// @flow

import bodyParser from 'koa-bodyparser'
import Router from 'koa-router'

import log from './log'

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

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

  const router = new Router()
  router.use(bodyParser({ enableTypes: ['json'] }))

  router.post('/enable', ctx => {
    handlers.enable && handlers.enable(ctx.request.body || {}, context)
    ctx.body = { success: true }
  })

  router.post('/disable', ctx => {
    handlers.disable && handlers.disable(ctx.request.body || {}, context)
    ctx.body = { success: true }
  })

  router.post('/conversation_added', ctx => {
    handlers.conversation_added &&
      handlers.conversation_added(ctx.request.body || {}, context)
    ctx.body = { success: true }
  })

  router.post('/conversation_removed', ctx => {
    handlers.conversation_removed &&
      handlers.conversation_removed(ctx.request.body || {}, context)
    ctx.body = { success: true }
  })

  router.post('/edit_subscription', ctx => {
    handlers.edit_subscription &&
      handlers.edit_subscription(ctx.request.body || {}, context)
    ctx.body = { success: true }
  })

  router.post('/delete_subscription', ctx => {
    handlers.delete_subscription &&
      handlers.delete_subscription(ctx.request.body || {}, context)
    ctx.body = { success: true }
  })

  router.post('/mention', ctx => {
    handlers.mention && handlers.mention(ctx.request.body || {}, context)
    ctx.body = { success: true }
  })

  router.post('/post', async ctx => {
    if (!handlers.post) {
      ctx.body = { success: false, message: 'post endpoint not implemented' }
      return
    }

    const params = ctx.request.body || {}

    let missingParam
    if (!params.data) {
      missingParam = 'data'
    } else if (!params.context) {
      missingParam = 'context'
    }

    if (missingParam) {
      ctx.status = 400
      ctx.body = `Missing ${missingParam}`
      return
    }

    try {
      const res = handlers.post(params, context)
      const payload = res && res.then ? await res : res
      ctx.body = payload || { success: true }
    } catch (err) {
      log('error handling post request', params, err)
      ctx.status = 500
    }
  })

  router.post('/preview', async ctx => {
    if (!handlers.preview) {
      ctx.body = { success: false }
      return
    }

    const params = ctx.request.body || {}

    try {
      const res = handlers.preview(params, context)
      const payload = res && res.then ? await res : res
      ctx.body = payload || { success: true }
    } catch (err) {
      log('error handling preview request', params, err)
      ctx.status = 500
    }
  })

  return router
}