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

#include <stdint.h>
#include <stddef.h>
#include "../lib/platform_compat.h"
#include "secure_channel.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
#define CFG_SERVER_TYPE_LOCAL   4

#define CFG_IPV6_MODE_NONE      0 // normal explicit address
#define CFG_IPV6_MODE_TEMPORARY 1 // temporary IPv6 from interface
#define CFG_IPV6_MODE_PERMANENT 2 // permanent IPv6 from interface

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;
    int fib;       // FreeBSD FIB (routing table), -1 = don't set
    uint8_t type;  // public/nat/private
    uint8_t transport;  // 0=udp (default), 1=tcp
    uint8_t ipv6_mode; // CFG_IPV6_MODE_*
    int mtu;
    uint8_t only_local;  // 1 = only local connections, no forwarding
};

struct CFG_CLIENT_LINK {
    struct CFG_CLIENT_LINK *next;                // Next link in linked list
    struct CFG_SERVER* local_srv;
    char server_name[MAX_CONN_NAME_LEN];         // Name of local server for this link
    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_NETWORK {
    struct CFG_NETWORK* next;
    char name[64];
    uint64_t id;                                    // 56-bit network ID
    char pubkey_hex[SC_PUBKEY_SIZE * 2 + 1];        // 64 hex chars
    char signing_key_hex[SC_PRIVKEY_SIZE * 2 + 1];  // 64 hex chars
};

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

struct CFG_FIREWALL_RULE {
    uint32_t ip;      // IPv4 in host byte order for sorting
    uint16_t port;    // 0 means any port
    uint8_t  bypass;  // 1 for allow=all (bypass all checks)
};

struct CFG_CONTROL_ALLOW {
    uint32_t network;  // IPv4 network in host byte order
    uint32_t netmask;  // netmask in host byte order (e.g. 0xffffff00 for /24)
};

struct CFG_ALLOWED_KEY {
    uint8_t key_bin[SC_PUBKEY_SIZE];  // public key in binary (32 bytes, X25519)
    struct CFG_ALLOWED_KEY *next;
};

#define MAX_TCP_PROXY_CLIENT_MAPPINGS 32
struct tcp_proxy_client_mapping_config {
    uint16_t local_port;
    char     remote_ip[64];
    uint16_t remote_port;
};

struct global_config {
    char name[16];                    // Instance name
    char my_private_key_hex[MAX_KEY_LEN];
    char my_public_key_hex[MAX_KEY_LEN];
    uint64_t my_node_id;
    int  tun_enabled;          // 1 = create TUN (default), 0 = skip TUN (run without root)
    char tun_ifname[16];       // TUN interface name (e.g., "tun12")
    struct IP tun_ip;
    int mtu;
    struct sockaddr_storage control_sock;
    char control_ip[MAX_ADDR_LEN];  // Control server IP address
    struct sockaddr_storage msg_transport_sock;

    // Debug and logging configuration
    char log_file[256];        // Path to log file (empty = stdout)
    char db_path[256];         // Path to SQLite database (empty = disabled)
    int  db_sync_enabled;      // 1 = enable distributed DB sync (default: 0)
    uint32_t db_sync_ttl;      // TTL for unsent records in seconds (default: 86400)
    char debug_level[16];      // debug level: error, warn, info, debug, trace
    int enable_timestamp;      // enable timestamps in logs
    int enable_function_names; // enable function names in logs
    int enable_file_lines;     // enable file:line in logs
    int enable_colors;         // enable ANSI colors in logs
    
    // Per-category debug levels (loaded from [debug] section)
    struct {
        char category[16][16];  // category name
        char level[16][16];    // level string
        int count;
    } debug_levels;
    
    int tun_test_mode;         // test mode: 1 = don't open real TUN, queues only
    int keepalive_timeout;     // keepalive timeout in ms (default: 2000)
    int keepalive_interval;    // keepalive interval in ms (default: 200)
    int keepalive_adaptive;    // 1 = adaptive period (default), 0 = fixed interval
    int bbr_max_cwnd;          // BBR cwnd cap in bytes (default: 100000)

    // Firewall configuration
    struct CFG_FIREWALL_RULE *firewall_rules;
    int firewall_rule_count;
    int firewall_bypass_all;

    // Control server configuration ([control] section)
    struct CFG_CONTROL_ALLOW *control_allows;
    int control_allow_count;

    // Allowed keys configuration ([allowed_keys] section)
    struct CFG_ALLOWED_KEY *allowed_keys;
    int allowed_keys_count;
    int allowed_keys_allow_all;

    // NAT configuration ([nat] section)
    int nat_enabled;
    char nat_tun_ifname[16];
    struct IP nat_tun_ip;
    uint64_t nat_via_node_id;     // 0 = this node is provider; !=0 = client, use this provider
    uint16_t nat_port_start;
    uint16_t nat_port_end;
    #define MAX_NAT_FORWARDS 64
    struct {
        uint8_t  proto;
        uint32_t internal_ip_host;
        uint16_t internal_port_net;
        uint16_t external_port;
    } nat_forwards[MAX_NAT_FORWARDS];
    int nat_forward_count;

    // TCP proxy client configuration ([tcp_proxy_client] section)
    int      tcp_proxy_client_enabled;
    char     tcp_proxy_client_tun_name[16];
    char     tcp_proxy_client_tun_ip[64];
    int      tcp_proxy_client_mtu;
    uint64_t tcp_proxy_client_via_node_id;  // через этот узел проксируются все forward-правила
    struct   tcp_proxy_client_mapping_config tcp_proxy_client_mappings[MAX_TCP_PROXY_CLIENT_MAPPINGS];
    int      tcp_proxy_client_mapping_count;
    int      tcp_proxy_client_socks_enabled;
    char     tcp_proxy_client_socks_addr[64];       // e.g. "127.0.0.1:1080"
    int      tcp_proxy_client_http_proxy_enabled;
    char     tcp_proxy_client_http_proxy_addr[64];  // e.g. "127.0.0.1:8080"

    // TCP proxy server (exit node) configuration ([tcp_proxy_server] section)
    int      tcp_proxy_server_enabled;
    int      tcp_recv_buf;                // SO_RCVBUF для TCP сокетов (0=default ОС)

    // NTP configuration ([ntp] section)
    int ntp_enabled;
    char ntp_servers[5][256];             // up to 5 NTP server hostnames
    int ntp_server_count;
    int ntp_resync_interval;              // seconds, default 3600
};

struct utun_config {
    struct global_config global;
    struct CFG_SERVER* servers;
    struct CFG_CLIENT* clients;
    struct CFG_ROUTE_ENTRY* route_subnets;
    struct CFG_ROUTE_ENTRY* my_subnets;
    struct CFG_NETWORK* networks;
};

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