/* $Id$
 *
 * Lasso - A free implementation of the Liberty Alliance specifications.
 *
 * Copyright (C) 2004-2007 Entr'ouvert
 * http://lasso.entrouvert.org
 *
 * Authors: See AUTHORS file in top-level directory.
 *
 * 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
 */

/**
 * SECTION:discovery
 * @short_description: ID-WSF Discovery Service Profile
 *
 * The Discovery service usually runs on the principal identity provider and
 * knowns about resources and services related to the principal.  Attribute
 * providers can register themselves as offering resources for an user while
 * other services can ask where to find a given resource.
 *
 * The following example is a service provider asking for a "PP" service (an
 * attribute provider for the "Personal Profile"):
 *
 * <informalexample>
 * <programlisting>
 * LassoServer *server;  // initialized before
 * char* session_dump;   // initialized before
 *
 * LassoDiscovery *discovery;    // discovery service
 * char *soap_answer;            // SOAP answer from disco service
 * LassoProfileService *service; // instance to perform on requested service
 *
 * discovery = lasso_discovery_new(server);
 * lasso_wsf_profile_set_session_from_dump(LASSO_WSF_PROFILE(discovery), session_dump);
 * lasso_discovery_init_query(discovery);
 * lasso_discovery_add_requested_service(discovery, LASSO_PP10_HREF);
 * lasso_discovery_build_request_msg(discovery);
 *
 * // service must perform SOAP call to LASSO_WSF_PROFILE(discovery)->msg_url
 * // the SOAP message is LASSO_WSF_PROFILE(discovery)->msg_body.  The answer
 * // is stored in char* soap_answer;
 *
 * lasso_discovery_process_query_response_msg(discovery, soap_answer);
 *
 * // get an object to access the first service returned, or NULL if an error happened
 * service = lasso_discovery_get_service(discovery);
 * </programlisting>
 * </informalexample>
 *
 */

#include "../xml/private.h"
#include <libxml/xpath.h>
#include <libxml/xpathInternals.h>

#include <xmlsec/xmltree.h>

#include "../utils.h"
#include "../xml/soap_binding_correlation.h"
#include "../xml/saml_assertion.h"
#include "../xml/saml_attribute.h"
#include "../xml/saml_attribute_value.h"
#include "../xml/disco_modify.h"
#include "../xml/saml_assertion.h"
#include "../xml/idwsf_strings.h"

#include "../id-ff/server.h"
#include "../id-ff/provider.h"
#include "../id-ff/providerprivate.h"
#include "../id-ff/sessionprivate.h"

#include "./id_wsf.h"
#include "./wsf_profile_private.h"
#include "./wsf_utils.h"
#include "../utils.h"
#include "./discovery.h"

struct _LassoDiscoveryPrivate
{
	gboolean dispose_has_run;
	GList *new_entry_ids;
	char *security_mech_id;
};

#define assign_resource_id(from,to) \
	if ((from)->ResourceID) {\
		lasso_assign_gobject((to)->ResourceID, (from)->ResourceID); \
	} else if ((from)->EncryptedResourceID) {\
		lasso_assign_gobject((to)->EncryptedResourceID, (from)->EncryptedResourceID); \
	} else { \
		rc = LASSO_WSF_PROFILE_ERROR_MISSING_RESOURCE_ID;\
		goto_cleanup_if_fail(0); \
	}

/*****************************************************************************/
/* static methods/functions */
/*****************************************************************************/

static gchar* lasso_discovery_build_credential(LassoDiscovery *discovery, const gchar *providerId);
static LassoWsfProfile *lasso_discovery_build_wsf_profile(LassoDiscovery *discovery,
	LassoDiscoResourceOffering *offering);
static LassoWsfProfileConstructor lookup_registry(gchar const *service_type);
static void remove_registry(gchar const *service_type);
static void set_registry(gchar const *service_type, LassoWsfProfileConstructor constructor);
static LassoDsKeyInfo* lasso_discovery_build_key_info_node(LassoDiscovery *discovery,
	const gchar *providerID);
static LassoDiscoResourceOffering* lasso_discovery_get_resource_offering_auto(
	LassoDiscovery *discovery, const gchar *service_type);
static gint lasso_discovery_init_resource_offering(LassoDiscovery *discovery,
		const gchar *security_mech_id, LassoDiscoResourceOffering **output_offering);
static gint lasso_discovery_process_modify_msg(LassoDiscovery *discovery);
static gint lasso_discovery_process_query_msg(LassoDiscovery *discovery);
static gint lasso_discovery_build_query_response_msg(LassoDiscovery *discovery);
static gint lasso_discovery_build_modify_response_msg(LassoDiscovery *discovery);

/**
 * lasso_discovery_add_insert_entry:
 * @discovery: a #LassoDiscovery object
 * @serviceInstance: an optional #LassoDiscoServiceInstance object
 * @resourceID: the new #LassoDiscoResourceID used to create the #LassoDiscoResrouceOffering
 *
 * Add an #LassoDiscoInsertEntry containing a new #LassoDiscoResourceOffering, and initialize the
 * #LassoDiscoResourceOffering using the #LassoDiscoServiceInstance and #LassoDiscoResourceId
 * object.
 *
 * Return value: the newly created #LassoDiscoInsertEntry or NULL if some preconditions failed.
 **/
gint
lasso_discovery_add_insert_entry(LassoDiscovery *discovery,
		LassoDiscoServiceInstance *serviceInstance,
		LassoDiscoResourceID *resourceId)
{
	LassoDiscoModify *modify = NULL;
	LassoDiscoInsertEntry *insertEntry = NULL;
	LassoDiscoResourceOffering *resourceOffering = NULL;
	int rc = 0;

	lasso_bad_param(DISCOVERY, discovery);
	lasso_bad_param(DISCO_SERVICE_INSTANCE, serviceInstance);
	lasso_bad_param(DISCO_RESOURCE_ID, resourceId);
	g_return_val_if_fail(LASSO_IS_DISCO_MODIFY(LASSO_WSF_PROFILE(discovery)->request), LASSO_PARAM_ERROR_NON_INITIALIZED_OBJECT);

