/* Copyright (C) 2018  Causal Agent June <june@causal.agency>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <err.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sysexits.h>
#include <unistd.h>

int main(int argc, char *argv[]) {
    if (argc < 2) errx(EX_USAGE, "missing public id");

    uint32_t id[4];
    char public[7 + 32 + 1];
    char private[8 + 32 + 1];

    arc4random_buf(id, sizeof(id));
    snprintf(public, sizeof(public), "public/%s", argv[1]);
    snprintf(
        private, sizeof(private),
        "private/%08x%08x%08x%08x",
        id[0], id[1], id[2], id[3]
    );

    int fd = open(public, O_CREAT | O_EXCL, 0644);
    if (fd < 0) err(EX_CANTCREAT, "%s", public);

    snprintf(public, sizeof(public), "../public/%s", argv[1]);
    int error = symlink(public, private);
    if (error) err(EX_CANTCREAT, "%s", private);

    printf("%08x%08x%08x%08x\n", id[0], id[1], id[2], id[3]);
    return EX_OK;
}