/**
 * @file test_route_ping.c
 * @brief Интеграционный тест route_ping через три инстанса
 *
 * Топология: A -> B -> C
 * - A отправляет запрос route_ping на B для узла C
 * - B пингует C через ETCP ping
 * - C отвечает PONG
 * - B отправляет BGP_PING_RESPONSE на A
 * - A получает ответ через route_ping_send_req callback
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "test_utils.h"
#include "etcp.h"
#include "etcp_connections.h"
#include "../src/config_parser.h"
#include "../src/config_updater.h"
#include "../src/utun_instance.h"
#include "routing.h"
#include "topo_group.h"
#include "route_ping.h"
#include "../src/tun_if.h"
#include "secure_channel.h"
#include "../lib/u_async.h"
#include "../lib/debug_config.h"

#define TEST_TIMEOUT_MS 10000
static uint64_t g_node_id_a = 0;
static uint64_t g_node_id_b = 0;
static uint64_t g_node_id_c = 0;

static struct UTUN_INSTANCE* inst_a = NULL;
static struct UTUN_INSTANCE* inst_b = NULL;
static struct UTUN_INSTANCE* inst_c = NULL;
static struct UASYNC* ua = NULL;
static int test_timed_out = 0;
static void* test_timeout_id = NULL;

static char temp_dir[] = "/tmp/utun_route_ping_test_XXXXXX";
static char config_a[256];
static char config_b[256];
static char config_c[256];

static struct {
    int done;
    int success;
    uint16_t avg_rtt;
    uint8_t count_sent;
    uint8_t count_ok;
} ping_result;

static int write_config(const char* path, const char* content) {
    FILE* f = fopen(path, "w");
    if (!f) return -1;
    fprintf(f, "%s", content);
    fclose(f);
    return 0;
}

static char* get_pubkey_from_config(const char* path) {
    struct utun_config* cfg = parse_config(path);
    if (!cfg) return NULL;
    char* pub = strdup(cfg->global.my_public_key_hex);
    free_config(cfg);
    return pub;
}

static int create_temp_configs(void) {
    if (test_mkdtemp(temp_dir) != 0) {
        fprintf(stderr, "Failed to create temp directory\n");
        return -1;
    }
    snprintf(config_a, sizeof(config_a), "%s/a.conf", temp_dir);
    snprintf(config_b, sizeof(config_b), "%s/b.conf", temp_dir);
    snprintf(config_c, sizeof(config_c), "%s/c.conf", temp_dir);

    // 1. Config C (no keys)
    const char* tpl_c =
        "[global]\n"
        "tun_ip=10.100.0.3/24\n"
        "tun_ifname=tun102\n"
        "\n"
        "[server:test_c]\n"
        "addr=127.0.0.1:39013\n"
        "type=public\n"
        "\n"
        "[allowed_keys]\n"
        "allow_all=1\n";
    if (write_config(config_c, tpl_c) != 0) return -1;
    if (config_ensure_keys_and_node_id(config_c) != 0) return -1;
    char* pub_c = get_pubkey_from_config(config_c);
    if (!pub_c) return -1;

    // 2. Config B (no own keys, but needs peer_public_key of C)
    char tpl_b[4096];
    snprintf(tpl_b, sizeof(tpl_b),
        "[global]\n"
        "tun_ip=10.100.0.2/24\n"
        "tun_ifname=tun101\n"
        "\n"
        "[server:test_b]\n"
        "addr=127.0.0.1:39012\n"
        "type=public\n"
        "\n"
        "[allowed_keys]\n"
        "allow_all=1\n"
        "\n"
        "[client:to_c]\n"
        "keepalive=1\n"
        "peer_public_key=%s\n"
        "link=test_b:127.0.0.1:39013\n",
        pub_c);
    free(pub_c);
    if (write_config(config_b, tpl_b) != 0) return -1;
    if (config_ensure_keys_and_node_id(config_b) != 0) return -1;
    char* pub_b = get_pubkey_from_config(config_b);
    if (!pub_b) return -1;

