/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2006 Tatsuhiro Tsujikawa
 *
 * 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
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 * You must obey the GNU General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
 */
/* copyright --> */
#include "PeerInteractionCommand.h"

#include <algorithm>

#include "DownloadEngine.h"
#include "PeerInitiateConnectionCommand.h"
#include "DefaultBtInteractive.h"
#include "DlAbortEx.h"
#include "message.h"
#include "prefs.h"
#include "SocketCore.h"
#include "Option.h"
#include "DownloadContext.h"
#include "Peer.h"
#include "BtMessage.h"
#include "BtHandshakeMessage.h"
#include "BtRuntime.h"
#include "PeerStorage.h"
#include "DefaultBtMessageDispatcher.h"
#include "DefaultBtMessageReceiver.h"
#include "DefaultBtRequestFactory.h"
#include "DefaultBtMessageFactory.h"
#include "DefaultBtInteractive.h"
#include "PeerConnection.h"
#include "ExtensionMessageFactory.h"
#include "DHTRoutingTable.h"
#include "DHTTaskQueue.h"
#include "DHTTaskFactory.h"
#include "DHTNode.h"
#include "DHTRegistry.h"
#include "DHTPeerAnnounceStorage.h"
#include "DHTTokenTracker.h"
#include "DHTMessageDispatcher.h"
#include "DHTMessageReceiver.h"
#include "DHTMessageFactory.h"
#include "DHTMessageCallback.h"
#include "PieceStorage.h"
#include "RequestGroup.h"
#include "DefaultExtensionMessageFactory.h"
#include "RequestGroupMan.h"
#include "ExtensionMessageRegistry.h"
#include "bittorrent_helper.h"
#include "UTMetadataRequestFactory.h"
#include "UTMetadataRequestTracker.h"
#include "BtRegistry.h"

namespace aria2 {

PeerInteractionCommand::PeerInteractionCommand
(cuid_t cuid,
 RequestGroup* requestGroup,
 const std::shared_ptr<Peer>& p,
 DownloadEngine* e,
 const std::shared_ptr<BtRuntime>& btRuntime,
 const std::shared_ptr<PieceStorage>& pieceStorage,
 const std::shared_ptr<PeerStorage>& peerStorage,
 const std::shared_ptr<SocketCore>& s,
 Seq sequence,
 std::unique_ptr<PeerConnection> peerConnection)
  : PeerAbstractCommand{cuid, p, e, s},
    requestGroup_{requestGroup},
    btRuntime_{btRuntime},
    pieceStorage_{pieceStorage},
    peerStorage_{peerStorage},
    sequence_{sequence}
{
  // TODO move following bunch of processing to separate method, like init()
  if(sequence_ == INITIATOR_SEND_HANDSHAKE) {
    disableReadCheckSocket();
    setWriteCheckSocket(getSocket());
    setTimeout(getOption()->getAsInt(PREF_PEER_CONNECTION_TIMEOUT));
  }

  int family;
  unsigned char compact[COMPACT_LEN_IPV6];
  int compactlen = bittorrent::packcompact
    (compact, getPeer()->getIPAddress(), getPeer()->getPort());
  if(compactlen == COMPACT_LEN_IPV6) {
    family = AF_INET6;
  } else {
    family = AF_INET;
  }

  auto torrentAttrs =
    bittorrent::getTorrentAttrs(requestGroup_->getDownloadContext());
  bool metadataGetMode = torrentAttrs->metadata.empty();

  auto exMsgRegistry = make_unique<ExtensionMessageRegistry>();
  exMsgRegistry->setExtensionMessageID(ExtensionMessageRegistry::UT_PEX, 8);
  // http://www.bittorrent.org/beps/bep_0009.html
  exMsgRegistry->setExtensionMessageID(ExtensionMessageRegistry::UT_METADATA,
                                       9);

  auto extensionMessageFactory =
    make_unique<DefaultExtensionMessageFactory>(getPeer(),
                                                exMsgRegistry.get());
  auto extensionMessageFactoryPtr = extensionMessageFactory.get();
  extensionMessageFactory->setPeerStorage(peerStorage.get());
  extensionMessageFactory->setDownloadContext
    (requestGroup_->getDownloadContext().get());
  // PieceStorage will be set later.

