#ifndef UTUN_INSTANCE_H
#define UTUN_INSTANCE_H

#ifdef __cplusplus
extern "C" {
#endif


#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include "../lib/memory_pool.h"
#include "../lib/sqlite3.h"
#include "secure_channel.h"
#include "etcp_api.h"
#include "config_parser.h"
#include "stcp_link.h"
#include "firewall.h"
#include "eim_nat.h"
#include "nat_transport.h"
#include "media_delivery/media_delivery.h"
#include "media_async/media_async.h"
#include "proxy/tcp_proxy_client.h"
#include "etcp_router.h"
#include "proxy/tcp_proxy_server.h"
#include "ntp_time.h"
#include "ntp_node_time.h"

#include "etcp_api.h"
#include "config_parser.h"

// Forward declarations
struct utun_config;
struct uasync_s;
struct ROUTE_TABLE;
struct ETCP_CONN;
typedef void (*etcp_new_conn_fn)(struct ETCP_CONN* conn, void* arg);
struct ETCP_SOCKET;
struct TCP_SOCKET;
struct NODE_CONN_DIRECT;
struct tun_if;
struct ETCP_BINDINGS;
struct ETCP_ROUTER_BINDINGS;
struct TOPO_GROUP;
struct TOPO_GROUPS;
struct control_server;

struct PING_CONTEXT;
struct CONN_MGR;
struct ETCP_CONNECT;
struct DB_SYNC;
struct NAT_DETECTION;
struct merkle_sync;

struct NETWORK_ENTRY {
    uint64_t id;                                // 56-bit (offset 0 = index key)
    uint8_t pubkey[SC_PUBKEY_SIZE];             // 32 bytes binary
    uint8_t signing_key[SC_PRIVKEY_SIZE];       // 32 bytes binary
    char name[64];
};

// Queue entry for instance->connections (indexed by peer_node_id)
struct conn_queue_entry {
    uint64_t peer_node_id;
    struct ETCP_CONN* conn;
};

// Handle for config-based connections via node_conn_direct
struct CONFIG_CONN_HANDLE {
    uint64_t node_id;
    char name[MAX_CONN_NAME_LEN];
    struct NODE_CONN_DIRECT* handle;
    struct CONFIG_CONN_HANDLE* next;
};

// Queue entry for instance->tcp_connections (indexed by node_id)
struct tcp_conn_entry {
    uint64_t node_id;                    // index key
    struct stcp_link*  link;             // active TCP link
    struct ETCP_CONN*  etcp_conn;        // = stcp_link_get_etcp_conn(link) — for etcp_send() compat
};

// uTun instance configuration
struct UTUN_INSTANCE {
    // Identification
    char name[16];    // Instance name from config

    // Configuration (moved from utun_state)
    struct utun_config *config;
    
    // TUN interface
    struct tun_if* tun;
    
    // Route subnets (for cleanup on shutdown)
    struct CFG_ROUTE_ENTRY* route_subnets;

    struct ROUTE_TABLE* rt;
    struct TOPO_GROUPS* topo_groups;    // Groups module for topology exchange
    sqlite3* topo_sqlite_db;            // Shared SQLite DB (nodes/channels/peers)
    struct NAT_DETECTION* nat_det;      // NAT detection module
    struct merkle_sync* msync;         // Merkle tree sync module (per-instance)
    
    // Identification
    uint64_t node_id;

    char stats_dir[512];             // <config_dir>/stats/ для файлов метрик

    struct SC_MYKEYS my_keys;

    uint8_t my_ed25519_pubkey[SC_PUBKEY_SIZE];  // свой Ed25519 pubkey (для подписи метрик)
    uint8_t my_ed25519_privkey[SC_PRIVKEY_SIZE]; // свой Ed25519 privkey (derived from X25519)
    
    uint8_t next_socket_id;  // Counter for unique socket IDs (0-255)

    // Main async context
    struct UASYNC* ua;
    
    // State
    int running;

    // Connections (очередь всех подключений для instance)
    struct ll_queue* connections;        // indexed by peer_node_id (0=pending), data=conn_queue_entry
    struct ll_queue* tcp_connections;    // indexed by node_id, data=tcp_conn_entry [TCP-only]
    
    // Callback chain for new ETCP connections
    struct etcp_inst_cbk_entry* new_conn_cbks;
    struct etcp_status_cbk_entry* conn_status_cbks;  // instance-level: NEW/UP/DOWN/DELETE
    void* test_user_ptr;             // Generic user pointer (used by tests)

    struct memory_pool* data_pool;// для входных-выходных данных пакета
    struct memory_pool* pkt_pool;
    struct memory_pool* ack_pool;
    
