#include <stdlib.h>
#include <string.h>
#include <stdint.h>

#include "../lib/ll_queue.h"
#include "../lib/debug_config.h"
#include "../lib/mem.h"
#include "utun_instance.h"
#include "etcp.h"
#include "config_parser.h"
#include "route_node.h"
#include "route_bgp.h"
#include "etcp_debug.h"

static const uint8_t* node_dyn_start(const struct NODEINFO* info) {
    return (const uint8_t*)info + sizeof(struct NODEINFO);
}

static const uint8_t* skip_name(const uint8_t* p, uint8_t name_len) {
    return p + name_len;
}

static const uint8_t* skip_v4_sockets_meta(const uint8_t* p, uint8_t count) {
    return p + count * sizeof(struct NODEINFO_IPV4_SOCKET_META);
}

static const uint8_t* skip_v4_addrs(const uint8_t* p, uint8_t count) {
    return p + count * sizeof(struct NODEINFO_IPV4_ADDR);
}

static const uint8_t* skip_v6_sockets_meta(const uint8_t* p, uint8_t count) {
    return p + count * sizeof(struct NODEINFO_IPV6_SOCKET_META);
}

static const uint8_t* skip_v6_addrs(const uint8_t* p, uint8_t count) {
    return p + count * sizeof(struct NODEINFO_IPV6_ADDR);
}

static const uint8_t* skip_v4_subnets(const uint8_t* p, uint8_t count) {
    return p + count * sizeof(struct NODEINFO_IPV4_SUBNET);
}

int get_node_v4_sockets_meta(struct NODEINFO_Q *node, const struct NODEINFO_IPV4_SOCKET_META **out_meta) {
    if (!node || !out_meta) return -1;
    *out_meta = NULL;
    const struct NODEINFO *info = &node->node;
    if (info->local_v4_sockets == 0) return 0;
    const uint8_t *dynamic = node_dyn_start(info);
    dynamic = skip_name(dynamic, info->node_name_len);
    *out_meta = (const struct NODEINFO_IPV4_SOCKET_META *)dynamic;
    return (int)info->local_v4_sockets;
}

int get_node_v4_addrs(struct NODEINFO_Q *node, const struct NODEINFO_IPV4_ADDR **out_addrs) {
    if (!node || !out_addrs) return -1;
    *out_addrs = NULL;
    const struct NODEINFO *info = &node->node;
    if (info->local_v4_addrs == 0) return 0;
    const uint8_t *dynamic = node_dyn_start(info);
    dynamic = skip_name(dynamic, info->node_name_len);
    dynamic = skip_v4_sockets_meta(dynamic, info->local_v4_sockets);
    *out_addrs = (const struct NODEINFO_IPV4_ADDR *)dynamic;
    return (int)info->local_v4_addrs;
}

int get_node_v6_sockets_meta(struct NODEINFO_Q *node, const struct NODEINFO_IPV6_SOCKET_META **out_meta) {
    if (!node || !out_meta) return -1;
    *out_meta = NULL;
    const struct NODEINFO *info = &node->node;
    if (info->local_v6_sockets == 0) return 0;
    const uint8_t *dynamic = node_dyn_start(info);
    dynamic = skip_name(dynamic, info->node_name_len);
    dynamic = skip_v4_sockets_meta(dynamic, info->local_v4_sockets);
    dynamic = skip_v4_addrs(dynamic, info->local_v4_addrs);
    *out_meta = (const struct NODEINFO_IPV6_SOCKET_META *)dynamic;
    return (int)info->local_v6_sockets;
}

int get_node_v6_addrs(struct NODEINFO_Q *node, const struct NODEINFO_IPV6_ADDR **out_addrs) {
    if (!node || !out_addrs) return -1;
    *out_addrs = NULL;
    const struct NODEINFO *info = &node->node;
    if (info->local_v6_addrs == 0) return 0;
    const uint8_t *dynamic = node_dyn_start(info);
    dynamic = skip_name(dynamic, info->node_name_len);
    dynamic = skip_v4_sockets_meta(dynamic, info->local_v4_sockets);
    dynamic = skip_v4_addrs(dynamic, info->local_v4_addrs);
    dynamic = skip_v6_sockets_meta(dynamic, info->local_v6_sockets);
    *out_addrs = (const struct NODEINFO_IPV6_ADDR *)dynamic;
    return (int)info->local_v6_addrs;
}

