import jwt_decode from 'jwt-decode';
import auth from '@/api/auth';
import useCookies from '@/composables/useCookies';

export default () => {
  const getRaw = (key = 'access') => {
    const { getItem } = useCookies();
    // Get the token
    const jwt = getItem(key);
    // If it is not returned, it's expired or doesn't exist
    if (!jwt) return null;
    // Isolate the header and payload portions
    const [header, payload, ...rest] = jwt.split('.');
    // Return them, concatenated by a period
    return `${header}.${payload}`;
  }

  const getDecoded = (jwt = null) => {
    // Get the token if required
    if (!jwt) jwt = getRaw();
    // If it is not returned, it's expired or doesn't exist
    if (!jwt) return null;
    // Decode the token
    const payload = jwt_decode(jwt);
    // If it is not returned then it is invalid
    if (!payload) return null;
    // Case to numeric id
    payload.sub = parseInt(payload.sub);
    // Return the decoded payload
    return payload;
  }

  const isAccessValid = async () => {
    console.log('isAccessValid');
    // Check the validity of the access token
    if (isAccessTokenExpired()) {
      console.log('its expired');
      // Check the validity of the refresh token
      if (isRefreshTokenExpired()) return false;
      console.log('refresh token is okay');
      // If the refresh was not permitted
      if (!await attemptRefresh()) return false;
      console.log('managed to refresh it');
    }
    console.log('it is valid');
    // At this point the token is valid
    return true;
  }

  const getDecodedOrRefresh = async (jwt = null) => {
    console.log('getDecodedOrRefresh')
    let decodedJwt = getDecoded(jwt);
    if (decodedJwt) return decodedJwt;
    const tokenValid = await isAccessValid();
    if (!tokenValid) return null;
    decodedJwt = getDecoded();
    return decodedJwt;
  }

  const attemptRefresh = async () => {
    const { status } = await auth.refresh();
    if (status !== 200) return false;
    return true;
  }

  const isAccessTokenExpired = () => {
    // Check the validity of the access token
    return isTokenExpired('access');
  }

  const isRefreshTokenExpired = () => {
    // Check the validity of the refresh token
    return isTokenExpired('refresh');
  }

  const isTokenExpired = (key = null, jwt = null) => {
    if (!key && !jwt) {
      console.log('Invalid usage for checkTokenExpiry');
      return true;
    }
    // Get the access / refresh token cookie if the key is present
    if (key) jwt = getRaw(key);
    console.log('isTokenExpired within useJwt, key jwt', key, jwt)
    // Ensure that the cookie exists
    if (!jwt) return true;
    // Try to decode the payload
    const payload = getDecoded(jwt);
    console.log('isTokenExpired within useJwt, decoded payload', payload)
    // If the cookie has expired then no cookie is returned
    if (!payload) return true;
    // Check the current system time
    const timeNow = new Date().getTime();
    console.log('isTokenExpired within useJwt, timeNow', timeNow)
    console.log('isTokenExpired within useJwt, typeof timeNow', typeof timeNow)
    console.log('isTokenExpired within useJwt, payload.exp*1000', payload.exp*1000)
    console.log('isTokenExpired within useJwt, typeof payload.exp*1000', typeof (payload.exp*1000))
    console.log('isTokenExpired within useJwt, timeNow >= (payload.exp*1000)', timeNow >= parseInt(payload.exp*1000))
    // When the token has expired
    if (timeNow >= (payload.exp*1000)) return true;
    // The token has not expired
    return false;
  }
  // From auth0 jwt handbook
  // const getDecoded = (jwt = null) => {
  //   if (!jwt) jwt = getRaw();
  //   if (!jwt) return null;
  //   const [headerB64, payloadB64] = jwt.split('.');
  //   // These supports parsing the URL safe variant of Base64 as well.
  //   const headerStr = new Buffer(headerB64, 'base64').toString();
  //   const payloadStr = new Buffer(payloadB64, 'base64').toString();
  //   return {
  //     header: JSON.parse(headerStr),
  //     payload: JSON.parse(payloadStr)
  //   };
  // }

  return {
    getRaw,
    getDecoded,
    getDecodedOrRefresh,
    isTokenExpired,
    isAccessValid,
    attemptRefresh
  };
};