import axios from 'axios';
import { dev } from '$app/environment';
import { goto } from '$app/navigation';
import { get } from 'svelte/store';
import { persistentSettings, clearLoginState } from '$lib/persistent_store';

if (dev) {
  axios.defaults.baseURL = "http://localhost:8000/api/v1"
} else {
  axios.defaults.baseURL = "/api/v1"
}

// Get access token from local storage
axios.defaults.headers.common['Authorization'] = "Bearer " + get(persistentSettings).accessToken;

function createTokenRefreshInterceptor() {
  const interceptor = axios.interceptors.response.use(
    (response) => response,
    (error) => {
      // Reject promise if usual error
      if (error.response.status !== 401) {
        return Promise.reject(error);
      }

      /*
      * When response code is 401, try to refresh the token.
      * Eject the interceptor so it doesn't loop in case
      * token refresh causes the 401 response.
      *
      * Must be re-attached later on or the token refresh will only happen once
      */
      axios.interceptors.response.eject(interceptor);

      return axios
        .post("/auth/refresh", {
          refresh_token: get(persistentSettings).refreshToken,
        })
        .then((response) => {
          // Save new tokens
          persistentSettings.update(settings => {
            settings.accessToken = response.data.access_token
            settings.refreshToken = response.data.refresh_token;
            return settings;
          })

          // Update access token
          const authHeader = "Bearer " + response.data.access_token;
          axios.defaults.headers.common['Authorization'] = authHeader;
          error.response.config.headers["Authorization"] = authHeader;

          // Retry initial request with new token
          return axios(error.response.config);
        })
        .catch((retryError) => {
          // Retry failed, clean up and reject the promise
          clearLoginState();
          axios.defaults.headers.common['Authorization'] = "";
          goto('/login?reauth')
          return Promise.reject(retryError);
        })
        .finally(createTokenRefreshInterceptor); // Re-attach interceptor for future requests
      }
  );
}

createTokenRefreshInterceptor();

export const login = async function(email: string, password: string) {
  await axios
  .post('/auth/login', {
    email,
    password,
  })
  .then((response) => {
    persistentSettings.update(settings => {
      settings.loggedIn = true
      settings.accessToken = response.data.access_token
      settings.refreshToken = response.data.refresh_token
      return settings;
    })
    axios.defaults.headers.common['Authorization'] = 'Bearer ' + response.data.access_token
    axios.get('/me').then((response) => {
      persistentSettings.update(settings => {
        settings.email = response.data.email
        settings.friendlyName = response.data.friendly_name
        settings.role = response.data.role
        return settings;
      })
    })
    goto('/')
    return Promise.resolve();
  })
  .catch((error) => {
    return Promise.reject(error);
  })
}

export const logout = function() {
  axios
  .post('/auth/logout')
  .then(() => {
    clearLoginState();
    axios.defaults.headers.common['Authorization'] = "";
    goto('/login?logout')
  });
}

export default axios;