/* notmuch - Not much of an email program, (just index and search)
 *
 * Copyright © 2010 David Bremner
 *
 * 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: David Bremner <david@tethera.net>
 */

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

#include "notmuch-client.h"
/*
   Look a key up in the config file; open the corresponding file as a
   log.

   Return a file descriptor to the open log file, or -1 if an error
   occurs.
  */

int
notmuch_log_open (const char *path)
{
    int fd;

    fd = open (path, O_CREAT|O_WRONLY|O_APPEND);
    if (fd < 0) {
	fprintf (stderr, "Failed to open %s: %s\n",
		 path, strerror (errno));
    }

    return fd;
}

notmuch_status_t
notmuch_log_append (int file_desc, const char *buffer, size_t len){

    struct flock lock;

    lock.l_type = F_WRLCK;
    lock.l_whence = SEEK_SET;
    lock.l_start = 0;
    lock.l_len = 0;

    if (fcntl (file_desc, F_SETLKW, &lock) != 0) {
	fprintf (stderr, "Failed to lock  %s\n",
		 strerror (errno));

	return NOTMUCH_STATUS_FILE_ERROR;
    }

    while (len > 0)
    {
	int written;

	written = write(file_desc, buffer, len);
	if (written < 0 || (written == 0 && errno !=0))
	{
	    fprintf (stderr, "Failed to write %zd characters: %s\n",
		     len, strerror (errno));

	    return NOTMUCH_STATUS_FILE_ERROR;
	}

	len -= written;
	buffer += written;

    }

    if (fdatasync (file_desc) != 0) {
	fprintf (stderr, "Failed to sync:  %s\n",
		 strerror (errno));

	return NOTMUCH_STATUS_FILE_ERROR;
    }

    lock.l_type=F_UNLCK;

    if (fcntl (file_desc, F_SETLK, &lock) != 0) {
	fprintf (stderr, "Failed to unlock:  %s\n",
		 strerror (errno));

	return NOTMUCH_STATUS_FILE_ERROR;
    }

    return NOTMUCH_STATUS_SUCCESS;
}