interface SessionInterface

interface SessionInterface {
    
    /**
     * Starts the session storage.
     *
     * @throws \RuntimeException if session fails to start
     */
    public function start() : bool;
    
    /**
     * Returns the session ID.
     */
    public function getId() : string;
    
    /**
     * Sets the session ID.
     */
    public function setId(string $id) : void;
    
    /**
     * Returns the session name.
     */
    public function getName() : string;
    
    /**
     * Sets the session name.
     */
    public function setName(string $name) : void;
    
    /**
     * Invalidates the current session.
     *
     * Clears all session attributes and flashes and regenerates the
     * session and deletes the old session from persistence.
     *
     * @param int|null $lifetime Sets the cookie lifetime for the session cookie. A null value
     *                           will leave the system settings unchanged, 0 sets the cookie
     *                           to expire with browser session. Time is in seconds, and is
     *                           not a Unix timestamp.
     */
    public function invalidate(?int $lifetime = null) : bool;
    
    /**
     * Migrates the current session to a new session id while maintaining all
     * session attributes.
     *
     * @param bool     $destroy  Whether to delete the old session or leave it to garbage collection
     * @param int|null $lifetime Sets the cookie lifetime for the session cookie. A null value
     *                           will leave the system settings unchanged, 0 sets the cookie
     *                           to expire with browser session. Time is in seconds, and is
     *                           not a Unix timestamp.
     */
    public function migrate(bool $destroy = false, ?int $lifetime = null) : bool;
    
    /**
     * Force the session to be saved and closed.
     *
     * This method is generally not required for real sessions as
     * the session will be automatically saved at the end of
     * code execution.
     */
    public function save() : void;
    
    /**
     * Checks if an attribute is defined.
     */
    public function has(string $name) : bool;
    
    /**
     * Returns an attribute.
     */
    public function get(string $name, mixed $default = null) : mixed;
    
    /**
     * Sets an attribute.
     */
    public function set(string $name, mixed $value) : void;
    
    /**
     * Returns attributes.
     */
    public function all() : array;
    
    /**
     * Sets attributes.
     */
    public function replace(array $attributes) : void;
    
    /**
     * Removes an attribute.
     *
     * @return mixed The removed value or null when it does not exist
     */
    public function remove(string $name) : mixed;
    
    /**
     * Clears all attributes.
     */
    public function clear() : void;
    
    /**
     * Checks if the session was started.
     */
    public function isStarted() : bool;
    
    /**
     * Registers a SessionBagInterface with the session.
     */
    public function registerBag(SessionBagInterface $bag) : void;
    
    /**
     * Gets a bag instance by name.
     */
    public function getBag(string $name) : SessionBagInterface;
    
    /**
     * Gets session meta.
     */
    public function getMetadataBag() : MetadataBag;

}