/*
 * xcap_auth.c
 *
 * Copyright (C) 2007 Voice Sistem S.R.L.
 *
 * Copyright (C) 2009 Juha Heinanen
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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
 *
 * Kamailio 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

/*!
 * \file
 * \brief Kamailio utils ::
 * \ingroup utils
 * Module: \ref utils
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <libxml/parser.h>

#include "../../str.h"
#include "../../dprint.h"
#include "../../pvar.h"
#include "../../parser/parse_uri.h"
#include "../../modules/presence/subscribe.h"
#include "../../modules/presence/utils_func.h"
#include "../../modules/presence/hash.h"
#include "../../modules/xcap_client/xcap_callbacks.h"
#include "utils.h"
#include "pidf.h"

xmlNodePtr get_rule_node(subs_t* subs, xmlDocPtr xcap_tree)
{
	str w_uri = {0, 0};
	char* id = NULL, *domain = NULL, *time_cont= NULL;
	int apply_rule = -1;
	xmlNodePtr ruleset_node = NULL, node1= NULL, node2= NULL;
	xmlNodePtr cond_node = NULL, except_node = NULL;
	xmlNodePtr identity_node = NULL;
	xmlNodePtr iden_child;
	xmlNodePtr validity_node, time_node;
	time_t t_init, t_fin, t;
	int valid= 0;

	uandd_to_uri(subs->from_user, subs->from_domain, &w_uri);
	if (w_uri.s == NULL) {
		LM_ERR("while creating uri\n");
		return NULL;
	}
	ruleset_node = xmlDocGetNodeByName(xcap_tree, "ruleset", NULL);
	if (ruleset_node == NULL) {
		LM_DBG("ruleset_node NULL\n");
		goto error;
	}
	for (node1 = ruleset_node->children; node1; node1 = node1->next) {
		if (xmlStrcasecmp(node1->name, (unsigned char*)"text") == 0)
			continue;

		/* process conditions */
		LM_DBG("node1->name= %s\n", node1->name);

		cond_node = xmlNodeGetChildByName(node1, "conditions");
		if(cond_node == NULL) {
			LM_DBG("cond node NULL\n");
			goto error;
		}
		LM_DBG("cond_node->name= %s\n", cond_node->name);

		validity_node = xmlNodeGetChildByName(cond_node, "validity");
		if (validity_node != NULL) {
			LM_DBG("found validity tag\n");

			t= time(NULL);

			/* search all from-until pair */
			for (time_node = validity_node->children; time_node;
					time_node = time_node->next) {
				if (xmlStrcasecmp(time_node->name, (unsigned char*)"from")!= 0)
					continue;

				time_cont= (char*)xmlNodeGetContent(time_node);
				t_init= xml_parse_dateTime(time_cont);
				xmlFree(time_cont);
				if (t_init< 0) {
					LM_ERR("failed to parse xml dateTime\n");
					goto error;
				}

				if (t< t_init) {
					LM_DBG("the lower time limit is not respected\n");
					continue;
				}

				time_node= time_node->next;
				while (1) {
					if (time_node == NULL) {
						LM_ERR("bad formatted xml doc:until child not found in"
								" validity pair\n");
						goto error;
					}
					if( xmlStrcasecmp(time_node->name,
								(unsigned char*)"until")== 0)
						break;
					time_node= time_node->next;
				}

				time_cont = (char*)xmlNodeGetContent(time_node);
				t_fin= xml_parse_dateTime(time_cont);
				xmlFree(time_cont);

				if (t_fin< 0) {
					LM_ERR("failed to parse xml dateTime\n");
					goto error;
				}

				if (t <= t_fin) {
					LM_DBG("the rule is active at this time\n");
					valid= 1;
				}

			}

			if (!valid) {
				LM_DBG("the rule is not active at this time\n");
				continue;
			}

