/**
 * @file purple-dnsquery.c
 *
 * pidgin-sipe
 *
 * Copyright (C) 2010-2017 SIPE Project <http://sipe.sourceforge.net/>
 *
 * 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
 */

#include <glib.h>

#include "version.h"

#if PURPLE_VERSION_CHECK(3,0,0)
#include "protocols.h"
#include <gio/gio.h>
#else

#ifdef _WIN32
/* wrappers for write() & friends for socket handling */
#include "win32/win32dep.h"
#include <ws2tcpip.h>
#else
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#endif

#include "dnsquery.h"
#include "dnssrv.h"

#endif

#include "sipe-backend.h"
#include "sipe-core.h"

#include "purple-private.h"

struct sipe_dns_query {
	struct sipe_backend_private *purple_private;
	sipe_dns_resolved_cb  callback;
	gpointer	      extradata;
	gpointer	      purple_query_data;
	gboolean              is_valid;
#if PURPLE_VERSION_CHECK(3,0,0)
	guint		      port;
#else
	enum {
		A,
		SRV
	} type;
#endif
};

static void sipe_dns_query_free(struct sipe_dns_query *query)
{
#if PURPLE_VERSION_CHECK(3,0,0)
	g_object_unref(query->purple_query_data);
#endif
	g_free(query);
}

#if PURPLE_VERSION_CHECK(3,0,0)
static void dns_a_response(GObject *source,
			   GAsyncResult *res,
			   gpointer user_data)
{
	struct sipe_dns_query *query = user_data;
	GList *hosts;
	GError *error = NULL;
	gchar *address_str = NULL;

	if (!query->is_valid) {
		/* Ignore spurious responses after disconnect */
		return;
	}

	query->purple_private->dns_queries =
			g_slist_remove(query->purple_private->dns_queries,
				       query);

	hosts = g_resolver_lookup_by_name_finish(G_RESOLVER(source), res,
						 &error);

	if (!error && g_list_length(hosts) > 0) {
		address_str = g_inet_address_to_string(hosts->data);
	}

	query->callback(query->extradata, address_str,
			address_str ? query->port : 0);

	g_free(address_str);
	if (error)
		g_error_free(error);
	g_resolver_free_addresses(hosts);
	sipe_dns_query_free(query);
}
#else
static void dns_a_response(GSList *hosts,
			   struct sipe_dns_query *query,
			   const char *error_message)
{
	char ipstr[INET6_ADDRSTRLEN];
	struct sockaddr *addr;
	const void *addrdata;
	int port;

        /* Ignore spurious responses after disconnect */
	if (query->is_valid) {
		struct sipe_backend_private *purple_private = query->purple_private;

		purple_private->dns_queries = g_slist_remove(purple_private->dns_queries,
							     query);

		if (error_message || !g_slist_next(hosts)) {
			query->callback(query->extradata, NULL, 0);
			g_slist_free(hosts);
			return;
		}

		addr = g_slist_next(hosts)->data;
		if (addr->sa_family == AF_INET6) {
			/* OS provides addr so it must be properly aligned */
			struct sockaddr_in6 *sin6 = (void *) addr;
			addrdata = &sin6->sin6_addr;
			port = sin6->sin6_port;
		} else {
			/* OS provides addr so it must be properly aligned */
			struct sockaddr_in *sin = (void *) addr;
			addrdata = &sin->sin_addr;
			port = sin->sin_port;
		}

		inet_ntop(addr->sa_family, addrdata, ipstr, sizeof (ipstr));

		query->callback(query->extradata, ipstr, port);

		g_free(query);
	}

	for (; hosts; hosts = g_slist_delete_link(hosts, hosts)) {
		// Free the addrlen, no data in this link
		hosts = g_slist_delete_link(hosts, hosts);
		// Free the address
		g_free(hosts->data);
	}
}
#endif

struct sipe_dns_query *sipe_backend_dns_query_a(struct sipe_core_public *sipe_public,
						const gchar *hostname,
						guint port,
						sipe_dns_resolved_cb callback,
						gpointer data)
{
	struct sipe_dns_query *query = g_new(struct sipe_dns_query, 1);
	struct sipe_backend_private *purple_private = sipe_public->backend_private;
#if PURPLE_VERSION_CHECK(3,0,0)
	GResolver *resolver = g_resolver_get_default();
#endif

	query->purple_private = purple_private;
	query->callback       = callback;
	query->extradata      = data;
	query->is_valid       = TRUE;

	purple_private->dns_queries = g_slist_prepend(purple_private->dns_queries,
						      query);

