// @flow

import bodyParser from 'body-parser'
import { Router } from 'express'

import log from './log'

import type { BotContext, Handlers } from './types'

const jsonParser = bodyParser.json()

export const createRouter = (
  handlers: Handlers,
  context: BotContext,
): Router => {
  log('create router with handlers: %s', Object.keys(handlers).join(', '))

  const router = new Router()

  router.use(jsonParser)

  if (handlers.enable) {
    router.post('/enable', (req, res) => {
      handlers.enable(req.body || {}, context)
      res.sendStatus(200)
    })
  }

  if (handlers.disable) {
    router.post('/disable', (req, res) => {
      handlers.disable(req.body || {}, context)
      res.sendStatus(200)
    })
  }

  if (handlers.conversation_added) {
    router.post('/conversation_added', (req, res) => {
      handlers.conversation_added(req.body || {}, context)
      res.sendStatus(200)
    })
  }

  if (handlers.conversation_removed) {
    router.post('/conversation_removed', (req, res) => {
      handlers.conversation_removed(req.body || {}, context)
      res.sendStatus(200)
    })
  }

  if (handlers.edit_subscription) {
    router.post('/edit_subscription', (req, res) => {
      handlers.edit_subscription(req.body || {}, context)
      res.sendStatus(200)
    })
  }

  if (handlers.delete_subscription) {
    router.post('/delete_subscription', (req, res) => {
      handlers.delete_subscription(req.body || {}, context)
      res.sendStatus(200)
    })
  }

  if (handlers.post) {
    router.post('/post', async (req, res) => {
      const params = req.body || {}
      if (!params.user_id) {
        return res.status(400).send('Missing user_id')
      }
      if (!params.data) {
        return res.status(400).send('Missing data')
      }
      if (!params.context) {
        return res.status(400).send('Missing context')
      }
      try {
        const postResult = handlers.post(params, context)
        const payload = postResult.then ? await postResult : postResult
        if (payload) {
          res.send(payload)
        } else {
          res.send({ success: true })
        }
      } catch (err) {
        log('error handling post request', params, err)
        res.sendStatus(500)
      }
    })
  }

  return router
}