		}

		identity_node = xmlNodeGetChildByName(cond_node, "identity");
		if (identity_node == NULL) {
			LM_ERR("didn't find identity tag\n");
			goto error;
		}

		iden_child = xmlNodeGetChildByName(identity_node, "one");
		if(iden_child) {
			for (node2 = identity_node->children; node2; node2 = node2->next) {
				if(xmlStrcasecmp(node2->name, (unsigned char*)"one")!= 0)
					continue;

				id = xmlNodeGetAttrContentByName(node2, "id");
				if(id== NULL) {
					LM_ERR("while extracting attribute\n");
					goto error;
				}
				if ((strlen(id)== w_uri.len &&
							(strncmp(id, w_uri.s, w_uri.len)==0))) {
					apply_rule = 1;
					xmlFree(id);
					break;
				}
				xmlFree(id);
			}
		}

		/* search for many node*/
		iden_child = xmlNodeGetChildByName(identity_node, "many");
		if (iden_child)	{
			domain = NULL;
			for (node2 = identity_node->children; node2; node2 = node2->next) {
				if (xmlStrcasecmp(node2->name, (unsigned char*)"many") != 0)
					continue;

				domain = xmlNodeGetAttrContentByName(node2, "domain");
				if(domain == NULL) {
					LM_DBG("No domain attribute to many\n");
				} else	{
					LM_DBG("<many domain= %s>\n", domain);
					if((strlen(domain)!= subs->from_domain.len &&
								strncmp(domain, subs->from_domain.s,
									subs->from_domain.len) )) {
						xmlFree(domain);
						continue;
					}
				}
				xmlFree(domain);
				apply_rule = 1;
				if (node2->children == NULL)       /* there is no exception */
					break;

				for (except_node = node2->children; except_node;
						except_node= except_node->next) {
					if(xmlStrcasecmp(except_node->name,
								(unsigned char*)"except"))
						continue;

					id = xmlNodeGetAttrContentByName(except_node, "id");
					if (id != NULL) {
						if((strlen(id)- 1== w_uri.len &&
									(strncmp(id, w_uri.s, w_uri.len)==0))) {
							xmlFree(id);
							apply_rule = 0;
							break;
						}
						xmlFree(id);
					} else {
						domain = NULL;
						domain = xmlNodeGetAttrContentByName(except_node,
								"domain");
						if(domain!=NULL) {
							LM_DBG("Found except domain= %s\n- strlen(domain)= %d\n",
									domain, (int)strlen(domain));
							if (strlen(domain)==subs->from_domain.len &&
									(strncmp(domain,subs->from_domain.s ,
											subs->from_domain.len)==0)) {
								LM_DBG("except domain match\n");
								xmlFree(domain);
								apply_rule = 0;
								break;
							}
							xmlFree(domain);
						}
					}
				}
				if (apply_rule == 1)  /* if a match was found no need to keep searching*/
					break;
			}
		}
		if (apply_rule ==1)
			break;
	}

	LM_DBG("apply_rule= %d\n", apply_rule);
	if(w_uri.s!=NULL)
		pkg_free(w_uri.s);

	if( !apply_rule || !node1)
		return NULL;

	return node1;

error:
	if(w_uri.s)
		pkg_free(w_uri.s);
	return NULL;
}

int pres_watcher_allowed(subs_t* subs)
{
	xmlDocPtr xcap_tree= NULL;
	xmlNodePtr node= NULL,  actions_node = NULL;
	xmlNodePtr sub_handling_node = NULL;
	char* sub_handling = NULL;

	subs->status= PENDING_STATUS;
	subs->reason.s= NULL;
	subs->reason.len= 0;

	if (subs->auth_rules_doc== NULL)
		return 0;

	xcap_tree= xmlParseMemory(subs->auth_rules_doc->s,
			subs->auth_rules_doc->len);
	if (xcap_tree== NULL) {
		LM_ERR("parsing xml memory\n");
		return -1;
	}

	node= get_rule_node(subs, xcap_tree);
	if (node== NULL) {
		xmlFreeDoc(xcap_tree);
		return 0;
	}