    // Active sockets (UDP)
    struct ETCP_SOCKET* etcp_sockets;// linked-list
    struct TCP_SOCKET*  tcp_sockets; // linked-list [TCP-only]
    struct stcp_server *stcp_server; // TCP server (single for now)
    
    // Pending one-shot pings (for callback on PONG or timeout)
    struct PING_CONTEXT* pending_pings;
    
    // Routing statistics
    uint64_t routed_packets;
    uint64_t dropped_packets;
    
    // ETCP API bindings (per-instance)
    struct ETCP_BINDINGS api_bindings;
    
    // Control server for monitoring
    struct control_server* control_srv;
    
    // Firewall
    struct firewall_ctx fw;
    
    // EIM NAT
    struct eim_nat_ctx nat;
    struct nat_transport_ctx nat_tr;

    // Media delivery
    struct media_delivery_ctx md;

    // Media async engine (thread-per-task for crypto/file ops)
    struct media_async* media_async;
    
    // Socket initialization status: 0=OK, 1=partial (some sockets failed), -1=error (none created)
    int socket_init_status;

    // TCP proxy client (optional, NULL if not enabled)
    struct tcp_proxy_client* tcp_proxy_client;

    // etcp_router bindings и seq-connections (per-instance service routing)
    struct ETCP_ROUTER_BINDINGS router_bindings;
    struct ll_queue* router_conns;
    struct CONN_MGR* conn_mgr;       // Connection Manager (может быть NULL)
    struct DB_SYNC* db_sync;         // Distributed DB sync (может быть NULL)

    // TCP proxy server (exit node)
    struct tcp_proxy_server tcp_proxy_server;

    // Networks (queue of NETWORK_ENTRY, indexed by 56-bit id)
    struct ll_queue* networks;

    // Pending background connections (etcp_connect API)
    struct ETCP_CONNECT* pending_connects;
    uint32_t etcp_connect_timeout_tb;  // Initial timeout in 0.1ms units, default 20000 (2s)

    // NTP time synchronization
    struct NTP_TIME ntp;
    struct NTP_NODE_TIME ntp_node;

    // Config-based connection handles (node_conn_direct)
    struct CONFIG_CONN_HANDLE* config_conn_handles;

    // Per-instance NCD state (replaces global statics in node_conn_direct.c)
    void*  ncd_registry;        // struct ncd_entry* linked list
    uint8_t ncd_control_bound;  // 1 = etcp_bind(ETCP_RT_ID_NCD_CONTROL) сделан
};

// Functions
struct UTUN_INSTANCE* utun_instance_create(struct UASYNC* ua, const char* config_file);
struct UTUN_INSTANCE* utun_instance_create_from_config(struct UASYNC* ua, struct utun_config* config);
struct UTUN_INSTANCE* utun_instance_create_from_str(struct UASYNC* ua, const char* config_text);
void utun_instance_destroy(struct UTUN_INSTANCE* instance);
int utun_instance_init(struct UTUN_INSTANCE *instance);
struct UTUN_INSTANCE *utun_instance_reload(struct UTUN_INSTANCE *instance, struct UASYNC *ua, const char *config_file);
void utun_instance_run(struct UTUN_INSTANCE *instance);
void utun_instance_stop(struct UTUN_INSTANCE *instance);
void utun_instance_set_tun_init_enabled(int enabled);
void utun_instance_set_topo_group_enabled(int enabled);

// Diagnostic function for memory leak analysis
void utun_instance_diagnose_leaks(struct UTUN_INSTANCE* instance, const char* phase);

/* Find active connection by node_id — searches both UDP (connections) and TCP (tcp_connections) queues.
   Returns ETCP_CONN* ready for etcp_send(), or NULL if not found. */
static inline struct ETCP_CONN* instance_find_conn(struct UTUN_INSTANCE* inst, uint64_t node_id) {
    if (inst->connections) {
        struct ll_entry* e = queue_find_data_by_index(inst->connections, (const uint8_t*)&node_id);
        if (e) return ((struct conn_queue_entry*)e->data)->conn;
    }
    if (inst->tcp_connections) {
        struct ll_entry* e = queue_find_data_by_index(inst->tcp_connections, (const uint8_t*)&node_id);
        if (e) return ((struct tcp_conn_entry*)e->data)->etcp_conn;
    }
    return NULL;
}


#ifdef __cplusplus
}
#endif
#endif // UTUN_INSTANCE_H