// remote_proxy.h — Удаленный TCP прокси (exit node)
// Создаёт OS сокеты к адресатам по запросам от других нод через etcp_router
#ifndef REMOTE_PROXY_H
#define REMOTE_PROXY_H

#include <stdint.h>
#include "../lib/socket_compat.h"

struct UTUN_INSTANCE;
struct UASYNC;
struct ll_entry;
struct ETCP_CONN;
struct remote_proxy_ctx;

// Sub-commands for ETCP_ID_TCP_PROXY protocol
#define TCP_PROXY_SUBCMD_CONNECT   0x01
#define TCP_PROXY_SUBCMD_CONNECTED 0x02
#define TCP_PROXY_SUBCMD_DATA      0x03
#define TCP_PROXY_SUBCMD_CLOSE     0x04

#define TCP_PROXY_CONNECTED_OK     0
#define TCP_PROXY_CONNECTED_REFUSED 1

#define TCP_PROXY_HDR_SIZE          12  // svc_id(1)+subcmd(1)+stream_id(8)+seq(2)
#define TCP_PROXY_CONNECT_HDR_SIZE  18  // HDR_SIZE + dest_ip(4)+dest_port(2)
#define TCP_PROXY_CONNECTED_HDR_SIZE 15 // HDR_SIZE + local_port(2)+status(1)

struct remote_proxy_conn {
    struct remote_proxy_conn* next;
    struct remote_proxy_ctx* ctx;
    uint64_t stream_id;
    uint64_t peer_node_id;
    socket_t sock;
    void*    read_id;
    struct UASYNC* ua;
    int      connected;
    int      connect_called;
    uint8_t  dest_ip[4];
    uint16_t dest_port;
    uint16_t send_seq;
    uint16_t recv_last_seq;
    uint8_t  recv_seq_init;
};

struct remote_proxy_ctx {
    int enabled;
    int conn_count;
    struct remote_proxy_conn* conns;
    struct UTUN_INSTANCE* inst;
};

int  remote_proxy_init(struct UTUN_INSTANCE* inst);
void remote_proxy_destroy(struct UTUN_INSTANCE* inst);

struct remote_proxy_conn* remote_proxy_find_conn(struct remote_proxy_ctx* ctx, uint64_t stream_id);

int  remote_proxy_handle_connect(struct UTUN_INSTANCE* inst, struct ll_entry* entry,
                                  uint64_t stream_id, uint64_t src_node_id);
int  remote_proxy_handle_data(struct UTUN_INSTANCE* inst, struct ll_entry* entry, uint64_t stream_id);
void remote_proxy_handle_close(struct UTUN_INSTANCE* inst, uint64_t stream_id);

#endif