/**
 * Copyright - See the COPYRIGHT that is included with this distribution.
 * pvAccessCPP is distributed subject to a Software License Agreement found
 * in file LICENSE that is included with this distribution.
 */

#include <epicsSignal.h>

#define epicsExportSharedSymbols
#include <pv/responseHandlers.h>
#include <pv/logger.h>
#include <pv/serverContext.h>
#include <pv/security.h>

using namespace std;
using namespace epics::pvData;
using std::tr1::dynamic_pointer_cast;
using std::tr1::static_pointer_cast;

namespace epics { namespace pvAccess {

const char* ServerContextImpl::StateNames[] = { "NOT_INITIALIZED", "INITIALIZED", "RUNNING", "SHUTDOWN", "DESTROYED"};
const Version ServerContextImpl::VERSION("pvAccess Server", "cpp", 
    EPICS_PVA_MAJOR_VERSION, EPICS_PVA_MINOR_VERSION, EPICS_PVA_MAINTENANCE_VERSION, EPICS_PVA_DEVELOPMENT_FLAG);

ServerContextImpl::ServerContextImpl():
				_state(NOT_INITIALIZED),
				_beaconAddressList(),
				_ignoreAddressList(),
				_autoBeaconAddressList(true),
				_beaconPeriod(15.0),
				_broadcastPort(PVA_BROADCAST_PORT),
				_serverPort(PVA_SERVER_PORT),
				_receiveBufferSize(MAX_TCP_RECV),
				_timer(),
				_broadcastTransport(),
				_beaconEmitter(),
				_acceptor(),
				_transportRegistry(),
				_channelProviderRegistry(),
				_channelProviderNames(PVACCESS_DEFAULT_PROVIDER),
				_channelProviders(),
                _beaconServerStatusProvider(),
                _startTime()

{
    epicsTimeGetCurrent(&_startTime);

    // TODO maybe there is a better place for this (when there will be some factory)
    epicsSignalInstallSigAlarmIgnore ();
    epicsSignalInstallSigPipeIgnore ();

    generateGUID();
	initializeLogger();
	loadConfiguration();
}

ServerContextImpl::shared_pointer ServerContextImpl::create()
{
    ServerContextImpl::shared_pointer thisPointer(new ServerContextImpl());
    return thisPointer;
}

ServerContextImpl::~ServerContextImpl()
{
    dispose();
}

const GUID& ServerContextImpl::getGUID()
{
    return _guid;
}

const Version& ServerContextImpl::getVersion()
{
    return ServerContextImpl::VERSION;
}

void ServerContextImpl::generateGUID()
{
    // TODO use UUID
    epics::pvData::TimeStamp startupTime;
 	startupTime.getCurrent();

 	ByteBuffer buffer(_guid.value, sizeof(_guid.value));
 	buffer.putLong(startupTime.getSecondsPastEpoch());
    buffer.putInt(startupTime.getNanoseconds());
}

void ServerContextImpl::initializeLogger()
{
    //createFileLogger("serverContextImpl.log");
}

struct noop_deleter
{
    template<class T> void operator()(T * p) {}
};

Configuration::shared_pointer ServerContextImpl::getConfiguration()
{
	Lock guard(_mutex);
	if (configuration.get() == 0)
	{
		ConfigurationProvider::shared_pointer configurationProvider = ConfigurationFactory::getProvider();
		configuration = configurationProvider->getConfiguration("pvAccess-server");
		if (configuration.get() == 0)
		{
			configuration = configurationProvider->getConfiguration("system");
		}
	}
	return configuration;
}

/**
 * Load configuration.
 */
void ServerContextImpl::loadConfiguration()
{
	Configuration::shared_pointer config = getConfiguration();

    // TODO for now just a simple switch
    int32 debugLevel = config->getPropertyAsInteger(PVACCESS_DEBUG, 0);
    if (debugLevel > 0)
        SET_LOG_LEVEL(logLevelDebug);

