#include <sys/prctl.h>
#include <unistd.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <linux/tcp.h>
#include <linux/netfilter.h> // for NF_ACCEPT
#include <libnetfilter_queue/libnetfilter_queue.h>
#include <linux/if_tun.h>
#include <MESA/MESA_prof_load.h>

#include <bpf_obj.h>
#include <tfe_utils.h>
#include <tfe_cmsg.h>
#include <proxy.h>
#include "io_uring.h"
#include "tfe_packet_io_fs.h"
#include "tfe_tcp_restore.h"
#include "acceptor_kni_v4.h"
#include "tap.h"
#include "tfe_packet_io.h"
#include "tfe_session_table.h"
#include "tfe_fieldstat.h"


void * g_packet_io_logger = NULL;

static int tap_read(int tap_fd, char *buff, int buff_size, void *logger)
{
    int ret = read(tap_fd, buff, buff_size);
    if (ret < 0)
    {
        if (errno != EWOULDBLOCK && errno != EAGAIN)
        {
            TFE_LOG_ERROR(logger, "%s: unable to read data from tapfd %d, aborting: %s", LOG_TAG_PKTIO, tap_fd, strerror(errno));
        }
    }

    return ret;
}

static struct tfe_fieldstat_metric_t *create_fieldstat_instance(const char *profile, const char *section, int max_thread, void *logger)
{
	int cycle=0;
	unsigned short telegraf_port=0;
	char telegraf_ip[TFE_STRING_MAX]={0};
	char app_name[TFE_STRING_MAX]={0};
    struct tfe_fieldstat_metric_t *dynamic_fieldstat=NULL;

	MESA_load_profile_short_nodef(profile, section, "telegraf_port", (short *)&(telegraf_port));
	MESA_load_profile_string_nodef(profile, section, "telegraf_ip", telegraf_ip, sizeof(telegraf_ip));
	MESA_load_profile_string_def(profile, section, "app_name", app_name, sizeof(app_name), "metric");
	MESA_load_profile_int_def(profile, section, "cycle", &cycle, 1000);

    dynamic_fieldstat = tfe_fieldstat_metric_create(telegraf_ip, telegraf_port, app_name, cycle, max_thread, logger);
    if (dynamic_fieldstat == NULL)
    {
        TFE_LOG_ERROR(logger, "tfe fieldstat init failed, error to create fieldstat metric.");
        return NULL;
    }
    TFE_LOG_INFO(logger, "tfe fieldstat telegraf_ip     : %s", telegraf_ip);
	TFE_LOG_INFO(logger, "tfe fieldstat telegraf_port   : %d", telegraf_port);
    TFE_LOG_INFO(logger, "tfe fieldstat app_name        : %s", app_name);
    TFE_LOG_INFO(logger, "tfe fieldstat cycle           : %d", cycle);

    return dynamic_fieldstat;
}

void acceptor_kni_v4_destroy(struct acceptor_kni_v4 *ctx)
{
    if (ctx)
    {
        packet_io_destory(ctx->io);
        packet_io_fs_destory(ctx->packet_io_fs);
        tfe_fieldstat_metric_destroy(ctx->metric);
        free(ctx);
        ctx = NULL;
    }
    return;
}

struct acceptor_kni_v4 *acceptor_ctx_create(const char *profile, void *logger)
{
    struct acceptor_kni_v4 *ctx = ALLOC(struct acceptor_kni_v4, 1);

    MESA_load_profile_int_def(profile, "PACKET_IO", "firewall_sids", (int *)&(ctx->firewall_sids), 1000);
    MESA_load_profile_int_def(profile, "PACKET_IO", "proxy_sids", (int *)&(ctx->proxy_sids), 1001);
    MESA_load_profile_int_def(profile, "PACKET_IO", "service_chaining_sids", (int *)&(ctx->sce_sids), 1002);
    MESA_load_profile_int_def(profile, "PACKET_IO", "packet_io_debug", (int *)&(ctx->debug), 0);
    MESA_load_profile_int_def(profile, "PACKET_IO", "packet_io_threads", (int *)&(ctx->nr_worker_threads), 8);
    MESA_load_profile_uint_range(profile, "PACKET_IO", "packet_io_cpu_affinity_mask", TFE_THREAD_MAX, (unsigned int *)ctx->cpu_affinity_mask);
    ctx->nr_worker_threads = MIN(ctx->nr_worker_threads, TFE_THREAD_MAX);

