/***************************************************************************
 *   Copyright (C) 12/2010 by Olaf Rempel                                  *
 *   razzor@kopf-tisch.de                                                  *
 *                                                                         *
 *   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, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/stat.h>
#include <errno.h>

#include <rrd.h>

#include "configfile.h"
#include "linebuffer.h"
#include "list.h"
#include "logging.h"

#define DEFAULT_STEP	10

#define ARGCMAX		64
#define ARGVSIZE	1024
#define BUFSIZE		1024

static const char *rrd_dir;

int my_rrd_init(void)
{
	rrd_dir = config_get_string("global", "rrd_dir", ".");
	return 0;
}

static int strsplit(char *string, char *delim, char **fields, int size)
{
	int i = 0;
	char *tmp, *ptr = string;

	while ((fields[i] = strtok_r(ptr, delim, &tmp)) != NULL) {
		ptr = NULL;
		i++;

		if (i >= size)
			break;
	}
	return i;
}

static int do_rrd(int (*rrd_func)(int, char **), struct lbuf *buffer)
{
	size_t len;
	char *cmd = lbuf_getdata(buffer, &len);
	if (len < ARGVSIZE -1)
		cmd[len] = '\0';

	char *argv[ARGCMAX];
	int argc = strsplit(cmd, " \t\n", argv, ARGCMAX -1);
	argv[argc] = NULL;

	optind = 0;
	rrd_clear_error();

	int retval = rrd_func(argc, argv);
	if (retval == -1) {
		errno = 0;
		log_print(LOG_ERROR, "rrd_func failed: %s: %s", argv[1], rrd_get_error());
	}

	return retval;
}

static int rrd_create_file(const char *filename, const char *ds_define, int interval)
{
	struct lbuf *buffer = lbuf_create(ARGVSIZE);
	if (buffer == NULL) {
		log_print(LOG_ERROR, "rrd_create_file: out of memory");
		return -1;
	}

	int ret = lbuf_printf(buffer, "create %s -s %d %s ", filename, interval, ds_define);
	if (ret == -1) {
		log_print(LOG_ERROR, "rrd_create_file: arguments too long");
		lbuf_free(buffer);
		return -1;
	}

	ret = do_rrd(&rrd_create, buffer);
	lbuf_free(buffer);
	return ret;
}

static int rrd_update_file(const char *filename, const char *values)
{
	struct lbuf *buffer = lbuf_create(ARGVSIZE);
	if (buffer == NULL) {
		log_print(LOG_ERROR, "append_ds_config: out of memory");
		return -1;
	}

	int ret = lbuf_printf(buffer, "update %s %s", filename, values);
	if (ret == -1) {
		log_print(LOG_ERROR, "rrd_update_file: arguments too long");
		lbuf_free(buffer);
		return -1;
	}

	ret = do_rrd(&rrd_update, buffer);
	lbuf_free(buffer);
	return ret;
}

static int check_create_dir(const char *dir)
{
	struct stat statbuf;
	if (stat(dir, &statbuf) == -1) {
		if (errno == ENOENT) {
			errno = 0;
			if (mkdir(dir, 0755) == -1) {
				log_print(LOG_ERROR, "check_create_dir: mkdir(%s)", dir);
				return -1;
			}

		} else {
			log_print(LOG_ERROR, "check_create_dir: stat(%s)", dir);
			return -1;
		}

	} else if (!S_ISDIR (statbuf.st_mode)) {
		log_print(LOG_ERROR, "check_create_dir: stat(%s): Not a directory!", dir);
		return -1;
	}
	return 0;
}

static int create_parent_dirs(char *filename)
{
	char *nextslash = filename;

	char *lastslash = strrchr(filename, '/');
	if (lastslash == NULL) {
		log_print(LOG_ERROR, "create_parent_dirs: invalid file name");
		return -1;
	}

	*lastslash = '\0';

	while (1) {
		if (strchr(nextslash, '/') == NULL) {
			if (*lastslash == '\0')
				*lastslash = '/';
			else
				break;
		}
		nextslash = strchr(nextslash, '/');

		*nextslash = '\0';
		if (filename != nextslash) {
			if (check_create_dir(filename) == -1) {
				*nextslash = '/';
				*lastslash = '/';
				return -1;
			}
		}
		*nextslash++ = '/';
	}
	return 0;
}

int rrd_submit(const char *filename, const char *ds_define, int interval, const char *data)
{
	char *fullfile = malloc(BUFSIZE);
	if (fullfile == NULL) {
		log_print(LOG_ERROR, "rrd_submit: out of memory");
		return -1;
	}

	int len = snprintf(fullfile, BUFSIZE, "%s/%s", rrd_dir, filename);
	if (len < 0 || len >= BUFSIZE) {
		log_print(LOG_ERROR, "rrd_submit: arguments too long");
		free(fullfile);
		return -1;
	}

	struct stat statbuf;
	if (stat(fullfile, &statbuf) == -1) {
		if (errno == ENOENT) {
			errno = 0;

			if (create_parent_dirs(fullfile) == -1) {
				free(fullfile);
				return -1;
			}

			if (rrd_create_file(fullfile, ds_define, interval) == -1) {
				free(fullfile);
				return -1;
			}

		} else {
			log_print(LOG_ERROR, "rrd_submit: stat(%s):", fullfile);
			free(fullfile);
			return -1;
		}

	} else if (!S_ISREG (statbuf.st_mode)) {
		log_print(LOG_ERROR, "rrd_submit: stat(%s): Not a regular file!", fullfile);
		free(fullfile);
		return -1;
	}

	rrd_update_file(fullfile, data);
	free(fullfile);
	return 0;
}