	lasso_extract_node_or_fail(modify, LASSO_WSF_PROFILE(discovery)->request, DISCO_MODIFY,
			LASSO_PROFILE_ERROR_MISSING_REQUEST);
	resourceOffering = lasso_disco_resource_offering_new(serviceInstance);
	lasso_assign_gobject(resourceOffering->ResourceID, resourceId);
	insertEntry = lasso_disco_insert_entry_new(resourceOffering);
	lasso_list_add_gobject(modify->InsertEntry, insertEntry);

cleanup:
	lasso_release_gobject(resourceOffering);
	return rc;
}

/**
 * lasso_discovery_add_remove_entry:
 * @discovery: a #LassoDiscovery object
 * @entryID: the idenitfier of a ResourceOffering to remove.
 *
 * Add a RemoveEntry to the current Modify message for a Discovery service,
 * to remove the resource offering identified by entryID (returned in the
 * response to a Modify/InsertEntry message).
 *
 * Return value: 0 if successful, an error code otherwise.
 **/
gint
lasso_discovery_add_remove_entry(LassoDiscovery *discovery,
		const gchar    *entryID)
{
	LassoDiscoModify *modify = NULL;
	gint rc = 0;

	lasso_bad_param(DISCOVERY, discovery);
	lasso_null_param(entryID);
	lasso_extract_node_or_fail(modify, LASSO_WSF_PROFILE(discovery)->request, DISCO_MODIFY,
			LASSO_PROFILE_ERROR_MISSING_REQUEST);

	lasso_list_add_new_gobject(modify->RemoveEntry, lasso_disco_remove_entry_new(entryID));

cleanup:
	return rc;
}

/**
 * lasso_discovery_add_requested_service_type:
 * @discovery: a #LassoDiscovery
 * @service_type: requested service type
 * @option: option to the requested service
 *
 * Adds a request for service of @service_type to the disco:Query being built.
 *
 * Return value: 0 if successful
 **/
gint
lasso_discovery_add_requested_service_type(LassoDiscovery *discovery,
		const gchar    *service_type,
		const gchar    *option)
{
	LassoDiscoRequestedServiceType *rst = NULL;
	LassoDiscoOptions *opts = NULL;
	LassoDiscoQuery *query = NULL;
	gint rc = 0;

	lasso_bad_param(DISCOVERY, discovery);
	lasso_null_param(service_type);
	lasso_extract_node_or_fail(query, LASSO_WSF_PROFILE(discovery)->request, DISCO_QUERY,
			LASSO_PARAM_ERROR_NON_INITIALIZED_OBJECT);

	rst = lasso_disco_requested_service_type_new(service_type);
	if (option != NULL) {
		opts = lasso_disco_options_new();
		lasso_list_add_string(opts->Option, option);
		lasso_assign_new_gobject(rst->Options, opts);
	}
	lasso_list_add_new_gobject(query->RequestedServiceType, rst);

cleanup:
	return rc;
}

/**
 * lasso_discovery_init_query
 * @discovery: a #LassoDiscovery
 * @security_mech_id: (allow-none): identifier of a wished security mechanism, or NULL if any is ok
 *
 * Initializes a disco:Query message.
 *
 * Return value: 0 on success; or a negative value otherwise.
 **/
gint
lasso_discovery_init_query(LassoDiscovery *discovery, const gchar *security_mech_id)
{
	LassoWsfProfile *profile = NULL;
	LassoDiscoQuery *query = NULL;
	LassoDiscoResourceOffering *offering = NULL;
	gint rc = 0;

	lasso_bad_param(DISCOVERY, discovery);

	profile = &discovery->parent;
	/* 1. Get an offering */
	rc = lasso_discovery_init_resource_offering(discovery, security_mech_id, &offering);
	goto_cleanup_if_fail(! rc);

	/* 2. Create SOAP envelope and set profile->request */
	query = lasso_disco_query_new();
	lasso_wsf_profile_init_soap_request(profile, LASSO_NODE(query));
	assign_resource_id(offering, query);

cleanup:
	lasso_release_gobject(query);
	return rc;
}

/**
 * lasso_discovery_init_modify:
 * @discovery: a #LassoDiscovery
 * @security_mech_id: (allow-none): the security mechanism identifier
 *
 * Initializes a disco Modify/InsertEntry
 *
 * Return value: 0 on success; an error code otherwise.
 **/
gint
lasso_discovery_init_modify(LassoDiscovery *discovery,
		const char *security_mech_id)
{
	LassoWsfProfile *profile = NULL;
	LassoDiscoModify *modify = NULL;
	LassoDiscoResourceOffering *offering = NULL;
	gint rc = 0;

	lasso_bad_param(DISCOVERY, discovery);

	profile = &discovery->parent;
	/* 1. Get an offering */
	rc = lasso_discovery_init_resource_offering(discovery, security_mech_id, &offering);
	goto_cleanup_if_fail (! rc);

	/* 2. Set message content */
	modify = lasso_disco_modify_new();
	assign_resource_id(offering, modify);
	lasso_wsf_profile_init_soap_request(profile, LASSO_NODE(modify));
cleanup:
	lasso_release_gobject(modify);
	return rc;
}

/**
 * lasso_discovery_process_request_msg:
 * @discovery: a #LassoDiscovery object
 * @message: a serialized SOAP message
 * @security_mech_id: (allow-none): the security mech id to use for validating authorizations
 *
 * Process a received SOAP message for the discovery service.
 *
 * Return value: 0 if successfull, an error code otherwise.
 */
gint
lasso_discovery_process_request_msg(LassoDiscovery *discovery, const gchar *message,
	const gchar *security_mech_id)
{
	gint rc = 0;
	LassoWsfProfile *profile = NULL;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery), LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);
	g_return_val_if_fail(message != NULL, LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);

	profile = LASSO_WSF_PROFILE(discovery);
	rc = lasso_wsf_profile_process_soap_request_msg(profile, message,
			security_mech_id);
	if (rc) {
		return rc;
	}
	if (LASSO_IS_DISCO_MODIFY(profile->request)) {
		return lasso_discovery_process_modify_msg(discovery);
	} else if (LASSO_IS_DISCO_QUERY(profile->request)) {
		return lasso_discovery_process_query_msg(discovery);
	} else {
		return LASSO_PROFILE_ERROR_INVALID_MSG;
	}
	return rc;
}

