//
// Copyright © 2022 Hardcore Engineering Inc.
//
// Licensed under the Eclipse Public License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License. You may
// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//
// See the License for the specific language governing permissions and
// limitations under the License.
//

interface Config {
  Port: number

  ServiceID: string
  Secret: string
}

const envMap: { [key in keyof Config]: string } = {
  Port: 'PORT',

  ServiceID: 'SERVICE_ID',
  Secret: 'SECRET'
}

const required: Array<keyof Config> = ['ServiceID', 'Secret']

const parseNumber = (str: string | undefined): number | undefined => (str !== undefined ? Number(str) : undefined)

const config: Config = (() => {
  const params: Partial<Config> = {
    Port: parseNumber(process.env[envMap.Port] ?? '4004'),
    ServiceID: process.env[envMap.ServiceID] ?? 'rekoni-service',
    Secret: process.env[envMap.Secret] ?? 'secret'
  }

  const missingEnv = required.filter((key) => params[key] === undefined).map((key) => envMap[key])

  if (missingEnv.length > 0) {
    throw Error(`Missing env variables: ${missingEnv.join(', ')}`)
  }

  return params as Config
})()

export default config