/* notmuch - Not much of an email program, (just index and search)
 *
 * Copyright © 2013 Peter Wang
 *
 * 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 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 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/ .
 *
 * Author: Peter Wang <novalazy@gmail.com>
 */

#include "notmuch-client.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

/* Like gethostname but guarantees that a null-terminated hostname is
 * returned, even if it has to make one up.
 * Returns true unless hostname contains a slash. */
static notmuch_bool_t
safe_gethostname (char *hostname, size_t len)
{
    if (gethostname (hostname, len) == -1) {
	strncpy (hostname, "unknown", len);
    }
    hostname[len - 1] = '\0';

    return (strchr (hostname, '/') == NULL);
}

/* Open a unique file in the Maildir 'tmp' directory.
 * Returns the file descriptor on success, or -1 on failure.
 * On success, file paths for the message in the 'tmp' and 'new'
 * directories are returned via tmppath and newpath. */
static int
maildir_open_tmp_file (void *ctx, const char *dir,
		       char **tmppath, char **newpath)
{
    pid_t pid;
    char hostname[256];
    struct timeval tv;
    char *filename;
    int fd = -1;

    /* We follow the Dovecot file name generation algorithm. */
    pid = getpid ();
    if (! safe_gethostname (hostname, sizeof (hostname))) {
	fprintf (stderr, "Error: invalid host name.\n");
	return -1;
    }
    do {
	gettimeofday (&tv, NULL);
	filename = talloc_asprintf (ctx, "%ld.M%ldP%d.%s",
				    tv.tv_sec, tv.tv_usec, pid, hostname);
	if (! filename) {
	    fprintf (stderr, "Out of memory\n");
	    return -1;
	}

	*tmppath = talloc_asprintf (ctx, "%s/tmp/%s", dir, filename);
	if (! *tmppath) {
	    fprintf (stderr, "Out of memory\n");
	    return -1;
	}

	fd = open (*tmppath, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 0600);
    } while (fd == -1 && errno == EEXIST);

    if (fd == -1) {
	fprintf (stderr, "Error: opening %s: %s\n", *tmppath, strerror (errno));
	return -1;
    }

    *newpath = talloc_asprintf (ctx, "%s/new/%s", dir, filename);
    if (! *newpath) {
	fprintf (stderr, "Out of memory\n");
	close (fd);
	unlink (*tmppath);
	return -1;
    }

    talloc_free (filename);

    return fd;
}

static notmuch_bool_t
insert_message (void *ctx, notmuch_database_t *notmuch, int fdin,
	        const char *dir)
{
    char *tmppath;
    char *newpath;
    int fdout;

    fdout = maildir_open_tmp_file (ctx, dir, &tmppath, &newpath);
    if (fdout < 0) {
	return FALSE;
    }

    /* For now we just delete the tmp file immediately. */
    close (fdout);
    unlink (tmppath);
    return FALSE;
}

int
notmuch_insert_command (void *ctx, int argc, char *argv[])
{
    notmuch_config_t *config;
    notmuch_database_t *notmuch;
    const char *db_path;
    char *maildir;
    notmuch_bool_t ret;

    config = notmuch_config_open (ctx, NULL, NULL);
    if (config == NULL)
	return 1;

    db_path = notmuch_config_get_database_path (config);

    maildir = talloc_asprintf (ctx, "%s", db_path);
    if (! maildir) {
	fprintf (stderr, "Out of memory\n");
	return 1;
    }

    if (notmuch_database_open (notmuch_config_get_database_path (config),
			       NOTMUCH_DATABASE_MODE_READ_WRITE, &notmuch))
	return 1;

    ret = insert_message (ctx, notmuch, STDIN_FILENO, maildir);

    notmuch_database_destroy (notmuch);

    return (ret) ? 0 : 1;
}