/*
 * This file is part of mpv video player.
 * Copyright © 2014 Alexander Preisinger <alexander.preisinger@gmail.com>
 *
 * mpv is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * mpv 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>

#include "video/out/wayland/memfile.h"

/* copied from weston clients */
static int set_cloexec_or_close(int fd)
{
    long flags;

    if (fd == -1)
        return -1;

    if ((flags = fcntl(fd, F_GETFD)) == -1)
        goto err;

    if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1)
        goto err;

    return fd;

err:
    close(fd);
    return -1;
}

static int create_tmpfile_cloexec(char *tmpname)
{
    int fd;

#ifdef HAVE_MKOSTEMP
    fd = mkostemp(tmpname, O_CLOEXEC);
    if (fd >= 0)
        unlink(tmpname);
#else
    fd = mkstemp(tmpname);
    if (fd >= 0) {
        fd = set_cloexec_or_close(fd);
        unlink(tmpname);
    }
#endif

    return fd;
}

static int os_create_anonymous_file(off_t size)
{
    static const char template[] = "/mpv-temp-XXXXXX";
    const char *path;
    char *name;
    int fd;

    path = getenv("XDG_RUNTIME_DIR");
    if (!path) {
        errno = ENOENT;
        return -1;
    }

    name = malloc(strlen(path) + sizeof(template));
    if (!name)
        return -1;

    strcpy(name, path);
    strcat(name, template);

    fd = create_tmpfile_cloexec(name);

    free(name);

    if (fd < 0)
        return -1;

    if (ftruncate(fd, size) < 0) {
        close(fd);
        return -1;
    }

    return fd;
}

int memfile_create(off_t size)
{
    return os_create_anonymous_file(size);
}