    CPU_ZERO(&ctx->coremask);
    for (int i = 0; i < ctx->nr_worker_threads; i++)
    {
        int cpu_id = ctx->cpu_affinity_mask[i];
        CPU_SET(cpu_id, &ctx->coremask);
    }

    ctx->io = packet_io_create(profile, ctx->nr_worker_threads, &ctx->coremask, logger);
    if (ctx->io == NULL)
    {
        goto error_out;
    }

    ctx->packet_io_fs = packet_io_fs_create(profile);
    if (ctx->packet_io_fs == NULL)
    {
        goto error_out;
    }

    ctx->metric = create_fieldstat_instance(profile, "proxy_hits", ctx->nr_worker_threads, logger);
    if(ctx->metric == NULL)
    {
        goto error_out;
    }

    return ctx;

error_out:
    acceptor_kni_v4_destroy(ctx);
    return NULL;
}

static void *worker_thread_cycle(void *arg)
{
    struct packet_io_thread_ctx *thread_ctx = (struct packet_io_thread_ctx *)arg;
    struct packet_io *handle = thread_ctx->ref_io;
    void * logger = thread_ctx->logger;

    int pkg_len = 0;
    char thread_name[16];
    int n_pkt_recv_from_nf = 0;
    int n_pkt_recv_from_tap = 0;
    int n_pkt_recv_from_tap_c = 0;
    int n_pkt_recv_from_tap_s = 0;

    snprintf(thread_name, sizeof(thread_name), "pkt:worker-%d", thread_ctx->thread_index);
    prctl(PR_SET_NAME, (unsigned long long)thread_name, NULL, NULL, NULL);

    while (!worker_thread_ready) {
        sleep(1);
    }

    if (packet_io_thread_init(handle, thread_ctx, logger) != 0)
    {
        goto error_out;
    }

    if (is_enable_iouring(handle)) {
        io_uring_register_read_callback(thread_ctx->tap_ctx->io_uring_fd, handle_raw_packet_from_tap, thread_ctx);
        io_uring_register_read_callback(thread_ctx->tap_ctx->io_uring_c, handle_decryption_packet_from_tap, thread_ctx);
        io_uring_register_read_callback(thread_ctx->tap_ctx->io_uring_s, handle_decryption_packet_from_tap, thread_ctx);
    }
    else {
        thread_ctx->tap_ctx->buff_size = 3000;
        thread_ctx->tap_ctx->buff = ALLOC(char, thread_ctx->tap_ctx->buff_size);
    }

    TFE_LOG_INFO(logger, "%s: worker thread %d is running", "LOG_TAG_KNI", thread_ctx->thread_index);

    while(1) {
        n_pkt_recv_from_nf = packet_io_polling_nf_interface(handle, thread_ctx->thread_index, thread_ctx);
        if (is_enable_iouring(handle)) {
            n_pkt_recv_from_tap = io_uring_peek_ready_entrys(thread_ctx->tap_ctx->io_uring_fd);
            n_pkt_recv_from_tap_c = io_uring_peek_ready_entrys(thread_ctx->tap_ctx->io_uring_c);
            n_pkt_recv_from_tap_s = io_uring_peek_ready_entrys(thread_ctx->tap_ctx->io_uring_s);
        }
        else {
            if ((pkg_len = tap_read(thread_ctx->tap_ctx->tap_fd, thread_ctx->tap_ctx->buff, thread_ctx->tap_ctx->buff_size, logger)) > 0)
            {
                handle_raw_packet_from_tap(thread_ctx->tap_ctx->buff, pkg_len, thread_ctx);
            }

