/*
 * 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>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/time.h>
#include <time.h>

#include "uuidP.h"

time_t uuid_time(const uuid_t uu, struct timeval *ret_tv)
{
        struct timeval          tv;
        struct uuid             uuid;
        uint32_t                high;
        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:
                printf("\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, (long)tv.tv_usec,
               ctime(&time_reg));

        return 0;
}
#endif