owncloud / core

	 * @param string $url

	 * @return bool

	 */

	public function serverExists($url) {

		$hash = $this->hash($url);

		$query = $this->connection->getQueryBuilder();

		$query->select('url')->from($this->dbTable)

			->where($query->expr()->eq('url_hash', $query->createParameter('url_hash')))

			->setParameter('url_hash', $hash);

		$result = $query->execute()->fetchAll();

		return !empty($result);

	}

	/**

	 * write token to database. Token is used to exchange the secret

	 * @param string $url

	 * @param string $token

	 */

	public function addToken($url, $token) {

		$hash = $this->hash($url);

		$query = $this->connection->getQueryBuilder();

		$query->update($this->dbTable)

			->set('token', $query->createParameter('token'))

			->where($query->expr()->eq('url_hash', $query->createParameter('url_hash')))

			->setParameter('url_hash', $hash)

			->setParameter('token', $token);

		$query->execute();

	}

	/**

	 * get token stored in database

	 * @param string $url

	 * @param string $sharedSecret

	 */

	public function addSharedSecret($url, $sharedSecret) {

		$hash = $this->hash($url);

		$query = $this->connection->getQueryBuilder();

		$query->update($this->dbTable)

			->set('shared_secret', $query->createParameter('sharedSecret'))

			->where($query->expr()->eq('url_hash', $query->createParameter('url_hash')))

			->setParameter('url_hash', $hash)

			->setParameter('sharedSecret', $sharedSecret);

		$query->execute();

	}

	/**

	 * get shared secret from database

	 * @param string $url

	 * @return string

	 */

	public function getSharedSecret($url) {

		$hash = $this->hash($url);

		$query = $this->connection->getQueryBuilder();

		$query->select('shared_secret')->from($this->dbTable)

			->where($query->expr()->eq('url_hash', $query->createParameter('url_hash')))

			->setParameter('url_hash', $hash);

		$result = $query->execute()->fetch();

		return $result['shared_secret'];

	}

	/**

	 * set server status

	 * @param string $url

	 * @return int

	 */

	public function getServerStatus($url) {

		$hash = $this->hash($url);

		$query = $this->connection->getQueryBuilder();

		$query->select('status')->from($this->dbTable)

				->where($query->expr()->eq('url_hash', $query->createParameter('url_hash')))

				->setParameter('url_hash', $hash);

		$result = $query->execute()->fetch();

		return (int)$result['status'];

	}

	/**

	 * create hash from URL

	 * @return string[]

	 * @codeCoverageIgnore - no need to test this

	 */

	public function getMigratedVersions() {

		$this->createMigrationTable();

		$qb = $this->connection->getQueryBuilder();

		$qb->select('version')

			->from('migrations')

			->where($qb->expr()->eq('app', $qb->createNamedParameter($this->getApp())))

			->orderBy('version');

		$result = $qb->execute();

		$rows = $result->fetchAll(\PDO::FETCH_COLUMN);

		$result->closeCursor();

		return $rows;

	}

	/**

	 * Returns all versions which are available in the migration folder