/**
 * lasso_discovery_build_modify_response_msg:
 * @discovery: a #LassoDiscovery
 *
 * Builds a disco:ModifyResponse message; answer to the disco:Modify passed
 * to lasso_discovery_process_modify_msg().  It inserts and removed
 * ResourceOfferings from identity; it must be saved afterwards.
 *
 * Sets @msg_body to the SOAP answer.
 *
 * Return value: 0 on success; or a negative value otherwise.
 **/
static gint
lasso_discovery_build_modify_response_msg(LassoDiscovery *discovery)
{
	/* FIXME: Check all error cases, set the right status code,
	   and don't return without building a response, and
	   ensure atomicity, everything fails or everythig succeed. */

	LassoWsfProfile *profile = NULL;
	LassoDiscoModify *request = NULL;
	LassoDiscoModifyResponse *response = NULL;
	LassoUtilityStatus *status = NULL;
	LassoDiscoRemoveEntry *remove_entry = NULL;
	LassoDiscoInsertEntry *insert_entry = NULL;
	char *new_entry_ids = NULL;
	char *t_new_entry_ids = NULL;
	GList *iter = NULL;
	int res = 0;
	int res2 = 0;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery), LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);

	profile = LASSO_WSF_PROFILE(discovery);
	request = LASSO_DISCO_MODIFY(profile->request);
	response = LASSO_DISCO_MODIFY_RESPONSE(profile->response);

	if (profile->identity == NULL) {
		return LASSO_PROFILE_ERROR_IDENTITY_NOT_FOUND;
	}

	/* First verify remove entries are all ok */
	for (iter = request->RemoveEntry; iter != NULL; iter = g_list_next(iter)) {
		if (! LASSO_IS_DISCO_REMOVE_ENTRY(iter->data)) {
			continue;
		}
		remove_entry = LASSO_DISCO_REMOVE_ENTRY(iter->data);

		if (! lasso_identity_get_resource_offering(profile->identity,
					remove_entry->entryID)) {
			res = LASSO_PROFILE_ERROR_MISSING_RESOURCE_OFFERING;
			break;
		}
	}

	/* Then remove the entries */
	if (res == 0) {
		for (iter = request->RemoveEntry; iter != NULL; iter = g_list_next(iter)) {
			remove_entry = LASSO_DISCO_REMOVE_ENTRY(iter->data);
			if (! lasso_identity_remove_resource_offering(profile->identity,
						remove_entry->entryID)) {
				/* Set the right error code */
				res = -1;
				break;
			}
		}
	}

	if (request->InsertEntry) {
		new_entry_ids = g_malloc(10 * g_list_length(request->InsertEntry));
		t_new_entry_ids = new_entry_ids;
	}

	for (iter = request->InsertEntry; iter != NULL; iter = g_list_next(iter)) {
		if (! LASSO_IS_DISCO_INSERT_ENTRY(iter->data)) {
			continue;
		}
		insert_entry = LASSO_DISCO_INSERT_ENTRY(iter->data);

		lasso_identity_add_resource_offering(profile->identity,
				insert_entry->ResourceOffering);

		t_new_entry_ids = g_stpcpy(t_new_entry_ids,
				insert_entry->ResourceOffering->entryID);
		t_new_entry_ids = g_stpcpy(t_new_entry_ids, " ");
	}
	if (t_new_entry_ids) {
		t_new_entry_ids[-1] = 0; /* remove trailing white space */
	}

	if (new_entry_ids) {
		response->newEntryIDs = g_strdup(new_entry_ids);
		lasso_release(new_entry_ids);
	}

	if (res != 0) {
		lasso_assign_string(status->code, LASSO_DISCO_STATUS_CODE_FAILED);
	}

	res2 = lasso_wsf_profile_build_soap_response_msg(profile);
	if (res != 0) {
		return res;
	} else {
		return res2;
	}
}

/**
 * lasso_discovery_process_modify_response_msg:
 * @discovery: a #LassoDiscovery
 * @message: the disco:ModifyResponse SOAP message
 *
 * Processes a disco:ModifyResponse SOAP message.
 *
 * Return value: 0 on success; or a negative value otherwise.
 **/
gint
lasso_discovery_process_modify_response_msg(LassoDiscovery *discovery, const gchar *message)
{
	LassoWsfProfile *profile = NULL;
	LassoDiscoModifyResponse *response = NULL;
	int rc = 0;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery), LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);
	g_return_val_if_fail(message != NULL, LASSO_PARAM_ERROR_INVALID_VALUE);

	profile = LASSO_WSF_PROFILE(discovery);

	rc = lasso_wsf_profile_process_soap_response_msg(profile, message);
	if (rc) {
		return rc;
	}

	response = LASSO_DISCO_MODIFY_RESPONSE(profile->response);

	if (strcmp(response->Status->code, LASSO_DISCO_STATUS_CODE_OK) != 0) {
		return LASSO_PROFILE_ERROR_STATUS_NOT_SUCCESS;
	}

	return 0;
}

/**
 * lasso_discovery_build_response_msg:
 * @discovery: a #LassoDiscovery object
 *
 * Execute needed action for the received request, and produce a response message.
 *
 * If any critical error occur, it tries to produce a SOAP fault.
 *
 * Return value: 0 on success; or an error code otherwise.
 */
gint
lasso_discovery_build_response_msg(LassoDiscovery *discovery)
{
	gint rc = LASSO_PROFILE_ERROR_INVALID_MSG;
	LassoWsfProfile *profile = NULL;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery), LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);
	profile = &discovery->parent;

