// @flow

import fetch from 'node-fetch'

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

export const createContext = (
  config: Config,
  handlers: Handlers,
): BotContext => {
  const callMainframe = (endpoint: string, data: ?Object = {}) => {
    return fetch(config.mainframe_url + endpoint, {
      body: JSON.stringify(data),
      method: 'post',
      headers: {
        Authorization: `Mainframe-Bot ${config.mainframe_secret}`,
        'Content-Type': 'application/json',
      },
    }).then(res => {
      if (res.ok) return res.json()
      else {
        const error: Object = new Error(res.statusText)
        error.status = res.status
        error.enpoint = endpoint
        error.data = data
        throw error
      }
    })
  }

  const sendEvent = (payload: ?Object) => callMainframe('/event', payload)

  return { config, callMainframe, sendEvent }
}