#include <pcap/pcap.h>
#include <pthread.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>

#include "tuple.h"
#include "utils.h"
#include "log_internal.h"
#include "pcap_io.h"
#include "packet_dump.h"
#include "packet_parser.h"
#include "packet_internal.h"

#define PCAP_IO_LOG_FATAL(format, ...) STELLAR_LOG_FATAL(__thread_local_logger, "pcap io", format, ##__VA_ARGS__)
#define PCAP_IO_LOG_ERROR(format, ...) STELLAR_LOG_ERROR(__thread_local_logger, "pcap io", format, ##__VA_ARGS__)

#define MAX_PACKET_QUEUE_SIZE (4096 * 1000)

struct pcap_io
{
    struct packet_io_config cfg;

    pcap_t *pcap;
    struct logger *logger;
    struct packet_queue *queue[MAX_THREAD_NUM];
    struct packet_io_stat stat[MAX_THREAD_NUM];
    uint64_t io_thread_need_exit;
    uint64_t io_thread_is_runing;
    uint64_t io_thread_wait_exit;

    uint64_t read_pcap_files;
    uint64_t read_pcap_pkts;
};

struct pcap_pkt
{
    char *data;
    int len;
    struct timeval ts;
};

/******************************************************************************
 * Private API -- queue
 ******************************************************************************/

struct packet_queue
{
    uint64_t *queue;
    uint32_t size;
    uint32_t head;
    uint32_t tail;
};

static struct packet_queue *packet_queue_new(uint32_t size)
{
    struct packet_queue *queue = (struct packet_queue *)calloc(1, sizeof(struct packet_queue));
    if (queue == NULL)
    {
        PCAP_IO_LOG_ERROR("unable to new packet queue");
        return NULL;
    }

    queue->queue = (uint64_t *)calloc(size, sizeof(uint64_t));
    if (queue->queue == NULL)
    {
        PCAP_IO_LOG_ERROR("unable to new packet queue");
        free(queue);
        return NULL;
    }

    queue->size = size;
    queue->head = 0;
    queue->tail = 0;

    return queue;
}

static void packet_queue_free(struct packet_queue *queue)
{
    if (queue == NULL)
    {
        return;
    }

    if (queue->queue)
    {
        free(queue->queue);
        queue->queue = NULL;
    }

    free(queue);
}

static int packet_queue_push(struct packet_queue *queue, void *data)
{
    if (__sync_val_compare_and_swap(&queue->queue[queue->tail], 0, data) != 0)
    {
        PCAP_IO_LOG_ERROR("packet queue is full, retry later");
        return -1;
    }

    queue->tail = (queue->tail + 1) % queue->size;
    return 0;
}

static void packet_queue_pop(struct packet_queue *queue, void **data)
{
    uint64_t read = ATOMIC_READ(&queue->queue[queue->head]);
    if (read == 0)
    {
        *data = NULL;
        return;
    }
    __sync_val_compare_and_swap(&queue->queue[queue->head], read, 0);
    *data = (void *)read;
    queue->head = (queue->head + 1) % queue->size;
}

/******************************************************************************
 * Private API -- utils
 ******************************************************************************/

static void pcap_pkt_handler(u_char *user, const struct pcap_pkthdr *h, const u_char *bytes)
{
    struct pcap_io *handle = (struct pcap_io *)user;

    // copy packet data to new memory
    struct pcap_pkt *pcap_pkt = (struct pcap_pkt *)calloc(1, sizeof(struct pcap_pkt) + h->caplen);
    if (pcap_pkt == NULL)
    {
        PCAP_IO_LOG_ERROR("unable to alloc packet");
        return;
    }
    pcap_pkt->data = (char *)pcap_pkt + sizeof(struct pcap_pkt);
    pcap_pkt->len = h->caplen;
    pcap_pkt->ts = h->ts;
    memcpy((char *)pcap_pkt->data, bytes, h->caplen);
    ATOMIC_INC(&handle->read_pcap_pkts);