	if (G_IS_OBJECT(profile->request)) {

		if (LASSO_IS_DISCO_MODIFY(profile->request)) {
			rc = lasso_discovery_build_modify_response_msg(discovery);
		}
		if (LASSO_IS_DISCO_QUERY(profile->request)) {
			rc = lasso_discovery_build_query_response_msg(discovery);
		}
	}
	if (rc < 0) {
		rc = lasso_wsf_profile_build_soap_fault_response_msg(profile, rc);
	}
	rc = lasso_wsf_profile_build_soap_response_msg(profile);

	return rc;
}

/**
 * lasso_discovery_build_query_response_msg
 * @discovery: a #LassoDiscovery
 *
 * Builds a disco:QueryResponse message; answer to the disco:Query passed to
 * lasso_discovery_process_query_msg().  It looks up resource offerings in the
 * principal identity and extracts those of the requested service type.
 *
 * Sets @msg_body to the SOAP answer.
 *
 * Return value: 0 on success; or a negative value otherwise.
 **/
static gint
lasso_discovery_build_query_response_msg(LassoDiscovery *discovery)
{
	LassoWsfProfile *profile = NULL;
	LassoDiscoQuery *request = NULL;
	LassoDiscoQueryResponse *response = NULL;
	LassoSoapEnvelope *envelope = NULL;
	LassoSoapFault *fault = NULL;
	GList *offerings = NULL;
	GList *iter = NULL;
	GList *iter2 = NULL;
	GList *iter3 = NULL;
	int res = 0;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery), LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);

	profile = LASSO_WSF_PROFILE(discovery);
	request = LASSO_DISCO_QUERY(profile->request);
	envelope = profile->soap_envelope_response;
	response = LASSO_DISCO_QUERY_RESPONSE(profile->response);

	if (profile->identity == NULL) {
		fault = lasso_soap_fault_new();
		fault->faultcode = LASSO_SOAP_FAULT_CODE_SERVER;
		fault->faultstring = LASSO_SOAP_FAULT_STRING_IDENTITY_NOT_FOUND;
		lasso_list_add_gobject(envelope->Body->any, fault);
		return lasso_wsf_profile_build_soap_response_msg(profile);
	}

	iter = request->RequestedServiceType;
	while (iter) {
		LassoDiscoRequestedServiceType *service_type = iter->data;
		iter = g_list_next(iter);
		offerings = g_list_concat(offerings, lasso_identity_get_offerings(
					profile->identity,
					service_type->ServiceType));
	}

	/* build response */
	response->ResourceOffering = offerings;

	/* Add needed credentials for offerings */
	iter = offerings;
	while (iter) {
		LassoDiscoResourceOffering *resource_offering = iter->data;
		iter = g_list_next(iter);
		iter2 = resource_offering->ServiceInstance->Description;
		while (iter2) {
			LassoDiscoDescription *description = LASSO_DISCO_DESCRIPTION(iter2->data);
			iter3 = description->SecurityMechID;
			while (iter3) {
				if (lasso_security_mech_id_is_saml_authentication(
							iter3->data) == TRUE) {
					gchar *credentialRef = lasso_discovery_build_credential(
							discovery, NULL);
					lasso_list_add_new_string(description->CredentialRef, (void*)credentialRef);
				}
				iter3 = g_list_next(iter3);
			}
			iter2 = g_list_next(iter2);
		}
	}

	res = lasso_wsf_profile_build_soap_response_msg(profile);

	return res;
}

const char*
get_assertion_id(xmlNode *node) {
	return (char*)xmlGetProp(node, (xmlChar*)"AssertionID");
}

/**
 * lasso_discovery_process_query_response_msg:
 * @discovery: a #LassoDiscovery
 * @message: the disco:QueryResponse message
 *
 * Processes a disco:QueryResponse message.
 * Extract credentials from the response and put them in the session,
 * for later use by a request from a #LassoWsfProfile.
 *
 * Return value: 0 on success; or a negative value otherwise.
 **/
gint
lasso_discovery_process_query_response_msg(LassoDiscovery *discovery, const gchar *message)
{
	LassoWsfProfile *profile = NULL;
	LassoDiscoQueryResponse *response;
	int rc = 0;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery),
			LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);
	g_return_val_if_fail(message != NULL,
			LASSO_PARAM_ERROR_INVALID_VALUE);

	profile = LASSO_WSF_PROFILE(discovery);
	rc = lasso_wsf_profile_process_soap_response_msg(profile, message);
	if (rc)
		goto cleanup;
	response = LASSO_DISCO_QUERY_RESPONSE(profile->response);
	if (strcmp(response->Status->code, LASSO_DISCO_STATUS_CODE_OK) != 0 &&
			strcmp(response->Status->code, LASSO_DISCO_STATUS_CODE_DISCO_OK) != 0) {
		return LASSO_PROFILE_ERROR_STATUS_NOT_SUCCESS;
	}
	/** Process the credentials, add them to the session */
	if (response->Credentials) {
		GList *assertions = response->Credentials->any;
		for (; assertions; assertions = g_list_next(assertions)) {
			xmlNode *assertion = (xmlNode*)assertions->data;
			if (! (assertion->type == XML_ELEMENT_NODE &&
						strcmp((char*)assertion->name, "Assertion") == 0)) {
				continue;
			}
			if (profile->session) {
				lasso_session_add_assertion_with_id(profile->session,
						get_assertion_id(assertion),
						assertion);
			} else {
				rc = LASSO_PROFILE_ERROR_SESSION_NOT_FOUND;
				goto cleanup;
			}
		}
	}
cleanup:
	return rc;
}