    _beaconAddressList = config->getPropertyAsString("EPICS_PVA_ADDR_LIST", _beaconAddressList);
    _beaconAddressList = config->getPropertyAsString("EPICS_PVAS_BEACON_ADDR_LIST", _beaconAddressList);

    _autoBeaconAddressList = config->getPropertyAsBoolean("EPICS_PVA_AUTO_ADDR_LIST", _autoBeaconAddressList);
    _autoBeaconAddressList = config->getPropertyAsBoolean("EPICS_PVAS_AUTO_BEACON_ADDR_LIST", _autoBeaconAddressList);

    _beaconPeriod = config->getPropertyAsFloat("EPICS_PVA_BEACON_PERIOD", _beaconPeriod);
    _beaconPeriod = config->getPropertyAsFloat("EPICS_PVAS_BEACON_PERIOD", _beaconPeriod);

    _serverPort = config->getPropertyAsInteger("EPICS_PVA_SERVER_PORT", _serverPort);
    _serverPort = config->getPropertyAsInteger("EPICS_PVAS_SERVER_PORT", _serverPort);

    _broadcastPort = config->getPropertyAsInteger("EPICS_PVA_BROADCAST_PORT", _broadcastPort);
    _broadcastPort = config->getPropertyAsInteger("EPICS_PVAS_BROADCAST_PORT", _broadcastPort);

    _receiveBufferSize = config->getPropertyAsInteger("EPICS_PVA_MAX_ARRAY_BYTES", _receiveBufferSize);
    _receiveBufferSize = config->getPropertyAsInteger("EPICS_PVAS_MAX_ARRAY_BYTES", _receiveBufferSize);

    _channelProviderNames = config->getPropertyAsString("EPICS_PVA_PROVIDER_NAMES", _channelProviderNames);
    _channelProviderNames = config->getPropertyAsString("EPICS_PVAS_PROVIDER_NAMES", _channelProviderNames);
}

bool ServerContextImpl::isChannelProviderNamePreconfigured()
{
    Configuration::shared_pointer config = getConfiguration();
    return config->hasProperty("EPICS_PVA_PROVIDER_NAMES") || config->hasProperty("EPICS_PVAS_PROVIDER_NAMES");
}

void ServerContextImpl::initialize(ChannelProviderRegistry::shared_pointer const & channelProviderRegistry)
{
	Lock guard(_mutex);
    if (!channelProviderRegistry.get())
	{
		THROW_BASE_EXCEPTION("non null channelProviderRegistry expected");
	}

	if (_state == DESTROYED)
	{
		THROW_BASE_EXCEPTION("Context destroyed.");
	}
	else if (_state != NOT_INITIALIZED)
	{
		THROW_BASE_EXCEPTION("Context already initialized.");
	}

	_channelProviderRegistry = channelProviderRegistry;


    // user all providers
    if (_channelProviderNames == PVACCESS_ALL_PROVIDERS)
    {
        _channelProviderNames.resize(0); // VxWorks 5.5 omits clear()

        std::auto_ptr<ChannelProviderRegistry::stringVector_t> names = _channelProviderRegistry->getProviderNames();
        for (ChannelProviderRegistry::stringVector_t::iterator iter = names->begin(); iter != names->end(); iter++)
        {
            ChannelProvider::shared_pointer channelProvider = _channelProviderRegistry->getProvider(*iter);
            if (channelProvider)
            {
                _channelProviders.push_back(channelProvider);

                // compile a list
                if (!_channelProviderNames.empty())
                    _channelProviderNames += ' ';
                _channelProviderNames += *iter;
            }
        }
    }
    else
    {
        // split space separated names
        std::stringstream ss(_channelProviderNames);
        std::string providerName;
        while (std::getline(ss, providerName, ' '))
        {
            ChannelProvider::shared_pointer channelProvider = _channelProviderRegistry->getProvider(providerName);
            if (channelProvider)
                _channelProviders.push_back(channelProvider);
        }
    }    

