import axios, { AxiosRequestConfig } from "axios";
import { normalizeApiError } from "./errors";

const defaultTimeout = 12000;
export const searchTimeout = 8000;
export const uploadTimeout = 30000;

export const api = axios.create({
  baseURL: "/api",
  withCredentials: true,
  headers: {
    "Content-Type": "application/json",
  },
  timeout: defaultTimeout,
});

const refreshApi = axios.create({
  baseURL: "/api",
  withCredentials: true,
  headers: {
    "Content-Type": "application/json",
  },
  timeout: defaultTimeout,
});

let accessToken: string | null = null;
let refreshToken: string | null = null;
let refreshPromise: Promise<string | null> | null = null;

export function setAccessToken(token: string | null) {
  accessToken = token;
  if (token) {
    localStorage.setItem("access_token", token);
  } else {
    localStorage.removeItem("access_token");
  }
}

export function getAccessToken(): string | null {
  if (!accessToken) {
    accessToken = localStorage.getItem("access_token");
  }
  return accessToken;
}

export function setRefreshToken(token: string | null) {
  refreshToken = token;
  if (token) {
    sessionStorage.setItem("refresh_token", token);
  } else {
    sessionStorage.removeItem("refresh_token");
  }
}

export function getRefreshToken(): string | null {
  if (!refreshToken) {
    refreshToken = sessionStorage.getItem("refresh_token");
  }
  return refreshToken;
}

export function clearRefreshToken() {
  refreshToken = null;
  sessionStorage.removeItem("refresh_token");
}

async function refreshAccessToken() {
  const token = getRefreshToken();
  if (!token) {
    return null;
  }
  if (!refreshPromise) {
    refreshPromise = refreshApi
      .post<{ access_token: string, refresh_token: string, token_type: string }>(
        "/auth/refresh",
        { refresh_token: token }
      )
      .then((response) => {
        setAccessToken(response.data.access_token);
        setRefreshToken(response.data.refresh_token);
        return response.data.access_token;
      })
      .catch(() => {
        setAccessToken(null);
        clearRefreshToken();
        return null;
      })
      .finally(() => {
        refreshPromise = null;
      });
  }
  return refreshPromise;
}

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

api.interceptors.response.use(
  (response) => response,
  async (error) => {
    const config = error?.config as (AxiosRequestConfig & { _retry?: boolean }) | undefined;

    if (error?.response?.status === 401 && config && !config._retry) {
      config._retry = true;
      const newToken = await refreshAccessToken();
      if (newToken) {
        config.headers = { ...(config.headers || {}), Authorization: `Bearer ${newToken}` };
        return api(config);
      }
      setAccessToken(null);
      clearRefreshToken();
    }

    if (config && !config._retry && (!error.response || (error.response.status >= 500 && error.response.status < 600))) {
      const method = (config.method || "get").toLowerCase();
      if (["get", "head", "options"].includes(method)) {
        config._retry = true;
        return api(config);
      }
    }

    return Promise.reject(normalizeApiError(error));
  }
);