  auto factory = make_unique<DefaultBtMessageFactory>();
  auto factoryPtr = factory.get();
  factory->setCuid(cuid);
  factory->setDownloadContext(requestGroup_->getDownloadContext().get());
  factory->setPieceStorage(pieceStorage.get());
  factory->setPeerStorage(peerStorage.get());
  factory->setExtensionMessageFactory(extensionMessageFactory.get());
  factory->setPeer(getPeer());
  if(family == AF_INET) {
    factory->setLocalNode(DHTRegistry::getData().localNode.get());
    factory->setRoutingTable(DHTRegistry::getData().routingTable.get());
    factory->setTaskQueue(DHTRegistry::getData().taskQueue.get());
    factory->setTaskFactory(DHTRegistry::getData().taskFactory.get());
  } else {
    factory->setLocalNode(DHTRegistry::getData6().localNode.get());
    factory->setRoutingTable(DHTRegistry::getData6().routingTable.get());
    factory->setTaskQueue(DHTRegistry::getData6().taskQueue.get());
    factory->setTaskFactory(DHTRegistry::getData6().taskFactory.get());
  }
  if(metadataGetMode) {
    factory->enableMetadataGetMode();
  }

  if(!peerConnection) {
    peerConnection = make_unique<PeerConnection>(cuid, getPeer(), getSocket());
  } else {
    if(sequence_ == RECEIVER_WAIT_HANDSHAKE &&
       peerConnection->getBufferLength() > 0) {
      setStatus(Command::STATUS_ONESHOT_REALTIME);
      getDownloadEngine()->setNoWait(true);
    }
  }
  // If the number of pieces gets bigger, the length of Bitfield
  // message payload exceeds the initial buffer capacity of
  // PeerConnection, which is MAX_PAYLOAD_LEN.  We expand buffer as
  // necessary so that PeerConnection can receive the Bitfield
  // message.
  size_t bitfieldPayloadSize =
    1+(requestGroup_->getDownloadContext()->getNumPieces()+7)/8;
  peerConnection->reserveBuffer(bitfieldPayloadSize);

  auto dispatcher = make_unique<DefaultBtMessageDispatcher>();
  auto dispatcherPtr = dispatcher.get();
  dispatcher->setCuid(cuid);
  dispatcher->setPeer(getPeer());
  dispatcher->setDownloadContext(requestGroup_->getDownloadContext().get());
  dispatcher->setRequestTimeout(getOption()->
                                   getAsInt(PREF_BT_REQUEST_TIMEOUT));
  dispatcher->setBtMessageFactory(factory.get());
  dispatcher->setRequestGroupMan
    (getDownloadEngine()->getRequestGroupMan().get());
  dispatcher->setPeerConnection(peerConnection.get());

  auto receiver = make_unique<DefaultBtMessageReceiver>();
  receiver->setDownloadContext(requestGroup_->getDownloadContext().get());
  receiver->setPeerConnection(peerConnection.get());
  receiver->setDispatcher(dispatcher.get());
  receiver->setBtMessageFactory(factory.get());

  auto reqFactory = make_unique<DefaultBtRequestFactory>();
  reqFactory->setPeer(getPeer());
  reqFactory->setPieceStorage(pieceStorage.get());
  reqFactory->setBtMessageDispatcher(dispatcher.get());
  reqFactory->setBtMessageFactory(factory.get());
  reqFactory->setCuid(cuid);