/**
 * lasso_discovery_get_service:
 * @discovery: a #LassoDiscovery
 * @service_type: the requested service type
 *
 * After a disco:query message, creates a #LassoDataService instance for the
 * requested @service_type with the first resource offering found or the first resource offering
 * matching the service type.
 *
 * Return value:(transfer full)(allow-none): a newly created #LassoDataService object; or NULL if an
 *     error occured.
 **/
LassoWsfProfile*
lasso_discovery_get_service(LassoDiscovery *discovery, const char *service_type)
{
	LassoWsfProfile *profile = NULL;
	LassoDiscoQueryResponse *response = NULL;
	GList *iter = NULL;
	LassoDiscoResourceOffering *offering = NULL;
	LassoWsfProfile *service = NULL;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery), NULL);
	profile = LASSO_WSF_PROFILE(discovery);
	g_return_val_if_fail(LASSO_IS_DISCO_QUERY_RESPONSE(profile->response), NULL);
	response = LASSO_DISCO_QUERY_RESPONSE(profile->response);

	iter = response->ResourceOffering;
	for (;iter; iter = g_list_next(iter)) {
		LassoDiscoResourceOffering *t = iter->data;

		if (! LASSO_IS_DISCO_RESOURCE_OFFERING(t)) {
			continue;
		}
		if (t->ServiceInstance == NULL)
			continue;
		if (service_type == NULL || strcmp(t->ServiceInstance->ServiceType, service_type) == 0) {
			offering = t;
			break;
		}
	}
	if (offering) {
		service = lasso_discovery_build_wsf_profile(discovery, offering);
	}
	return service;
}


/**
 * lasso_discovery_get_services:
 * @discovery: a #LassoDiscovery
 *
 * After a disco:query message, creates a GList object of #LassoDataService.
 *
 * Return value:(transfer full)(element-type LassoNode): a newly created GList object of #LassoDataService;
 *     or NULL if an error occured.
 **/
GList*
lasso_discovery_get_services(LassoDiscovery *discovery)
{
	LassoWsfProfile *profile = NULL;
	LassoDiscoQueryResponse *response;
	GList *iter;
	LassoDiscoResourceOffering *offering;
	LassoWsfProfile *service;
	GList *services = NULL;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery), NULL);
	profile = LASSO_WSF_PROFILE(discovery);
	goto_cleanup_if_fail(LASSO_IS_DISCO_QUERY_RESPONSE(profile->response));
	response = LASSO_DISCO_QUERY_RESPONSE(profile->response);

	iter = response->ResourceOffering;
	while (iter) {
		offering = iter->data;
		iter = g_list_next(iter);
		if (offering->ServiceInstance == NULL) {
			continue;
		}
		service = lasso_discovery_build_wsf_profile(discovery, offering);
		lasso_list_add_new_gobject(services, service);
	}

cleanup:
	return services;
}

/**
 * lasso_discovery_register_constructor_for_service_type:
 * @service_type: the URI of the service type
 * @constructor: a constructor function for the profile handling this service type
 *
 * This function permits to subclass of #LassoWsfProfile to register a
 * constructor for the service type they supports.
 */
void
lasso_discovery_register_constructor_for_service_type(const gchar *service_type,
		LassoWsfProfileConstructor constructor)
{
	LassoWsfProfileConstructor old_constructor;

	g_return_if_fail(service_type);
	g_return_if_fail(constructor);
	old_constructor = lookup_registry(service_type);
	if (old_constructor) {
		message(G_LOG_LEVEL_WARNING, "Service type already registered: %s", service_type);
		return;
	}
	set_registry(service_type, constructor);
}

/**
 * lasso_discovery_unregister_constructor_for_service_type:
 * @service_type: the URI of the service type
 * @constructor: a constructor function for the profile handling this service type
 *
 * This function permits to subclass of #LassoWsfProfile to unregister a
 * constructor for the service type they previously registered using
 * lasso_discovery_register_constructor_for_service_type().
 */
void
lasso_discovery_unregister_constructor_for_service_type(
		gchar const *service_type,
		LassoWsfProfileConstructor constructor) {
	LassoWsfProfileConstructor old_constructor;

	g_return_if_fail(service_type);
	g_return_if_fail(constructor);
	old_constructor = lookup_registry(service_type);
	if (old_constructor != constructor) {
		message(G_LOG_LEVEL_WARNING,
			"Mismatch of constructors when unregistering service type: %s",
				service_type);
		return;
	}
	remove_registry(service_type);
}

/*****************************************************************************/
/* private methods                                                           */
/*****************************************************************************/

static LassoNodeClass *parent_class = NULL;
static GHashTable *registry = NULL;

/**
 * lasso_discovery_process_modify_msg:
 * @discovery: a #LassoDiscovery
 * @message: the disco:Modify SOAP message
 *
 * Processes a disco:Modify message.  Rebuilds a request object from the
 * message and extracts ResourceID.
 *
 * Return value: 0 on success; or a negative value otherwise.
 **/
static gint
lasso_discovery_process_modify_msg(LassoDiscovery *discovery)
{
	LassoWsfProfile *profile = NULL;
	LassoDiscoModify *request = NULL;
	LassoDiscoModifyResponse *response = NULL;
	gint rc = 0;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery), LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);
	g_return_val_if_fail(LASSO_IS_DISCO_MODIFY(LASSO_WSF_PROFILE(discovery)->request),
				LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);

	profile = LASSO_WSF_PROFILE(discovery);
	request = LASSO_DISCO_MODIFY(profile->request);
	assign_resource_id(request, discovery);
	response = lasso_disco_modify_response_new(
			lasso_utility_status_new(LASSO_DST_STATUS_CODE_OK));
	rc = lasso_wsf_profile_init_soap_response(profile, LASSO_NODE(response));
cleanup:
	lasso_release_gobject(response);
	return rc;
}

/**
 * lasso_discovery_process_query_msg:
 * @discovery: a #LassoDiscovery
 *
 * Processes a disco:Query SOAP message.  Rebuilds a request object from the
 * message and extracts ResourceID.
 *
 * Return value: 0 on success; or a negative value otherwise.
 **/
static gint
lasso_discovery_process_query_msg(LassoDiscovery *discovery)
{
	LassoWsfProfile *profile = NULL;
	LassoDiscoQuery *request = NULL;
	LassoDiscoQueryResponse *response = NULL;
	gint rc = 0;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery), LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);
	g_return_val_if_fail(LASSO_IS_DISCO_QUERY(LASSO_WSF_PROFILE(discovery)->request),
				LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);

	profile = LASSO_WSF_PROFILE(discovery);
	request = LASSO_DISCO_QUERY(profile->request);
	assign_resource_id(request, discovery);
	response = lasso_disco_query_response_new(
			lasso_utility_status_new(LASSO_DST_STATUS_CODE_OK));
	rc = lasso_wsf_profile_init_soap_response(profile, LASSO_NODE(response));
cleanup:
	lasso_release_gobject(response);
	return rc;
}

