/*
 * Copyright 2017 Red Hat Inc., Durham, North Carolina.
 * All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * Authors:
 * 		Katarina Jankov <kj226@cornell.edu>
 *
 */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>

#include <libxml/xmlreader.h>
#include <libxml/tree.h>
#include <libxml/xpath.h>
#include <libxml/parser.h>
#include <libxml/xpathInternals.h>

#include "public/cvrf.h"
#include "cvrf_priv.h"

#include "common/list.h"
#include "common/_error.h"
#include "common/xmltext_priv.h"
#include "common/elements.h"
#include "common/oscap_string.h"
#include "common/util.h"

#include "CPE/cpelang_priv.h"
#include "CPE/public/cpe_dict.h"
#include "CVSS/cvss_priv.h"
#include "CVSS/public/cvss_score.h"

#include "source/public/oscap_source.h"
#include "source/oscap_source_priv.h"
#include "source/public/oscap_source.h"

#include "OVAL/public/oval_system_characteristics.h"
#include "OVAL/public/oval_definitions.h"
#include "OVAL/adt/oval_string_map_impl.h"
#include "OVAL/public/oval_types.h"
#include "OVAL/public/oval_probe_session.h"
#include "OVAL/public/oval_probe.h"
#include "OVAL/oval_definitions_impl.h"


/*****************************************************************************
 * Structure definitions
 */

struct cvrf_session {
	struct cvrf_index *index;
	struct cvrf_model *model;
	char *os_name;
	struct oscap_source *source;
	struct oscap_stringlist *product_ids;
	struct oval_definition_model *def_model;
};
OSCAP_ACCESSOR_SIMPLE(struct cvrf_index*, cvrf_session, index)
OSCAP_ACCESSOR_STRING(cvrf_session, os_name);

struct oscap_string_iterator *cvrf_session_get_product_ids(struct cvrf_session *session) {
	return oscap_stringlist_get_strings(session->product_ids);
}
struct cvrf_model *cvrf_session_get_model(struct cvrf_session *session) {
	return session->model;
}
void cvrf_session_set_model(struct cvrf_session *session, struct cvrf_model *model) {
	session->model = model;
}

struct cvrf_session *cvrf_session_new_from_source_model(struct oscap_source *source) {
	if (source == NULL)
		return NULL;

	struct cvrf_model *model = cvrf_model_import(source);
	if (model == NULL) {
		return NULL;
	}
	struct cvrf_session *ret = malloc(sizeof(struct cvrf_session));
	ret->source = source;
	ret->index = NULL;
	ret->model = model;
	ret->os_name = NULL;
	ret->product_ids = oscap_stringlist_new();
	ret->def_model = oval_definition_model_new();
	return ret;
}

struct cvrf_session *cvrf_session_new_from_source_index(struct oscap_source *source) {
	if (source == NULL)
		return NULL;

	struct cvrf_session *ret = malloc(sizeof(struct cvrf_session));
	ret->source = source;
	ret->index = cvrf_index_import(source);
	ret->model = NULL;
	ret->os_name = NULL;
	ret->product_ids = oscap_stringlist_new();
	ret->def_model = oval_definition_model_new();
	return ret;
}

void cvrf_session_free(struct cvrf_session *session) {
	if (session == NULL)
		return;

	cvrf_index_free(session->index);
	cvrf_model_free(session->model);
	free(session->os_name);
	oscap_source_free(session->source);
	oscap_stringlist_free(session->product_ids);
	oval_definition_model_free(session->def_model);
	free(session);
}


struct cvrf_rpm_attributes {
	char *full_package_name;
	char *rpm_name;
	char *evr_format;
};
OSCAP_ACCESSOR_STRING(cvrf_rpm_attributes, full_package_name)
OSCAP_ACCESSOR_STRING(cvrf_rpm_attributes, rpm_name)
OSCAP_ACCESSOR_STRING(cvrf_rpm_attributes, evr_format)


struct cvrf_rpm_attributes *cvrf_rpm_attributes_new() {
	struct cvrf_rpm_attributes *ret = malloc(sizeof(struct cvrf_rpm_attributes));
	if (ret == NULL)
		return NULL;

	ret->full_package_name = NULL;
	ret->rpm_name = NULL;
	ret->evr_format = NULL;
	return ret;
}

void cvrf_rpm_attributes_free(struct cvrf_rpm_attributes *attributes) {
	if (attributes == NULL)
		return;

	free(attributes->full_package_name);
	free(attributes->rpm_name);
	free(attributes->evr_format);
	free(attributes);
}

/*
 * End of structure definitions
 *****************************************************************************/


#define TAG_CVRF_DOC BAD_CAST "cvrfdoc"
#define TAG_DOC_TITLE BAD_CAST "DocumentTitle"
#define TAG_DOC_TYPE BAD_CAST "DocumentType"
#define ATTR_PRODUCT_ID "ProductID"

static int find_all_cvrf_product_ids_from_cpe(struct cvrf_session *session) {
	if (cvrf_model_filter_by_cpe(session->model, session->os_name) == -1)
		return -1;

	struct cvrf_product_tree *tree = cvrf_model_get_product_tree(session->model);
	struct cvrf_relationship_iterator *relationships = cvrf_product_tree_get_relationships(tree);
	while (cvrf_relationship_iterator_has_more(relationships)) {
		struct cvrf_relationship *relation = cvrf_relationship_iterator_next(relationships);
		struct cvrf_product_name *name = cvrf_relationship_get_product_name(relation);
		oscap_stringlist_add_string(session->product_ids, cvrf_product_name_get_product_id(name));
	}
	cvrf_relationship_iterator_free(relationships);
	return 0;
}

