/******************************************************************************
 * 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 "base/dynamicobject.h"
#include "base/dynamictype.h"
#include "base/netstring.h"
#include "base/registry.h"
#include "base/stdiostream.h"
#include "base/debug.h"
#include "base/objectlock.h"
#include "base/logger_fwd.h"
#include "base/exception.h"
#include "base/timer.h"
#include "base/scriptfunction.h"
#include <fstream>
#include <boost/make_shared.hpp>
#include <boost/tuple/tuple.hpp>
#include <boost/foreach.hpp>
#include <boost/exception/errinfo_api_function.hpp>
#include <boost/exception/errinfo_errno.hpp>
#include <boost/exception/errinfo_file_name.hpp>

using namespace icinga;

boost::signals2::signal<void (const DynamicObject::Ptr&)> DynamicObject::OnStarted;
boost::signals2::signal<void (const DynamicObject::Ptr&)> DynamicObject::OnStopped;
boost::signals2::signal<void (const DynamicObject::Ptr&)> DynamicObject::OnStateChanged;

DynamicObject::DynamicObject(void)
	: m_Active(false)
{ }

DynamicObject::~DynamicObject(void)
{ }

Dictionary::Ptr DynamicObject::Serialize(int attributeTypes) const
{
	Dictionary::Ptr update = boost::make_shared<Dictionary>();

	ASSERT(!OwnsLock());
	ObjectLock olock(this);

	InternalSerialize(update, attributeTypes);

	/* Make sure our own InternalSerialize() method was called. */
	ASSERT(update->Contains("__marker"));
	update->Remove("__marker");

	return update;
}

void DynamicObject::Deserialize(const Dictionary::Ptr& update, int attributeTypes)
{
	ASSERT(!OwnsLock());

	{
		ObjectLock olock(this);
		InternalDeserialize(update, attributeTypes);
	}
}

void DynamicObject::InternalSerialize(const Dictionary::Ptr& bag, int attributeTypes) const
{
	if (attributeTypes & Attribute_Config) {
		bag->Set("__name", m_Name);
		bag->Set("__type", m_Type);
		bag->Set("methods", m_Methods);
		bag->Set("custom", m_Custom);
	}

	bag->Set("extensions", m_Extensions);

	/* This attribute is used by Serialize() to check that this
	 * method was called. */
	bag->Set("__marker", 1);
}

void DynamicObject::InternalDeserialize(const Dictionary::Ptr& bag, int attributeTypes)
{
	if (attributeTypes & Attribute_Config) {
		m_Name = bag->Get("__name");
		m_Type = bag->Get("__type");
		m_Methods = bag->Get("methods");
		m_Custom = bag->Get("custom");
	}

	m_Extensions = bag->Get("extensions");
}

DynamicType::Ptr DynamicObject::GetType(void) const
{
	return DynamicType::GetByName(m_Type);
}

String DynamicObject::GetName(void) const
{
	return m_Name;
}

bool DynamicObject::IsActive(void) const
{
	return m_Active;
}

void DynamicObject::SetExtension(const String& key, const Object::Ptr& object)
{
	Dictionary::Ptr extensions = m_Extensions;

	if (!extensions) {
		extensions = boost::make_shared<Dictionary>();
		m_Extensions = extensions;
	}

	extensions->Set(key, object);
}

Object::Ptr DynamicObject::GetExtension(const String& key)
{
	Dictionary::Ptr extensions = m_Extensions;

	if (!extensions)
		return Object::Ptr();

	return extensions->Get(key);
}

void DynamicObject::ClearExtension(const String& key)
{
	Dictionary::Ptr extensions = m_Extensions;

	if (!extensions)
		return;

	extensions->Remove(key);
}

void DynamicObject::Register(void)
{
	ASSERT(!OwnsLock());

	DynamicType::Ptr dtype = GetType();
	dtype->RegisterObject(GetSelf());
}

void DynamicObject::Start(void)
{
	ASSERT(!OwnsLock());

	ASSERT(!m_Active);
	m_Active = true;

	OnStarted(GetSelf());
}

void DynamicObject::Stop(void)
{
	ASSERT(!OwnsLock());

	ASSERT(m_Active);
	m_Active = false;

