<?php

final class PassphraseSSHKey extends PassphraseAbstractKey {

  private $keyFile;

  public static function loadFromPHID($phid, PhabricatorUser $viewer) {
    $key = new PassphraseSSHKey();
    return $key->loadAndValidateFromPHID(
      $phid,
      $viewer,
      PassphraseCredentialTypeSSHPrivateKey::PROVIDES_TYPE);
  }

  public function getKeyfileEnvelope() {
    $credential = $this->requireCredential();

    $file_type = PassphraseCredentialTypeSSHPrivateKeyFile::CREDENTIAL_TYPE;
    if ($credential->getCredentialType() != $file_type) {
      // If the credential does not store a file, write the key text out to a
      // temporary file so we can pass it to `ssh`.
      if (!$this->keyFile) {
        $secret = $credential->getSecret();
        if (!$secret) {
          throw new Exception(
            pht(
              'Attempting to use a credential ("%s") but the credential '.
              'secret has been destroyed!',
              $credential->getMonogram()));
        }

        $temporary_file = new TempFile('passphrase-ssh-key');
        Filesystem::changePermissions($temporary_file, 0600);
        Filesystem::writeFile($temporary_file, $secret->openEnvelope());

        $this->keyFile = $temporary_file;
      }

      return new PhutilOpaqueEnvelope((string)$this->keyFile);
    }

    return $credential->getSecret();
  }

}