import * as jwt from 'jsonwebtoken'
import { logger } from '../../utils/logger'

import { prismaClient as prisma } from '../../prismaClient'

export async function handleUnsubscribe(req, res) {
  const { token } = req.query

  // if no token was provided
  if (!token) return res.send('Invalid token')

  // verify that the token signature matches our env signature
  try {
    jwt.verify(token, process.env.APP_SECRET || '')
  } catch (err) {
    // if the signature can't be verified
    let errMessage
    if (err.name === 'TokenExpiredError') {
      errMessage =
        'This unsubscribe token has expired. You can unsubscribe from this email type in your user settings.'
    } else {
      errMessage =
        'This unsubscribe token is invalid. You can unsubscribe from this email type in your user settings.'
    }
    return res.send(errMessage)
  }

  // once the token is verified, we can decode it to get the userId
  type Jwttoken = {
    userId: string
  }
  const { userId } = <Jwttoken>jwt.decode(token)

  // if the token doesn't have the necessary info
  if (!userId) {
    return res.send('Invalid token')
  }

  // and send a database request to unsubscribe from a particular email type
  try {
    await prisma.user.update({
      where: { id: userId },
      data: { cantDeliverEmail: true, cantDeliverEmailReason: 'BLOCKED' },
    })
    return res
      .status(200)
      .send('You were unsubscribed, you will no longer receive any email notifications')
  } catch (err) {
    logger.error(err)
    return res.send('Something went wrong, we\'re on it')
  }
}