/**

 * libtransport -- C++ library for easy XMPP Transports development

 *

 * Copyright (C) 2011, Jan Kaluza <hanzz.k@gmail.com>

 *

 * 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 Street, Fifth Floor, Boston, MA  02111-1301  USA

 */

#include "transport/networkpluginserver.h"

#include "transport/user.h"

#include "transport/transport.h"

#include "transport/storagebackend.h"

#include "transport/rostermanager.h"

#include "transport/usermanager.h"

#include "transport/conversationmanager.h"

#include "transport/localbuddy.h"

#include "transport/config.h"

#include "transport/conversation.h"

#include "transport/vcardresponder.h"

#include "transport/rosterresponder.h"

#include "transport/memoryreadbytestream.h"

#include "blockresponder.h"

#include "Swiften/Swiften.h"

#include "Swiften/Server/ServerStanzaChannel.h"

#include "Swiften/Elements/StreamError.h"

#include "Swiften/Network/BoostConnectionServer.h"

#include "Swiften/Elements/AttentionPayload.h"

#include "Swiften/Elements/XHTMLIMPayload.h"

#include "Swiften/Elements/InvisiblePayload.h"

#include "Swiften/Elements/SpectrumErrorPayload.h"

#include "transport/protocol.pb.h"

#include "log4cxx/logger.h"

#include <Swiften/FileTransfer/ReadBytestream.h>

#include <Swiften/Elements/StreamInitiationFileInfo.h>

#ifdef _WIN32

#include "windows.h"

#else

#include "sys/wait.h"

#include "sys/signal.h"

#include "popt.h"

#endif

using namespace log4cxx;

namespace Transport {

static unsigned long backend_id;

static unsigned long bytestream_id;

static LoggerPtr logger = Logger::getLogger("NetworkPluginServer");

class NetworkConversation : public Conversation {

	public:

		NetworkConversation(ConversationManager *conversationManager, const std::string &legacyName, bool muc = false) : Conversation(conversationManager, legacyName, muc) {

		}

		// Called when there's new message to legacy network from XMPP network

		void sendMessage(boost::shared_ptr<Swift::Message> &message) {

			onMessageToSend(this, message);

		}

		boost::signal<void (NetworkConversation *, boost::shared_ptr<Swift::Message> &)> onMessageToSend;

};

class NetworkFactory : public Factory {

	public:

		NetworkFactory(NetworkPluginServer *nps) {

			m_nps = nps;

		}

		// Creates new conversation (NetworkConversation in this case)

		Conversation *createConversation(ConversationManager *conversationManager, const std::string &legacyName) {

			NetworkConversation *nc = new NetworkConversation(conversationManager, legacyName);

			nc->onMessageToSend.connect(boost::bind(&NetworkPluginServer::handleMessageReceived, m_nps, _1, _2));

			return nc;

		}

		// Creates new LocalBuddy

		Buddy *createBuddy(RosterManager *rosterManager, const BuddyInfo &buddyInfo) {

			LocalBuddy *buddy = new LocalBuddy(rosterManager, buddyInfo.id);

			buddy->setAlias(buddyInfo.alias);

			buddy->setName(buddyInfo.legacyName);

			buddy->setSubscription(buddyInfo.subscription);

			buddy->setGroups(buddyInfo.groups);

			buddy->setFlags((BuddyFlag) (buddyInfo.flags));

			if (buddyInfo.settings.find("icon_hash") != buddyInfo.settings.end())

				buddy->setIconHash(buddyInfo.settings.find("icon_hash")->second.s);

			return buddy;

		}

	private:

		NetworkPluginServer *m_nps;

};

// Wraps google protobuf payload into WrapperMessage and serialize it to string

#define WRAP(MESSAGE, TYPE) 	pbnetwork::WrapperMessage wrap; \

	wrap.set_type(TYPE); \

	wrap.set_payload(MESSAGE); \

	wrap.SerializeToString(&MESSAGE);

// Executes new backend

static unsigned long exec_(std::string path, const char *host, const char *port, const char *config) {

	std::string original_path = path;

	// BACKEND_ID is replaced with unique ID. The ID is increasing for every backend.

	boost::replace_all(path, "BACKEND_ID", boost::lexical_cast<std::string>(backend_id++));

	// Add host and port.

	path += std::string(" --host ") + host + " --port " + port + " " + config;

	LOG4CXX_INFO(logger, "Starting new backend " << path);

#ifdef _WIN32

	STARTUPINFO         si;

	PROCESS_INFORMATION pi;

	ZeroMemory (&si, sizeof(si));

	si.cb=sizeof (si);

	if (! CreateProcess(

	NULL,

	(LPSTR)path.c_str(),         // command line

	0,                    // process attributes

	0,                    // thread attributes

	0,                    // inherit handles

	0,                    // creation flags

	0,                    // environment

	0,                    // cwd

	&si,

	&pi

	)