/**
 * lasso_discovery_init_resource_offering:
 * @discovery: a #LassoDiscovery object
 * @security_mech_id: (allow-none): a security mechanism string identifier
 * @output_offering: (allow-none) (out): a pointer to a variable to hold the found resource offering
 *
 * Return value: 0 if successfull, an error code otherwise.
 **/
static gint
lasso_discovery_init_resource_offering(LassoDiscovery *discovery,
		const gchar *security_mech_id, LassoDiscoResourceOffering **output_offering)
{
	gint rc = 0;
	LassoDiscoResourceOffering *offering = NULL;

	g_return_val_if_fail(LASSO_IS_DISCOVERY(discovery), LASSO_PARAM_ERROR_BAD_TYPE_OR_NULL_OBJ);

	if (! (offering = lasso_wsf_profile_get_resource_offering(&discovery->parent))) {
		offering = lasso_discovery_get_resource_offering_auto(discovery, LASSO_DISCO_HREF);
		lasso_wsf_profile_set_resource_offering(&discovery->parent, offering);
	}
	goto_cleanup_if_fail_with_rc(LASSO_IS_DISCO_RESOURCE_OFFERING(offering),
		LASSO_PROFILE_ERROR_MISSING_RESOURCE_OFFERING);
	rc = lasso_wsf_profile_set_security_mech_id(&discovery->parent, security_mech_id);
	goto_cleanup_if_fail (! rc);
	rc = lasso_wsf_profile_set_msg_url_from_description(&discovery->parent);
	goto_cleanup_if_fail (! rc);
cleanup:
	if (output_offering) {
		lasso_assign_gobject(*output_offering, offering);
	}
	lasso_release_gobject(offering);
	return rc;
}
/**
 * lasso_discovery_build_key_info_node:
 * @discovery: a #LassoDiscovery object
 * @providerID: the provider ID of the provider whose public key is requested.
 *
 * Construct a #LassoDsKeyInfo containing the public key of the targeted web
 * service provider. Fills the Modulus and Exponent composant of the RsaKeyValue.
 * It does not handle DSAKeyValue.
 *
 * Return value: a new #LassoDsKeyIfno or NULL if no provider or no public key were found.
 */
static LassoDsKeyInfo*
lasso_discovery_build_key_info_node(LassoDiscovery *discovery, const gchar *providerID)
{
	LassoWsfProfile *profile;
	LassoDsKeyInfo *key_info = NULL;
	LassoDsRsaKeyValue *rsa_key_value = NULL;
	LassoDsKeyValue *key_value = NULL;
	LassoProvider *provider = NULL;
	xmlSecKeyInfoCtx *ctx = NULL;
	xmlSecKey *public_key = NULL;
	xmlDoc *doc = NULL;
	xmlNode *key_info_node = NULL;
	xmlNode *xmlnode = NULL;
	xmlXPathContext *xpathCtx = NULL;
	xmlXPathObject *xpathObj = NULL;

	lasso_return_val_if_invalid_param(DISCOVERY, discovery, NULL);
	g_return_val_if_fail(providerID != NULL, NULL);

	profile = &discovery->parent;
	provider = lasso_server_get_provider(profile->server, providerID);
	if (provider == NULL) {
		return NULL;
	}

	public_key = lasso_provider_get_public_key(provider);
	if (public_key == NULL) {
		return NULL;
	}

	ctx = xmlSecKeyInfoCtxCreate(NULL);
	xmlSecKeyInfoCtxInitialize(ctx, NULL);
	ctx->mode = xmlSecKeyInfoModeWrite;
	ctx->keyReq.keyType = xmlSecKeyDataTypePublic;

	doc = xmlSecCreateTree((xmlChar*)"KeyInfo",
			(xmlChar*)"http://www.w3.org/2000/09/xmldsig#");
	key_info_node = xmlDocGetRootElement(doc);
	xmlSecAddChild(key_info_node, (xmlChar*)"KeyValue",
			(xmlChar*)"http://www.w3.org/2000/09/xmldsig#");

	xmlSecKeyInfoNodeWrite(key_info_node, public_key, ctx);

	xpathCtx = xmlXPathNewContext(doc);
	xmlXPathRegisterNs(xpathCtx, (xmlChar*)"ds",
			(xmlChar*)"http://www.w3.org/2000/09/xmldsig#");

	rsa_key_value = lasso_ds_rsa_key_value_new();
	xpathObj = xmlXPathEvalExpression((xmlChar*)"//ds:Modulus", xpathCtx);
	if (xpathObj->nodesetval && xpathObj->nodesetval->nodeNr) {
		xmlnode = xpathObj->nodesetval->nodeTab[0];
		rsa_key_value->Modulus = (gchar *) xmlNodeGetContent(xmlnode);
	}
	xmlXPathFreeObject(xpathObj);

	xpathObj = xmlXPathEvalExpression((xmlChar*)"//ds:Exponent", xpathCtx);
	if (xpathObj->nodesetval && xpathObj->nodesetval->nodeNr) {
		xmlnode = xpathObj->nodesetval->nodeTab[0];
		rsa_key_value->Exponent = (gchar *) xmlNodeGetContent(xmlnode);
	}
	xmlXPathFreeObject(xpathObj);

	key_value = lasso_ds_key_value_new();
	key_value->RSAKeyValue = rsa_key_value;
	key_info = lasso_ds_key_info_new();
	key_info->KeyValue = key_value;

	xmlXPathFreeContext(xpathCtx);
	lasso_release_doc(doc);

	return key_info;
}

static LassoDiscoResourceOffering*
lasso_discovery_get_resource_offering_auto(LassoDiscovery *discovery, const gchar *service_type)
{
	LassoWsfProfile *profile = LASSO_WSF_PROFILE(discovery);
	LassoDiscoResourceOffering *resource_offering = NULL;
	LassoSession *session = NULL;
	GList *assertions = NULL;
	LassoSamlAssertion *assertion = NULL;
	LassoSamlAttribute *attribute = NULL;
	LassoSamlAttributeValue *attribute_value = NULL;
	LassoDiscoResourceOffering *offering = NULL;
	GList *iter = NULL;
	GList *iter2 = NULL;
	GList *iter3 = NULL;
	GList *iter4 = NULL;

