Oidc = {};

OAuth.registerService('oidc', 2, null, function (query) {

  var debug = process.env.DEBUG || false;
  var token = getToken(query);
  if (debug) console.log('XXX: register token:', token);

  var accessToken = token.access_token || token.id_token;
  var expiresAt = (+new Date) + (1000 * parseInt(token.expires_in, 10));

  var userinfo = getUserInfo(accessToken);
  if (userinfo.ocs) userinfo = userinfo.ocs.data; // Nextcloud hack
  if (debug) console.log('XXX: userinfo:', userinfo);

  var serviceData = {};
  serviceData.id = userinfo[process.env.OAUTH2_ID_MAP]; // || userinfo["id"];
  serviceData.username = userinfo[process.env.OAUTH2_USERNAME_MAP]; // || userinfo["uid"];
  serviceData.fullname = userinfo[process.env.OAUTH2_FULLNAME_MAP]; // || userinfo["displayName"];
  serviceData.accessToken = accessToken;
  serviceData.expiresAt = expiresAt;
  serviceData.email = userinfo[process.env.OAUTH2_EMAIL_MAP]; // || userinfo["email"];

  if (accessToken) {
    var tokenContent = getTokenContent(accessToken);
    var fields = _.pick(tokenContent, getConfiguration().idTokenWhitelistFields);
    _.extend(serviceData, fields);
  }

  if (token.refresh_token)
    serviceData.refreshToken = token.refresh_token;
  if (debug) console.log('XXX: serviceData:', serviceData);

  var profile = {};
  profile.name = userinfo[process.env.OAUTH2_FULLNAME_MAP]; // || userinfo["displayName"];
  profile.email = userinfo[process.env.OAUTH2_EMAIL_MAP]; // || userinfo["email"];
  if (debug) console.log('XXX: profile:', profile);

  return {
    serviceData: serviceData,
    options: { profile: profile }
  };
});

var userAgent = "Meteor";
if (Meteor.release) {
  userAgent += "/" + Meteor.release;
}

var getToken = function (query) {
  var debug = process.env.DEBUG || false;
  var config = getConfiguration();
  if(config.tokenEndpoint.includes('https://')){
    var serverTokenEndpoint = config.tokenEndpoint;
  }else{
    var serverTokenEndpoint = config.serverUrl + config.tokenEndpoint;
  }
  var requestPermissions = config.requestPermissions;
  var response;

  try {
    response = HTTP.post(
      serverTokenEndpoint,
      {
        headers: {
          Accept: 'application/json',
          "User-Agent": userAgent
        },
        params: {
          code: query.code,
          client_id: config.clientId,
          client_secret: OAuth.openSecret(config.secret),
          redirect_uri: OAuth._redirectUri('oidc', config),
          grant_type: 'authorization_code',
          scope: requestPermissions,
          state: query.state
        }
      }
    );
  } catch (err) {
    throw _.extend(new Error("Failed to get token from OIDC " + serverTokenEndpoint + ": " + err.message),
      { response: err.response });
  }
  if (response.data.error) {
    // if the http response was a json object with an error attribute
    throw new Error("Failed to complete handshake with OIDC " + serverTokenEndpoint + ": " + response.data.error);
  } else {
    if (debug) console.log('XXX: getToken response: ', response.data);
    return response.data;
  }
};

var getUserInfo = function (accessToken) {
  var debug = process.env.DEBUG || false;
  var config = getConfiguration();
  // Some userinfo endpoints use a different base URL than the authorization or token endpoints.
  // This logic allows the end user to override the setting by providing the full URL to userinfo in their config.
  if (config.userinfoEndpoint.includes("https://")) {
    var serverUserinfoEndpoint = config.userinfoEndpoint;
  } else {
    var serverUserinfoEndpoint = config.serverUrl + config.userinfoEndpoint;
  }
  var response;
  try {
    response = HTTP.get(
      serverUserinfoEndpoint,
      {
        headers: {
          "User-Agent": userAgent,
          "Authorization": "Bearer " + accessToken
        }
      }
    );
  } catch (err) {
    throw _.extend(new Error("Failed to fetch userinfo from OIDC " + serverUserinfoEndpoint + ": " + err.message),
                   {response: err.response});
  }
  if (debug) console.log('XXX: getUserInfo response: ', response.data);
  return response.data;
};

var getConfiguration = function () {
  var config = ServiceConfiguration.configurations.findOne({ service: 'oidc' });
  if (!config) {
    throw new ServiceConfiguration.ConfigError('Service oidc not configured.');
  }
  return config;
};

var getTokenContent = function (token) {
  var content = null;
  if (token) {
    try {
      var parts = token.split('.');
      var header = JSON.parse(Buffer.from(parts[0], 'base64').toString());
      content = JSON.parse(Buffer.from(parts[1], 'base64').toString());
      var signature = Buffer.from(parts[2], 'base64');
      var signed = parts[0] + '.' + parts[1];
    } catch (err) {
      this.content = {
        exp: 0
      };
    }
  }
  return content;
}

Oidc.retrieveCredential = function (credentialToken, credentialSecret) {
  return OAuth.retrieveCredential(credentialToken, credentialSecret);
};
