/*
 * Copyright (C) 1999  Internet Software Consortium.
 * 
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#include <config.h>

#include <ctype.h>

#include <isc/assertions.h>
#include <isc/error.h>
#include <isc/boolean.h>
#include <isc/region.h>
#include <isc/buffer.h>

#include <dns/result.h>
#include <dns/ttl.h>

#define RETERR(x) do { \
	dns_result_t __r = (x); \
	if (__r != DNS_R_SUCCESS) \
		return (__r); \
	} while (0)


/* Helper for dns_ttl_totext(). */

static dns_result_t
ttlfmt(unsigned int t, char *s, isc_boolean_t verbose,
       isc_boolean_t space, isc_buffer_t *target)
{
	char tmp[60];
	size_t len;
	isc_region_t region;
	if (verbose)
		len = sprintf(tmp, "%s%u %s%s",
			      space ? " " : "",
			      t, s,
			      t == 1 ? "" : "s");
	else
		len = sprintf(tmp, "%u%c", t, s[0]);		
	INSIST(len + 1 <= sizeof tmp);
	isc_buffer_available(target, &region);
	if (len > region.length)
		return (DNS_R_NOSPACE);
	memcpy(region.base, tmp, len);
	isc_buffer_add(target, len);
	return (DNS_R_SUCCESS);
}

/* Derived from bind8 ns_format_ttl(). */

dns_result_t
dns_ttl_totext(isc_uint32_t src, isc_boolean_t verbose,
	       isc_buffer_t *target)
{
	unsigned secs, mins, hours, days, weeks, x;

	secs = src % 60;   src /= 60;
	mins = src % 60;   src /= 60;
	hours = src % 24;  src /= 24;
	days = src % 7;    src /= 7;
	weeks = src;       src = 0;

	x = 0;
	if (weeks != 0) {
		RETERR(ttlfmt(weeks, "week", verbose, (x > 0), target));
		x++;
	}
	if (days != 0) {
		RETERR(ttlfmt(days, "day", verbose, (x > 0), target));
		x++;
	}
	if (hours != 0) {
		RETERR(ttlfmt(hours, "hour", verbose, (x > 0), target));
		x++;
	}
	if (mins != 0) {
		RETERR(ttlfmt(mins, "minute", verbose, (x > 0), target));
		x++;
	}
	if (secs != 0 || (weeks == 0 && days == 0 && hours == 0 && mins == 0)) {
		RETERR(ttlfmt(secs, "second", verbose, (x > 0), target));
		x++;
	}
	INSIST (x > 0);
	/*
	 * If only a single unit letter is printed, print it
	 * in upper case. (Why?  Because BIND 8 does that.
	 * Presumably it has a reason.)
	 */
	if (x == 1 && !verbose) {
		isc_region_t region;
		/*
		 * The unit letter is the last character in the 
		 * used region of the buffer.
		 */
		isc_buffer_used(target, &region);
		region.base[region.length - 1] =
			toupper(region.base[region.length - 1]);
	}
	return (DNS_R_SUCCESS);
}