/******************************************************************************
 * Icinga 2                                                                   *
 * Copyright (C) 2012 Icinga Development Team (http://www.icinga.org/)        *
 *                                                                            *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.             *
 ******************************************************************************/

#include "i2-icinga.h"

using namespace icinga;

boost::mutex ServiceGroup::m_Mutex;
map<String, vector<Service::WeakPtr> > ServiceGroup::m_MembersCache;
bool ServiceGroup::m_MembersCacheNeedsUpdate = false;
Timer::Ptr ServiceGroup::m_MembersCacheTimer;

REGISTER_TYPE(ServiceGroup);

ServiceGroup::ServiceGroup(const Dictionary::Ptr& properties)
	: DynamicObject(properties)
{
	RegisterAttribute("display_name", Attribute_Config, &m_DisplayName);
	RegisterAttribute("notes_url", Attribute_Config, &m_NotesUrl);
	RegisterAttribute("action_url", Attribute_Config, &m_ActionUrl);
}

ServiceGroup::~ServiceGroup(void)
{
	InvalidateMembersCache();
}

/**
 * @threadsafety Always.
 */
void ServiceGroup::OnRegistrationCompleted(void)
{
	ASSERT(!OwnsLock());

	InvalidateMembersCache();
}

/**
 * @threadsafety Always.
 */
String ServiceGroup::GetDisplayName(void) const
{
	if (!m_DisplayName.Get().IsEmpty())
		return m_DisplayName;
	else
		return GetName();
}

/**
 * @threadsafety Always.
 */
String ServiceGroup::GetNotesUrl(void) const
{
	return m_NotesUrl;
}

/**
 * @threadsafety Always.
 */
String ServiceGroup::GetActionUrl(void) const
{
	return m_ActionUrl;
}

/**
 * @threadsafety Always.
 */
ServiceGroup::Ptr ServiceGroup::GetByName(const String& name)
{
	DynamicObject::Ptr configObject = DynamicObject::GetObject("ServiceGroup", name);

	if (!configObject)
		BOOST_THROW_EXCEPTION(invalid_argument("ServiceGroup '" + name + "' does not exist."));

	return dynamic_pointer_cast<ServiceGroup>(configObject);
}

/**
 * @threadsafety Always.
 */
set<Service::Ptr> ServiceGroup::GetMembers(void) const
{
	set<Service::Ptr> services;

	{
		boost::mutex::scoped_lock lock(m_Mutex);

		BOOST_FOREACH(const Service::WeakPtr& wservice, m_MembersCache[GetName()]) {
			Service::Ptr service = wservice.lock();

			if (!service)
				continue;

			services.insert(service);
		}
	}

	return services;
}

/**
 * @threadsafety Always.
 */
void ServiceGroup::InvalidateMembersCache(void)
{
	boost::mutex::scoped_lock lock(m_Mutex);

	if (m_MembersCacheNeedsUpdate)
		return; /* Someone else has already requested a refresh. */

	if (!m_MembersCacheTimer) {
		m_MembersCacheTimer = boost::make_shared<Timer>();
		m_MembersCacheTimer->SetInterval(0.5);
		m_MembersCacheTimer->OnTimerExpired.connect(boost::bind(&ServiceGroup::RefreshMembersCache));
		m_MembersCacheTimer->Start();
	}

	m_MembersCacheNeedsUpdate = true;
}

/**
 * @threadsafety Always.
 */
void ServiceGroup::RefreshMembersCache(void)
{
	{
		boost::mutex::scoped_lock lock(m_Mutex);

		if (!m_MembersCacheNeedsUpdate)
			return;

		m_MembersCacheNeedsUpdate = false;
	}

	Logger::Write(LogInformation, "icinga", "Updating ServiceGroup members cache.");

	map<String, vector<Service::WeakPtr> > newMembersCache;

	BOOST_FOREACH(const DynamicObject::Ptr& object, DynamicType::GetObjects("Service")) {
		const Service::Ptr& service = static_pointer_cast<Service>(object);

		Dictionary::Ptr dict;
		dict = service->GetGroups();

		if (dict) {
			ObjectLock mlock(dict);
			Value servicegroup;
			BOOST_FOREACH(tie(tuples::ignore, servicegroup), dict) {
				newMembersCache[servicegroup].push_back(service);
			}
		}
	}

	boost::mutex::scoped_lock lock(m_Mutex);
	m_MembersCache.swap(newMembersCache);
}