/* vi: set sw=4 ts=4: */
/*
 * uuid_time.c --- Interpret the time field from a uuid.  This program
 *  violates the UUID abstraction barrier by reaching into the guts
 *  of a UUID and interpreting it.
 *
 * Copyright (C) 1998, 1999 Theodore Ts'o.
 *
 * %Begin-Header%
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, and the entire permission notice in its entirety,
 *    including the disclaimer of warranties.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote
 *    products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
 * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 * %End-Header%
 */

#include <stdio.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdlib.h>
#include <sys/types.h>
#include <time.h>
#ifdef HAVE_WINSOCK_H
#include <winsock.h> /* timeval */
#endif

#include "uuidP.h"

time_t uuid_time(const uuid_t uu, struct timeval *ret_tv)
{
  struct uuid    uuid;
  uint32_t      high;
  struct timeval    tv;
  uint64_t  clock_reg;

  uuid_unpack(uu, &uuid);

  high = uuid.time_mid | ((uuid.time_hi_and_version & 0xFFF) << 16);
  clock_reg = uuid.time_low | ((uint64_t) high << 32);

  clock_reg -= (((uint64_t) 0x01B21DD2) << 32) + 0x13814000;
  tv.tv_sec = clock_reg / 10000000;
  tv.tv_usec = (clock_reg % 10000000) / 10;

  if (ret_tv)
    *ret_tv = tv;

  return tv.tv_sec;
}

int uuid_type(const uuid_t uu)
{
  struct uuid    uuid;

  uuid_unpack(uu, &uuid);
  return ((uuid.time_hi_and_version >> 12) & 0xF);
}

int uuid_variant(const uuid_t uu)
{
  struct uuid    uuid;
  int      var;

  uuid_unpack(uu, &uuid);
  var = uuid.clock_seq;

  if ((var & 0x8000) == 0)
    return UUID_VARIANT_NCS;
  if ((var & 0x4000) == 0)
    return UUID_VARIANT_DCE;
  if ((var & 0x2000) == 0)
    return UUID_VARIANT_MICROSOFT;
  return UUID_VARIANT_OTHER;
}

#ifdef DEBUG
static const char *variant_string(int variant)
{
  switch (variant) {
  case UUID_VARIANT_NCS:
    return "NCS";
  case UUID_VARIANT_DCE:
    return "DCE";
  case UUID_VARIANT_MICROSOFT:
    return "Microsoft";
  default:
    return "Other";
  }
}


int
main(int argc, char **argv)
{
  uuid_t    buf;
  time_t    time_reg;
  struct timeval  tv;
  int    type, variant;

  if (argc != 2) {
    fprintf(stderr, "Usage: %s uuid\n", argv[0]);
    exit(1);
  }
  if (uuid_parse(argv[1], buf)) {
    fprintf(stderr, "Invalid UUID: %s\n", argv[1]);
    exit(1);
  }
  variant = uuid_variant(buf);
  type = uuid_type(buf);
  time_reg = uuid_time(buf, &tv);

  printf("UUID variant is %d (%s)\n", variant, variant_string(variant));
  if (variant != UUID_VARIANT_DCE) {
    printf("Warning: This program only knows how to interpret "
           "DCE UUIDs.\n\tThe rest of the output is likely "
           "to be incorrect!!\n");
  }
  printf("UUID type is %d", type);
  switch (type) {
  case 1:
    printf(" (time based)\n");
    break;
  case 2:
    printf(" (DCE)\n");
    break;
  case 3:
    printf(" (name-based)\n");
    break;
  case 4:
    printf(" (random)\n");
    break;
  default:
    bb_putchar('\n');
  }
  if (type != 1) {
    printf("Warning: not a time-based UUID, so UUID time "
           "decoding will likely not work!\n");
  }
  printf("UUID time is: (%ld, %ld): %s\n", tv.tv_sec, tv.tv_usec,
         ctime(&time_reg));

  return 0;
}
#endif