    // calculate packet hash
    struct packet pkt;
    memset(&pkt, 0, sizeof(struct packet));
    packet_parse(&pkt, pcap_pkt->data, pcap_pkt->len);
    uint64_t hash = packet_ldbc_hash(&pkt, PKT_LDBC_METH_OUTERMOST_INT_EXT_IP, PACKET_DIRECTION_OUTGOING);

    // push packet to queue
    struct packet_queue *queue = handle->queue[hash % handle->cfg.nr_worker_thread];
    while (packet_queue_push(queue, pcap_pkt) == -1)
    {
        if (ATOMIC_READ(&handle->io_thread_need_exit))
        {
            free(pcap_pkt);
            PCAP_IO_LOG_FATAL("pcap io thread need exit");
            pcap_breakloop(handle->pcap);
            break;
        }
        usleep(1000);
    }

    if (ATOMIC_READ(&handle->io_thread_need_exit))
    {
        PCAP_IO_LOG_FATAL("pcap io thread need exit");
        pcap_breakloop(handle->pcap);
    }
}

static int pcap_io_handler(struct pcap_io *handle, const char *pcap_file)
{
    char resolved_path[256];
    char pcap_errbuf[PCAP_ERRBUF_SIZE];

    realpath(pcap_file, resolved_path);
    PCAP_IO_LOG_FATAL("pcap %s in-processing", resolved_path)

    handle->pcap = pcap_open_offline(resolved_path, pcap_errbuf);
    if (handle->pcap == NULL)
    {
        PCAP_IO_LOG_ERROR("unable to open pcap file: %s, %s", resolved_path, pcap_errbuf);
        return -1;
    }
    handle->read_pcap_files++;
    pcap_loop(handle->pcap, -1, pcap_pkt_handler, (u_char *)handle);
    pcap_close(handle->pcap);

    PCAP_IO_LOG_FATAL("pcap %s processed", resolved_path)

    return 0;
}

static int all_packet_consumed(struct pcap_io *handle)
{
    uint64_t consumed_pkts = 0;
    uint64_t read_pcap_pkts = ATOMIC_READ(&handle->read_pcap_pkts);
    for (uint16_t i = 0; i < handle->cfg.nr_worker_thread; i++)
    {
        consumed_pkts += ATOMIC_READ(&handle->stat[i].pkts_rx);
    }
    if (consumed_pkts == read_pcap_pkts)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

static void *pcap_io_thread(void *arg)
{
    struct pcap_io *handle = (struct pcap_io *)arg;
    __thread_local_logger = handle->logger;

    ATOMIC_SET(&handle->io_thread_is_runing, 1);
    PCAP_IO_LOG_FATAL("pcap io thread is running");

    if (handle->cfg.mode == PACKET_IO_PCAPFILE)
    {
        pcap_io_handler(handle, handle->cfg.pcap_path);
    }
    else // PACKET_IO_PCAPLIST
    {
        FILE *fp = NULL;
        if (strcmp(handle->cfg.pcap_path, "-") == 0)
        {
            PCAP_IO_LOG_ERROR("pcap path is empty, read from stdin");
            fp = stdin;
        }
        else
        {
            fp = fopen(handle->cfg.pcap_path, "r");
            if (fp == NULL)
            {
                PCAP_IO_LOG_ERROR("unable to open pcap path: %s", handle->cfg.pcap_path);
                goto erro_out;
            }
        }

        char line[PATH_MAX];
        while (ATOMIC_READ(&handle->io_thread_need_exit) == 0 && fgets(line, sizeof(line), fp))
        {
            if (line[0] == '#')
            {
                continue;
            }

            char *pos = strchr(line, '\n');
            if (pos)
            {
                *pos = '\0';
            }

            pcap_io_handler(handle, line);
        }
        if (fp != stdin)
        {
            fclose(fp);
        }
    }
    PCAP_IO_LOG_FATAL("pcap io thread read all pcap files");

