#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <inttypes.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>

#include <hexagram/pcapng.h>

static void usage(int argc, char **argv, const char *message, ...) {
    if (message) {
        va_list args;

        va_start(args, message);
        vfprintf(stderr, message, args);
        va_end(args);
    }

    fprintf(stderr, "usage: %s [file.pcapng]\n", argv[0]);

    exit(1);
}

static int handle_block(int fd, uint32_t type, size_t len) {
    printf("Read block type %08"PRIx32" len %zu\n",
        type, len);

    if (lseek(fd, len, SEEK_CUR) < 0) {
        perror("lseek()");

        goto error_io;
    }

    return 0;

error_io:
    return -1;
}

int main(int argc, char **argv) {
    int fd, error;

    if (argc == 1) {
        fd = fileno(stdin);
    } else if (argc == 2) {
        if ((fd = open(argv[1], O_RDONLY)) < 0) {
            perror("open()");

            goto error_open;
        }
    } else {
        usage(argc, argv, NULL);
    }

    if (hexagram_pcapng_stream_read(fd, handle_block, &error) < 0) {
        perror("hexagram_pcapng_stream_read()");

        goto error_io;
    }

    if (argc == 2) {
        close(fd);
    }

    return 0;

error_io:
    if (argc == 2) {
        close(fd);
    }

error_open:
    return 1;
}