	if (profile->session == NULL) {
		return NULL;
	}

	session = profile->session;
	assertions = lasso_session_get_assertions(session, NULL);
	for (iter = assertions; iter != NULL; iter = g_list_next(iter)) {
		if (! LASSO_IS_SAML_ASSERTION(iter->data)) {
			continue;
		}
		assertion = LASSO_SAML_ASSERTION(iter->data);
		if (assertion->AttributeStatement == NULL) {
			continue;
		}
		for (iter2 = assertion->AttributeStatement->Attribute; iter2 != NULL;
				iter2 = g_list_next(iter2)) {
			if (! LASSO_IS_SAML_ATTRIBUTE(iter2->data)) {
				continue;
			}
			attribute = LASSO_SAML_ATTRIBUTE(iter2->data);
			if (strcmp(attribute->attributeName, "DiscoveryResourceOffering") != 0) {
				continue;
			}
			for (iter3 = attribute->AttributeValue; iter3 != NULL;
					iter3 = g_list_next(iter3)) {
				if (! LASSO_IS_SAML_ATTRIBUTE_VALUE(iter3->data)) {
					continue;
				}
				attribute_value = LASSO_SAML_ATTRIBUTE_VALUE(iter3->data);
				for (iter4 = attribute_value->any; iter4 != NULL;
						iter4 = g_list_next(iter4)) {
					if (! LASSO_IS_DISCO_RESOURCE_OFFERING(iter4->data)) {
						continue;
					}
					offering = LASSO_DISCO_RESOURCE_OFFERING(iter4->data);
					if (offering->ServiceInstance == NULL) {
						continue;
					}
					if (strcmp(offering->ServiceInstance->ServiceType,
								service_type) == 0) {
						resource_offering = offering;
						goto cleanup;
					}
				}
			}
		}
	}

cleanup:
	lasso_release_list(assertions);
	return resource_offering;
}

/**
 * lasso_discovery_build_credential:
 * @discovery: an ID-WSF 1.0 discovery service object
 * @providerId: the providerId for which the credential is build
 *
 * This function create a SAML assertion associating the public key of the given provider with its
 * provider ID. This assertion will be signed by our own private key, creating a kind of
 * certificate.
 *
 * Return value: the value of the attribute AssertionID of the created assertion.
 */
static gchar*
lasso_discovery_build_credential(LassoDiscovery *discovery, const gchar *providerId)
{
	LassoWsfProfile *profile = NULL;
	LassoSoapHeader *header = NULL;
	LassoSoapBindingProvider *provider = NULL;
	LassoDiscoQueryResponse *response = NULL;
	LassoDiscoCredentials *credentials = NULL;
	LassoSamlAssertion *assertion = NULL;
	LassoSamlAuthenticationStatement *authentication_statement = NULL;
	LassoSamlSubject *subject = NULL;
	LassoSamlNameIdentifier *name_identifier = NULL;
	LassoSamlSubjectConfirmation *subject_confirmation = NULL;
	LassoDsKeyInfo *key_info = NULL;
	GList *iter = NULL;
	LassoProvider *our_provider =
		LASSO_PROVIDER(LASSO_WSF_PROFILE(discovery)->server);
	gchar *assertionID = NULL;

	lasso_return_val_if_invalid_param(DISCOVERY, discovery, NULL);

	/* Init assertion informations */
	assertion = lasso_saml_assertion_new();
	assertion->AssertionID = lasso_build_unique_id(32);
	assertion->MajorVersion = LASSO_SAML_MAJOR_VERSION_N;
	assertion->MinorVersion = LASSO_SAML_MINOR_VERSION_N;
	assertion->IssueInstant = lasso_get_current_time();
	lasso_assign_string(assertion->Issuer, our_provider->ProviderID);

	/* Add AuthenticationStatement */
	authentication_statement = LASSO_SAML_AUTHENTICATION_STATEMENT(
		lasso_saml_authentication_statement_new());
	authentication_statement->AuthenticationInstant = lasso_get_current_time();

	subject = LASSO_SAML_SUBJECT(lasso_saml_subject_new());

	/* NameIdentifier */
	name_identifier = lasso_saml_name_identifier_new();
	name_identifier->NameQualifier = g_strdup(
		our_provider->ProviderID);

	/* If no providerId was given use the one from the request */
	if (providerId == NULL) {
		header = LASSO_WSF_PROFILE(discovery)->soap_envelope_request->Header;
		iter = header->Other;
		while (iter) {
			if (LASSO_IS_SOAP_BINDING_PROVIDER(iter->data) == TRUE) {
				provider = LASSO_SOAP_BINDING_PROVIDER(iter->data);
				break;
			}
		}
		providerId = provider->providerID;
	}

	if (providerId != NULL) {
		lasso_assign_string(name_identifier->Format, LASSO_LIB_NAME_IDENTIFIER_FORMAT_ENTITYID);
		lasso_assign_string(name_identifier->content, providerId);
	} else {
		goto exit;
	}
	subject->NameIdentifier = name_identifier;

	/* SubjectConfirmation */
	subject_confirmation = lasso_saml_subject_confirmation_new();
	lasso_list_add_string(subject_confirmation->ConfirmationMethod,
		LASSO_SAML_CONFIRMATION_METHOD_HOLDER_OF_KEY);

	/* Add public key value in credential */
	key_info = lasso_discovery_build_key_info_node(discovery, provider->providerID);
	if (key_info != NULL) {
		subject_confirmation->KeyInfo = key_info;
	}
	subject->SubjectConfirmation = subject_confirmation;

	/* Add the subject in the authentication statement */
	LASSO_SAML_SUBJECT_STATEMENT_ABSTRACT(authentication_statement)->Subject = subject;
	assertion->AuthenticationStatement = authentication_statement;

