const { Resolver } = require('dns').promises;
import ipaddr from 'ipaddr.js';
import isbot from 'isbot';
import { secret } from 'lib/crypto';
import { useCors, useSession } from 'lib/middleware';
import { getIpAddress } from 'lib/request';
import { createToken, forbidden, send, unauthorized } from 'next-basics';

export default async (req, res) => {
  await useCors(req, res);

  if (isbot(req.headers['user-agent']) && !process.env.DISABLE_BOT_CHECK) {
    return unauthorized(res);
  }

  const ignoreIps = process.env.IGNORE_IP;
  const ignoreHostnames = process.env.IGNORE_HOSTNAME;

  if (ignoreIps || ignoreHostnames) {
    const ips = [];

    if (ignoreIps) {
      ips.push(...ignoreIps.split(',').map(n => n.trim()));
    }

    if (ignoreHostnames) {
      const resolver = new Resolver();
      const promises = ignoreHostnames
        .split(',')
        .map(n => resolver.resolve4(n.trim()).catch(() => {}));

      await Promise.all(promises).then(resolvedIps => {
        ips.push(...resolvedIps.filter(n => n).flatMap(n => n));
      });
    }

    const clientIp = getIpAddress(req);

    const blocked = ips.find(ip => {
      if (ip === clientIp) return true;

      // CIDR notation
      if (ip.indexOf('/') > 0) {
        const addr = ipaddr.parse(clientIp);
        const range = ipaddr.parseCIDR(ip);

        if (addr.kind() === range[0].kind() && addr.match(range)) return true;
      }

      return false;
    });

    if (blocked) {
      return forbidden(res);
    }
  }

  await useSession(req, res);

  const {
    session: { website_id, session },
  } = req;

  // const { type, payload } = getJsonBody(req);

  // let { url, referrer, event_name, event_data } = payload;

  // if (process.env.REMOVE_TRAILING_SLASH) {
  //   url = url.replace(/\/$/, '');
  // }

  // const event_uuid = uuid();

  // if (type === 'pageview' && 1 === 0) {
  //   await savePageView(website_id, { session, url, referrer });
  // } else if (type === 'event' && 1 === 0) {
  //   await saveEvent(website_id, {
  //     session,
  //     event_uuid,
  //     url,
  //     event_name,
  //     event_data,
  //   });
  // } else {
  //   return badRequest(res);
  // }

  const token = createToken(
    { website_id, session_id: session.session_id, session_uuid: session.session_uuid },
    secret(),
  );

  return send(res, token);
};