/*
  $Id: quota.c 1550 2005-01-07 12:23:02Z paul $
 Copyright (C) 1999-2004 IC & S  dbmail@ic-s.nl

 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <string.h>
#include "db.h"
#include "auth.h"
#include "quota.h"

/* Allocate a quota structure for `n_resources' resources. 
 * Returns NULL on failure.
 */
quota_t *quota_alloc(int n_resources)
{
	quota_t *quota;

	quota =
	    dm_malloc(sizeof(quota_t) +
		   n_resources * sizeof(resource_limit_t));
	if (quota != NULL) {
		quota->root = NULL;
		quota->n_resources = n_resources;
	}

	return quota;
}

/* Set a resource limit in a quota structure.
 * quota:        the quota object to modify.
 * resource_idx: the index of the resource to modify.
 * type:         the type of the resource, e.g. RT_STORAGE.
 * usage:        the current usage of the resource.
 * limit:        the usage limit for the resource.
 */
void quota_set_resource_limit(quota_t * quota, int resource_idx,
			      resource_type_t type,
			      u64_t usage, u64_t limit)
{
	resource_limit_t *rl = &(quota->resource[resource_idx]);
	rl->type = type;
	rl->usage = usage;
	rl->limit = limit;
}

/* Set the name of the quota root.
 * Returns 0 on success, 1 on failure.
 * quota: the quota object to modify.
 * root:  the (new) name of the quota root.
 */
int quota_set_root(quota_t * quota, char *root)
{
	dm_free(quota->root);
	quota->root = dm_strdup(root);
	return (quota->root == NULL);
}

/* Free a quota structure. */
void quota_free(quota_t * quota)
{
	dm_free(quota->root);
	dm_free(quota);
}


/* Get the quota root for a given mailbox.
 * Currently, the only supported quota root is "".
 * Returns the name of the quota root, or NULL on failure
 * (e.g. quota root not found). When NULL is returned, a pointer to 
 * an appropriate error message is stored in *errormsg.
 *   useridnr: the useridnr of the mailbox owner.
 *   mailbox:  the name of the mailbox.
 *   errormsg: will point to an error message if NULL is returned.
 */
char *quota_get_quotaroot(u64_t useridnr, const char *mailbox,
			  char **errormsg)
{
	u64_t mailbox_idnr;

	if (db_findmailbox(mailbox, useridnr, &mailbox_idnr) <= 0) {
		*errormsg = "mailbox not found";
		return NULL;
	}

	return "";
}

/* Get the quota for a given quota root.
 * Currently, the only supported quota root is "".
 * Returns a quota structure describing the given quota root,
 * or NULL on failure. When NULL is returned, a pointer to 
 * an appropriate error message is stored in *errormsg.
 *   useridnr:  the useridnr of the mailbox owner.
 *   quotaroot: the quotaroot.
 *   errormsg:  will point to an error message if NULL is returned.
 */
quota_t *quota_get_quota(u64_t useridnr, char *quotaroot, char **errormsg)
{
	quota_t *quota;
	u64_t maxmail_size, usage;

	/* Currently, there's only the quota root "". */
	if (strcmp(quotaroot, "") != 0) {
		trace(TRACE_ERROR,
		      "quota_get_quota(): unknown quota root \"%s\"\n",
		      quotaroot);
		*errormsg = "unknown quota root";
		return NULL;
	}

	if (auth_getmaxmailsize(useridnr, &maxmail_size) == -1) {
		trace(TRACE_ERROR,
		      "quota_get_quota(): auth_getmaxmailsize() failed\n");
		*errormsg = "invalid user";
		return NULL;
	}

	if (db_get_quotum_used(useridnr, &usage) == -1) {
		trace(TRACE_ERROR,
		      "quota_get_quota(): db_get_quotum_used() failed\n");
		*errormsg = "internal error";
		return NULL;
	}

	/* We support exactly one resource: RT_STORAGE */
	quota = quota_alloc(1);
	if (quota == NULL) {
		trace(TRACE_ERROR, "quota_get_quota(): out of memory\n");
		*errormsg = "out of memory";
		return NULL;
	}

	/* Set quota root */
	if (quota_set_root(quota, quotaroot)) {
		trace(TRACE_ERROR,
		      "quota_get_quota(): quota_set_root() failed\n");
		*errormsg = "out of memory";
		return NULL;
	}

	/* Set usage and limit for RT_STORAGE */
	quota_set_resource_limit(quota, 0, RT_STORAGE, usage,
				 maxmail_size);

	return quota;
}