int get_node_routes(struct NODEINFO_Q *node, const struct NODEINFO_IPV4_SUBNET **out_subnets) {
    if (!node || !out_subnets) return -1;
    *out_subnets = NULL;
    const struct NODEINFO *info = &node->node;
    if (info->local_v4_subnets == 0) return 0;
    const uint8_t *dynamic = node_dyn_start(info);
    dynamic = skip_name(dynamic, info->node_name_len);
    dynamic = skip_v4_sockets_meta(dynamic, info->local_v4_sockets);
    dynamic = skip_v4_addrs(dynamic, info->local_v4_addrs);
    dynamic = skip_v6_sockets_meta(dynamic, info->local_v6_sockets);
    dynamic = skip_v6_addrs(dynamic, info->local_v6_addrs);
    *out_subnets = (const struct NODEINFO_IPV4_SUBNET *)dynamic;
    return (int)info->local_v4_subnets;
}

int get_node_v6_routes(struct NODEINFO_Q *node, const struct NODEINFO_IPV6_SUBNET **out_subnets) {
    if (!node || !out_subnets) return -1;
    *out_subnets = NULL;
    const struct NODEINFO *info = &node->node;
    if (info->local_v6_subnets == 0) return 0;
    const uint8_t *dynamic = node_dyn_start(info);
    dynamic = skip_name(dynamic, info->node_name_len);
    dynamic = skip_v4_sockets_meta(dynamic, info->local_v4_sockets);
    dynamic = skip_v4_addrs(dynamic, info->local_v4_addrs);
    dynamic = skip_v6_sockets_meta(dynamic, info->local_v6_sockets);
    dynamic = skip_v6_addrs(dynamic, info->local_v6_addrs);
    dynamic = skip_v4_subnets(dynamic, info->local_v4_subnets);
    *out_subnets = (const struct NODEINFO_IPV6_SUBNET *)dynamic;
    return (int)info->local_v6_subnets;
}

int route_bgp_update_my_nodeinfo(struct UTUN_INSTANCE* instance, struct ROUTE_BGP* bgp) {
    if (!instance || !bgp) {
        DEBUG_ERROR(DEBUG_CATEGORY_BGP, "route_bgp_update_my_nodeinfo: invalid args");
        return -1;
    }
    size_t name_len = 0;
    if (instance->name[0]) {
        name_len = strlen(instance->name);
        if (name_len > 63) name_len = 63;
    }
    int vc = 0, vc6 = 0;
    struct CFG_ROUTE_ENTRY* s = instance->config->my_subnets;
    while (s) { if (s->ip.family == AF_INET) vc++; else if (s->ip.family == AF_INET6) vc6++; s = s->next; }

    int sock_count = 0, addr_count = 0;
    int sock6_count = 0, addr6_count = 0;
    struct ETCP_SOCKET* e_sock = instance->etcp_sockets;
    while (e_sock) {
        if (e_sock->local_addr.ss_family == AF_INET) {
            sock_count++;
            addr_count++; // INTERFACE
            if (e_sock->nat_addr.ss_family == AF_INET) {
                struct sockaddr_in* nat_sin = (struct sockaddr_in*)&e_sock->nat_addr;
                if (nat_sin->sin_addr.s_addr != 0) {
                    if (e_sock->nat_type != NAT_VERIFIED_STRICT) addr_count++;
                }
            }
            if (e_sock->nat_type == NAT_VERIFIED_DIRECT ||
                (e_sock->type == CFG_SERVER_TYPE_PUBLIC && e_sock->nat_type < NAT_VERIFIED_UNKNOWN)) addr_count++;
        } else if (e_sock->local_addr.ss_family == AF_INET6) {
            sock6_count++;
            addr6_count++; // INTERFACE only (no NAT for IPv6)
        }
        e_sock = e_sock->next;
    }