	//_channelProvider = _channelProviderRegistry->getProvider(_channelProviderNames);
	if (_channelProviders.size() == 0)
	{
		std::string msg = "None of the specified channel providers are available: " + _channelProviderNames + ".";
		THROW_BASE_EXCEPTION(msg.c_str());
	}

	internalInitialize();

	_state = INITIALIZED;
}

std::auto_ptr<ResponseHandler> ServerContextImpl::createResponseHandler()
{
    ServerContextImpl::shared_pointer thisContext = shared_from_this();
    return std::auto_ptr<ResponseHandler>(new ServerResponseHandler(thisContext));    
}

void ServerContextImpl::internalInitialize()
{
    osiSockAttach();

	_timer.reset(new Timer("pvAccess-server timer", lowerPriority));
	_transportRegistry.reset(new TransportRegistry());

    ServerContextImpl::shared_pointer thisServerContext = shared_from_this();

	_acceptor.reset(new BlockingTCPAcceptor(thisServerContext, thisServerContext, _serverPort, _receiveBufferSize));
	_serverPort = ntohs(_acceptor->getBindAddress()->ia.sin_port);

    // setup broadcast UDP transport
    initializeBroadcastTransport();

    // TODO introduce a constant
    _beaconEmitter.reset(new BeaconEmitter("tcp", _broadcastTransport, thisServerContext));
}

void ServerContextImpl::initializeBroadcastTransport()
{
	// setup UDP transport
	try
	{
		// where to bind (listen) address
	    osiSockAddr listenLocalAddress;
	    listenLocalAddress.ia.sin_family = AF_INET;
	    listenLocalAddress.ia.sin_port = htons(_broadcastPort);
	    listenLocalAddress.ia.sin_addr.s_addr = htonl(INADDR_ANY);

		// where to send addresses
	    SOCKET socket = epicsSocketCreate(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	    if (socket == INVALID_SOCKET)
	    {
	    	THROW_BASE_EXCEPTION("Failed to initialize broadcast UDP transport");
	    }
	    auto_ptr<InetAddrVector> broadcastAddresses(getBroadcastAddresses(socket,_broadcastPort));
	    epicsSocketDestroy(socket);

        TransportClient::shared_pointer nullTransportClient;

        auto_ptr<BlockingUDPConnector> broadcastConnector(new BlockingUDPConnector(true, true, true));
	    auto_ptr<epics::pvAccess::ResponseHandler> responseHandler = createResponseHandler();
        _broadcastTransport = static_pointer_cast<BlockingUDPTransport>(broadcastConnector->connect(
                nullTransportClient, responseHandler,
                listenLocalAddress, PVA_PROTOCOL_REVISION,
                PVA_DEFAULT_PRIORITY));
        _broadcastTransport->setSendAddresses(broadcastAddresses.get());

		// set ignore address list
		if (!_ignoreAddressList.empty())
		{
			// we do not care about the port
			auto_ptr<InetAddrVector> list(getSocketAddressList(_ignoreAddressList, 0, NULL));
			if (list.get() != NULL && list->size() > 0)
			{
				_broadcastTransport->setIgnoredAddresses(list.get());
			}
		}
		// set broadcast address list
		if (!_beaconAddressList.empty())
		{
			// if auto is true, add it to specified list
			InetAddrVector* appendList = NULL;
			if (_autoBeaconAddressList == true)
			{
				appendList = _broadcastTransport->getSendAddresses();
			}

			auto_ptr<InetAddrVector> list(getSocketAddressList(_beaconAddressList, _broadcastPort, appendList));
			if (list.get() != NULL  && list->size() > 0)
			{
                _broadcastTransport->setSendAddresses(list.get());
			}
		}


