#ifndef _SESSION_PRIV_H
#define _SESSION_PRIV_H

#ifdef __cplusplus
extern "C"
{
#endif

#include "list.h"
#include "packet_priv.h"
#include "timeout.h"
#include "uthash.h"
#include "stellar/tuple.h"
#include "stellar/session.h"
#include "tcp_reassembly.h"
#include "session_manager.h"

#define EX_DATA_MAX_COUNT 4

// tuple6 str format: "src_addr:src_port -> dst_addr:dst_port, proto: ip_proto, domain: domain"
// tuple6 max len: 46 + 1 + 5 + 4 + 46 + 1 + 5 + 9 + 1 + 10 + 20 = 107
#define TUPLE6_STR_SIZE 108

struct tcp_half
{
    struct tcp_reassembly *assembler;
    struct tcp_segment in_order;

    uint32_t seq;
    uint32_t ack;
    uint16_t len;
    uint8_t flags;
};

/*
 * sizeof(struct session) = 1024 bytes
 * max thread number = 128
 * per thread max tcp session number = 50000
 * per thread max udp session number = 50000
 *
 * session memory usage = 128 * (50000 + 50000) * 1024 = 13107200000 bytes = 12.2 GB
 */
struct session
{
    uint64_t id;                                   //   8 bytes
    uint64_t stats[MAX_DIRECTION][MAX_STAT];       // 480 bytes
    uint64_t timestamps[MAX_TIMESTAMP];            //  16 bytes
    struct tcp_half tcp_halfs[MAX_DIRECTION];      //  80 bytes
    struct timeout timeout;                        //  72 bytes -- used for timer
    struct list_head lru;                          //  16 bytes -- used for lru queue
    struct list_head free;                         //  16 bytes -- used for free queue
    struct list_head evicte;                       //  16 bytes -- used for evicte queue
    UT_hash_handle hh1;                            //  56 bytes -- used for hash table (tuple6)
    UT_hash_handle hh2;                            //  56 bytes -- used for hash table (tuple4)
    UT_hash_handle hh3;                            //  56 bytes -- used for hash table (session id)
    struct tuple6 tuple;                           //  56 bytes
    char tuple_str[TUPLE6_STR_SIZE];               // 108 bytes
    const struct packet *first_pkt[MAX_DIRECTION]; //  16 bytes
    const struct packet *curr_pkt;                 //   8 bytes
    void *ex_data[EX_DATA_MAX_COUNT];              //  32 bytes
    void *user_data;                               //   8 bytes
    int is_symmetric;                              //   4 bytes
    int dup;                                       //   4 bytes
    enum session_direction tuple_dir;              //   4 bytes
    enum session_direction cur_dir;                //   4 bytes
    enum session_type type;                        //   4 bytes
    enum session_state state;                      //   4 bytes
    enum closing_reason reason;                    //   4 bytes
    struct session_manager_stat *mgr_stat;         //   8 bytes
};

void session_init(struct session *sess);
void session_set_id(struct session *sess, uint64_t id);
void session_set_tuple(struct session *sess, const struct tuple6 *key);
const struct tuple6 *session_get_tuple(const struct session *sess);
void session_set_tuple_direction(struct session *sess, enum session_direction dir);
enum session_direction session_get_tuple_direction(const struct session *sess);
void session_set_current_direction(struct session *sess, enum session_direction dir);
void session_set_state(struct session *sess, enum session_state state);
void session_set_type(struct session *sess, enum session_type type);
void session_set_dup_traffic(struct session *sess);
void session_set_closing_reason(struct session *sess, enum closing_reason reason);
void session_inc_stat(struct session *sess, enum session_direction dir, enum session_stat stat, uint64_t val);
void session_set_timestamp(struct session *sess, enum session_timestamp type, uint64_t value);
void session_set_1st_packet(struct session *sess, enum session_direction dir, const struct packet *pkt);
void session_set_current_packet(struct session *sess, const struct packet *pkt);
const struct packet *session_get_current_packet(const struct session *sess);
void session_set_user_data(struct session *sess, void *user_data);
void *session_get_user_data(const struct session *sess);
struct tcp_segment *session_get_tcp_segment(struct session *sess);
void session_free_tcp_segment(struct session *sess, struct tcp_segment *seg);

/******************************************************************************
 * 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_all_ex_data(struct session *sess);

/******************************************************************************
 * debug
 ******************************************************************************/

void session_print(struct session *sess);
int session_to_json(struct session *sess, char *buff, int size);

#ifdef __cplusplus
}
#endif

#endif