#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <pthread.h>
#include <sys/prctl.h>

#include "sce.h"
#include "log.h"
#include "utils.h"
#include "sf_metrics.h"
#include "health_check.h"
#include "global_metrics.h"

static void sig_handler(int signo)
{
    if (signo == SIGHUP)
    {
        LOG_INFO("%s: recv SIGHUP, reload zlog.conf", LOG_TAG_SCE);
        LOG_RELOAD();
    }
}

static int thread_set_affinity(int core_id)
{
    int num_cores = sysconf(_SC_NPROCESSORS_ONLN);
    if (core_id < 0 || core_id >= num_cores)
    {
        return EINVAL;
    }

    cpu_set_t cpuset;
    CPU_ZERO(&cpuset);
    CPU_SET(core_id, &cpuset);

    return pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);
}

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

    char thread_name[16];
    snprintf(thread_name, sizeof(thread_name), "sce:worker-%d", thread_ctx->thread_index);
    prctl(PR_SET_NAME, (unsigned long long)thread_name, NULL, NULL, NULL);

    char affinity[32] = {0};
    if (thread_ctx->cpu_mask >= 0)
    {
        thread_set_affinity(thread_ctx->cpu_mask);
        snprintf(affinity, sizeof(affinity), "affinity cpu%d", thread_ctx->cpu_mask);
    }

    LOG_INFO("%s: worker thread %d %s is running", LOG_TAG_SCE, thread_ctx->thread_index, thread_ctx->cpu_mask >= 0 ? affinity : "");

    while (1)
    {
        n_packet_recv = packet_io_polling_nf_interface(handle, thread_ctx->thread_index, thread_ctx);
        if (n_packet_recv)
        {
            // LOG_INFO("%s: worker thread %d recv %03d packets from nf_interface", LOG_TAG_SCE, thread_ctx->thread_index, n_packet_recv);
        }

        n_packet_recv = packet_io_polling_endpoint(handle, thread_ctx->thread_index, thread_ctx);
        if (n_packet_recv)
        {
            // LOG_INFO("%s: worker thread %d recv %03d packets from endpoint", LOG_TAG_SCE, thread_ctx->thread_index, n_packet_recv);
        }

        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);
        }

        if (__atomic_fetch_add(&thread_ctx->sf_metrics_need_send, 0, __ATOMIC_RELAXED) > 0)
        {
            sf_metrics_send(thread_ctx->sf_metrics);
            sf_metrics_reset(thread_ctx->sf_metrics);
            __atomic_fetch_and(&thread_ctx->sf_metrics_need_send, 0, __ATOMIC_RELAXED);
        }
    }

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

int main(int argc, char **argv)
{
    const char *profile = "./conf/sce.conf";

    if (LOG_INIT("./conf/zlog.conf") == -1)
    {
        return -1;
    }

    if (signal(SIGHUP, sig_handler) == SIG_ERR)
    {
        LOG_ERROR("%s: unable to register SIGHUP signal handler, error %d: %s", LOG_TAG_SCE, errno, strerror(errno));
        LOG_CLOSE();
        return -1;
    }

    health_check_session_init(profile);

    struct sce_ctx *ctx = sce_ctx_create(profile);
    if (ctx == NULL)
    {
        LOG_CLOSE();
        return -1;
    }

    for (int i = 0; i < ctx->nr_worker_threads; i++)
    {
        ctx->work_threads[i].tid = 0;
        ctx->work_threads[i].thread_index = i;
        ctx->work_threads[i].session_table = session_table_create();
        ctx->work_threads[i].sf_metrics = sf_metrics_create(profile);
        ctx->work_threads[i].ref_io = ctx->io;
        ctx->work_threads[i].ref_metrics = ctx->metrics;
        ctx->work_threads[i].ref_enforcer = ctx->enforcer;
        ctx->work_threads[i].ref_sce_ctx = ctx;
        ctx->work_threads[i].session_table_need_reset = 0;
        ctx->work_threads[i].sf_metrics_need_send = 0;
        ctx->work_threads[i].cpu_mask = ctx->enable_cpu_affinity ? ctx->cpu_affinity_mask[i] : -1;
    }

    for (int i = 0; i < ctx->nr_worker_threads; i++)
    {
        struct thread_ctx *thread_ctx = &ctx->work_threads[i];
        if (pthread_create(&thread_ctx->tid, NULL, worker_thread_cycle, (void *)thread_ctx) < 0)
        {
            LOG_ERROR("%s: unable to create worker thread %d, error %d: %s", LOG_TAG_SCE, i, errno, strerror(errno));
            goto error_out;
        }
    }

    struct timespec current_time;
    struct timespec g_metrics_last_send_time;
    struct timespec sf_metrics_last_send_time;

    clock_gettime(CLOCK_MONOTONIC, &current_time);
    clock_gettime(CLOCK_MONOTONIC, &g_metrics_last_send_time);
    clock_gettime(CLOCK_MONOTONIC, &sf_metrics_last_send_time);

    while (1)
    {
        if (current_time.tv_sec - g_metrics_last_send_time.tv_sec >= ctx->metrics->config.statsd_cycle)
        {
            clock_gettime(CLOCK_MONOTONIC, &g_metrics_last_send_time);
            global_metrics_dump(ctx->metrics);
        }

        if (current_time.tv_sec - sf_metrics_last_send_time.tv_sec >= sf_metrics_get_interval(ctx->work_threads[0].sf_metrics))
        {
            clock_gettime(CLOCK_MONOTONIC, &sf_metrics_last_send_time);
            for (int i = 0; i < ctx->nr_worker_threads; i++)
            {
                struct thread_ctx *thread_ctx = &ctx->work_threads[i];
                __atomic_fetch_add(&thread_ctx->sf_metrics_need_send, 1, __ATOMIC_RELAXED);
            }
        }

        sleep(MIN(ctx->metrics->config.statsd_cycle, sf_metrics_get_interval(ctx->work_threads[0].sf_metrics)));
        clock_gettime(CLOCK_MONOTONIC, &current_time);
    }

error_out:
    for (int i = 0; i < ctx->nr_worker_threads; i++)
    {
        struct thread_ctx *thread_ctx = &ctx->work_threads[i];
        session_table_destory(thread_ctx->session_table);
        sf_metrics_destory(thread_ctx->sf_metrics);
    }
    sce_ctx_destory(ctx);

    LOG_CLOSE();

    return 0;
}