  // reverse depends
  factory->setBtMessageDispatcher(dispatcher.get());
  factory->setBtRequestFactory(reqFactory.get());
  factory->setPeerConnection(peerConnection.get());

  extensionMessageFactory->setBtMessageDispatcher(dispatcher.get());
  extensionMessageFactory->setBtMessageFactory(factory.get());

  getPeer()->allocateSessionResource
    (requestGroup_->getDownloadContext()->getPieceLength(),
     requestGroup_->getDownloadContext()->getTotalLength());
  getPeer()->setBtMessageDispatcher(dispatcher.get());

  auto btInteractive = make_unique<DefaultBtInteractive>
    (requestGroup_->getDownloadContext(), getPeer());
  btInteractive->setBtRuntime(btRuntime_);
  btInteractive->setPieceStorage(pieceStorage_);
  btInteractive->setPeerStorage(peerStorage); // Note: Not a member variable.
  btInteractive->setCuid(cuid);
  btInteractive->setBtMessageReceiver(std::move(receiver));
  btInteractive->setDispatcher(std::move(dispatcher));
  btInteractive->setBtRequestFactory(std::move(reqFactory));
  btInteractive->setPeerConnection(std::move(peerConnection));
  btInteractive->setExtensionMessageFactory
    (std::move(extensionMessageFactory));
  btInteractive->setExtensionMessageRegistry(std::move(exMsgRegistry));
  btInteractive->setKeepAliveInterval
    (getOption()->getAsInt(PREF_BT_KEEP_ALIVE_INTERVAL));
  btInteractive->setRequestGroupMan
    (getDownloadEngine()->getRequestGroupMan().get());
  btInteractive->setBtMessageFactory(std::move(factory));
  if((metadataGetMode || !torrentAttrs->privateTorrent) &&
     !getPeer()->isLocalPeer()) {
    if(getOption()->getAsBool(PREF_ENABLE_PEER_EXCHANGE)) {
      btInteractive->setUTPexEnabled(true);
    }
    if(family == AF_INET) {
      if(DHTRegistry::isInitialized()) {
        btInteractive->setDHTEnabled(true);
        factoryPtr->setDHTEnabled(true);
        btInteractive->setLocalNode(DHTRegistry::getData().localNode.get());
      }
    } else {
      if(DHTRegistry::isInitialized6()) {
        btInteractive->setDHTEnabled(true);
        factoryPtr->setDHTEnabled(true);
        btInteractive->setLocalNode(DHTRegistry::getData6().localNode.get());
      }
    }
  }

  if(metadataGetMode) {
    auto utMetadataRequestFactory = make_unique<UTMetadataRequestFactory>();
    auto utMetadataRequestTracker = make_unique<UTMetadataRequestTracker>();

    utMetadataRequestFactory->setCuid(cuid);
    utMetadataRequestFactory->setDownloadContext
      (requestGroup_->getDownloadContext().get());
    utMetadataRequestFactory->setBtMessageDispatcher(dispatcherPtr);
    utMetadataRequestFactory->setBtMessageFactory(factoryPtr);
    utMetadataRequestFactory->setPeer(getPeer());
    utMetadataRequestFactory->setUTMetadataRequestTracker
      (utMetadataRequestTracker.get());

    extensionMessageFactoryPtr->setUTMetadataRequestTracker
      (utMetadataRequestTracker.get());

    btInteractive->setUTMetadataRequestFactory
      (std::move(utMetadataRequestFactory));
    btInteractive->setUTMetadataRequestTracker
      (std::move(utMetadataRequestTracker));
  }

  btInteractive->setTcpPort(e->getBtRegistry()->getTcpPort());
  if(metadataGetMode) {
    btInteractive->enableMetadataGetMode();
  }
  btInteractive_ = std::move(btInteractive);

  btRuntime_->increaseConnections();
  requestGroup_->increaseNumCommand();
}

PeerInteractionCommand::~PeerInteractionCommand() {
  if(getPeer()->getCompletedLength() > 0) {
    pieceStorage_->subtractPieceStats(getPeer()->getBitfield(),
                                      getPeer()->getBitfieldLength());
  }
  getPeer()->releaseSessionResource();

