/* See the DRL-LICENSE file for this file's software license. */

#ifndef _SWIM_H_
#define _SWIM_H_

#define AWOL (0)
#define ALIVE (1)
#define MAX_FRIENDS (5)
#define UPDATE_THRESHOLD (3)
#define FRIEND_THRESHOLD (4)
#define SOURCE_THRESHOLD (8)

static const uint16_t CHECK = 3;
static const uint16_t CHECK_ACK = 4;
static const uint16_t PING = 5;
static const uint16_t PING_ACK = 6;

/** Structs needed to maintain the list of nodes to which
* ping messages have been sent. This list is maintained
* by one of the "friend" nodes
*/
typedef struct ping_target {
    // node which has been targetted
    remote_node_t target;
    // node which requested the ping target
    // so that CHECK_ACK could be sent with ALIVE / AWOL
    remote_node_t source;
    // count of gossip rounds to keep timeout
    uint32_t count;
    // this has to be a list as well because we have to
    // remember all the suspects a particular node has
    // pinged and is waiting for a response
    struct ping_target *next;
} ping_target_t;

typedef struct update {
    /*Remote limiter whose update this is*/
    remote_limiter_t *remote;
    /*Number of times, update has been piggy 
     *backed on a gossip message*/
    int count;
    struct update *next;
} update_t;

typedef struct swim_comm {
    /*Incarnation number of the node*/
    uint32_t incarnation;

    /*List of updates currently held by the node*/
    update_t *updates;
    int count_updates;

    /** Keep track of the ping messages being sent and wait for timeout */
    ping_target_t *ping_targets;
} swim_comm_t;

int swim_init(comm_t *comm, uint32_t id);

void swim_teardown(comm_t *comm);

int swim_receive(comm_t *comm, uint32_t id, int sock, remote_limiter_t *remote, message_t *msg);

int send_gossip_swim(comm_t *comm, uint32_t id, int sock);

void swim_restart(comm_t *comm, int32_t view_number);

#endif  /* _SWIM_H_ */