<?php
/**
 * MediaWiki\Session entry point interface
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Session
 */

namespace MediaWiki\Session;

use Psr\Log\LoggerAwareInterface;
use User;
use WebRequest;

/**
 * This exists to make IDEs happy, so they don't see the
 * internal-but-required-to-be-public methods on SessionManager.
 *
 * @ingroup Session
 * @since 1.27
 */
interface SessionManagerInterface extends LoggerAwareInterface {
	/**
	 * Fetch the session for a request (or a new empty session if none is
	 * attached to it)
	 *
	 * @note You probably want to use $request->getSession() instead. It's more
	 *  efficient and doesn't break FauxRequests or sessions that were changed
	 *  by $this->getSessionById() or $this->getEmptySession().
	 * @param WebRequest $request Any existing associated session will be reset
	 *  to the session corresponding to the data in the request itself.
	 * @return Session
	 * @throws \OverflowException if there are multiple sessions tied for top
	 *  priority in the request. Exception has a property "sessionInfos"
	 *  holding the SessionInfo objects for the sessions involved.
	 */
	public function getSessionForRequest( WebRequest $request );

	/**
	 * Fetch a session by ID
	 *
	 * @param string $id
	 * @param bool $create If no session exists for $id, try to create a new one.
	 *  May still return null if a session for $id exists but cannot be loaded.
	 * @param WebRequest|null $request Corresponding request. Any existing
	 *  session associated with this WebRequest object will be overwritten.
	 * @return Session|null
	 */
	public function getSessionById( $id, $create = false, WebRequest $request = null );

	/**
	 * Create a new, empty session
	 *
	 * The first provider configured that is able to provide an empty session
	 * will be used.
	 *
	 * @param WebRequest|null $request Corresponding request. Any existing
	 *  session associated with this WebRequest object will be overwritten.
	 * @return Session
	 */
	public function getEmptySession( WebRequest $request = null );

	/**
	 * Invalidate sessions for a user
	 *
	 * After calling this, existing sessions should be invalid. For mutable
	 * session providers, this generally means the user has to log in again;
	 * for immutable providers, it generally means the loss of session data.
	 *
	 * @param User $user
	 */
	public function invalidateSessionsForUser( User $user );

	/**
	 * Return the HTTP headers that need varying on.
	 *
	 * The return value is such that someone could theoretically do this:
	 * @code
	 * foreach ( $provider->getVaryHeaders() as $header => $options ) {
	 *   $outputPage->addVaryHeader( $header, $options );
	 * }
	 * @endcode
	 *
	 * @return array
	 */
	public function getVaryHeaders();

	/**
	 * Return the list of cookies that need varying on.
	 * @return string[]
	 */
	public function getVaryCookies();

}