/***************************************************************************
 *   Copyright (C) 2005 by Joris Guisson                                   *
 *   joris.guisson@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 02110-1301, USA.             *
 ***************************************************************************/
#include "announcetask.h"
#include <util/log.h>
#include <torrent/globals.h>
#include "node.h"
#include "pack.h"
#include "announcereq.h"
#include "getpeersrsp.h"


using namespace bt;

namespace dht
{

	AnnounceTask::AnnounceTask(Database* db,
	                           RPCServer* rpc,
	                           Node* node,
	                           const dht::Key & info_hash,
	                           bt::Uint16 port,
	                           QObject* parent)
			: Task(rpc, node, parent),
			info_hash(info_hash),
			port(port),
			db(db)
	{}


	AnnounceTask::~AnnounceTask()
	{}

	void AnnounceTask::handleNodes(const QByteArray& nodes, int ip_version)
	{
		Uint32 address_size = ip_version == 4 ? 26 : 38;
		Uint32 nval = nodes.size() / address_size;
		for (Uint32 i = 0;i < nval;i++)
		{
			// add node to todo list
			try
			{
				KBucketEntry e = UnpackBucketEntry(nodes, i * address_size, ip_version);
				if (!visited.contains(e) && todo.size() < 100)
				{
					todo.insert(e);
					//	Out(SYS_DHT|LOG_DEBUG) << "DHT: GetPeers returned node " << e.getAddress().toString() << endl;
				}
			}
			catch (...)
			{
				// not enough size in buffer, just ignore the error
			}
		}
	}


	void AnnounceTask::callFinished(RPCCall* c, RPCMsg::Ptr rsp)
	{
		//Out(SYS_DHT|LOG_DEBUG) << "AnnounceTask::callFinished" << endl;
		// if we do not have a get peers response, return
		// announce_peer's response are just empty anyway
		if (c->getMsgMethod() != dht::GET_PEERS)
			return;

		GetPeersRsp::Ptr gpr = rsp.dynamicCast<GetPeersRsp>();
		if (!gpr)
			return;

		if (gpr->containsNodes())
		{
			const QByteArray & n = gpr->getNodes();
			if (n.size() > 0)
				handleNodes(n, 4);

			const QByteArray & n6 = gpr->getNodes6();
			if (n6.size() > 0)
				handleNodes(n6, 6);
		}

		// store the items in the database if there are any present
		const DBItemList & items = gpr->getItemList();
		for (DBItemList::const_iterator i = items.begin();i != items.end();++i)
		{
			//	Out(SYS_DHT|LOG_DEBUG) << "DHT: GetPeers returned item " << i->getAddress().toString() << endl;
			db->store(info_hash, *i);
			// also add the items to the returned_items list
			returned_items.append(*i);
		}

		if (items.size() > 0)
			emitDataReady();

		// add the peer who responded to the answered list, so we can do an announce
		KBucketEntry e(rsp->getOrigin(), rsp->getID());
		if (!answered_visited.contains(e))
		{
			answered.insert(KBucketEntryAndToken(e, gpr->getToken()));
		}
	}

	void AnnounceTask::callTimeout(RPCCall*)
	{
		//Out(SYS_DHT|LOG_DEBUG) << "AnnounceTask::callTimeout " << endl;
	}

	void AnnounceTask::update()
	{
		/*	Out(SYS_DHT|LOG_DEBUG) << "AnnounceTask::update " << endl;
			Out(SYS_DHT|LOG_DEBUG) << "todo " << todo.count() << " ; answered " << answered.count() << endl;
			Out(SYS_DHT|LOG_DEBUG) << "visited " << visited.count() << " ; answered_visited " << answered_visited.count() << endl;
		*/
		while (!answered.empty() && canDoRequest())
		{
			std::set<KBucketEntryAndToken>::iterator itr = answered.begin();
			if (!answered_visited.contains(*itr))
			{
				RPCMsg::Ptr anr(new AnnounceReq(node->getOurID(), info_hash, port, itr->getToken()));
				anr->setOrigin(itr->getAddress());
				//		Out(SYS_DHT|LOG_DEBUG) << "DHT: Announcing to " << e.getAddress().toString() << endl;
				rpcCall(anr);
				answered_visited.insert(*itr);
			}
			answered.erase(itr);
		}

		// go over the todo list and send get_peers requests
		// until we have nothing left
		while (!todo.empty() && canDoRequest())
		{
			KBucketEntrySet::iterator itr = todo.begin();
			// onLy send a findNode if we haven't allrready visited the node
			if (!visited.contains(*itr))
			{
				// send a findNode to the node
				//		Out(SYS_DHT|LOG_DEBUG) << "DHT: Sending GetPeers to " << e.getAddress().toString() << endl;
				RPCMsg::Ptr gpr(new GetPeersReq(node->getOurID(), info_hash));
				gpr->setOrigin(itr->getAddress());
				rpcCall(gpr);
				visited.insert(*itr);
			}
			// remove the entry from the todo list
			todo.erase(itr);
		}


		if (todo.empty() && answered.empty() && getNumOutstandingRequests() == 0 && !isFinished())
		{
			Out(SYS_DHT | LOG_NOTICE) << "DHT: AnnounceTask done" << endl;
			done();
		}
		else if (answered_visited.size() > 50 || visited.size() > 200)
		{
			// don't let the task run forever
			Out(SYS_DHT | LOG_NOTICE) << "DHT: AnnounceTask done" << endl;
			done();
		}
	}

	bool AnnounceTask::takeItem(DBItem & item)
	{
		if (returned_items.empty())
			return false;

		item = returned_items.first();
		returned_items.pop_front();
		return true;
	}
}

