const evals = ['false', 'true', 'null', 'undefined']
const numberRegex = /^\d+$/

export function read(columns, defaults = {}) {
  columns = [...new Set(columns.concat(Object.keys(defaults)))].sort()

  const missing = []

  const result = columns.reduce((result, variable) => {
    /* eslint-disable-next-line n/no-process-env */
    let value = process.env[variable] || defaults[variable]

    if (value === undefined) {
      missing.push(variable)
    } else {
      if (typeof value === 'string') {
        if (numberRegex.test(value)) {
          value = Number.parseInt(value)
        } else if (evals.includes(value)) {
          // eslint-disable-next-line no-eval
          value = eval(value)
        }
      }

      result[variable] = value
    }

    return result
  }, {})

  if (missing.length) {
    throw new Error(`Missing required env variables: ${missing.join(', ')}`)
  }

  return result
}

export default read(['PGDATABASE', 'PGHOST', 'PGPASSWORD', 'PGPORT', 'PGUSER'], {
  PGPASSWORD: null,
  PGPORT: null,
  PGUSER: null,
})