    // 3. Config A (no own keys, but needs peer_public_key of B)
    char tpl_a[4096];
    snprintf(tpl_a, sizeof(tpl_a),
        "[global]\n"
        "tun_ip=10.100.0.1/24\n"
        "tun_ifname=tun100\n"
        "\n"
        "[server:test_a]\n"
        "addr=127.0.0.1:39011\n"
        "type=public\n"
        "\n"
        "[allowed_keys]\n"
        "allow_all=1\n"
        "\n"
        "[client:to_b]\n"
        "keepalive=1\n"
        "peer_public_key=%s\n"
        "link=test_a:127.0.0.1:39012\n",
        pub_b);
    free(pub_b);
    if (write_config(config_a, tpl_a) != 0) return -1;
    if (config_ensure_keys_and_node_id(config_a) != 0) return -1;

    return 0;
}

static void cleanup_temp_configs(void) {
    test_unlink(config_a);
    test_unlink(config_b);
    test_unlink(config_c);
    test_rmdir(temp_dir);
}

static int has_initialized_link(struct UTUN_INSTANCE* inst) {
    if (!inst || !inst->connections) return 0;
    struct ll_entry* entry = inst->connections->head;
    while (entry) {
        struct conn_queue_entry* ce = (struct conn_queue_entry*)entry->data;
        struct ETCP_CONN* conn = ce->conn;
        struct ETCP_LINK* link = conn->links;
        while (link) {
            if (link->initialized) return 1;
            link = link->next;
        }
        entry = entry->next;
    }
    return 0;
}

static struct ETCP_CONN* find_conn_to_peer(struct UTUN_INSTANCE* inst, uint64_t peer_node_id) {
    if (!inst || !inst->connections) return NULL;
    struct ll_entry* entry = queue_find_data_by_index(inst->connections, (const uint8_t*)&peer_node_id);
    return entry ? ((struct conn_queue_entry*)entry->data)->conn : NULL;
}

static void test_timeout_cb(void* arg) {
    (void)arg;
    test_timed_out = 1;
    DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "test_route_ping: overall test timeout");
}

static void ping_resp_cb(int success, uint16_t avg_rtt, uint8_t count_sent, uint8_t count_ok, void* arg) {
    (void)arg;
    ping_result.done = 1;
    ping_result.success = success;
    ping_result.avg_rtt = avg_rtt;
    ping_result.count_sent = count_sent;
    ping_result.count_ok = count_ok;
    DEBUG_INFO(DEBUG_CATEGORY_BGP, "ping_resp_cb: success=%d avg_rtt=%u sent=%u ok=%u",
               success, (unsigned)avg_rtt, (unsigned)count_sent, (unsigned)count_ok);
}

int main(void) {
    int test_result = 1;
    debug_config_init();
    debug_set_level(DEBUG_LEVEL_INFO);
    debug_set_categories(DEBUG_CATEGORY_ETCP | DEBUG_CATEGORY_BGP | DEBUG_CATEGORY_ROUTING);
    utun_instance_set_tun_init_enabled(0);

    if (create_temp_configs() != 0) {
        fprintf(stderr, "Failed to create temp configs\n");
        return 1;
    }

    ua = uasync_create();
    if (!ua) {
        cleanup_temp_configs();
        return 1;
    }

    inst_a = utun_instance_create(ua, config_a);
    inst_b = utun_instance_create(ua, config_b);
    inst_c = utun_instance_create(ua, config_c);
    if (!inst_a || !inst_b || !inst_c) {
        DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "Failed to create instances");
        goto cleanup;
    }

    if (utun_instance_init(inst_a) != 0 || utun_instance_init(inst_b) != 0 || utun_instance_init(inst_c) != 0) {
        DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "Failed to init connections");
        goto cleanup;
    }

    g_node_id_a = inst_a->node_id; g_node_id_b = inst_b->node_id; g_node_id_c = inst_c->node_id;

    test_timeout_id = uasync_set_timeout(ua, TEST_TIMEOUT_MS * 10, NULL, test_timeout_cb, "test_route_ping");

    // 1. Wait for links A->B and B->C to initialize
    DEBUG_INFO(DEBUG_CATEGORY_ETCP, "Waiting for ETCP links to initialize...");
    while (!test_timed_out) {
        if (has_initialized_link(inst_a) && has_initialized_link(inst_b)) {
            DEBUG_INFO(DEBUG_CATEGORY_ETCP, "Links initialized");
            break;
        }
        uasync_poll(ua, 10);
    }
    if (test_timed_out) {
        DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "Timeout waiting for links");
        goto cleanup;
    }

