// @flow

import express from 'express'

import { createConfig, validateConfig } from './config'
import { createContext } from './context'
import log from './log'
import { createRouter } from './router'
import type { Config, Handlers } from './types'

export const createServer = (config: Config, handlers: Handlers) => {
  const server = express()
  server.set('x-powered-by', 'mainframe-bot-sdk')

  const context = createContext(config, handlers)
  const router = createRouter(context, handlers)
  server.use(router)

  return server
}

export const startServer = (cfg: Object, handlers?: Handlers) => {
  let config

  if (handlers) {
    config = createConfig(cfg)
  } else {
    config = createConfig()
    handlers = cfg
  }

  validateConfig(config)

  const server = createServer(config, handlers)
  server.listen(config.port, () => {
    log(`listening on port ${config.port}`)
  })
}