// @flow
import Sequelize from 'sequelize';
import crypto from 'crypto';
import Router from 'koa-router';
import { capitalize } from 'lodash';
import { OAuth2Client } from 'google-auth-library';
import { User, Team, Event } from '../models';
import auth from '../middlewares/authentication';

const Op = Sequelize.Op;

const router = new Router();
const client = new OAuth2Client(
  process.env.GOOGLE_CLIENT_ID,
  process.env.GOOGLE_CLIENT_SECRET,
  `${process.env.URL}/auth/google.callback`
);
const allowedDomainsEnv = process.env.GOOGLE_ALLOWED_DOMAINS;

// start the oauth process and redirect user to Google
router.get('google', async ctx => {
  // Generate the url that will be used for the consent dialog.
  const authorizeUrl = client.generateAuthUrl({
    access_type: 'offline',
    scope: [
      'https://www.googleapis.com/auth/userinfo.profile',
      'https://www.googleapis.com/auth/userinfo.email',
    ],
    prompt: 'consent',
  });
  ctx.redirect(authorizeUrl);
});

// signin callback from Google
router.get('google.callback', auth({ required: false }), async ctx => {
  const { code } = ctx.request.query;
  ctx.assertPresent(code, 'code is required');
  const response = await client.getToken(code);
  client.setCredentials(response.tokens);

  const profile = await client.request({
    url: 'https://www.googleapis.com/oauth2/v1/userinfo',
  });

  if (!profile.data.hd) {
    ctx.redirect('/?notice=google-hd');
    return;
  }

  // allow all domains by default if the env is not set
  const allowedDomains = allowedDomainsEnv && allowedDomainsEnv.split(',');
  if (allowedDomains && !allowedDomains.includes(profile.data.hd)) {
    ctx.redirect('/?notice=hd-not-allowed');
    return;
  }

  const googleId = profile.data.hd;
  const hostname = profile.data.hd.split('.')[0];
  const teamName = capitalize(hostname);

  // attempt to get logo from Clearbit API. If one doesn't exist then
  // fall back to using tiley to generate a placeholder logo
  const hash = crypto.createHash('sha256');
  hash.update(googleId);
  const hashedGoogleId = hash.digest('hex');
  const cbUrl = `https://logo.clearbit.com/${profile.data.hd}`;
  const tileyUrl = `https://tiley.herokuapp.com/avatar/${hashedGoogleId}/${
    teamName[0]
  }.png`;
  const cbResponse = await fetch(cbUrl);
  const avatarUrl = cbResponse.status === 200 ? cbUrl : tileyUrl;

  const [team, isFirstUser] = await Team.findOrCreate({
    where: {
      googleId,
    },
    defaults: {
      name: teamName,
      avatarUrl,
    },
  });

  try {
    const [user, isFirstSignin] = await User.findOrCreate({
      where: {
        [Op.or]: [
          {
            service: 'google',
            serviceId: profile.data.id,
          },
          {
            service: { [Op.eq]: null },
            email: profile.data.email,
          },
        ],
        teamId: team.id,
      },
      defaults: {
        service: 'google',
        serviceId: profile.data.id,
        name: profile.data.name,
        email: profile.data.email,
        isAdmin: isFirstUser,
        avatarUrl: profile.data.picture,
      },
    });

    // update the user with fresh details if they just accepted an invite
    if (!user.serviceId || !user.service) {
      await user.update({
        service: 'google',
        serviceId: profile.data.id,
        avatarUrl: profile.data.picture,
      });
    }

    // update email address if it's changed in Google
    if (!isFirstSignin && profile.data.email !== user.email) {
      await user.update({ email: profile.data.email });
    }

    if (isFirstUser) {
      await team.provisionFirstCollection(user.id);
      await team.provisionSubdomain(hostname);
    }

    if (isFirstSignin) {
      await Event.create({
        name: 'users.create',
        actorId: user.id,
        userId: user.id,
        teamId: team.id,
        data: {
          name: user.name,
          service: 'google',
        },
        ip: ctx.request.ip,
      });
    }

    // set cookies on response and redirect to team subdomain
    ctx.signIn(user, team, 'google', isFirstSignin);
  } catch (err) {
    if (err instanceof Sequelize.UniqueConstraintError) {
      const exists = await User.findOne({
        where: {
          service: 'email',
          email: profile.data.email,
          teamId: team.id,
        },
      });

      if (exists) {
        ctx.redirect(`${team.url}?notice=email-auth-required`);
      } else {
        ctx.redirect(`${team.url}?notice=auth-error`);
      }

      return;
    }

    throw err;
  }
});

export default router;