	/* FIXME: add resource access statement */

	/* Add credential to disco:QueryResponse */
	response = LASSO_DISCO_QUERY_RESPONSE(profile->response);
	credentials = lasso_disco_credentials_new();
	lasso_list_add_gobject(credentials->any, assertion);
	lasso_assign_gobject(response->Credentials, credentials);

	lasso_assign_string(assertionID, assertion->AssertionID);

exit:
	lasso_release_gobject(assertion);
	lasso_release_gobject(credentials);

	return assertionID;
}

static GHashTable *
get_constructors_registry()
{
	if (registry == NULL) {
		registry = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);
	}
	return registry;
}

static LassoWsfProfileConstructor
lookup_registry(gchar const *service_type) {
	gpointer *t;

	g_return_val_if_fail(service_type, NULL);
	t = g_hash_table_lookup(get_constructors_registry(), service_type);
	return (LassoWsfProfileConstructor)t;
}

static void
remove_registry(gchar const *service_type)
{
	g_return_if_fail(service_type);
	g_hash_table_remove(get_constructors_registry(), service_type);
}

static void
set_registry(gchar const *service_type, LassoWsfProfileConstructor constructor)
{
	g_return_if_fail(service_type);
	g_return_if_fail(constructor);
	g_hash_table_insert(get_constructors_registry(),
			g_strdup(service_type), constructor);
}

static LassoWsfProfile *
lasso_discovery_build_wsf_profile(LassoDiscovery *discovery, LassoDiscoResourceOffering *offering)
{
	LassoWsfProfile *a_wsf_profile = NULL;
	LassoWsfProfileConstructor a_constructor;
	LassoServer *server;
	gchar *service_type = NULL;

	g_return_val_if_fail(offering, NULL);
	g_return_val_if_fail(offering->ServiceInstance, NULL);
	g_return_val_if_fail(offering->ServiceInstance->ServiceType, NULL);

	service_type = offering->ServiceInstance->ServiceType;
	a_constructor = lookup_registry(service_type);
	server = LASSO_WSF_PROFILE(discovery)->server;

	if (a_constructor) {
		a_wsf_profile = a_constructor(server, offering);
	} else {
		message(G_LOG_LEVEL_WARNING, "No constructor registered for service type: %s", service_type);
		a_wsf_profile = LASSO_WSF_PROFILE(lasso_data_service_new_full(server, offering));
	}
	lasso_assign_gobject(a_wsf_profile->session, discovery->parent.session);

	return a_wsf_profile;
}

static xmlNode*
get_xmlNode(LassoNode *node, gboolean lasso_dump)
{
	xmlNode *xmlnode;

	xmlnode = parent_class->get_xmlNode(node, lasso_dump);
	xmlNodeSetName(xmlnode, (xmlChar*)"Discovery");
	xmlSetProp(xmlnode, (xmlChar*)"DiscoveryDumpVersion", (xmlChar*)"2");

	return xmlnode;
}

/*****************************************************************************/
/* overrided parent class methods */
/*****************************************************************************/

static void
dispose(GObject *object)
{
	LassoDiscovery *discovery = LASSO_DISCOVERY(object);

	if (discovery->private_data->dispose_has_run == TRUE)
		return;
	discovery->private_data->dispose_has_run = TRUE;

	G_OBJECT_CLASS(parent_class)->dispose(object);
}

static void
finalize(GObject *object)
{
	LassoDiscovery *discovery = LASSO_DISCOVERY(object);
	lasso_release(discovery->private_data);
	discovery->private_data = NULL;
	G_OBJECT_CLASS(parent_class)->finalize(object);
}

/*****************************************************************************/
/* instance and class init functions */
/*****************************************************************************/

static void
instance_init(LassoDiscovery *discovery)
{
	discovery->private_data = g_new0(LassoDiscoveryPrivate, 1);
	discovery->private_data->dispose_has_run = FALSE;
}

static void
class_init(LassoDiscoveryClass *klass)
{
	parent_class = g_type_class_peek_parent(klass);

	LASSO_NODE_CLASS(klass)->get_xmlNode = get_xmlNode;

	G_OBJECT_CLASS(klass)->dispose = dispose;
	G_OBJECT_CLASS(klass)->finalize = finalize;
}

GType
lasso_discovery_get_type()
{
	static GType this_type = 0;

	if (!this_type) {
		static const GTypeInfo this_info = {
			sizeof(LassoDiscoveryClass),
			NULL,
			NULL,
			(GClassInitFunc) class_init,
			NULL,
			NULL,
			sizeof(LassoDiscovery),
			0,
			(GInstanceInitFunc) instance_init,
			NULL
		};

		this_type = g_type_register_static(LASSO_TYPE_WSF_PROFILE,
				"LassoDiscovery", &this_info, 0);
	}
	return this_type;
}

/**
 * lasso_discovery_new:
 * @server: the #LassoServer
 *
 * Creates a new #LassoDiscovery.
 *
 * Return value: a newly created #LassoDiscovery object; or NULL if an error occured.
 **/
LassoDiscovery*
lasso_discovery_new(LassoServer *server)
{
	LassoDiscovery *discovery = NULL;

	g_return_val_if_fail(LASSO_IS_SERVER(server), NULL);

	discovery = g_object_new(LASSO_TYPE_DISCOVERY, NULL);
	lasso_wsf_profile_init(&discovery->parent, server, NULL);

	return discovery;
}

/**
 * lasso_discovery_new_full:
 * @server: the #LassoServer
 * @offering: the #LassoDiscoResourceOffering
 *
 * Creates a new #LassoDiscovery.
 *
 * Return value: a newly created #LassoDiscovery object; or NULL if an error occured.
 **/
LassoDiscovery*
lasso_discovery_new_full(LassoServer *server, LassoDiscoResourceOffering *offering)
{
	LassoDiscovery *discovery = NULL;

	g_return_val_if_fail(LASSO_IS_SERVER(server), NULL);

	discovery = g_object_new(LASSO_TYPE_DISCOVERY, NULL);
	lasso_wsf_profile_init(&discovery->parent, server, offering);

	return discovery;
}