let username
let password
let cluster
let hosts
let databaseName
let replicaSet

if (process.env.NODE_ENV === 'production') {
  username = process.env.ATLAS_HUB_USERNAME
  password = process.env.ATLAS_HUB_PASSWORD
  cluster = process.env.ATLAS_CLUSTER
  hosts = process.env.ATLAS_HOSTS
  databaseName = process.env.ATLAS_DATABASE
  replicaSet = process.env.ATLAS_REPLICA_SET
} else {
  username = process.env.MONGO_HUB_USERNAME
  password = process.env.MONGO_HUB_PASSWORD
  cluster = process.env.MONGO_CLUSTER
  hosts = process.env.MONGO_HOSTS
  databaseName = process.env.MONGO_DATABASE
  replicaSet = process.env.MONGO_REPLICA_SET
}
const config = { username, password, cluster, hosts, databaseName, replicaSet }

const config = {
  username:     process.env.NODE_ENV === 'production' ? process.env.ATLAS_HUB_USERNAME : process.env.MONGO_HUB_USERNAME,
  password:     process.env.NODE_ENV === 'production' ? process.env.ATLAS_HUB_PASSWORD : process.env.MONGO_HUB_PASSWORD,
  cluster:      process.env.NODE_ENV === 'production' ? process.env.ATLAS_CLUSTER : process.env.MONGO_CLUSTER,
  hosts:        process.env.NODE_ENV === 'production' ? process.env.ATLAS_HOSTS : process.env.MONGO_HOSTS,
  databaseName: process.env.NODE_ENV === 'production' ? process.env.ATLAS_DATABASE : process.env.MONGO_DATABASE,
  replicaSet:   process.env.NODE_ENV === 'production' ? process.env.ATLAS_REPLICA_SET : process.env.MONGO_REPLICA_SET
}

const config = ({
  username: [process.env.MONGO_HUB_USERNAME, process.env.ATLAS_HUB_USERNAME],
  password: [process.env.MONGO_HUB_PASSWORD, process.env.ATLAS_HUB_PASSWORD],
  cluster: [process.env.MONGO_CLUSTER, process.env.ATLAS_CLUSTER],
  hosts: [process.env.MONGO_HOSTS, process.env.ATLAS_HOSTS],
  databaseName: [process.env.MONGO_DATABASE, process.env.ATLAS_DATABASE],
  replicaSet: [process.env.MONGO_REPLICA_SET, process.env.ATLAS_REPLICA_SET]
}).*[new Number(process.env.NODE_ENV === 'production')]

function fromEach (obj, key) {
  const final = {}
  Object.keys(obj).forEach((k) => {
    final[k] = obj[k][key]
  })
  return final
}
const config = fromEach({
  username: [process.env.MONGO_HUB_USERNAME, process.env.ATLAS_HUB_USERNAME],
  password: [process.env.MONGO_HUB_PASSWORD, process.env.ATLAS_HUB_PASSWORD],
  cluster: [process.env.MONGO_CLUSTER, process.env.ATLAS_CLUSTER],
  hosts: [process.env.MONGO_HOSTS, process.env.ATLAS_HOSTS],
  databaseName: [process.env.MONGO_DATABASE, process.env.ATLAS_DATABASE],
  replicaSet: [process.env.MONGO_REPLICA_SET, process.env.ATLAS_REPLICA_SET]
}, new Number(process.env.NODE_ENV === 'production'))