        // setup local broadcasting
        // TODO configurable local NIF, address
        osiSockAddr loAddr;
        getLoopbackNIF(loAddr, "", 0);
        if (true)
        {
            try
            {
                osiSockAddr group;
                aToIPAddr("224.0.0.128", _broadcastPort, &group.ia);
                _broadcastTransport->join(group, loAddr);

                osiSockAddr anyAddress;
                anyAddress.ia.sin_family = AF_INET;
                anyAddress.ia.sin_port = htons(0);
                anyAddress.ia.sin_addr.s_addr = htonl(INADDR_ANY);

                // NOTE: localMulticastTransport is not started (no read is called on a socket)
                auto_ptr<epics::pvAccess::ResponseHandler> responseHandler2 = createResponseHandler();
                _localMulticastTransport = static_pointer_cast<BlockingUDPTransport>(broadcastConnector->connect(
                        nullTransportClient, responseHandler2,
                        anyAddress, PVA_PROTOCOL_REVISION,
                        PVA_DEFAULT_PRIORITY));
                _localMulticastTransport->setMutlicastNIF(loAddr, true);
                InetAddrVector sendAddressList;
                sendAddressList.push_back(group);
                _localMulticastTransport->setSendAddresses(&sendAddressList);

                LOG(logLevelDebug, "Local multicast enabled on %s using network interface %s.",
                    inetAddressToString(group).c_str(), inetAddressToString(loAddr, false).c_str());
            }
            catch (std::exception& ex)
            {
                LOG(logLevelDebug, "Failed to initialize local multicast, funcionality disabled. Reason: %s.", ex.what());
            }
        }
        else
        {
            LOG(logLevelDebug, "Failed to detect a loopback network interface, local multicast disabled.");
        }

        _broadcastTransport->start();
        if (_localMulticastTransport)
            _localMulticastTransport->start();
	}
	catch (std::exception& e)
	{
		THROW_BASE_EXCEPTION_CAUSE("Failed to initialize broadcast UDP transport", e);
	}
	catch (...)
	{
		THROW_BASE_EXCEPTION("Failed to initialize broadcast UDP transport");
	}
}

void ServerContextImpl::run(int32 seconds)
{
	if (seconds < 0)
	{
		THROW_BASE_EXCEPTION("seconds cannot be negative.");
	}

	{
		Lock guard(_mutex);

		if (_state == NOT_INITIALIZED)
		{
			THROW_BASE_EXCEPTION("Context not initialized.");
		}
		else if (_state == DESTROYED)
		{
			THROW_BASE_EXCEPTION("Context destroyed.");
		}
		else if (_state == RUNNING)
		{
			THROW_BASE_EXCEPTION("Context is already running.");
		}
		else if (_state == SHUTDOWN)
		{
			THROW_BASE_EXCEPTION("Context was shutdown.");
		}

		_state = RUNNING;
	}

	// run...
	_beaconEmitter->start();

	//TODO review this
	if(seconds == 0)
	{
		_runEvent.wait();
	}
	else
	{
		_runEvent.wait(seconds);
	}

	{
		Lock guard(_mutex);
		_state = SHUTDOWN;
	}
}

void ServerContextImpl::shutdown()
{
	Lock guard(_mutex);
	if(_state == DESTROYED)
	{
		THROW_BASE_EXCEPTION("Context already destroyed.");
	}

	// notify to stop running...
	_runEvent.signal();
}

void ServerContextImpl::destroy()
{
	Lock guard(_mutex);
	if (_state == DESTROYED)
	{
		// silent return
		return;
		// exception is not OK, since we use
		// shared_pointer-s auto-cleanup/destruction
		// THROW_BASE_EXCEPTION("Context already destroyed.");
	}

	// shutdown if not already
	shutdown();