	OnStopped(GetSelf());
}

void DynamicObject::OnConfigLoaded(void)
{
	/* Nothing to do here. */
}

void DynamicObject::OnStateLoaded(void)
{
	/* Nothing to do here. */
}

Value DynamicObject::InvokeMethod(const String& method,
    const std::vector<Value>& arguments)
{
	Dictionary::Ptr methods;

	methods = m_Methods;

	if (!methods)
		BOOST_THROW_EXCEPTION(std::invalid_argument("Method '" + method + "' does not exist."));

	String funcName = methods->Get(method);

	if (funcName.IsEmpty())
		BOOST_THROW_EXCEPTION(std::invalid_argument("Method '" + method + "' does not exist."));

	ScriptFunction::Ptr func = ScriptFunctionRegistry::GetInstance()->GetItem(funcName);

	if (!func)
		BOOST_THROW_EXCEPTION(std::invalid_argument("Function '" + funcName + "' does not exist."));

	return func->Invoke(arguments);
}

void DynamicObject::DumpObjects(const String& filename, int attributeTypes)
{
	Log(LogInformation, "base", "Dumping program state to file '" + filename + "'");

	String tempFilename = filename + ".tmp";

	std::fstream fp;
	fp.open(tempFilename.CStr(), std::ios_base::out);

	if (!fp)
		BOOST_THROW_EXCEPTION(std::runtime_error("Could not open '" + filename + "' file"));

	StdioStream::Ptr sfp = boost::make_shared<StdioStream>(&fp, false);

	BOOST_FOREACH(const DynamicType::Ptr& type, DynamicType::GetTypes()) {
		BOOST_FOREACH(const DynamicObject::Ptr& object, type->GetObjects()) {
			Dictionary::Ptr persistentObject = boost::make_shared<Dictionary>();

			persistentObject->Set("type", type->GetName());
			persistentObject->Set("name", object->GetName());

			Dictionary::Ptr update = object->Serialize(attributeTypes);

			if (!update)
				continue;

			persistentObject->Set("update", update);

			Value value = persistentObject;
			String json = value.Serialize();

			NetString::WriteStringToStream(sfp, json);
		}
	}

	sfp->Close();

	fp.close();

#ifdef _WIN32
	_unlink(filename.CStr());
#endif /* _WIN32 */

	if (rename(tempFilename.CStr(), filename.CStr()) < 0) {
		BOOST_THROW_EXCEPTION(posix_error()
		    << boost::errinfo_api_function("rename")
		    << boost::errinfo_errno(errno)
		    << boost::errinfo_file_name(tempFilename));
	}
}

void DynamicObject::RestoreObjects(const String& filename, int attributeTypes)
{
	Log(LogInformation, "base", "Restoring program state from file '" + filename + "'");

	std::fstream fp;
	fp.open(filename.CStr(), std::ios_base::in);

	StdioStream::Ptr sfp = boost::make_shared<StdioStream>(&fp, false);

	unsigned long restored = 0;

	String message;
	while (NetString::ReadStringFromStream(sfp, &message)) {
		Dictionary::Ptr persistentObject = Value::Deserialize(message);

		String type = persistentObject->Get("type");
		String name = persistentObject->Get("name");
		Dictionary::Ptr update = persistentObject->Get("update");

		DynamicType::Ptr dt = DynamicType::GetByName(type);

		if (!dt)
			continue;

		DynamicObject::Ptr object = dt->GetObject(name);

		if (object) {
			ASSERT(!object->IsActive());
			Log(LogDebug, "base", "Restoring object '" + name + "' of type '" + type + "'.");
			object->Deserialize(update, attributeTypes);
			object->OnStateLoaded();
		}

		restored++;
	}

	sfp->Close();

	std::ostringstream msgbuf;
	msgbuf << "Restored " << restored << " objects";
	Log(LogInformation, "base", msgbuf.str());
}

void DynamicObject::StopObjects(void)
{
	BOOST_FOREACH(const DynamicType::Ptr& dt, DynamicType::GetTypes()) {
		BOOST_FOREACH(const DynamicObject::Ptr& object, dt->GetObjects()) {
			if (object->IsActive())
				object->Stop();
		}
	}
}

DynamicObject::Ptr DynamicObject::GetObject(const String& type, const String& name)
{
	DynamicType::Ptr dtype = DynamicType::GetByName(type);
	return dtype->GetObject(name);
}

Dictionary::Ptr DynamicObject::GetCustom(void) const
{
	return m_Custom;
}