erro_out:
    while (ATOMIC_READ(&handle->io_thread_need_exit) == 0)
    {
        if (all_packet_consumed(handle))
        {
            ATOMIC_SET(&handle->io_thread_wait_exit, 1);
        }

        usleep(1000); // 1ms
    }

    PCAP_IO_LOG_FATAL("pcap io thread exit (read_pcap_files: %lu, read_pcap_pkts: %lu)", handle->read_pcap_files, ATOMIC_READ(&handle->read_pcap_pkts));
    ATOMIC_SET(&handle->io_thread_is_runing, 0);

    return NULL;
}

/******************************************************************************
 * Public API
 ******************************************************************************/

void *pcap_io_new(const struct packet_io_config *cfg)
{
    pthread_t tid;
    struct pcap_io *handle = (struct pcap_io *)calloc(1, sizeof(struct pcap_io));
    if (handle == NULL)
    {
        PCAP_IO_LOG_ERROR("unable to allocate memory for pcap_io");
        return NULL;
    }

    handle->logger = __thread_local_logger;
    memcpy(&handle->cfg, cfg, sizeof(struct packet_io_config));

    for (uint16_t i = 0; i < handle->cfg.nr_worker_thread; i++)
    {
        handle->queue[i] = packet_queue_new(MAX_PACKET_QUEUE_SIZE);
        if (handle->queue[i] == NULL)
        {
            PCAP_IO_LOG_ERROR("unable to create packet queue");
            goto error_out;
        }
    }
    if (pthread_create(&tid, NULL, pcap_io_thread, (void *)handle) != 0)
    {
        PCAP_IO_LOG_ERROR("unable to create pcap io thread");
        goto error_out;
    }

    return handle;

error_out:
    pcap_io_free(handle);
    return NULL;
}

void pcap_io_free(void *handle)
{
    struct pcap_io *pcap_io = (struct pcap_io *)handle;
    if (pcap_io)
    {
        ATOMIC_SET(&pcap_io->io_thread_need_exit, 1);

        while (ATOMIC_READ(&pcap_io->io_thread_is_runing))
        {
            usleep(1000);
        }

        struct pcap_pkt *pcap_pkt = NULL;
        for (uint16_t i = 0; i < pcap_io->cfg.nr_worker_thread; i++)
        {
            while (1)
            {
                packet_queue_pop(pcap_io->queue[i], (void **)&pcap_pkt);
                if (pcap_pkt)
                {
                    free(pcap_pkt);
                }
                else
                {
                    break;
                }
            }

            packet_queue_free(pcap_io->queue[i]);
        }
        free(pcap_io);
        pcap_io = NULL;
    }
}

int pcap_io_isbreak(void *handle)
{
    struct pcap_io *pcap_io = (struct pcap_io *)handle;

    return ATOMIC_READ(&pcap_io->io_thread_wait_exit);
}

int pcap_io_init(void *handle __attribute__((unused)), uint16_t thr_idx __attribute__((unused)))
{
    return 0;
}

uint16_t pcap_io_ingress(void *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
{
    uint16_t nr_packet_parsed = 0;
    struct packet *pkt = NULL;
    struct pcap_pkt *pcap_pkt = NULL;
    struct pcap_io *pcap_io = (struct pcap_io *)handle;
    struct packet_queue *queue = pcap_io->queue[thr_idx];
    struct packet_io_stat *stat = &pcap_io->stat[thr_idx];

    for (uint16_t i = 0; i < nr_pkts; i++)
    {
        packet_queue_pop(queue, (void **)&pcap_pkt);
        if (pcap_pkt == NULL)
        {
            break;
        }
        else
        {
            ATOMIC_INC(&stat->pkts_rx);
            stat->bytes_rx += pcap_pkt->len;

            stat->raw_pkts_rx++;
            stat->raw_bytes_rx += pcap_pkt->len;