    size_t dyn = name_len + sock_count * sizeof(struct NODEINFO_IPV4_SOCKET_META)
               + addr_count * sizeof(struct NODEINFO_IPV4_ADDR)
               + sock6_count * sizeof(struct NODEINFO_IPV6_SOCKET_META)
               + addr6_count * sizeof(struct NODEINFO_IPV6_ADDR)
               + vc * sizeof(struct NODEINFO_IPV4_SUBNET)
               + vc6 * sizeof(struct NODEINFO_IPV6_SUBNET);

    int changed = 1;
    uint8_t old_ver = 0;
    if (bgp->local_node) {
        old_ver = bgp->local_node->node.ver;
        changed = (vc != (int)bgp->local_node->node.local_v4_subnets)
               || (sock_count != (int)bgp->local_node->node.local_v4_sockets)
               || (addr_count != (int)bgp->local_node->node.local_v4_addrs)
               || (name_len != bgp->local_node->node.node_name_len)
               || (memcmp(bgp->local_node->node.public_key, instance->my_keys.public_key, SC_PUBKEY_SIZE) != 0)
               || (vc6 != (int)bgp->local_node->node.local_v6_subnets)
               || (sock6_count != (int)bgp->local_node->node.local_v6_sockets)
               || (addr6_count != (int)bgp->local_node->node.local_v6_addrs);
    }

    if (changed) {
        if (bgp->local_node) u_free(bgp->local_node);
        bgp->local_node = u_calloc(1, sizeof(struct NODEINFO_Q) + dyn);
        if (!bgp->local_node) return -1;
        bgp->local_node->node.node_id = instance->node_id;
        bgp->local_node->node.hop_count = 0;
        bgp->local_node->node.ver = (old_ver % 255) + 1;
        bgp->local_node->node.local_v4_sockets = sock_count;
        bgp->local_node->node.local_v4_addrs = addr_count;
        bgp->local_node->node.local_v6_sockets = sock6_count;
        bgp->local_node->node.local_v6_addrs = addr6_count;
        bgp->local_node->node.local_v4_subnets = vc;
        bgp->local_node->node.local_v6_subnets = vc6;
        bgp->local_node->node.node_name_len = name_len;
        memcpy(bgp->local_node->node.public_key, instance->my_keys.public_key, SC_PUBKEY_SIZE);
        bgp->local_node->dirty = 1;
        bgp->local_node->last_ver = bgp->local_node->node.ver;

        uint8_t* dp = (uint8_t*)&bgp->local_node->node + sizeof(struct NODEINFO);
        if (name_len) { memcpy(dp, instance->name, name_len); dp += name_len; }

        // Write IPv4 socket meta
        struct NODEINFO_IPV4_SOCKET_META* meta = (struct NODEINFO_IPV4_SOCKET_META*)dp;
        e_sock = instance->etcp_sockets;
        int midx = 0;
        while (e_sock) {
            if (e_sock->local_addr.ss_family == AF_INET) {
                meta[midx].id = e_sock->sock_id;
                meta[midx].type = e_sock->nat_type;
                midx++;
            }
            e_sock = e_sock->next;
        }
        dp += sock_count * sizeof(struct NODEINFO_IPV4_SOCKET_META);

        // Write IPv4 addresses
        struct NODEINFO_IPV4_ADDR* addrs = (struct NODEINFO_IPV4_ADDR*)dp;
        int aidx = 0;
        e_sock = instance->etcp_sockets;
        while (e_sock) {
            if (e_sock->local_addr.ss_family == AF_INET) {
                struct sockaddr_in* if_sin = (struct sockaddr_in*)&e_sock->interface_addr;
                struct sockaddr_in* nat_sin = (struct sockaddr_in*)&e_sock->nat_addr;

                memcpy(addrs[aidx].addr, &if_sin->sin_addr.s_addr, 4);
                addrs[aidx].port = ntohs(if_sin->sin_port);
                addrs[aidx].type = ADDR_TYPE_INTERFACE;
                addrs[aidx].socket_id = e_sock->sock_id;
                aidx++;

