/*
 * hp_tcp_services.c
 * Generic TCP listener + public API for honeypot services.
 * Service handlers live in services/svc_*.c
 */
#include "sdkconfig.h"

#ifdef CONFIG_MODULE_HONEYPOT

#include <errno.h>
#include "esp_log.h"
#include "services/svc_common.h"
#include "hp_tcp_services.h"

#define TAG "HP_SVC"

#define SVC_STACK_SIZE   4096
#define SVC_PRIORITY     4
#define SVC_CORE         1
#define ACCEPT_TIMEOUT_S 2
#define CLIENT_TIMEOUT_S 5

/* ============================================================
 * Service descriptors
 * ============================================================ */
static hp_svc_desc_t services[HP_SVC_COUNT] = {
    [HP_SVC_SSH]    = { .name = "ssh",    .port = 22 },
    [HP_SVC_TELNET] = { .name = "telnet", .port = 23 },
    [HP_SVC_HTTP]   = { .name = "http",   .port = 80 },
    [HP_SVC_FTP]    = { .name = "ftp",    .port = 21 },
};

static const hp_client_handler_t handlers[HP_SVC_COUNT] = {
    [HP_SVC_SSH]    = handle_ssh_client,
    [HP_SVC_TELNET] = handle_telnet_client,
    [HP_SVC_HTTP]   = handle_http_client,
    [HP_SVC_FTP]    = handle_ftp_client,
};

/* ============================================================
 * Name <-> ID mapping
 * ============================================================ */
int hp_svc_name_to_id(const char *name)
{
    for (int i = 0; i < HP_SVC_COUNT; i++) {
        if (strcmp(services[i].name, name) == 0)
            return i;
    }
    return -1;
}

const char *hp_svc_id_to_name(hp_svc_id_t svc)
{
    if (svc >= HP_SVC_COUNT) return "unknown";
    return services[svc].name;
}

/* ============================================================
 * Client IP helper
 * ============================================================ */
static void sockaddr_to_str(const struct sockaddr_in *addr,
                            char *ip_buf, size_t ip_len,
                            uint16_t *port_out)
{
    inet_ntoa_r(addr->sin_addr, ip_buf, ip_len);
    *port_out = ntohs(addr->sin_port);
}

/* ============================================================
 * Generic listener task
 * ============================================================ */
static void listener_task(void *arg)
{
    hp_svc_desc_t *svc = (hp_svc_desc_t *)arg;
    int listen_fd = -1;

    struct sockaddr_in addr = {
        .sin_family = AF_INET,
        .sin_port = htons(svc->port),
        .sin_addr.s_addr = htonl(INADDR_ANY),
    };

    listen_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (listen_fd < 0) {
        ESP_LOGE(TAG, "%s: socket() failed: %d", svc->name, errno);
        goto done;
    }

    int opt = 1;
    setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));

    if (bind(listen_fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
        ESP_LOGE(TAG, "%s: bind(%d) failed: %d", svc->name, svc->port, errno);
        goto done;
    }

    if (listen(listen_fd, 2) < 0) {
        ESP_LOGE(TAG, "%s: listen() failed: %d", svc->name, errno);
        goto done;
    }

    struct timeval tv = { .tv_sec = ACCEPT_TIMEOUT_S, .tv_usec = 0 };
    setsockopt(listen_fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));

    ESP_LOGI(TAG, "%s listening on port %d", svc->name, svc->port);
    svc->running = true;

    while (!svc->stop_req) {
        struct sockaddr_in client_addr;
        socklen_t clen = sizeof(client_addr);
        int client_fd = accept(listen_fd,
            (struct sockaddr *)&client_addr, &clen);

        if (client_fd < 0) {
            if (errno == EAGAIN || errno == EWOULDBLOCK)
                continue;
            ESP_LOGW(TAG, "%s: accept error: %d", svc->name, errno);
            continue;
        }

        struct timeval ctv = { .tv_sec = CLIENT_TIMEOUT_S, .tv_usec = 0 };
        setsockopt(client_fd, SOL_SOCKET, SO_RCVTIMEO, &ctv, sizeof(ctv));

        char client_ip[16];
        uint16_t client_port;
        sockaddr_to_str(&client_addr, client_ip, sizeof(client_ip),
                         &client_port);

        hp_svc_id_t id = (hp_svc_id_t)(svc - services);
        if (id < HP_SVC_COUNT && handlers[id]) {
            handlers[id](client_fd, client_ip, client_port, svc);
        }

        close(client_fd);
    }

done:
    if (listen_fd >= 0)
        close(listen_fd);
    svc->running = false;
    svc->stop_req = false;
    ESP_LOGI(TAG, "%s stopped", svc->name);
    svc->task = NULL;
    vTaskDelete(NULL);
}

/* ============================================================
 * Public API
 * ============================================================ */
void hp_svc_start(hp_svc_id_t svc)
{
    if (svc >= HP_SVC_COUNT) return;
    hp_svc_desc_t *d = &services[svc];
    if (d->running || d->task) {
        ESP_LOGW(TAG, "%s already running", d->name);
        return;
    }

    d->stop_req = false;
    d->connections = 0;
    d->auth_attempts = 0;

    char name[16];
    snprintf(name, sizeof(name), "hp_%s", d->name);
    BaseType_t ret = xTaskCreatePinnedToCore(listener_task, name, SVC_STACK_SIZE,
        d, SVC_PRIORITY, &d->task, SVC_CORE);
    if (ret != pdPASS) {
        ESP_LOGE(TAG, "Failed to create %s task", d->name);
        d->task = NULL;
    }
}

void hp_svc_stop(hp_svc_id_t svc)
{
    if (svc >= HP_SVC_COUNT) return;
    hp_svc_desc_t *d = &services[svc];
    if (!d->running && !d->task) {
        ESP_LOGW(TAG, "%s not running", d->name);
        return;
    }
    d->stop_req = true;
    ESP_LOGI(TAG, "%s stop requested", d->name);
}

bool hp_svc_running(hp_svc_id_t svc)
{
    if (svc >= HP_SVC_COUNT) return false;
    return services[svc].running;
}

int hp_svc_status(hp_svc_id_t svc, char *buf, size_t len)
{
    if (svc >= HP_SVC_COUNT) return 0;
    hp_svc_desc_t *d = &services[svc];
    return snprintf(buf, len,
        "service=%s running=%s port=%d connections=%lu auth_attempts=%lu",
        d->name,
        d->running ? "yes" : "no",
        d->port,
        (unsigned long)d->connections,
        (unsigned long)d->auth_attempts);
}

#endif /* CONFIG_MODULE_HONEYPOT */