	)  {

		LOG4CXX_ERROR(logger, "Could not start process");

	}

	return 0;

#else

	// Create array of char * from string using -lpopt library

	char *p = (char *) malloc(path.size() + 1);

	strcpy(p, path.c_str());

	int argc;

	char **argv;

	poptParseArgvString(p, &argc, (const char ***) &argv);

	// fork and exec

	pid_t pid = fork();

	if ( pid == 0 ) {

		setsid();

		// child process

		exit(execv(argv[0], argv));

	} else if ( pid < 0 ) {

		// fork failed

	}

	free(p);

	return (unsigned long) pid;

#endif

}

#ifndef _WIN32

static void SigCatcher(int n) {

	pid_t result;

	int status;

	// Read exit code from all children to not have zombies arround

	// WARNING: Do not put LOG4CXX_ here, because it can lead to deadlock

		if (result != 0) {

			if (WIFEXITED(status)) {

				if (WEXITSTATUS(status) != 0) {

// 					LOG4CXX_ERROR(logger, "Backend can not be started, exit_code=" << WEXITSTATUS(status));

				}

			}

			else {

// 				LOG4CXX_ERROR(logger, "Backend can not be started");

			}

		}

	}

}

#endif

static void handleBuddyPayload(LocalBuddy *buddy, const pbnetwork::Buddy &payload) {

	buddy->setName(payload.buddyname());

	// Set alias only if it's not empty. Backends are allowed to send empty alias if it has

	// not changed.

	if (!payload.alias().empty()) {

		buddy->setAlias(payload.alias());

	}

	// Change groups if it's not empty. The same as above...

	std::vector<std::string> groups;

	for (int i = 0; i < payload.group_size(); i++) {

		groups.push_back(payload.group(i));

	}

	if (!groups.empty()) {

		buddy->setGroups(groups);

	}

	buddy->setStatus(Swift::StatusShow((Swift::StatusShow::Type) payload.status()), payload.statusmessage());

	buddy->setIconHash(payload.iconhash());

	buddy->setBlocked(payload.blocked());

}

NetworkPluginServer::NetworkPluginServer(Component *component, Config *config, UserManager *userManager, FileTransferManager *ftManager) {

	m_ftManager = ftManager;

	m_userManager = userManager;

	m_config = config;

	m_component = component;

	m_isNextLongRun = false;

	m_component->m_factory = new NetworkFactory(this);

	m_userManager->onUserCreated.connect(boost::bind(&NetworkPluginServer::handleUserCreated, this, _1));

	m_userManager->onUserDestroyed.connect(boost::bind(&NetworkPluginServer::handleUserDestroyed, this, _1));

	m_pingTimer = component->getNetworkFactories()->getTimerFactory()->createTimer(20000);

	m_pingTimer->onTick.connect(boost::bind(&NetworkPluginServer::pingTimeout, this));

	m_pingTimer->start();

	if (CONFIG_INT(m_config, "service.memory_collector_time") != 0) {

		m_collectTimer = component->getNetworkFactories()->getTimerFactory()->createTimer(CONFIG_INT(m_config, "service.memory_collector_time"));

		m_collectTimer->onTick.connect(boost::bind(&NetworkPluginServer::collectBackend, this));

		m_collectTimer->start();

	}

	m_vcardResponder = new VCardResponder(component->getIQRouter(), component->getNetworkFactories(), userManager);

	m_vcardResponder->onVCardRequired.connect(boost::bind(&NetworkPluginServer::handleVCardRequired, this, _1, _2, _3));

	m_vcardResponder->onVCardUpdated.connect(boost::bind(&NetworkPluginServer::handleVCardUpdated, this, _1, _2));

	m_vcardResponder->start();

	m_rosterResponder = new RosterResponder(component->getIQRouter(), userManager);

	m_rosterResponder->onBuddyAdded.connect(boost::bind(&NetworkPluginServer::handleBuddyAdded, this, _1, _2));

	m_rosterResponder->onBuddyRemoved.connect(boost::bind(&NetworkPluginServer::handleBuddyRemoved, this, _1));

	m_rosterResponder->onBuddyUpdated.connect(boost::bind(&NetworkPluginServer::handleBuddyUpdated, this, _1, _2));

	m_rosterResponder->start();

	m_blockResponder = new BlockResponder(component->getIQRouter(), userManager);

	m_blockResponder->onBlockToggled.connect(boost::bind(&NetworkPluginServer::handleBlockToggled, this, _1));

	m_blockResponder->start();

	m_server = component->getNetworkFactories()->getConnectionServerFactory()->createConnectionServer(Swift::HostAddress(CONFIG_STRING(m_config, "service.backend_host")), boost::lexical_cast<int>(CONFIG_STRING(m_config, "service.backend_port")));

	m_server->onNewConnection.connect(boost::bind(&NetworkPluginServer::handleNewClientConnection, this, _1));

	m_server->start();

