/*
 * (C) 2024 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
 * All Rights Reserved.
 *
 * Author: Neels Janosch Hofmeyr <nhofmeyr@sysmocom.de>
 *
 * SPDX-License-Identifier: GPL-2.0+
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <osmocom/core/socket.h>
#include <osmocom/core/utils.h>

#include <osmocom/upfloadgen/range.h>

void range_val_set_int(struct range_val *rv, uint32_t val)
{
	*rv = (struct range_val){
		.buf = { (uint64_t)val, 0 },
		.size = sizeof(val),
	};
}

uint32_t range_val_get_int(const struct range_val *rv)
{
	return rv->buf[0];
}

void range_val_set_addr(struct range_val *rv, const struct osmo_sockaddr *val)
{
	*rv = (struct range_val){};
	rv->size = osmo_sockaddr_to_octets((void *)rv->buf, sizeof(rv->buf), val);

#if !OSMO_IS_BIG_ENDIAN
	for (int i = 0; i < rv->size / 2; i++) {
		uint8_t *rvbuf = (void *)rv->buf;
		uint8_t tmp = rvbuf[i];
		rvbuf[i] = rvbuf[rv->size - 1 - i];
		rvbuf[rv->size - 1 - i] = tmp;
	}
#endif
}

void range_val_get_addr(struct osmo_sockaddr *dst, const struct range_val *rv)
{
	void *buf;
#if OSMO_IS_BIG_ENDIAN
	buf = rv->buf;
#else
	int i;
	uint8_t rev[sizeof(rv->buf)];
	uint8_t *val = (void *)rv->buf;
	for (i = 0; i < rv->size; i++)
		rev[i] = val[rv->size - 1 - i];
	buf = rev;
#endif
	osmo_sockaddr_from_octets(dst, buf, rv->size);
}

void range_val_inc(struct range_val *rv)
{
	uint64_t was = rv->buf[0];
	rv->buf[0]++;
	if (rv->buf[0] < was)
		rv->buf[1]++;
}

int range_val_cmp(const struct range_val *a, const struct range_val *b)
{
	int rc;
	if (a == b)
		return 0;
	if (!a)
		return -1;
	if (!b)
		return 1;
	rc = OSMO_CMP(a->buf[0], b->buf[0]);
	if (rc)
		return rc;
	rc = OSMO_CMP(a->buf[1], b->buf[1]);
	if (rc)
		return rc;
	return OSMO_CMP(a->size, b->size);
}

void range_next(struct range *r)
{
	if (range_val_cmp(&r->next, &r->first) < 0) {
		r->next = r->first;
		return;
	}
	if (range_val_cmp(&r->next, &r->last) >= 0) {
		r->next = r->first;
		r->wrapped = true;
		return;
	}
	range_val_inc(&r->next);
}