    // 2. Wait for BGP exchange so B learns C (registry has C's nodeinfo + addresses)
    DEBUG_INFO(DEBUG_CATEGORY_BGP, "Waiting for BGP exchange (B learns C)...");
    int bgp_wait_cycles = 0;
    while (!test_timed_out && bgp_wait_cycles < 500) {
        struct TOPO_NODE* ni_c = topo_node_registry_find(inst_b->topo_groups, g_node_id_c);
        if (ni_c && ni_c->v4_addrs) {
            DEBUG_INFO(DEBUG_CATEGORY_BGP, "B learned about C");
            break;
        }
        uasync_poll(ua, 10);
        bgp_wait_cycles++;
    }
    if (!topo_node_registry_find(inst_b->topo_groups, g_node_id_c)) {
        DEBUG_ERROR(DEBUG_CATEGORY_BGP, "B did not learn about C in time");
        goto cleanup;
    }

    // 3. Get target info for C and send route ping request from A to B
    struct ETCP_CONN* conn_ab = find_conn_to_peer(inst_a, g_node_id_b);
    if (!conn_ab) {
        DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "A has no connection to B");
        goto cleanup;
    }

    /* Получаем target IP:port из nodeinfo узла C */
    /* addr[] в network byte order, port в host byte order */
    uint32_t target_ip = 0;
    uint16_t target_port = 0;
    struct TOPO_GROUP_NODE* nq = topo_groups_get_default(inst_b->topo_groups) ? topo_node_find_by_id(topo_groups_get_default(inst_b->topo_groups), g_node_id_c) : NULL;
    struct TOPO_NODE* ni = nq ? topo_node_registry_find(inst_b->topo_groups, nq->node_id) : NULL;
    if (nq && ni) {
        const struct TOPO_ADDR4* a = ni->v4_addrs;
        if (a) {
            memcpy(&target_ip, a->addr, 4);
            target_port = a->port;
        }
    }
    if (target_ip == 0 || target_port == 0) {
        DEBUG_ERROR(DEBUG_CATEGORY_BGP, "Cannot resolve target for node C");
        goto cleanup;
    }

    DEBUG_INFO(DEBUG_CATEGORY_BGP, "Sending route ping request A->B for C (%s:%u)",
               ip_to_str(&target_ip, AF_INET).str, (unsigned)target_port);
    memset(&ping_result, 0, sizeof(ping_result));
    int ret = route_ping_send_req_addr(inst_a->nat_det, topo_groups_get_default(inst_a->topo_groups), conn_ab, target_ip, target_port,
                                        3,   // count
                                        10,  // interval_ms
                                        200, // timeout_ms
                                        5000,// wait_timeout_ms
                                        ping_resp_cb, NULL,
                                        ni ? ni->public_key : NULL);
    if (ret != 0) {
        DEBUG_ERROR(DEBUG_CATEGORY_BGP, "route_ping_send_req_addr failed: %d", ret);
        goto cleanup;
    }

    // 4. Wait for response
    DEBUG_INFO(DEBUG_CATEGORY_BGP, "Waiting for route ping response...");
    while (!test_timed_out && !ping_result.done) {
        uasync_poll(ua, 10);
    }

    if (test_timed_out) {
        DEBUG_ERROR(DEBUG_CATEGORY_BGP, "Timeout waiting for ping response");
        goto cleanup;
    }

    // 5. Verify results
    if (!ping_result.success) {
        DEBUG_ERROR(DEBUG_CATEGORY_BGP, "Ping reported failure (success=0)");
        goto cleanup;
    }
    if (ping_result.count_ok == 0) {
        DEBUG_ERROR(DEBUG_CATEGORY_BGP, "Ping count_ok is zero");
        goto cleanup;
    }
    if (ping_result.avg_rtt == 0) {
        DEBUG_ERROR(DEBUG_CATEGORY_BGP, "Ping avg_rtt is zero");
        goto cleanup;
    }

    DEBUG_INFO(DEBUG_CATEGORY_BGP, "Route ping test PASSED: sent=%u ok=%u avg_rtt=%u",
               (unsigned)ping_result.count_sent, (unsigned)ping_result.count_ok, (unsigned)ping_result.avg_rtt);
    test_result = 0;

cleanup:
    if (test_timeout_id) uasync_cancel_timeout(ua, test_timeout_id);
    if (inst_a) utun_instance_destroy(inst_a);
    if (inst_b) utun_instance_destroy(inst_b);
    if (inst_c) utun_instance_destroy(inst_c);
    if (ua) uasync_destroy(ua, 0);
    cleanup_temp_configs();
    return test_result;
}