<?php

final class PhabricatorUserUsernameTransaction
  extends PhabricatorUserTransactionType {

  const TRANSACTIONTYPE = 'user.rename';

  public function generateOldValue($object) {
    return $object->getUsername();
  }

  public function generateNewValue($object, $value) {
    return $value;
  }

  public function applyInternalEffects($object, $value) {
    $object->setUsername($value);
  }

  public function applyExternalEffects($object, $value) {
    $actor = $this->getActor();
    $user = $object;

    $old_username = $this->getOldValue();
    $new_username = $this->getNewValue();

    // The SSH key cache currently includes usernames, so dirty it. See T12554
    // for discussion.
    PhabricatorAuthSSHKeyQuery::deleteSSHKeyCache();

    id(new PhabricatorPeopleUsernameMailEngine())
      ->setSender($actor)
      ->setRecipient($object)
      ->setOldUsername($old_username)
      ->setNewUsername($new_username)
      ->sendMail();
  }

  public function getTitle() {
    if (!$this->getViewer()->getIsAdmin()) {
      return pht(
      '%s renamed this user.',
        $this->renderAuthor());
    }
    return pht(
      '%s renamed this user from %s to %s.',
      $this->renderAuthor(),
      $this->renderOldValue(),
      $this->renderNewValue());
  }

  public function getTitleForFeed() {
    if (!$this->getViewer()->getIsAdmin()) {
      return pht(
        '%s renamed %s.',
        $this->renderAuthor(),
        $this->renderObject());
    }
    return pht(
      '%s renamed %s from %s to %s.',
      $this->renderAuthor(),
      $this->renderObject(),
      $this->renderOldValue(),
      $this->renderNewValue());
  }

  public function validateTransactions($object, array $xactions) {
    $actor = $this->getActor();
    $errors = array();

    foreach ($xactions as $xaction) {
      $new = $xaction->getNewValue();
      $old = $xaction->getOldValue();

      if ($old === $new) {
        continue;
      }

      if (!$actor->getIsAdmin()) {
        $errors[] = $this->newInvalidError(
          pht('You must be an administrator to rename users.'));
      }

      if (!strlen($new)) {
        $errors[] = $this->newInvalidError(
          pht('New username is required.'),
          $xaction);
      } else if (!PhabricatorUser::validateUsername($new)) {
        $errors[] = $this->newInvalidError(
          PhabricatorUser::describeValidUsername($new),
          $xaction);
      } else if ($this->generateOldValue($object) === $new) {
        $errors[] = $this->newInvalidError(
          pht('New username cannot be the old username.'),
          $xaction);
      }

      $user = id(new PhabricatorPeopleQuery())
        ->setViewer(PhabricatorUser::getOmnipotentUser())
        ->withUsernames(array($new))
        ->executeOne();
      if ($user) {
        // See T13446. We may be changing the letter case of a username, which
        // is a perfectly fine edit.
        $is_self = ($user->getPHID() === $object->getPHID());
        if (!$is_self) {
          $errors[] = $this->newInvalidError(
            pht(
              'Another user already has the username "%s".',
              $new),
            $xaction);
        }
      }

    }

    return $errors;
  }

  public function getRequiredCapabilities(
    $object,
    PhabricatorApplicationTransaction $xaction) {

    // Unlike normal user edits, renames require admin permissions, which
    // is enforced by validateTransactions().

    return null;
  }

  public function shouldTryMFA(
    $object,
    PhabricatorApplicationTransaction $xaction) {
    return true;
  }

}