#if PURPLE_VERSION_CHECK(3,0,0)
	query->port = port;
	query->purple_query_data = g_cancellable_new();

	g_resolver_lookup_by_name_async(resolver,
					hostname,
					query->purple_query_data,
					dns_a_response,
					query);
	g_object_unref(resolver);
#else
	query->type = A;
	query->purple_query_data =
#if PURPLE_VERSION_CHECK(2,8,0)
					purple_dnsquery_a_account(
						     purple_private->account,
#else
					purple_dnsquery_a(
#endif
						     hostname,
						     port,
						     (PurpleDnsQueryConnectFunction) dns_a_response,
						     query);
#endif

	return query;
}

#if PURPLE_VERSION_CHECK(3,0,0)
static void dns_srv_response(GObject *source,
			     GAsyncResult *res,
			     gpointer user_data)
{
	struct sipe_dns_query *query = user_data;
	GError *error = NULL;
	GList *targets;

	if (!query->is_valid) {
		/* Ignore spurious responses after disconnect */
		return;
	}

	query->purple_private->dns_queries =
			g_slist_remove(query->purple_private->dns_queries,
				       query);

	targets = g_resolver_lookup_service_finish(G_RESOLVER(source), res,
						   &error);

	if (error || g_list_length(targets) == 0) {
		query->callback(query->extradata, NULL, 0);
	} else {
		query->callback(query->extradata,
				g_srv_target_get_hostname(targets->data),
				g_srv_target_get_port(targets->data));
	}

	if (error)
		g_error_free(error);
	g_resolver_free_targets(targets);
	sipe_dns_query_free(query);
}
#else
static void dns_srv_response(PurpleSrvResponse *resp,
			     int results,
			     struct sipe_dns_query *query)
{
        /* Ignore spurious responses after disconnect */
	if (query->is_valid) {
		struct sipe_backend_private *purple_private = query->purple_private;

		purple_private->dns_queries = g_slist_remove(purple_private->dns_queries,
							     query);

		if (results)
			query->callback(query->extradata, resp->hostname, resp->port);
		else
			query->callback(query->extradata, NULL, 0);

		g_free(query);
	}

	g_free(resp);
}
#endif

struct sipe_dns_query *sipe_backend_dns_query_srv(struct sipe_core_public *sipe_public,
						  const gchar *protocol,
						  const gchar *transport,
						  const gchar *domain,
						  sipe_dns_resolved_cb callback,
						  gpointer data)
{
	struct sipe_dns_query *query = g_new(struct sipe_dns_query, 1);
	struct sipe_backend_private *purple_private = sipe_public->backend_private;
#if PURPLE_VERSION_CHECK(3,0,0)
	GResolver *resolver = g_resolver_get_default();
#endif

	query->purple_private = purple_private;
	query->callback       = callback;
	query->extradata      = data;
	query->is_valid       = TRUE;

	purple_private->dns_queries = g_slist_prepend(purple_private->dns_queries,
						      query);

#if PURPLE_VERSION_CHECK(3,0,0)
	query->purple_query_data = g_cancellable_new();

	g_resolver_lookup_service_async(resolver,
					protocol,
					transport,
					domain,
					query->purple_query_data,
					dns_srv_response,
					query);
	g_object_unref(resolver);
#else
	query->type = SRV;
	query->purple_query_data =
#if PURPLE_VERSION_CHECK(2,8,0)
					purple_srv_resolve_account(
						      purple_private->account,
#else
					purple_srv_resolve(
#endif
						      protocol,
						      transport,
						      domain,
						      (PurpleSrvCallback) dns_srv_response,
						      query);
#endif

	return query;
}

static gboolean dns_query_deferred_destroy(gpointer user_data)
{
	/*
	 * All pending events on query have been processed.
	 * Now it is safe to destroy the data structure.
	 */
	SIPE_DEBUG_INFO("dns_query_deferred_destroy: %p", user_data);
	sipe_dns_query_free(user_data);
	return(FALSE);
}

void sipe_backend_dns_query_cancel(struct sipe_dns_query *query)
{
	SIPE_DEBUG_INFO("sipe_backend_dns_query_cancel: %p", query);

	if (query->is_valid) {
		struct sipe_backend_private *purple_private = query->purple_private;
		purple_private->dns_queries = g_slist_remove(purple_private->dns_queries,
							     query);

#if PURPLE_VERSION_CHECK(3,0,0)
		g_cancellable_cancel(query->purple_query_data);
#else
		switch (query->type) {
		case A:
			purple_dnsquery_destroy(query->purple_query_data);
			break;
		case SRV:
#if PURPLE_VERSION_CHECK(2,8,0)
			purple_srv_txt_query_destroy(query->purple_query_data);
#else
			purple_srv_cancel(query->purple_query_data);
#endif
			break;
		}
#endif

		/* defer deletion of query data structure to idle callback */
		query->is_valid = FALSE;
		g_idle_add(dns_query_deferred_destroy, query);
	}
}

void sipe_purple_dns_query_cancel_all(struct sipe_backend_private *purple_private)
{
	GSList *entry;
	SIPE_DEBUG_INFO_NOFORMAT("sipe_purple_dns_query_cancel_all: entered");
	while ((entry = purple_private->dns_queries) != NULL)
		sipe_backend_dns_query_cancel(entry->data);
}


/*
  Local Variables:
  mode: c
  c-file-style: "bsd"
  indent-tabs-mode: t
  tab-width: 8
  End:
*/
