/*

* Copyright (c) 2010 Remko Tronçon

* Licensed under the GNU General Public License v3.

* See Documentation/Licenses/GPLv3.txt for more information.

*/

#include <Swiften/Network/Connector.h>

#include <boost/bind.hpp>

#include <iostream>

#include <Swiften/Network/ConnectionFactory.h>

#include <Swiften/Network/DomainNameResolver.h>

#include <Swiften/Network/DomainNameAddressQuery.h>

#include <Swiften/Network/TimerFactory.h>

#include <Swiften/Base/Log.h>

namespace Swift {

Connector::Connector(const std::string& hostname, int port, const boost::optional<std::string>& serviceLookupPrefix, DomainNameResolver* resolver, ConnectionFactory* connectionFactory, TimerFactory* timerFactory) : hostname(hostname), port(port), serviceLookupPrefix(serviceLookupPrefix), resolver(resolver), connectionFactory(connectionFactory), timerFactory(timerFactory), timeoutMilliseconds(0), queriedAllServices(true), foundSomeDNS(false) {

}

void Connector::setTimeoutMilliseconds(int milliseconds) {

timeoutMilliseconds = milliseconds;

}

void Connector::start() {

SWIFT_LOG(debug) << "Starting connector for " << hostname << std::endl;

//std::cout << "Connector::start()" << std::endl;

assert(!currentConnection);

assert(!serviceQuery);

assert(!timer);

queriedAllServices = false;

if (timeoutMilliseconds > 0) {

timer = timerFactory->createTimer(timeoutMilliseconds);

timer->onTick.connect(boost::bind(&Connector::handleTimeout, shared_from_this()));

}

if (serviceLookupPrefix) {

serviceQuery->onResult.connect(boost::bind(&Connector::handleServiceQueryResult, shared_from_this(), _1));

serviceQuery->run();

}

else {

queryAddress(hostname);

}

}

void Connector::stop() {

finish(boost::shared_ptr<Connection>());

}

void Connector::queryAddress(const std::string& hostname) {

assert(!addressQuery);

addressQuery = resolver->createAddressQuery(hostname);

addressQuery->onResult.connect(boost::bind(&Connector::handleAddressQueryResult, shared_from_this(), _1, _2));

addressQuery->run();

}

void Connector::handleServiceQueryResult(const std::vector<DomainNameServiceQuery::Result>& result) {

SWIFT_LOG(debug) << result.size() << " SRV result(s)" << std::endl;

serviceQueryResults = std::deque<DomainNameServiceQuery::Result>(result.begin(), result.end());

serviceQuery.reset();

if (!serviceQueryResults.empty()) {

foundSomeDNS = true;

}

tryNextServiceOrFallback();

}

void Connector::tryNextServiceOrFallback() {

if (queriedAllServices) {

SWIFT_LOG(debug) << "Queried all services" << std::endl;

finish(boost::shared_ptr<Connection>());

}

else if (serviceQueryResults.empty()) {

SWIFT_LOG(debug) << "Falling back on A resolution" << std::endl;

// Fall back on simple address resolving

queriedAllServices = true;

queryAddress(hostname);

}

else {

SWIFT_LOG(debug) << "Querying next address" << std::endl;

queryAddress(serviceQueryResults.front().hostname);

}

}

void Connector::handleAddressQueryResult(const std::vector<HostAddress>& addresses, boost::optional<DomainNameResolveError> error) {

SWIFT_LOG(debug) << addresses.size() << " addresses" << std::endl;

addressQuery.reset();

if (error || addresses.empty()) {

if (!serviceQueryResults.empty()) {

serviceQueryResults.pop_front();

}

tryNextServiceOrFallback();

}

else {

foundSomeDNS = true;

addressQueryResults = std::deque<HostAddress>(addresses.begin(), addresses.end());

tryNextAddress();

}

}

void Connector::tryNextAddress() {

if (addressQueryResults.empty()) {

SWIFT_LOG(debug) << "Done trying addresses. Moving on." << std::endl;

// Done trying all addresses. Move on to the next host.

if (!serviceQueryResults.empty()) {

serviceQueryResults.pop_front();

}

tryNextServiceOrFallback();

}

else {

SWIFT_LOG(debug) << "Trying next address" << std::endl;

HostAddress address = addressQueryResults.front();

addressQueryResults.pop_front();

int connectPort = (port == -1 ? 5222 : port);

if (!serviceQueryResults.empty()) {

connectPort = serviceQueryResults.front().port;

}

tryConnect(HostAddressPort(address, connectPort));

}

}

void Connector::tryConnect(const HostAddressPort& target) {

assert(!currentConnection);

SWIFT_LOG(debug) << "Trying to connect to " << target.getAddress().toString() << ":" << target.getPort() << std::endl;

currentConnection = connectionFactory->createConnection();

currentConnection->onConnectFinished.connect(boost::bind(&Connector::handleConnectionConnectFinished, shared_from_this(), _1));

currentConnection->connect(target);

if (timer) {

timer->start();

}

}

void Connector::handleConnectionConnectFinished(bool error) {

SWIFT_LOG(debug) << "ConnectFinished: " << (error ? "error" : "success") << std::endl;

if (timer) {

timer->stop();

timer.reset();

}

currentConnection->onConnectFinished.disconnect(boost::bind(&Connector::handleConnectionConnectFinished, shared_from_this(), _1));

if (error) {

currentConnection.reset();

if (!addressQueryResults.empty()) {

tryNextAddress();

}

else {

if (!serviceQueryResults.empty()) {

serviceQueryResults.pop_front();

}

tryNextServiceOrFallback();

}

}

else {

finish(currentConnection);

}

}

void Connector::finish(boost::shared_ptr<Connection> connection) {

if (timer) {

timer->stop();

timer->onTick.disconnect(boost::bind(&Connector::handleTimeout, shared_from_this()));

timer.reset();

}

if (serviceQuery) {

serviceQuery->onResult.disconnect(boost::bind(&Connector::handleServiceQueryResult, shared_from_this(), _1));

serviceQuery.reset();

}

if (addressQuery) {

addressQuery->onResult.disconnect(boost::bind(&Connector::handleAddressQueryResult, shared_from_this(), _1, _2));

addressQuery.reset();

}

if (currentConnection) {

currentConnection->onConnectFinished.disconnect(boost::bind(&Connector::handleConnectionConnectFinished, shared_from_this(), _1));

currentConnection.reset();

}

onConnectFinished(connection, (connection || foundSomeDNS) ? boost::shared_ptr<Error>() : boost::make_shared<DomainNameResolveError>());

}

void Connector::handleTimeout() {

SWIFT_LOG(debug) << "Timeout" << std::endl;

handleConnectionConnectFinished(true);

}

}