	// go into destroyed state ASAP
	_state = DESTROYED;

	internalDestroy();
}


void ServerContextImpl::internalDestroy()
{
	// stop responding to search requests
    if (_broadcastTransport.get())
	{
		_broadcastTransport->close();
		_broadcastTransport.reset();
	}
    // and close local multicast transport
    if (_localMulticastTransport.get())
    {
        _localMulticastTransport->close();
        _localMulticastTransport.reset();
    }

	// stop accepting connections
    if (_acceptor.get())
	{
		_acceptor->destroy();
		_acceptor.reset();
	}

	// stop emitting beacons
    if (_beaconEmitter.get())
	{
		_beaconEmitter->destroy();
		_beaconEmitter.reset();
	}

	// this will also destroy all channels
	destroyAllTransports();
}

void ServerContextImpl::destroyAllTransports()
{

	// not initialized yet
    if (!_transportRegistry.get())
	{
		return;
	}

	std::auto_ptr<TransportRegistry::transportVector_t> transports = _transportRegistry->toArray();
	if (transports.get() == 0)
	   return;
	   
    int size = (int)transports->size();
	if (size == 0)
		return;

	LOG(logLevelInfo, "Server context still has %d transport(s) active and closing...", size);

	for (int i = 0; i < size; i++)
	{
		Transport::shared_pointer transport = (*transports)[i];
		try
		{
			transport->close();
		}
		catch (std::exception &e)
		{
			// do all exception safe, log in case of an error
			LOG(logLevelError, "Unhandled exception caught from client code at %s:%d: %s", __FILE__, __LINE__, e.what());
		}
		catch (...)
		{
			// do all exception safe, log in case of an error
			 LOG(logLevelError, "Unhandled exception caught from client code at %s:%d.", __FILE__, __LINE__);
		}
	}
	
	// now clear all (release)
	_transportRegistry->clear();
	
}

void ServerContextImpl::printInfo()
{
	printInfo(cout);
}

void ServerContextImpl::printInfo(ostream& str)
{
	Lock guard(_mutex);
	str << "VERSION : " << getVersion().getVersionString() << endl \
		<< "PROVIDER_NAMES : " << _channelProviderNames << endl \
		<< "BEACON_ADDR_LIST : " << _beaconAddressList << endl \
	    << "AUTO_BEACON_ADDR_LIST : " << _autoBeaconAddressList << endl \
	    << "BEACON_PERIOD : " << _beaconPeriod << endl \
	    << "BROADCAST_PORT : " << _broadcastPort << endl \
	    << "SERVER_PORT : " << _serverPort << endl \
	    << "RCV_BUFFER_SIZE : " << _receiveBufferSize << endl \
	    << "IGNORE_ADDR_LIST: " << _ignoreAddressList << endl \
	    << "STATE : " << ServerContextImpl::StateNames[_state] << endl;
}

void ServerContextImpl::dispose()
{
	try
	{
		destroy();
	}
	catch(...)
	{
		// noop
	}
}

void ServerContextImpl::setBeaconServerStatusProvider(BeaconServerStatusProvider::shared_pointer const & beaconServerStatusProvider)
{
	_beaconServerStatusProvider = beaconServerStatusProvider;
}

bool ServerContextImpl::isInitialized()
{
	Lock guard(_mutex);
	return _state == INITIALIZED || _state == RUNNING || _state == SHUTDOWN;
}

bool ServerContextImpl::isDestroyed()
{
	Lock guard(_mutex);
	return _state == DESTROYED;
}

std::string ServerContextImpl::getBeaconAddressList()
{
	return _beaconAddressList;
}

bool ServerContextImpl::isAutoBeaconAddressList()
{
	return _autoBeaconAddressList;
}

float ServerContextImpl::getBeaconPeriod()
{
	return _beaconPeriod;
}

int32 ServerContextImpl::getReceiveBufferSize()
{
	return _receiveBufferSize;
}

int32 ServerContextImpl::getServerPort()
{
	return _serverPort;
}

void ServerContextImpl::setServerPort(int32 port)
{
	_serverPort = port;
}

int32 ServerContextImpl::getBroadcastPort()
{
	return _broadcastPort;
}

std::string ServerContextImpl::getIgnoreAddressList()
{
	return _ignoreAddressList;
}