                if (e_sock->nat_addr.ss_family == AF_INET && nat_sin->sin_addr.s_addr != 0) {
                    if (e_sock->nat_type != NAT_VERIFIED_STRICT) {
                        memcpy(addrs[aidx].addr, &nat_sin->sin_addr.s_addr, 4);
                        addrs[aidx].port = ntohs(nat_sin->sin_port);
                        addrs[aidx].type = ADDR_TYPE_NAT;
                        addrs[aidx].socket_id = e_sock->sock_id;
                        aidx++;
                    }
                }
                if (e_sock->nat_type == NAT_VERIFIED_DIRECT ||
                    (e_sock->type == CFG_SERVER_TYPE_PUBLIC && e_sock->nat_type < NAT_VERIFIED_UNKNOWN)) {
                    memcpy(addrs[aidx].addr, &if_sin->sin_addr.s_addr, 4);
                    addrs[aidx].port = ntohs(if_sin->sin_port);
                    addrs[aidx].type = ADDR_TYPE_REAL;
                    addrs[aidx].socket_id = e_sock->sock_id;
                    aidx++;
                }
            }
            e_sock = e_sock->next;
        }
        dp += addr_count * sizeof(struct NODEINFO_IPV4_ADDR);

        // Write IPv6 socket meta
        struct NODEINFO_IPV6_SOCKET_META* meta6 = (struct NODEINFO_IPV6_SOCKET_META*)dp;
        e_sock = instance->etcp_sockets;
        int m6idx = 0;
        while (e_sock) {
            if (e_sock->local_addr.ss_family == AF_INET6) {
                meta6[m6idx].id = e_sock->sock_id;
                meta6[m6idx].type = e_sock->nat_type;
                m6idx++;
            }
            e_sock = e_sock->next;
        }
        dp += sock6_count * sizeof(struct NODEINFO_IPV6_SOCKET_META);

        // Write IPv6 addresses (INTERFACE only)
        struct NODEINFO_IPV6_ADDR* addrs6 = (struct NODEINFO_IPV6_ADDR*)dp;
        int a6idx = 0;
        e_sock = instance->etcp_sockets;
        while (e_sock) {
            if (e_sock->local_addr.ss_family == AF_INET6) {
                struct sockaddr_in6* if_sin6 = (struct sockaddr_in6*)&e_sock->interface_addr;
                memcpy(addrs6[a6idx].addr, &if_sin6->sin6_addr, 16);
                addrs6[a6idx].port = ntohs(if_sin6->sin6_port);
                addrs6[a6idx].type = ADDR_TYPE_INTERFACE;
                addrs6[a6idx].socket_id = e_sock->sock_id;
                a6idx++;
            }
            e_sock = e_sock->next;
        }
        dp += addr6_count * sizeof(struct NODEINFO_IPV6_ADDR);

        // Write IPv4 subnets
        struct NODEINFO_IPV4_SUBNET* ra = (struct NODEINFO_IPV4_SUBNET*)dp;
        s = instance->config->my_subnets;
        while (s) {
            if (s->ip.family == AF_INET) { memcpy(ra->addr, &s->ip.addr.v4, 4); ra->prefix_length = s->netmask; ra++; }
            s = s->next;
        }
        dp += vc * sizeof(struct NODEINFO_IPV4_SUBNET);

        // Write IPv6 subnets
        struct NODEINFO_IPV6_SUBNET* ra6 = (struct NODEINFO_IPV6_SUBNET*)dp;
        s = instance->config->my_subnets;
        while (s) {
            if (s->ip.family == AF_INET6) { memcpy(ra6->addr, &s->ip.addr.v6, 16); ra6->prefix_length = s->netmask; ra6++; }
            s = s->next;
        }

        DEBUG_INFO(DEBUG_CATEGORY_BGP, "my_nodeinfo updated: v4s=%d v4a=%d v6s=%d v6a=%d v4sub=%d v6sub=%d ver=%d",
                   sock_count, addr_count, sock6_count, addr6_count, vc, vc6, bgp->local_node->node.ver);
    } else {
        bgp->local_node->last_ver = bgp->local_node->node.ver;
    }
    return vc;
}