#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>

#include "log.h"
#include "hexdump.h"
#include "packet_dump.h"
#include "packet_utils.h"

#define PACKET_DUMP_LOG_ERROR(format, ...) LOG_ERROR("packet dump", format, ##__VA_ARGS__)

struct pcap_pkt_hdr
{
    unsigned int tv_sec;  // time stamp
    unsigned int tv_usec; // time stamp
    unsigned int caplen;  // length of portion present
    unsigned int len;     // length this packet (off wire)
};

struct pcap_file_hdr
{
    unsigned int magic;
    unsigned short version_major;
    unsigned short version_minor;
    unsigned int thiszone; // gmt to local correction
    unsigned int sigfigs;  // accuracy of timestamps
    unsigned int snaplen;  // max length saved portion of each pkt
    unsigned int linktype; // data link type (LINKTYPE_*)
};

// return  0: success
// return -1: failed
int packet_dump_pcap(const struct packet *pkt, const char *file)
{
    const char *data = packet_get_raw_data(pkt);
    uint16_t len = packet_get_raw_len(pkt);

    struct pcap_pkt_hdr pkt_hdr = {};
    struct pcap_file_hdr file_hdr = {
        .magic = 0xA1B2C3D4,
        .version_major = 0x0002,
        .version_minor = 0x0004,
        .thiszone = 0,
        .sigfigs = 0,
        .snaplen = 0xFFFF,
        .linktype = 1};

    if (file == NULL || data == NULL || len == 0)
    {
        PACKET_DUMP_LOG_ERROR("invalid parameter, file: %p, data: %p, len: %d", file, data, len);
        return -1;
    }

    FILE *fp = fopen(file, "w+");
    if (fp == NULL)
    {
        PACKET_DUMP_LOG_ERROR("fopen %s failed, %s", file, strerror(errno));
        return -1;
    }

    struct timeval ts = {};
    gettimeofday(&ts, NULL);

    pkt_hdr.tv_sec = ts.tv_sec;
    pkt_hdr.tv_usec = ts.tv_usec;
    pkt_hdr.caplen = len;
    pkt_hdr.len = len;

    fwrite(&file_hdr, sizeof(struct pcap_file_hdr), 1, fp);
    fwrite(&pkt_hdr, sizeof(struct pcap_pkt_hdr), 1, fp);
    fwrite(data, 1, len, fp);
    fflush(fp);
    fclose(fp);

    return 0;
}

void packet_dump_hex(const struct packet *pkt, int fd)
{
    uint16_t len = packet_get_raw_len(pkt);
    const char *data = packet_get_raw_data(pkt);

    hexdump_to_fd(fd, data, len);
}