import { existsSync, readFileSync } from 'node:fs';

import {
  backupEnvSchema,
  overlayEnv,
  parseEnv,
  parseSecretsFile,
  type BackupEnv,
} from '@dorfteich/shared';

/**
 * Loads the sidecar configuration the same way the api does (issue #80):
 * the wizard-written secret store fills SMTP variables the container env
 * does not set, and empty strings count as unset — compose passes optional
 * variables as `""`. Without this, a wizard-configured relay would never
 * reach the failure mail.
 */
export function loadBackupEnv(env: Record<string, string | undefined> = process.env): BackupEnv {
  const secretsFile = backupEnvSchema.shape.SECRETS_FILE.parse(env.SECRETS_FILE || undefined);
  const secrets = existsSync(secretsFile)
    ? parseSecretsFile(readFileSync(secretsFile, 'utf8'))
    : {};
  return parseEnv(backupEnvSchema, overlayEnv(env, secrets));
}