#include <assert.h>
#include <string.h>
#include "utun_instance.h"
#include "routing_layer/topo_group.h"
#include "transport_layer/etcp.h"
#include "transport_layer/etcp_api.h"
#include "transport_layer/node_conn_direct.h"
#include "../lib/u_async.h"
#include "../lib/debug_config.h"

static struct TOPO_GROUP_CONN_ITEM* peer(struct TOPO_GROUP* group) {
    assert(group->senders_list->head && !group->senders_list->head->next);
    return (struct TOPO_GROUP_CONN_ITEM*)group->senders_list->head->data;
}

static void receive(struct ETCP_CONN* conn, uint64_t group_id, uint8_t cmd, uint64_t exchange_id, size_t length) {
    struct TOPOMSG_TABLE_REQ msg = { .cmd = ETCP_ID_TOPO_ENTRY, .subcmd = cmd,
                                   .group_id = group_id, .exchange_id = exchange_id };
    assert(length <= sizeof(msg));
    struct ll_entry* packet = ll_alloc_lldgram(sizeof(msg)); assert(packet);
    memcpy(packet->dgram, &msg, sizeof(msg)); packet->len = length;
    conn->instance->api_bindings.callbacks[ETCP_ID_TOPO_ENTRY](conn, packet);
}

static void complete(struct TOPO_GROUP* group, struct ETCP_CONN* conn, uint64_t exchange_id) {
    receive(conn, group->group_id, TOPO_SUBCMD_TABLE_COMPLETE, exchange_id, sizeof(struct TOPOMSG_TABLE_REQ));
}

static void request(struct TOPO_GROUP* group, struct ETCP_CONN* conn) {
    receive(conn, group->group_id, TOPO_SUBCMD_REQUEST_TABLE, 123, sizeof(struct TOPOMSG_TABLE_REQ));
}

int main(void) {
    debug_config_init(); debug_set_level(DEBUG_LEVEL_INFO);
    utun_instance_set_tun_init_enabled(0);
    struct UASYNC* ua = uasync_create(); assert(ua);
    struct UTUN_INSTANCE* inst = utun_instance_create_from_str(ua,
        "[global]\n"
        "my_private_key=704f2e012c8fa8768130cb0f988a997dccb628372bc5ceccacc78dcbfec5916f\n"
        "my_public_key=b3193173def895bd0fcea6f86af077c7d77216f10395275f627ac18242ec0f01\n"
        "[server: udp]\naddr=127.0.0.1:0\ntype=public\n");
    assert(inst && utun_instance_init(inst) == 0);
    struct TOPO_GROUP* a = topo_groups_create_group(inst->topo_groups, 42, TOPO_GROUP_TYPE_UTUN, NULL);
    struct TOPO_GROUP* b = topo_groups_create_group(inst->topo_groups, 43, TOPO_GROUP_TYPE_UTUN, NULL);
    assert(a && b);
    struct SC_MYKEYS keys; assert(sc_generate_keypair(&keys) == SC_OK);
    struct TOPO_ADDR4 addr = { .addr = {127, 0, 0, 1}, .port = 9, .protocol = TOPO_PROTO_UDP };
    struct TOPO_NODE node = { .v4_addrs = &addr };
    memcpy(node.public_key, keys.public_key, SC_PUBKEY_SIZE);
    node.node_id = sc_derive_node_id_from_pubkey(node.public_key);
    struct NODE_CONN_DIRECT* owner = NULL;
    assert(node_conn_direct_open_node(inst, node.node_id, NULL, NULL, &owner, &node, NULL) == NCD_NEW);
    struct ETCP_CONN* conn = node_conn_direct_get_conn(owner); assert(conn);
    /* Детерминированная доставка управляющих пакетов через штатный BGP receiver.
     * Event loop не запускаем: транспортный handshake проверяют интеграционные тесты. */
    conn->links_up = 1;
    assert(topo_group_new_conn(a, conn) == 0 && topo_group_new_conn(b, conn) == 0);
    uint64_t a_id = peer(a)->exchange_id, b_id = peer(b)->exchange_id;
    assert(a_id && b_id && a_id != b_id);
    assert(!topo_group_peer_ready(a, node.node_id) && !topo_group_peer_ready(b, node.node_id));
    complete(a, conn, b_id);
    receive(conn, a->group_id, TOPO_SUBCMD_TABLE_COMPLETE, a_id, 2);
    assert(!peer(a)->table_received);
    complete(a, conn, a_id);
    assert(peer(a)->table_received && !topo_group_peer_ready(a, node.node_id));
    request(a, conn);
    assert(topo_group_peer_ready(a, node.node_id) && !topo_group_peer_ready(b, node.node_id));
    assert(topo_group_new_conn(a, conn) == 0 && peer(a)->exchange_id == a_id);
    receive(conn, a->group_id, TOPO_SUBCMD_JOIN_GROUP, 0, sizeof(struct TOPOMSG_JOIN_GROUP));
    assert(peer(a)->exchange_id == a_id);
    assert(queue_entry_count(a->senders_list) == 1 && topo_group_peer_ready(a, node.node_id));
    /* Другой порядок доставки: сначала наш снимок, потом подтверждение чужого. */
    request(b, conn);
    assert(!topo_group_peer_ready(b, node.node_id));
    complete(b, conn, b_id);
    assert(topo_group_peer_ready(b, node.node_id));

    etcp_fire_conn_status(conn, ETCP_CONN_STATUS_REINIT);
    assert(peer(a)->exchange_id != a_id && peer(b)->exchange_id != b_id);
    assert(!topo_group_peer_ready(a, node.node_id) && !topo_group_peer_ready(b, node.node_id));
    complete(a, conn, a_id); complete(b, conn, b_id);
    assert(!peer(a)->table_received && !peer(b)->table_received);
    /* Ошибка отправки снимка не разрешает TABLE_COMPLETE и READY. */
    int saved_limit = conn->send_input_q->size_limit;
    conn->send_input_q->size_limit = 0;
    request(a, conn);
    assert(!peer(a)->table_sent);
    conn->send_input_q->size_limit = saved_limit;
    complete(a, conn, peer(a)->exchange_id); request(a, conn);
    assert(topo_group_peer_ready(a, node.node_id));

    a_id = peer(a)->exchange_id;
    topo_group_remove_conn(a, conn, TOPO_REMOVE_LOCAL_LEAVE);
    complete(a, conn, a_id);
    assert(!topo_group_peer_ready(a, node.node_id));
    assert(topo_group_new_conn(a, conn) == 0 && peer(a)->exchange_id != a_id);
    complete(a, conn, a_id); request(a, conn);
    assert(!topo_group_peer_ready(a, node.node_id));
    complete(a, conn, peer(a)->exchange_id);
    assert(topo_group_peer_ready(a, node.node_id) && !topo_group_peer_ready(b, node.node_id));
    conn->links_up = 0;
    assert(!topo_group_peer_ready(a, node.node_id));
    node_conn_direct_close(owner);
    inst->running = 0; utun_instance_destroy(inst);
    uasync_poll(ua, 0); uasync_destroy(ua, 0);
    DEBUG_INFO(DEBUG_CATEGORY_BGP, "group exchange: isolation, duplicate attach, stale replies, send failure and REINIT passed");
    return 0;
}