import axios, { AxiosError } from "axios";
import { useAuthStore } from "@/store/auth";

// withCredentials so the httpOnly refresh cookie rides along on /api/auth/refresh.
const api = axios.create({
  baseURL: "/",
  withCredentials: true,
  // Arrays as `binds=a&binds=b`, which is what FastAPI reads as a list. Axios'
  // default `binds[]=a` is a different parameter name to it, so the folders and
  // volumes picked in the backup dialog were silently ignored on download.
  paramsSerializer: { indexes: null },
});

api.interceptors.request.use((config) => {
  const token = useAuthStore.getState().accessToken;
  if (token) {
    config.headers.Authorization = `Bearer ${token}`;
  }
  return config;
});

let refreshing: Promise<string | null> | null = null;

api.interceptors.response.use(
  (res) => res,
  async (error: AxiosError) => {
    const original = error.config as any;
    if (error.response?.status === 401 && original && !original._retry) {
      original._retry = true;
      if (!refreshing) {
        refreshing = useAuthStore
          .getState()
          .refresh()
          .finally(() => {
            refreshing = null;
          });
      }
      const newToken = await refreshing;
      if (newToken) {
        original.headers.Authorization = `Bearer ${newToken}`;
        return api(original);
      }
      // Refresh failed: the session is genuinely over (expired, password
      // changed, account disabled). refresh() has already cleared the store.
    }
    return Promise.reject(error);
  }
);

/**
 * The server's JSON error body behind a `responseType: "blob"` request (a
 * backup download), which axios hands back as a Blob. Without this such a
 * failure read "Request failed with status code 409" instead of saying the
 * stack was busy.
 */
export async function withBlobError<T>(request: Promise<T>): Promise<T> {
  try {
    return await request;
  } catch (err) {
    const e = err as AxiosError<any>;
    const data = e?.response?.data;
    if (e?.response && typeof Blob !== "undefined" && data instanceof Blob) {
      try {
        e.response.data = JSON.parse(await data.text());
      } catch {
        /* not JSON — keep the generic message */
      }
    }
    throw err;
  }
}

export function apiErrorMessage(err: unknown): string {
  const e = err as AxiosError<any>;
  const detail = e?.response?.data?.detail;
  if (typeof detail === "string") return detail;
  if (detail?.detail) return `${detail.error}: ${detail.detail}`;
  if (detail?.error) return detail.error;
  return e?.message || "Unexpected error";
}

export default api;