static xmlNode *cvrf_model_results_to_dom(struct cvrf_session *session) {
	xmlNode *root_node = xmlNewNode(NULL, BAD_CAST "cvrfdoc");
	xmlNewNs(root_node, CVRF_NS, NULL);
	xmlNewNs(root_node, CVRF_NS, BAD_CAST "cvrf");
	xmlNode *title_node = xmlNewTextChild(root_node, NULL, TAG_DOC_TITLE, BAD_CAST cvrf_model_get_doc_title(session->model));
	cvrf_element_add_attribute("xml:lang", "en", title_node);
	cvrf_element_add_child("DocumentType", cvrf_model_get_doc_type(session->model), root_node);
	xmlAddChildList(root_node, cvrf_document_to_dom(cvrf_model_get_document(session->model)));

	struct cvrf_vulnerability_iterator *it = cvrf_model_get_vulnerabilities(session->model);
	while (cvrf_vulnerability_iterator_has_more(it)) {
		struct cvrf_vulnerability *vuln = cvrf_vulnerability_iterator_next(it);
		xmlNode *vuln_node = cvrf_vulnerability_to_dom(vuln);
		xmlAddChild(root_node, vuln_node);
		xmlNode *results_node = xmlNewTextChild(vuln_node, NULL, BAD_CAST "Results", NULL);

		struct oscap_string_iterator *product_ids = cvrf_session_get_product_ids(session);
		while (oscap_string_iterator_has_more(product_ids)) {
			const char *product_id = oscap_string_iterator_next(product_ids);
			xmlNode *result_node = xmlNewTextChild(results_node, NULL, BAD_CAST "Result", NULL);
			cvrf_element_add_child("ProductID", product_id, result_node);

			if (cvrf_product_vulnerability_fixed(vuln, product_id)) {
				cvrf_element_add_child("VulnerabilityStatus", "FIXED", result_node);
			}
			else {
				cvrf_element_add_child("VulnerabilityStatus", "VULNERABLE", result_node);
			}
		}
		oscap_string_iterator_free(product_ids);
	}
	cvrf_vulnerability_iterator_free(it);
	return root_node;
}

struct oscap_source *cvrf_model_get_results_source(struct oscap_source *import_source, const char *os_name) {
	__attribute__nonnull__(import_source);
	__attribute__nonnull__(os_name);

	if (import_source == NULL)
		return NULL;
	struct cvrf_session *session = cvrf_session_new_from_source_model(import_source);
	if (session == NULL) {
		return NULL;
	}
	cvrf_session_set_os_name(session, os_name);

	if (find_all_cvrf_product_ids_from_cpe(session) != 0) {
		cvrf_session_free(session);
		return NULL;
	}

	xmlDocPtr doc = xmlNewDoc(BAD_CAST "1.0");
	if (doc == NULL) {
		oscap_setxmlerr(xmlGetLastError());
		cvrf_session_free(session);
		return NULL;
	}
	xmlNode *model_node = cvrf_model_results_to_dom(session);
	xmlDocSetRootElement(doc, model_node);

	struct oscap_source *source = oscap_source_new_from_xmlDoc(doc, NULL);
	cvrf_session_free(session);
	return source;
}

struct oscap_source *cvrf_index_get_results_source(struct oscap_source *import_source, const char *os_name) {
	struct cvrf_session *session = cvrf_session_new_from_source_index(import_source);
	cvrf_session_set_os_name(session, os_name);

	xmlDocPtr doc = xmlNewDoc(BAD_CAST "1.0");
	if (doc == NULL) {
		oscap_setxmlerr(xmlGetLastError());
		cvrf_session_free(session);
		return NULL;
	}
	xmlNode *index_node = xmlNewNode(NULL, BAD_CAST "Index");
	xmlDocSetRootElement(doc, index_node);

	struct cvrf_model_iterator *it = cvrf_index_get_models(session->index);
	while (cvrf_model_iterator_has_more(it)) {
		struct cvrf_model *model = cvrf_model_iterator_next(it);
		session->model = model;
		find_all_cvrf_product_ids_from_cpe(session);

		xmlNode *model_node = cvrf_model_results_to_dom(session);
		xmlAddChild(index_node, model_node);
	}
	cvrf_model_iterator_free(it);

	struct oscap_source *source = oscap_source_new_from_xmlDoc(doc, NULL);
	cvrf_session_free(session);
	return source;
}

bool cvrf_product_vulnerability_fixed(struct cvrf_vulnerability *vuln, const char *product) {
	struct cvrf_product_status_iterator *it = cvrf_vulnerability_get_product_statuses(vuln);
	while (cvrf_product_status_iterator_has_more(it)) {
		struct cvrf_product_status *stat = cvrf_product_status_iterator_next(it);
		struct oscap_string_iterator *product_ids = cvrf_product_status_get_ids(stat);

		while (oscap_string_iterator_has_more(product_ids)) {
			const char *product_id = oscap_string_iterator_next(product_ids);
			if (strcmp(product_id, product) == 0) {
				oscap_string_iterator_free(product_ids);
				cvrf_product_status_iterator_free(it);
				return true;
			}
		}
		oscap_string_iterator_free(product_ids);
	}
	cvrf_product_status_iterator_free(it);
	return false;
}