BeaconServerStatusProvider::shared_pointer ServerContextImpl::getBeaconServerStatusProvider()
{
	return _beaconServerStatusProvider;
}

osiSockAddr* ServerContextImpl::getServerInetAddress()
{
    if(_acceptor.get())
	{
		return const_cast<osiSockAddr*>(_acceptor->getBindAddress());
	}
	return NULL;
}

BlockingUDPTransport::shared_pointer ServerContextImpl::getBroadcastTransport()
{
	return _broadcastTransport;
}

BlockingUDPTransport::shared_pointer ServerContextImpl::getLocalMulticastTransport()
{
    return _localMulticastTransport;
}

ChannelProviderRegistry::shared_pointer ServerContextImpl::getChannelProviderRegistry()
{
	return _channelProviderRegistry;
}

std::string ServerContextImpl::getChannelProviderName()
{
	return _channelProviderNames;
}

// NOTE: not synced
void ServerContextImpl::setChannelProviderName(std::string channelProviderName)
{
    if (_state != NOT_INITIALIZED)
        throw std::logic_error("must be called before initialize");
    _channelProviderNames = channelProviderName;
}

std::vector<ChannelProvider::shared_pointer>& ServerContextImpl::getChannelProviders()
{
	return _channelProviders;
}

Timer::shared_pointer ServerContextImpl::getTimer()
{
	return _timer;
}

TransportRegistry::shared_pointer ServerContextImpl::getTransportRegistry()
{
	return _transportRegistry;
}

Channel::shared_pointer ServerContextImpl::getChannel(pvAccessID /*id*/)
{
	// not used
	return Channel::shared_pointer();
}

Transport::shared_pointer ServerContextImpl::getSearchTransport()
{
	// not used 
	return Transport::shared_pointer();
}

void ServerContextImpl::newServerDetected()
{
    // not used
}

epicsTimeStamp& ServerContextImpl::getStartTime()
{
    return _startTime;
}


std::map<std::string, std::tr1::shared_ptr<SecurityPlugin> >& ServerContextImpl::getSecurityPlugins()
{
    return SecurityPluginRegistry::instance().getServerSecurityPlugins();
}



struct ThreadRunnerParam {
    ServerContextImpl::shared_pointer ctx;
    int timeToRun;
};

static void threadRunner(void* usr)
{
    ThreadRunnerParam* pusr = static_cast<ThreadRunnerParam*>(usr);
    ThreadRunnerParam param = *pusr;
    delete pusr;

    param.ctx->run(param.timeToRun);
}



ServerContext::shared_pointer startPVAServer(std::string const & providerNames, int timeToRun, bool runInSeparateThread, bool printInfo)
{
    ServerContextImpl::shared_pointer ctx = ServerContextImpl::create();

    // do not override configuration
    if (!ctx->isChannelProviderNamePreconfigured())
        ctx->setChannelProviderName(providerNames);
    
    ChannelProviderRegistry::shared_pointer channelProviderRegistry = getChannelProviderRegistry();
    ctx->initialize(channelProviderRegistry);

    if (printInfo)
        ctx->printInfo();


    if (runInSeparateThread)
    {
        // delete left to the thread
        auto_ptr<ThreadRunnerParam> param(new ThreadRunnerParam());
        param->ctx = ctx;
        param->timeToRun = timeToRun;

        // TODO can this fail?
        epicsThreadCreate("startPVAServer",
                          epicsThreadPriorityMedium,
                          epicsThreadGetStackSize(epicsThreadStackBig),
                          threadRunner, param.get());

        param.release();
    }
    else
    {
        ctx->run(timeToRun);
    }

    return ctx;
}

}
}