	/* process actions */
	actions_node = xmlNodeGetChildByName(node, "actions");
	if (actions_node == NULL) {
		LM_DBG("actions_node NULL\n");
		xmlFreeDoc(xcap_tree);
		return 0;
	}
	LM_DBG("actions_node->name= %s\n", actions_node->name);

	sub_handling_node = xmlNodeGetChildByName(actions_node, "sub-handling");
	if (sub_handling_node== NULL) {
		LM_DBG("sub_handling_node NULL\n");
		xmlFreeDoc(xcap_tree);
		return 0;
	}
	sub_handling = (char*)xmlNodeGetContent(sub_handling_node);
	LM_DBG("sub_handling_node->name= %s\n", sub_handling_node->name);
	LM_DBG("sub_handling_node->content= %s\n", sub_handling);

	if (sub_handling == NULL) {
		LM_ERR("Couldn't get sub-handling content\n");
		xmlFreeDoc(xcap_tree);
		return -1;
	}
	if (strncmp((char*)sub_handling, "block", 5) == 0) {
		subs->status = TERMINATED_STATUS;
		subs->reason.s= "rejected";
		subs->reason.len = 8;
	} else {
		if (strncmp((char*)sub_handling, "confirm", 7) == 0) {
			subs->status = PENDING_STATUS;
		} else {
			if (strncmp((char*)sub_handling , "polite-block", 12) == 0) {
				subs->status = ACTIVE_STATUS;
				subs->reason.s= "polite-block";
				subs->reason.len = 12;
			} else {
				if (strncmp((char*)sub_handling, "allow", 5) == 0) {
					subs->status = ACTIVE_STATUS;
					subs->reason.s = NULL;
				} else {
					LM_ERR("unknown subscription handling action\n");
					xmlFreeDoc(xcap_tree);
					xmlFree(sub_handling);
					return -1;
				}
			}
		}
	}

	xmlFreeDoc(xcap_tree);
	xmlFree(sub_handling);

	return 0;

}

int get_rules_doc(str* user, str* domain, int type, str** rules_doc)
{
	db_key_t query_cols[5];
	db_val_t query_vals[5];
	db_key_t result_cols[3];
	int n_query_cols = 0;
	db1_res_t *result = 0;
	db_row_t *row;
	db_val_t *row_vals;
	str body;
	str* doc= NULL;
	int n_result_cols= 0, xcap_doc_col;
	static str tmp1 = str_init("username");
	static str tmp2 = str_init("domain");
	static str tmp3 = str_init("doc_type");
	static str tmp4 = str_init("doc");

	LM_DBG("[user]= %.*s\t[domain]= %.*s",
			user->len, user->s, domain->len, domain->s);

	query_cols[n_query_cols] = &tmp1;
	query_vals[n_query_cols].type = DB1_STR;
	query_vals[n_query_cols].nul = 0;
	query_vals[n_query_cols].val.str_val = *user;
	n_query_cols++;

	query_cols[n_query_cols] = &tmp2;
	query_vals[n_query_cols].type = DB1_STR;
	query_vals[n_query_cols].nul = 0;
	query_vals[n_query_cols].val.str_val = *domain;
	n_query_cols++;

	query_cols[n_query_cols] = &tmp3;
	query_vals[n_query_cols].type = DB1_INT;
	query_vals[n_query_cols].nul = 0;
	query_vals[n_query_cols].val.int_val= type;
	n_query_cols++;

	result_cols[xcap_doc_col= n_result_cols++] = &tmp4;

	if (pres_dbf.query(pres_dbh, query_cols, 0 , query_vals, result_cols,
				n_query_cols, 1, 0, &result) < 0) {
		LM_ERR("while querying table xcap for [user]=%.*s\t[domain]= %.*s\n",
				user->len, user->s, domain->len, domain->s);
		if (result)
			pres_dbf.free_result(pres_dbh, result);
		return -1;
	}

	if(result == NULL)
		return -1;

	if (result->n <= 0) {
		LM_DBG("No document found in db table for [user]=%.*s"
				"\t[domain]= %.*s\t[doc_type]= %d\n",user->len, user->s,
				domain->len, domain->s, type);
		pres_dbf.free_result(pres_dbh, result);
		return 0;
	}

	row = &result->rows[xcap_doc_col];
	row_vals = ROW_VALUES(row);