            if ((pkg_len = tap_read(thread_ctx->tap_ctx->tap_c, thread_ctx->tap_ctx->buff, thread_ctx->tap_ctx->buff_size, logger)) > 0)
            {
                handle_decryption_packet_from_tap(thread_ctx->tap_ctx->buff, pkg_len, thread_ctx);
            }

            if ((pkg_len = tap_read(thread_ctx->tap_ctx->tap_s, thread_ctx->tap_ctx->buff, thread_ctx->tap_ctx->buff_size, logger)) > 0)
            {
                handle_decryption_packet_from_tap(thread_ctx->tap_ctx->buff, pkg_len, thread_ctx);
            }
        }

        if (n_pkt_recv_from_nf == 0 && n_pkt_recv_from_tap == 0 && n_pkt_recv_from_tap_c == 0 && n_pkt_recv_from_tap_s == 0)
        {
            packet_io_thread_wait(handle, thread_ctx, -1);
        }

        if (__atomic_fetch_add(&thread_ctx->session_table_need_reset, 0, __ATOMIC_RELAXED) > 0)
        {
            session_table_reset(thread_ctx->session_table);
            __atomic_fetch_and(&thread_ctx->session_table_need_reset, 0, __ATOMIC_RELAXED);
        }
    }

error_out:
    TFE_LOG_ERROR(logger, "%s: worker thread %d exiting", LOG_TAG_SCE, thread_ctx->thread_index);
    return (void *)NULL;
}

struct acceptor_kni_v4 *acceptor_kni_v4_create(struct tfe_proxy *proxy, const char *profile)
{
    void *packet_io_logger = NULL;
    packet_io_logger = (void *)MESA_create_runtime_log_handle("packet_io", RLOG_LV_DEBUG);
    assert(packet_io_logger != NULL);

    g_packet_io_logger = packet_io_logger;
    struct acceptor_kni_v4 *acceptor_ctx = acceptor_ctx_create(profile, packet_io_logger);
    if (acceptor_ctx == NULL)
        return NULL;

    acceptor_ctx->ref_proxy = proxy;
    for (int i = 0; i < acceptor_ctx->nr_worker_threads; i++) {
        acceptor_ctx->work_threads[i].tid = 0;
        acceptor_ctx->work_threads[i].thread_index = i;
        acceptor_ctx->work_threads[i].ref_io = acceptor_ctx->io;
        acceptor_ctx->work_threads[i].ref_acceptor_ctx = acceptor_ctx;

        acceptor_ctx->work_threads[i].tap_ctx = tfe_tap_ctx_create(&acceptor_ctx->work_threads[i]);
        if (acceptor_ctx->work_threads[i].tap_ctx == NULL)
            goto error_out;

        acceptor_ctx->work_threads[i].session_table = session_table_create();
        acceptor_ctx->work_threads[i].ref_proxy = proxy;
        acceptor_ctx->work_threads[i].ret_fs_state = acceptor_ctx->packet_io_fs;
        acceptor_ctx->work_threads[i].logger = packet_io_logger;
        acceptor_ctx->work_threads[i].session_table_need_reset = 0;
    }

    for (int i = 0; i < acceptor_ctx->nr_worker_threads; i++) {
        struct packet_io_thread_ctx *thread_ctx = &acceptor_ctx->work_threads[i];
        if (pthread_create(&thread_ctx->tid, NULL, worker_thread_cycle, (void *)thread_ctx) < 0)
        {
            goto error_out;
        }
    }

    return acceptor_ctx;

error_out:
    for (int i = 0; i < acceptor_ctx->nr_worker_threads; i++) {
        tfe_tap_ctx_destory(acceptor_ctx->work_threads[i].tap_ctx);
        session_table_destory(acceptor_ctx->work_threads[i].session_table);
    }

    acceptor_kni_v4_destroy(acceptor_ctx);
    return NULL;
}