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

#include "log.h"
#include "system.h"
#include "packet_io.h"
#include "packet_stat.h"
#include "packet_handle.h"

#define LOG_MAIN "PacketAdapter"

#ifdef GIT_VERSION
static __attribute__((__used__)) const char *Packet_Adapter_Version = GIT_VERSION;
#else
static __attribute__((__used__)) const char *Packet_Adapter_Version = "Unknown";
#endif

/******************************************************************************
 * Struct
 ******************************************************************************/

struct thread
{
    int index;
    pthread_t tid;
    struct runtime_ctx *runtime;
};

struct runtime_ctx
{
    int enable_debug;
    int need_stop;

    struct metrics metrics;
    struct packet_io *handle;
    struct packet_stat *stat;
    struct thread threads[MAX_THREAD_NUM];
};

/******************************************************************************
 * Static
 ******************************************************************************/

struct runtime_ctx static_runtime_ctx = {0};
struct runtime_ctx *runtime = &static_runtime_ctx;

/******************************************************************************
 * API
 ******************************************************************************/

static enum action packet_handle_callback(const char *data, int len, void *args)
{
    struct metrics *metrics = (struct metrics *)args;
    packet_handle(data, len, metrics);

    return ACTION_BYPASS;
}

static void *worker_thread_cycle(void *arg)
{
    struct thread *thread = (struct thread *)arg;
    struct runtime_ctx *runtime = thread->runtime;
    struct packet_io *handle = runtime->handle;

    char thread_name[16];
    snprintf(thread_name, sizeof(thread_name), "pkt-adapter:%d", thread->index);
    prctl(PR_SET_NAME, (unsigned long long)thread_name, NULL, NULL, NULL);

    if (packet_io_thread_init(handle, thread->index) != 0)
    {
        goto error_out;
    }

    LOG_INFO("%s: worker thread %d is running", LOG_MAIN, thread->index);
    while (!runtime->need_stop)
    {
        if (packet_io_thread_polling(handle, thread->index) == 0)
        {
            packet_io_thread_wait(handle, thread->index, -1);
        }
    }

error_out:
    LOG_ERROR("%s: worker thread %d exiting", LOG_MAIN, thread->index);
    return (void *)NULL;
}

static void signal_handler(int signo)
{
    if (signo == SIGUSR1)
    {
        runtime->enable_debug = 1;
        LOG_ERROR("%s: received SIGUSR1, enable debug", LOG_MAIN);
    }
    if (signo == SIGUSR2)
    {
        runtime->enable_debug = 0;
        LOG_ERROR("%s: received SIGUSR2, disable debug", LOG_MAIN);
    }
    if (signo == SIGHUP)
    {
        LOG_RELOAD();
        LOG_ERROR("%s: received SIGHUP, reload zlog.conf", LOG_MAIN);
    }
    if (signo == SIGINT)
    {
        runtime->need_stop = 1;
        LOG_ERROR("%s: received SIGINT, exit !!!", LOG_MAIN);
    }
    if (signo == SIGQUIT)
    {
        runtime->need_stop = 1;
        LOG_ERROR("%s: received SIGQUIT, exit !!!", LOG_MAIN);
    }
    if (signo == SIGTERM)
    {
        runtime->need_stop = 1;
        LOG_ERROR("%s: received SIGTERM, exit !!!", LOG_MAIN);
    }
}

static void usage(char *cmd)
{
    fprintf(stderr, "USAGE: %s [OPTIONS]\n", cmd);
    fprintf(stderr, "    -v       -- show version\n");
    fprintf(stderr, "    -d       -- run daemon\n");
    fprintf(stderr, "    -h       -- show help\n");
    fprintf(stderr, "Signal: \n");
    fprintf(stderr, "    kill -s SIGUSR1 `pidof %s`     -- enable  debug\n", cmd);
    fprintf(stderr, "    kill -s SIGUSR2 `pidof %s`     -- disable debug\n", cmd);
}

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

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

    while ((opt = getopt(argc, argv, "vdh")) != -1)
    {
        switch (opt)
        {
        case 'v':
            fprintf(stderr, "Packet Adapter Version: %s\n", Packet_Adapter_Version);
            return 0;
        case 'd':
            run_daemon();
            break;
        case 'h': /* fall through */
        default:
            usage(argv[0]);
            return 0;
        }
    }

    LOG_ERROR("%s: TSG Packet Adapter Engine, Version: %s Start ...", LOG_MAIN, Packet_Adapter_Version);

    if (signal(SIGUSR1, signal_handler) == SIG_ERR)
    {
        LOG_ERROR("%s: failed at signal(SIGUSR1), %d: %s", LOG_MAIN, errno, strerror(errno));
        goto error;
    }
    if (signal(SIGUSR2, signal_handler) == SIG_ERR)
    {
        LOG_ERROR("%s: failed at signal(SIGUSR2), %d: %s", LOG_MAIN, errno, strerror(errno));
        goto error;
    }
    if (signal(SIGHUP, signal_handler) == SIG_ERR)
    {
        LOG_ERROR("%s: failed at signal(SIGHUP), %d: %s", LOG_MAIN, errno, strerror(errno));
        goto error;
    }
    if (signal(SIGINT, signal_handler) == SIG_ERR)
    {
        LOG_ERROR("%s: failed at signal(SIGINT), %d: %s", LOG_MAIN, errno, strerror(errno));
        goto error;
    }
    if (signal(SIGQUIT, signal_handler) == SIG_ERR)
    {
        LOG_ERROR("%s: failed at signal(SIGQUIT), %d: %s", LOG_MAIN, errno, strerror(errno));
        goto error;
    }

    if (signal(SIGTERM, signal_handler) == SIG_ERR)
    {
        LOG_ERROR("%s: failed at signal(SIGTERM), %d: %s", LOG_MAIN, errno, strerror(errno));
        goto error;
    }

    runtime->stat = packet_stat_create(profile);
    if (runtime->stat == NULL)
    {
        goto error;
    }

    runtime->handle = packet_io_create(profile);
    if (runtime->handle == NULL)
    {
        goto error;
    }

    packet_io_set_callback(runtime->handle, packet_handle_callback, &runtime->metrics);
    for (int i = 0; i < packet_io_thread_number(runtime->handle); i++)
    {
        runtime->threads[i].tid = 0;
        runtime->threads[i].index = i;
        runtime->threads[i].runtime = runtime;
    }

    for (int i = 0; i < packet_io_thread_number(runtime->handle); i++)
    {
        struct thread *thread = &runtime->threads[i];
        if (pthread_create(&thread->tid, NULL, worker_thread_cycle, (void *)thread) < 0)
        {
            LOG_ERROR("%s: unable to create worker thread %d, error %d: %s", LOG_MAIN, i, errno, strerror(errno));
            runtime->need_stop = 1;
        }
    }

    while (!runtime->need_stop)
    {
        packet_stat_output(runtime->stat, &runtime->metrics);
        sleep(packet_stat_cycle(runtime->stat));
    }

error:
    packet_stat_destory(runtime->stat);
    packet_io_destory(runtime->handle);
    LOG_CLOSE();

    return 0;
}