            pkt = &pkts[nr_packet_parsed];
            packet_parse(pkt, pcap_pkt->data, pcap_pkt->len);
            memset(&pkt->meta, 0, sizeof(pkt->meta));
            packet_set_origin_ctx(pkt, pcap_pkt);
            packet_set_action(pkt, PACKET_ACTION_FORWARD);
            packet_set_timeval(pkt, &pcap_pkt->ts);
            nr_packet_parsed++;
        }
    }

    return nr_packet_parsed;
}

void pcap_io_egress(void *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
{
    int len;
    struct tuple6 tuple;
    struct packet *pkt = NULL;
    struct pcap_io *pcap_io = (struct pcap_io *)handle;
    struct packet_io_stat *stat = &pcap_io->stat[thr_idx];

    char file[PATH_MAX] = {0};
    char src_addr[INET6_ADDRSTRLEN] = {0};
    char dst_addr[INET6_ADDRSTRLEN] = {0};

    for (uint16_t i = 0; i < nr_pkts; i++)
    {
        pkt = &pkts[i];
        len = packet_get_raw_len(pkt);

        stat->pkts_tx++;
        stat->bytes_tx += len;

        if (packet_is_ctrl(pkt))
        {
            stat->ctrl_pkts_tx++;
            stat->ctrl_bytes_tx += len;
        }
        else
        {
            stat->raw_pkts_tx++;
            stat->raw_bytes_tx += len;
        }

        struct pcap_pkt *pcap_pkt = (struct pcap_pkt *)packet_get_origin_ctx(pkt);
        if (pcap_pkt)
        {
            free(pcap_pkt);
        }
        else
        {
            stat->pkts_injected++;
            stat->bytes_injected += len;

            memset(&tuple, 0, sizeof(struct tuple6));
            packet_get_innermost_tuple6(pkt, &tuple);

            if (tuple.addr_family == AF_INET)
            {
                inet_ntop(AF_INET, &tuple.src_addr.v4, src_addr, INET6_ADDRSTRLEN);
                inet_ntop(AF_INET, &tuple.dst_addr.v4, dst_addr, INET6_ADDRSTRLEN);
            }
            else
            {
                inet_ntop(AF_INET6, &tuple.src_addr.v6, src_addr, INET6_ADDRSTRLEN);
                inet_ntop(AF_INET6, &tuple.dst_addr.v6, dst_addr, INET6_ADDRSTRLEN);
            }
            snprintf(file, sizeof(file), "inject-%s:%u-%s:%u-%lu.pcap", src_addr, ntohs(tuple.src_port), dst_addr, ntohs(tuple.dst_port), stat->pkts_injected);

            if (packet_dump_pcap(pkt, file) == -1)
            {
                PCAP_IO_LOG_ERROR("unable to dump pcap file: %s", file);
            }
            else
            {
                PCAP_IO_LOG_FATAL("dump inject packet: %s", file);
            }
        }
    }
}

void pcap_io_drop(void *handle, uint16_t thr_idx, struct packet *pkts, uint16_t nr_pkts)
{
    struct packet *pkt = NULL;
    struct pcap_io *pcap_io = (struct pcap_io *)handle;
    struct packet_io_stat *stat = &pcap_io->stat[thr_idx];

    for (uint16_t i = 0; i < nr_pkts; i++)
    {
        pkt = &pkts[i];
        struct pcap_pkt *pcap_pkt = (struct pcap_pkt *)packet_get_origin_ctx(pkt);
        if (pcap_pkt)
        {
            stat->pkts_dropped++;
            stat->bytes_dropped += packet_get_raw_len(pkt);
            free(pcap_pkt);
        }
        packet_free(pkt);
    }
}

void pcap_io_yield(void *handle __attribute__((unused)), uint16_t thr_idx __attribute__((unused)))
{
    return;
}

struct packet_io_stat *pcap_io_stat(void *handle, uint16_t thr_idx)
{
    struct pcap_io *pcap_io = (struct pcap_io *)handle;

    return &pcap_io->stat[thr_idx];
}