/*
    Copyright (c) 2009-2011 250bpm s.r.o.
    Copyright (c) 2007-2009 iMatix Corporation
    Copyright (c) 2011 VMware, Inc.
    Copyright (c) 2007-2011 Other contributors as noted in the AUTHORS file

    This file is part of Crossroads I/O project.

    Crossroads I/O is free software; you can redistribute it and/or modify it
    under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    Crossroads 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef __XS_SESSION_BASE_HPP_INCLUDED__
#define __XS_SESSION_BASE_HPP_INCLUDED__

#include <string>

#include "own.hpp"
#include "io_object.hpp"
#include "pipe.hpp"

namespace xs
{

    class pipe_t;
    class io_thread_t;
    class socket_base_t;
    struct i_engine;

    class session_base_t :
        public own_t,
        public io_object_t,
        public i_pipe_events
    {
    public:

        //  Create a session of the particular type.
        static session_base_t *create (xs::io_thread_t *io_thread_,
            bool connect_, xs::socket_base_t *socket_,
            const options_t &options_, const char *protocol_,
            const char *address_);

        //  To be used once only, when creating the session.
        void attach_pipe (xs::pipe_t *pipe_);

        //  Following functions are the interface exposed towards the engine.
        //  They can be overloaded by specific session types to intercept
        //  events coming from the engine.
        virtual int read (msg_t *msg_);
        virtual int write (msg_t *msg_);
        virtual void flush ();
        virtual void detach ();

        //  i_pipe_events interface implementation.
        void read_activated (xs::pipe_t *pipe_);
        void write_activated (xs::pipe_t *pipe_);
        void hiccuped (xs::pipe_t *pipe_);
        void terminated (xs::pipe_t *pipe_);

    protected:

        session_base_t (xs::io_thread_t *io_thread_, bool connect_,
            xs::socket_base_t *socket_, const options_t &options_,
            const char *protocol_, const char *address_);
        ~session_base_t ();

    private:

        void start_connecting (bool wait_);

        void detached ();

        //  Handlers for incoming commands.
        void process_plug ();
        void process_attach (xs::i_engine *engine_);
        void process_term (int linger_);

        //  i_poll_events handlers.
        void timer_event (handle_t handle_);

        //  Remove any half processed messages. Flush unflushed messages.
        //  Call this function when engine disconnect to get rid of leftovers.
        void clean_pipes ();

        //  Call this function to move on with the delayed process_term.
        void proceed_with_term ();

        //  If true, this session (re)connects to the peer. Otherwise, it's
        //  a transient session created by the listener.
        bool connect;

        //  Pipe connecting the session to its socket.
        xs::pipe_t *pipe;

        //  This flag is true if the remainder of the message being processed
        //  is still in the in pipe.
        bool incomplete_in;

        //  True if termination have been suspended to push the pending
        //  messages to the network.
        bool pending;

        //  The protocol I/O engine connected to the session.
        xs::i_engine *engine;

        //  The socket the session belongs to.
        xs::socket_base_t *socket;

        //  I/O thread the session is living in. It will be used to plug in
        //  the engines into the same thread.
        xs::io_thread_t *io_thread;

        //  If true, identity is to be sent to the network.
        bool send_identity;

        //  If true, identity was already sent to the current connection.
        bool identity_sent;

        //  If true, identity is to be received from the network.
        bool recv_identity;

        //  If true, identity was already received from the current connection.
        bool identity_recvd;

        //  Protocol and address to use when connecting.
        std::string protocol;
        std::string address;

        //  Handle of the linger timer, if active, NULL otherwise.
        handle_t linger_timer;

        session_base_t (const session_base_t&);
        const session_base_t &operator = (const session_base_t&);
    };

}

#endif