#ifndef _SESSION_H
#define _SESSION_H

#ifdef __cpluscplus
extern "C"
{
#endif

#include <stdint.h>

#include "tuple.h"
#include "packet.h"

enum tcp_state
{
    // HANDSHAKE
    TCP_SYN_RECVED = 1 << 0,
    TCP_SYNACK_RECVED = 1 << 1,
    TCP_C2S_ACK_RECVED = 1 << 2,
    TCP_S2C_ACK_RECVED = 1 << 3,
    // ESTABLISHED
    TCP_C2S_DATA_RECVED = 1 << 4,
    TCP_S2C_DATA_RECVED = 1 << 5,
    // FIN
    TCP_C2S_FIN_RECVED = 1 << 6,
    TCP_S2C_FIN_RECVED = 1 << 7,
    // RST
    TCP_C2S_RST_RECVED = 1 << 8,
    TCP_S2C_RST_RECVED = 1 << 9,
};

enum udp_state
{
    UDP_C2S_RECVED = 1 << 0,
    UDP_S2C_RECVED = 1 << 1,
};

enum session_state
{
    SESSION_STATE_OPENING = 0x1,
    SESSION_STATE_ACTIVE = 0x2,
    SESSION_STATE_CLOSING = 0x3,
    SESSION_STATE_CLOSED = 0x4,
};

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

enum session_dir
{
    SESSION_DIR_NONE = 0x0,
    SESSION_DIR_C2S = 0x1,
    SESSION_DIR_S2C = 0x2,
};

enum dup_traffic_flag
{
    DUP_TRAFFIC_NO = 0x0,
    DUP_TRAFFIC_YES = 0x1,
};

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,
};

struct session;

/******************************************************************************
 * session base info
 ******************************************************************************/

void session_init(struct session *sess);

// session id
void session_set_id(struct session *sess, uint64_t id);
uint64_t session_get_id(const struct session *sess);

// session key
void session_set_key(struct session *sess, const struct tuple6 *tuple);
const struct tuple6 *session_get0_key(const struct session *sess);
void session_set_key_dir(struct session *sess, enum session_dir dir);
enum session_dir session_get_key_dir(const struct session *sess);

// session state
void session_set_state(struct session *sess, enum session_state state);
enum session_state session_get_state(const struct session *sess);

// session type
void session_set_type(struct session *sess, enum session_type type);
enum session_type session_get_type(const struct session *sess);

// session dup traffic flag
void session_set_dup_traffic_flag(struct session *sess, enum dup_traffic_flag flag);
enum dup_traffic_flag session_get_dup_traffic_flag(const struct session *sess);

// closing reason
void session_set_closing_reason(struct session *sess, enum closing_reason reason);
enum closing_reason session_get_closing_reason(const struct session *sess);

// session metrics
void session_inc_c2s_metrics(struct session *sess, uint64_t packets, uint64_t bytes);
void session_inc_s2c_metrics(struct session *sess, uint64_t packets, uint64_t bytes);
uint64_t session_get_c2s_bytes(const struct session *sess);
uint64_t session_get_s2c_bytes(const struct session *sess);
uint64_t session_get_c2s_packets(const struct session *sess);
uint64_t session_get_s2c_packets(const struct session *sess);

// session timestamp
void session_set_create_time(struct session *sess, uint64_t timestamp);
void session_set_last_time(struct session *sess, uint64_t timestamp);
uint64_t session_get_create_time(const struct session *sess);
uint64_t session_get_last_time(const struct session *sess);

// session tcp state
void session_set_tcp_state(struct session *sess, enum tcp_state state);
enum tcp_state session_get_tcp_state(const struct session *sess);

// session udp state
void session_set_udp_state(struct session *sess, enum udp_state state);
enum udp_state session_get_udp_state(const struct session *sess);

/******************************************************************************
 * session packet
 ******************************************************************************/

void session_set_c2s_1st_pkt(struct session *sess, const struct packet *pkt);
void session_set_s2c_1st_pkt(struct session *sess, const struct packet *pkt);
const struct packet *session_get0_c2s_1st_pkt(const struct session *sess);
const struct packet *session_get0_s2c_1st_pkt(const struct session *sess);
const struct packet *session_get0_1st_pkt(const struct session *sess);

// session current packet
void session_set0_cur_pkt(struct session *sess, const struct packet *pkt);
const struct packet *session_get0_cur_pkt(const struct session *sess);

// session current dir
void session_set_cur_dir(struct session *sess, enum session_dir dir);
enum session_dir session_get_cur_dir(const struct session *sess);

/******************************************************************************
 * session ex data
 ******************************************************************************/

typedef void session_ex_free_cb(struct session *sess, uint8_t idx, void *ex_ptr, void *arg);

/*
 * the exdata prodoced by user, and comsumed by same user.
 * so, the exdata is not shared by different user.
 * otherwise, the exdata need dup by refer count, and free by refer count.
 *
 * if key exist, not allow update, return original index.
 */
uint8_t session_get_ex_new_index(const char *key, session_ex_free_cb *free_cb, void *args);
/*
 * Support update ex_data.
 *
 * if key exist: run free_cb free old value, then set new value.
 *     if not run free_cb, old value will be memory leak.
 *     if not allow update, new value will be memory leak.
 * if key not exist: set new value.
 */
void session_set_ex_data(struct session *sess, uint8_t idx, void *val);
void *session_get0_ex_data(const struct session *sess, uint8_t idx);
/*
 * after set ex_data, the owner of ex_data is session, so user should not free it directly.
 * if user want to free ex_data, should use session_free_ex_data.
 */
void session_free_ex_data(struct session *sess, uint8_t idx);
void session_free(struct session *sess);

/******************************************************************************
 * session expire
 ******************************************************************************/

typedef void (*session_expire_cb)(struct session *sess, void *arg);

// session timer
void session_set_expirecb(struct session *sess, session_expire_cb expire_cb, void *expire_arg, uint64_t expire_abs_ts);
void session_del_expirecb(struct session *sess);
void session_run_expirecb(struct session *sess);

/******************************************************************************
 * session dump
 ******************************************************************************/

const char *session_closing_reason_to_str(enum closing_reason reason);
const char *session_state_to_str(enum session_state state);
const char *session_type_to_str(enum session_type type);
const char *session_dir_to_str(enum session_dir dir);
void session_dump(struct session *sess);

#ifdef __cpluscplus
}
#endif

#endif