/*
 * $Id$
 *
 * Copyright (C) 2005 iptelorg GmbH
 *
 * This file is part of ser, a free SIP server.
 *
 * ser 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
 *
 * For a license to use the ser software under conditions
 * other than those described here, or to purchase support for this
 * software, please contact iptel.org by e-mail at the following addresses:
 *    info@iptel.org
 *
 * ser 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 "id.h"
#include "parser/parse_from.h"
#include "parser/parse_uri.h"
#include "parser/digest/digest.h"
#include "ut.h"

static str uid_name = STR_STATIC_INIT(AVP_UID);
static str did_name = STR_STATIC_INIT(AVP_DID);


/*
 * Set From UID
 */
int set_from_uid(str* uid)
{
	struct search_state s;
	int_str val, name;
	avp_t* a;

	name.s = uid_name;
	a = search_first_avp(AVP_CLASS_USER | AVP_TRACK_FROM | AVP_NAME_STR, name, 0, &s);
	while(a) {
		destroy_avp(a);
		a = search_next_avp(&s, 0);
	}

	val.s = *uid;
	return add_avp(AVP_CLASS_USER | AVP_TRACK_FROM | AVP_NAME_STR | AVP_VAL_STR, name, val);
}


/* Extract username attribute from authorized credentials */
static inline str* cred_user(struct sip_msg* msg)
{
	struct hdr_field* h;
	auth_body_t* cred;

	get_authorized_cred(msg->proxy_auth, &h);
	if (!h) get_authorized_cred(msg->authorization, &h);
	if (!h) return 0;
	cred = (auth_body_t*)(h->parsed);
	if (!cred || !cred->digest.username.user.len) return 0;
	return &cred->digest.username.user;
}

/*
 * Set From UID
 */
int get_from_uid(str* uid, struct sip_msg* msg)
{
	static char buf[MAX_URI_SIZE];
	struct to_body* from;
	struct sip_uri puri;
	str* du;
	int_str val, name;

	name.s = uid_name;
	if (search_first_avp(AVP_CLASS_USER | AVP_TRACK_FROM | AVP_NAME_STR, name, &val, 0)) {
		*uid = val.s;
		return 1;
	} else {
		du = cred_user(msg);
		if (du) {
			     /* Try digest username first */
			*uid = *du;
		} else {
			     /* Get From URI username */
			if (parse_from_header(msg) < 0) {
				LOG(L_ERR, "get_from_uid: Error while parsing From header\n");
				return -1;
			}
			from = get_from(msg);
			if (parse_uri(from->uri.s, from->uri.len, &puri) == -1) {
				LOG(L_ERR, "get_from_uid: Error while parsing From URI\n");
				return -1;
			}
		
			if (puri.user.len > MAX_URI_SIZE) {
				LOG(L_ERR, "get_from_uid: Username too long\n");
				return -1;
			}
			memcpy(buf, puri.user.s, puri.user.len);
			uid->s = buf;
			uid->len = puri.user.len;
			strlower(uid);
		}
		
		val.s = *uid;
		add_avp(AVP_CLASS_USER | AVP_TRACK_FROM | AVP_NAME_STR | AVP_VAL_STR, name, val);
		return 0;
	}
}


/*
 * Set To UID
 */
int set_to_uid(str* uid)
{
	struct search_state s;
	int_str val, name;
	avp_t* a;

	name.s = uid_name;
	a = search_first_avp(AVP_CLASS_USER | AVP_TRACK_TO | AVP_NAME_STR, name, 0, &s);
	while(a) {
		destroy_avp(a);
		a = search_next_avp(&s, 0);
	}

	val.s = *uid;
	return add_avp(AVP_CLASS_USER | AVP_TRACK_TO | AVP_NAME_STR | AVP_VAL_STR, name, val);
}


/** Retrieves the UID of the callee. This function retrieves the UID (unique
 * identifier) of the party being called. The function first searches the list
 * of available attributes and if it finds an attribute with name "uid" then
 * the value of the attribute is returned.  If no such attribute can be found
 * then the function retrieves the username from To header field of REGISTER
 * requests (because that is the party being registered), or the username from
 * the Reqeuest-URI of other requests. The username is then used as the UID
 * string identifying the callee. If no attribute with the UID was found and
 * the function successfully retrieved the UID from the SIP message then, in
 * addition to storing the result in the first parameter, the function will
 * also create the attribute named "uid" which will contain the UID. The
 * function is not reentrant because it uses an internal static buffer to
 * store the result.  
 * @param uid A pointer to ::str variable where the result will be stored, the
 *            pointer in the variable will be updated to point to a static
 *            buffer in the function.
 * @param msg The SIP message being processed.
 * @return 1 is returned when the attribute with UID exists and it is used, 0
 *         is returned when the function retrieved the UID from the SIP
 *         message and created the attribute, -1 is returned on error.
 */
int get_to_uid(str* uid, struct sip_msg* msg)
{
	static char buf[MAX_URI_SIZE];
	struct to_body* to;
	struct sip_uri puri;
	char* p;
	int_str val, name;

	name.s = uid_name;
	if (search_first_avp(AVP_CLASS_USER | AVP_TRACK_TO | AVP_NAME_STR, name, &val, 0)) {
		*uid = val.s;
		return 1;
	} else {
		if (msg->first_line.type == METHOD_REGISTER) {
			if ((msg->to==0) && 
				(parse_headers(msg, HDR_TO_F, 0) < 0 || msg->to == 0)) {
				DBG("get_to_uid: Error while parsing To URI: "
					" to header bad or missing\n");
				return -1;
			}
			to = get_to(msg);
			if (parse_uri(to->uri.s, to->uri.len, &puri) == -1) {
				DBG("get_to_uid: Error while parsing To URI\n");
				return -1;
			}
			p = puri.user.s;
			uid->len = puri.user.len;
		} else {
			if (!msg->parsed_uri_ok && (parse_sip_msg_uri(msg) < 0)) {
				DBG("Error while parsing the Request-URI\n");
				return -1;
			}
			p = msg->parsed_uri.user.s;
			uid->len = msg->parsed_uri.user.len;
		}
			
		if (uid->len > MAX_URI_SIZE) {
			DBG("get_to_uid: Username too long\n");
			return -1;
		}
		memcpy(buf, puri.user.s, puri.user.len);
		uid->s = buf;
		strlower(uid);

		val.s = *uid;
		add_avp(AVP_CLASS_USER | AVP_TRACK_TO | AVP_NAME_STR | AVP_VAL_STR, name, val);
		return 0;
	}
}


/*
 * Return current To domain id
 */
int get_to_did(str* did, struct sip_msg* msg)
{
	int_str val, name;

	name.s = did_name;
	if (search_first_avp(AVP_TRACK_TO | AVP_NAME_STR, name, &val, 0)) {
		*did = val.s;
		return 1;
	} 
	return 0;
}


/*
 * Return current To domain id
 */
int get_from_did(str* did, struct sip_msg* msg)
{
	int_str val, name;

	name.s = did_name;
	if (search_first_avp(AVP_TRACK_FROM | AVP_NAME_STR, name, &val, 0)) {
		*did = val.s;
		return 1;
	} 
	return 0;
}