#ifndef _SESSION_H
#define _SESSION_H

#ifdef __cplusplus
extern "C"
{
#endif

#include <stdint.h>

#include "packet.h"

enum session_state
{
    SESSION_STATE_INIT = 0,
    SESSION_STATE_OPENING = 1,
    SESSION_STATE_ACTIVE = 2,
    SESSION_STATE_CLOSING = 3,
    SESSION_STATE_DISCARD = 4,
    SESSION_STATE_CLOSED = 5,
    MAX_STATE = 6,
};

enum session_type
{
    SESSION_TYPE_TCP = 0x1,
    SESSION_TYPE_UDP = 0x2,
};

enum session_direction
{
    SESSION_DIRECTION_NONE = -1,
    SESSION_DIRECTION_C2S = 0,
    SESSION_DIRECTION_S2C = 1,
    MAX_DIRECTION = 2,
};

enum closing_reason
{
    CLOSING_BY_TIMEOUT = 0x1,
    CLOSING_BY_EVICTED = 0x2,
    CLOSING_BY_CLIENT_FIN = 0x3,
    CLOSING_BY_CLIENT_RST = 0x4,
    CLOSING_BY_SERVER_FIN = 0x5,
    CLOSING_BY_SERVER_RST = 0x6,
};

enum session_stat
{
    // raw packet
    STAT_RAW_PKTS_RX,
    STAT_RAW_BYTES_RX,

    STAT_RAW_PKTS_TX,
    STAT_RAW_BYTES_TX,

    STAT_RAW_PKTS_DROP,
    STAT_RAW_BYTES_DROP,

    STAT_DUP_PKTS_BYPASS,
    STAT_DUP_BYTES_BYPASS,

    // control packet
    STAT_CTRL_PKTS_RX,  // TODO
    STAT_CTRL_BYTES_RX, // TODO

    STAT_CTRL_PKTS_TX,
    STAT_CTRL_BYTES_TX,

    STAT_CTRL_PKTS_DROP,
    STAT_CTRL_BYTES_DROP,

    // TCP segment
    STAT_TCP_SEGS_RX,
    STAT_TCP_PLDS_RX,

    STAT_TCP_SEGS_EXPIRED,
    STAT_TCP_PLDS_EXPIRED,

    STAT_TCP_SEGS_OVERLAP,
    STAT_TCP_PLDS_OVERLAP,

    STAT_TCP_SEGS_NOSPACE,
    STAT_TCP_PLDS_NOSPACE,

    STAT_TCP_SEGS_INORDER,
    STAT_TCP_PLDS_INORDER,

    STAT_TCP_SEGS_REORDERED,
    STAT_TCP_PLDS_REORDERED,

    STAT_TCP_SEGS_BUFFERED,
    STAT_TCP_PLDS_BUFFERED,

    STAT_TCP_SEGS_RELEASED,
    STAT_TCP_PLDS_RELEASED,

    MAX_STAT,
};

enum session_timestamp
{
    SESSION_TIMESTAMP_START,
    SESSION_TIMESTAMP_LAST,
    MAX_TIMESTAMP,
};

struct session;

int session_has_dup_traffic(const struct session *sess);
enum session_type session_get_type(const struct session *sess);
enum session_state session_get_state(const struct session *sess);
enum closing_reason session_get_closing_reason(const struct session *sess);
enum session_direction session_get_current_direction(const struct session *sess);
const struct packet *session_get_1st_packet(const struct session *sess, enum session_direction dir);

uint64_t session_get_id(const struct session *sess);
uint64_t session_get_timestamp(const struct session *sess, enum session_timestamp type);
uint64_t session_get_stat(const struct session *sess, enum session_direction dir, enum session_stat stat);

const char *session_get_tuple_str(const struct session *sess);
const char *session_type_to_str(enum session_type type);
const char *session_state_to_str(enum session_state state);
const char *session_direction_to_str(enum session_direction dir);
const char *closing_reason_to_str(enum closing_reason reason);

#ifdef __cplusplus
}
#endif

#endif