	body.s = (char*)row_vals[0].val.string_val;
	if (body.s== NULL) {
		LM_ERR("Xcap doc NULL\n");
		goto error;
	}
	body.len = strlen(body.s);
	if (body.len== 0) {
		LM_ERR("Xcap doc empty\n");
		goto error;
	}
	LM_DBG("xcap document:\n%.*s", body.len,body.s);

	doc= (str*)pkg_malloc(sizeof(str));
	if (doc== NULL) {
		ERR_MEM(PKG_MEM_STR);
	}
	doc->s= (char*)pkg_malloc(body.len* sizeof(char));
	if (doc->s== NULL) {
		pkg_free(doc);
		ERR_MEM(PKG_MEM_STR);
	}
	memcpy(doc->s, body.s, body.len);
	doc->len= body.len;

	*rules_doc= doc;

	if (result)
		pres_dbf.free_result(pres_dbh, result);

	return 0;

error:
	if (result)
		pres_dbf.free_result(pres_dbh, result);

	return -1;

}


/*
 * Checks from presence server xcap table if watcher is authorized
 * to subscribe event 'presence' of presentity.
 */
int xcap_auth_status(struct sip_msg* _msg, char* _sp1, char* _sp2)
{
	pv_spec_t *sp;
	pv_value_t pv_val;
	str watcher_uri, presentity_uri;
	struct sip_uri uri;
	str* rules_doc = NULL;
	subs_t subs;
	int res;

	if (pres_dbh == 0) {
		LM_ERR("function is disabled, to enable define pres_db_url\n");
		return -1;
	}

	sp = (pv_spec_t *)_sp1;

	if (sp && (pv_get_spec_value(_msg, sp, &pv_val) == 0)) {
		if (pv_val.flags & PV_VAL_STR) {
			watcher_uri = pv_val.rs;
			if (watcher_uri.len == 0 || watcher_uri.s == NULL) {
				LM_ERR("missing watcher uri\n");
				return -1;
			}
		} else {
			LM_ERR("watcher pseudo variable value is not string\n");
			return -1;
		}
	} else {
		LM_ERR("cannot get watcher pseudo variable value\n");
		return -1;
	}

	sp = (pv_spec_t *)_sp2;

	if (sp && (pv_get_spec_value(_msg, sp, &pv_val) == 0)) {
		if (pv_val.flags & PV_VAL_STR) {
			presentity_uri = pv_val.rs;
			if (presentity_uri.len == 0 || presentity_uri.s == NULL) {
				LM_DBG("missing presentity uri\n");
				return -1;
			}
		} else {
			LM_ERR("presentity pseudo variable value is not string\n");
			return -1;
		}
	} else {
		LM_ERR("cannot get presentity pseudo variable value\n");
		return -1;
	}

	if (parse_uri(presentity_uri.s, presentity_uri.len, &uri) < 0) {
		LM_ERR("failed to parse presentity uri\n");
		return -1;
	}
	res = get_rules_doc(&uri.user, &uri.host, PRES_RULES, &rules_doc);
	if ((res < 0) || (rules_doc == NULL) || (rules_doc->s == NULL)) {
		LM_DBG("no xcap rules doc found for presentity uri\n");
		return PENDING_STATUS;
	}

	if (parse_uri(watcher_uri.s, watcher_uri.len, &uri) < 0) {
		LM_ERR("failed to parse watcher uri\n");
		goto err;
	}

	subs.from_user = uri.user;
	subs.from_domain = uri.host;
	subs.pres_uri = presentity_uri;
	subs.auth_rules_doc = rules_doc;
	if (pres_watcher_allowed(&subs) < 0) {
		LM_ERR("getting status from rules document\n");
		goto err;
	}
	LM_DBG("auth status of watcher <%.*s> on presentity <%.*s> is %d\n",
			watcher_uri.len, watcher_uri.s, presentity_uri.len, presentity_uri.s,
			subs.status);
	pkg_free(rules_doc->s);
	pkg_free(rules_doc);
	return subs.status;

err:
	pkg_free(rules_doc->s);
	pkg_free(rules_doc);
	return -1;
}