  requestGroup_->decreaseNumCommand();
  btRuntime_->decreaseConnections();
}

bool PeerInteractionCommand::executeInternal() {
  setNoCheck(false);
  bool done = false;
  while(!done) {
    switch(sequence_) {
    case INITIATOR_SEND_HANDSHAKE:
      if(!getSocket()->isWritable(0)) {
        done = true;
        break;
      }
      disableWriteCheckSocket();
      setReadCheckSocket(getSocket());
      //socket->setBlockingMode();
      setTimeout(getOption()->getAsInt(PREF_BT_TIMEOUT));
      btInteractive_->initiateHandshake();
      sequence_ = INITIATOR_WAIT_HANDSHAKE;
      break;
    case INITIATOR_WAIT_HANDSHAKE: {
      if(btInteractive_->countPendingMessage() > 0) {
        btInteractive_->sendPendingMessage();
        if(btInteractive_->countPendingMessage() > 0) {
          done = true;
          break;
        }
      }
      auto handshakeMessage = btInteractive_->receiveHandshake();
      if(!handshakeMessage) {
        done = true;
        break;
      }
      btInteractive_->doPostHandshakeProcessing();
      sequence_ = WIRED;
      break;
    }
    case RECEIVER_WAIT_HANDSHAKE: {
      auto handshakeMessage = btInteractive_->receiveAndSendHandshake();
      if(!handshakeMessage) {
        done = true;
        break;
      }
      btInteractive_->doPostHandshakeProcessing();
      sequence_ = WIRED;
      break;
    }
    case WIRED:
      // See the comment for writable check below.
      disableWriteCheckSocket();

      btInteractive_->doInteractionProcessing();
      if(btInteractive_->countReceivedMessageInIteration() > 0) {
        updateKeepAlive();
      }
      if((getPeer()->amInterested() && !getPeer()->peerChoking()) ||
         btInteractive_->countOutstandingRequest() ||
         (getPeer()->peerInterested() && !getPeer()->amChoking())) {

        // Writable check to avoid slow seeding
        if(btInteractive_->isSendingMessageInProgress()) {
          setWriteCheckSocket(getSocket());
        }

        if(getDownloadEngine()->getRequestGroupMan()->
           doesOverallDownloadSpeedExceed() ||
           requestGroup_->doesDownloadSpeedExceed()) {
          disableReadCheckSocket();
          setNoCheck(true);
        } else {
          setReadCheckSocket(getSocket());
        }
      } else {
        disableReadCheckSocket();
      }
      done = true;
      break;
    }
  }
  if(btInteractive_->countPendingMessage() > 0) {
    setNoCheck(true);
  }
  addCommandSelf();
  return false;
}

// TODO this method removed when PeerBalancerCommand is implemented
bool PeerInteractionCommand::prepareForNextPeer(time_t wait) {
  if(peerStorage_->isPeerAvailable() && btRuntime_->lessThanEqMinPeers()) {
    cuid_t ncuid = getDownloadEngine()->newCUID();
    std::shared_ptr<Peer> peer = peerStorage_->checkoutPeer(ncuid);
    // sanity check
    if(peer) {
      auto command = make_unique<PeerInitiateConnectionCommand>
        (ncuid, requestGroup_, peer, getDownloadEngine(), btRuntime_);
      command->setPeerStorage(peerStorage_);
      command->setPieceStorage(pieceStorage_);
      getDownloadEngine()->addCommand(std::move(command));
    }
  }
  return true;
}

void PeerInteractionCommand::onAbort() {
  btInteractive_->cancelAllPiece();
  peerStorage_->returnPeer(getPeer());
}

void PeerInteractionCommand::onFailure(const Exception& err)
{
  requestGroup_->setLastErrorCode(err.getErrorCode());
  requestGroup_->setHaltRequested(true);
  getDownloadEngine()->setRefreshInterval(0);
}

bool PeerInteractionCommand::exitBeforeExecute()
{
  return btRuntime_->isHalt();
}

const std::shared_ptr<Option>& PeerInteractionCommand::getOption() const
{
  return requestGroup_->getOption();
}

} // namespace aria2
