// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-

/// @file	MAVLink_routing.h
/// @brief	handle routing of MAVLink packets by ID

#ifndef __MAVLINK_ROUTING_H
#define __MAVLINK_ROUTING_H

#include <AP_HAL.h>
#include <AP_Common.h>
#include <GCS_MAVLink.h>

// 5 routes should be enough for now. This will need to increase as we
// make more extensive use of MAVLink forwarding
#define MAVLINK_MAX_ROUTES 5

/*
  object to handle MAVLink packet routing
 */
class MAVLink_routing
{
public:
    MAVLink_routing(void);

    /*
      forward a MAVLink message to the right port. This also
      automatically learns the route for the sender if it is not
      already known.

      This returns true if the message matched a route and was
      forwarded. 
    */
    bool check_and_forward(mavlink_channel_t in_channel, const mavlink_message_t* msg);

private:
    // a simple linear routing table. We don't expect to have a lot of
    // routes, so a scalable structure isn't worthwhile yet.
    uint8_t num_routes;
    struct route {
        uint8_t sysid;
        uint8_t compid;
        mavlink_channel_t channel;
    } routes[MAVLINK_MAX_ROUTES];

    // learn new routes
    void learn_route(mavlink_channel_t in_channel, const mavlink_message_t* msg);

    // extract target sysid and compid from a message
    void get_targets(const mavlink_message_t* msg, int16_t &sysid, int16_t &compid);

    // special handling for heartbeat messages
    void handle_heartbeat(mavlink_channel_t in_channel, const mavlink_message_t* msg);
};

#endif // __MAVLINK_ROUTING_H