digitransit-ui/server/reittiopasParameterMiddleware.js

import isFinite from 'lodash/isFinite';
import oldParamParser from '../app/util/oldParamParser';
import { getConfiguration } from '../app/config';

function formatQuery(query) {
  const params = Object.keys(query)
    .map(k => `${k}=${query[k]}`)
    .join('&');

  return `?${params}`;
}

function formatUrl(req) {
  const query = formatQuery(req.query);
  return `${req.path}?${query}`;
}

function removeUrlParam(req, param) {
  if (req.query[param]) {
    delete req.query[param];
  }

  return formatUrl(req);
}

export function validateParams(req, config) {
  let url;

  if (config.queryMaxAgeDays && req.query.time) {
    const now = Date.now() / 1000; // Convert to seconds
    if (now - req.query.time > config.queryMaxAgeDays * 24 * 3600) {
      url = removeUrlParam(req, 'time');
    }
  }

  const numericParams = ['time'];
  Object.keys(req.query).forEach(key => {
    if (numericParams.indexOf(key) > -1 && !isFinite(Number(req.query[key]))) {
      url = removeUrlParam(req, key);
    }
  });

  return url;
}

const fixLocaleParam = (req, lang) => {
  // override locale query param with the selected language
  req.query.locale = lang === 'slangi' ? 'fi' : lang;
  return formatQuery(req.query);
};

export const dropPathLanguageAndFixLocaleParam = (req, lang) => {
  const newPath = req.path.replace(`/${lang}`, '/').replace('//', '/');
  return newPath + fixLocaleParam(req, lang);
};

const dropPathLanguageAndRedirect = (req, res, lang) => {
  const trimmedUrl = dropPathLanguageAndFixLocaleParam(req, lang);
  res.redirect(trimmedUrl);
};

const fixLocaleParamAndRedirect = (req, res, lang) => {
  const fixedUrl = req.path + fixLocaleParam(req, lang);
  res.redirect(fixedUrl);
};

export default function reittiopasParameterMiddleware(req, res, next) {
  const config = getConfiguration(req);
  const newUrl = validateParams(req, config);
  if (newUrl) {
    res.redirect(newUrl);
  } else if (config.redirectReittiopasParams) {
    const parts = req.path.split('/');
    const lang = parts[1];
    if (config.availableLanguages.includes(lang)) {
      res.cookie('lang', lang, {
        // Good up to one year
        maxAge: 365 * 24 * 60 * 60,
        path: '/',
      });
    }
    if (
      req.query.from ||
      req.query.to ||
      req.query.from_in ||
      req.query.to_in
    ) {
      oldParamParser(req.query, config).then(url => res.redirect(url));
    } else if (['fi', 'en', 'sv', 'ru', 'slangi'].includes(lang)) {
      dropPathLanguageAndRedirect(req, res, lang);
    } else {
      const { locale } = req.query;
      const cookieLang = req.cookies.lang;

      if (cookieLang && locale && cookieLang !== locale) {
        fixLocaleParamAndRedirect(req, res, cookieLang);
      } else {
        next();
      }
    }
  } else {
    next();
  }
}