const err: ApiError = { error: message, status: resp.status };
    if (resp.status >= 500) notifyError(err);
    throw err;
  }

  return data as T;
}

export const api = {
  get: <T>(path: string) => request<T>("GET", path),
  post: <T>(path: string, body?: unknown) => request<T>("POST", path, body),
  patch: <T>(path: string, body?: unknown) => request<T>("PATCH", path, body),
  put: <T>(path: string, body?: unknown) => request<T>("PUT", path, body),
  del: <T>(path: string) => request<T>("DELETE", path),
  postForm: <T>(path: string, form: FormData) => request<T>("POST", path, form),
};