// config_parser.h - Configuration parser for utun application
#ifndef CONFIG_PARSER_H
#define CONFIG_PARSER_H

#include <stdint.h>
#include <stddef.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#ifdef __cplusplus
extern "C" {
#endif

#define MAX_CONN_NAME_LEN 64
#define MAX_KEY_LEN 256
#define MAX_ADDR_LEN 64

struct IP {
    sa_family_t family;
    union {
        struct in_addr  v4;
        struct in6_addr v6;
    } addr;
};

#define CFG_SERVER_TYPE_UNKNOWN 0
#define CFG_SERVER_TYPE_PUBLIC 1
#define CFG_SERVER_TYPE_NAT 2
#define CFG_SERVER_TYPE_PRIVATE 3

struct CFG_SERVER {
    struct CFG_SERVER* next;
    char name[MAX_CONN_NAME_LEN];
    struct sockaddr_storage ip; // ip:port
    uint32_t netif_index;// if_nameindex, 0 - no interface specified
    int so_mark;
    uint8_t type;  // public/nat/private
};

struct CFG_CLIENT_LINK {
    struct CFG_CLIENT_LINK *next;                // Next link in linked list
    struct CFG_SERVER* local_srv;
    struct sockaddr_storage remote_addr; // ip:port
};

struct CFG_CLIENT {
    char name[MAX_CONN_NAME_LEN];
    char peer_public_key_hex[MAX_KEY_LEN];
    int keepalive;
    struct CFG_CLIENT_LINK *links;           // Linked list of links
    struct CFG_CLIENT *next;              // Next client in linked list
};

struct CFG_ROUTE_ENTRY {
    struct CFG_ROUTE_ENTRY* next;
    struct IP ip;
    uint8_t netmask;
};

struct global_config {
    char my_private_key_hex[MAX_KEY_LEN];
    char my_public_key_hex[MAX_KEY_LEN];
    uint64_t my_node_id;
    char tun_ifname[16];       // TUN interface name (e.g., "tun12")
    struct IP tun_ip;
    int mtu;
    struct sockaddr_storage control_sock;
    int net_debug;
};

struct utun_config {
    struct global_config global;
    struct CFG_SERVER* servers;
    struct CFG_CLIENT* clients;
    struct CFG_ROUTE_ENTRY* allowed_subnets;
    struct CFG_ROUTE_ENTRY* my_subnets;
};

struct utun_config* parse_config(const char *filename);
void free_config(struct utun_config *config);
void print_config(const struct utun_config *config);
int update_config_keys(const char *filename, const char *priv_key, const char *pub_key);

#ifdef __cplusplus
}
#endif

#endif