	LOG4CXX_INFO(logger, "Listening on host " << CONFIG_STRING(m_config, "service.backend_host") << " port " << CONFIG_STRING(m_config, "service.backend_port"));

#ifndef _WIN32

	signal(SIGCHLD, SigCatcher);

#endif

	exec_(CONFIG_STRING(m_config, "service.backend"), CONFIG_STRING(m_config, "service.backend_host").c_str(), CONFIG_STRING(m_config, "service.backend_port").c_str(), m_config->getConfigFile().c_str());

	LOG4CXX_INFO(logger, "Backend should now connect to Spectrum2 instance. Spectrum2 won't accept any connection before backend connects");

}

NetworkPluginServer::~NetworkPluginServer() {

	for (std::list<Backend *>::const_iterator it = m_clients.begin(); it != m_clients.end(); it++) {

		LOG4CXX_INFO(logger, "Stopping backend " << *it);

		std::string message;

		pbnetwork::WrapperMessage wrap;

		wrap.set_type(pbnetwork::WrapperMessage_Type_TYPE_EXIT);

		wrap.SerializeToString(&message);

		Backend *c = (Backend *) *it;

		send(c->connection, message);

	}

	m_pingTimer->stop();

	m_server->stop();

	m_server.reset();

	delete m_component->m_factory;

	delete m_vcardResponder;

	delete m_rosterResponder;

	delete m_blockResponder;

}

void NetworkPluginServer::handleNewClientConnection(boost::shared_ptr<Swift::Connection> c) {

	// Create new Backend instance

	Backend *client = new Backend;

	client->pongReceived = -1;

	client->connection = c;

	client->res = 0;

	client->init_res = 0;

	client->shared = 0;

	client->willDie = 0;

	// Backend does not accept new clients automatically if it's long-running

	client->acceptUsers = !m_isNextLongRun;

	client->longRun = m_isNextLongRun;

	LOG4CXX_INFO(logger, "New" + (client->longRun ? std::string(" long-running") : "") +  " backend " << client << " connected. Current backend count=" << (m_clients.size() + 1));

	if (m_clients.size() == 0) {

		// first backend connected, start the server, we're ready.

		m_component->start();

	}

	m_clients.push_front(client);

	c->onDisconnected.connect(boost::bind(&NetworkPluginServer::handleSessionFinished, this, client));

	c->onDataRead.connect(boost::bind(&NetworkPluginServer::handleDataRead, this, client, _1));

	sendPing(client);

	// sendPing sets pongReceived to 0, but we want to have it -1 to ignore this backend

	// in first ::pingTimeout call, because it can be called right after this function

	// and backend wouldn't have any time to response to ping.

	client->pongReceived = -1;

	// some users are in queue waiting for this backend

	while(!m_waitingUsers.empty()) {

		// There's no new backend, so stop associating users and wait for new backend,

		// which has been already spawned in getFreeClient() call.

		if (getFreeClient() == NULL)

			break;

		User *u = m_waitingUsers.front();

		m_waitingUsers.pop_front();

		LOG4CXX_INFO(logger, "Associating " << u->getJID().toString() << " with this backend");

		// associate backend with user

		handleUserCreated(u);

		// connect user if it's ready

		if (u->isReadyToConnect()) {

			handleUserReadyToConnect(u);

		}

	}

}

void NetworkPluginServer::handleSessionFinished(Backend *c) {

	LOG4CXX_INFO(logger, "Backend " << c << " disconnected. Current backend count=" << (m_clients.size() - 1));

	// This backend will do, so we can't reconnect users to it in User::handleDisconnected call

	c->willDie = true;

	// If there are users associated with this backend, it must have crashed, so print error output

	// and disconnect users

	for (std::list<User *>::const_iterator it = c->users.begin(); it != c->users.end(); it++) {

		LOG4CXX_ERROR(logger, "Backend " << c << " disconnected (probably crashed) with active user " << (*it)->getJID().toString());

		(*it)->setData(NULL);

		(*it)->handleDisconnected("Internal Server Error, please reconnect.");

	}

	std::string message;

	pbnetwork::WrapperMessage wrap;

	wrap.set_type(pbnetwork::WrapperMessage_Type_TYPE_EXIT);

	wrap.SerializeToString(&message);

	send(c->connection, message);

	c->connection->onDisconnected.disconnect_all_slots();

	c->connection->onDataRead.disconnect_all_slots();

	c->connection->disconnect();

	c->connection.reset();

	m_clients.remove(c);

	delete c;

}

void NetworkPluginServer::handleConnectedPayload(const std::string &data) {

	pbnetwork::Connected payload;