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#include "bencodeparser.h"

#include "connectionmanager.h"

#include "torrentclient.h"

#include "torrentserver.h"

#include "trackerclient.h"

#include <QtCore>

TrackerClient::TrackerClient(TorrentClient *downloader, QObject *parent)

    : QObject(parent), torrentDownloader(downloader)

{

    length = 0;

    requestInterval = 5 * 60;

    requestIntervalTimer = -1;

    firstTrackerRequest = true;

    lastTrackerRequest = false;

    firstSeeding = true;

    connect(&http, SIGNAL(done(bool)), this, SLOT(httpRequestDone(bool)));

}

void TrackerClient::start(const MetaInfo &info)

{

    metaInfo = info;

    QTimer::singleShot(0, this, SLOT(fetchPeerList()));

    if (metaInfo.fileForm() == MetaInfo::SingleFileForm) {

        length = metaInfo.singleFile().length;

    } else {

        QList<MetaInfoMultiFile> files = metaInfo.multiFiles();

        for (int i = 0; i < files.size(); ++i)

            length += files.at(i).length;

    }

}

void TrackerClient::startSeeding()

{

    firstSeeding = true;

    fetchPeerList();

}

void TrackerClient::stop()

{

    lastTrackerRequest = true;

    http.abort();

    fetchPeerList();

}

void TrackerClient::timerEvent(QTimerEvent *event)

{

    if (event->timerId() == requestIntervalTimer) {

        if (http.state() == QHttp::Unconnected)

            fetchPeerList();

    } else {

        QObject::timerEvent(event);

    }

}

void TrackerClient::fetchPeerList()

{

    // Prepare connection details

    QString fullUrl = metaInfo.announceUrl();

    QUrl url(fullUrl);

    QString passkey = "?";

    if (fullUrl.contains("?passkey")) {

        passkey = metaInfo.announceUrl().mid(fullUrl.indexOf("?passkey"), -1);

        passkey += "&";

    }

    // Percent encode the hash

    QByteArray infoHash = torrentDownloader->infoHash();

    QString encodedSum;

    for (int i = 0; i < infoHash.size(); ++i) {

        encodedSum += '%';

        encodedSum += QString::number(infoHash[i], 16).right(2).rightJustified(2, '0');

    }

    bool seeding = (torrentDownloader->state() == TorrentClient::Seeding);

    QByteArray query;

    query += url.path().toLatin1();

    query += passkey;

    query += "info_hash=" + encodedSum;

    query += "&peer_id=" + ConnectionManager::instance()->clientId();

    query += "&port=" + QByteArray::number(TorrentServer::instance()->serverPort());

    query += "&compact=1";

    query += "&uploaded=" + QByteArray::number(torrentDownloader->uploadedBytes());

    if (!firstSeeding) {

        query += "&downloaded=0";

        query += "&left=0";

    } else {

        query += "&downloaded=" + QByteArray::number(

            torrentDownloader->downloadedBytes());

        int left = qMax<int>(0, metaInfo.totalSize() - torrentDownloader->downloadedBytes());

        query += "&left=" + QByteArray::number(seeding ? 0 : left);

    }

    if (seeding && firstSeeding) {

        query += "&event=completed";

        firstSeeding = false;

    } else if (firstTrackerRequest) {

        firstTrackerRequest = false;

        query += "&event=started";

    } else if(lastTrackerRequest) {

        query += "&event=stopped";

    }

    if (!trackerId.isEmpty())

        query += "&trackerid=" + trackerId;

    http.setHost(url.host(), url.port() == -1 ? 80 : url.port());

    if (!url.userName().isEmpty())

        http.setUser(url.userName(), url.password());

    http.get(query);

}

void TrackerClient::httpRequestDone(bool error)

{

    if (lastTrackerRequest) {

        emit stopped();

        return;

    }

    if (error) {

        emit connectionError(http.error());

        return;

    }

    QByteArray response = http.readAll();

    http.abort();

    BencodeParser parser;

    if (!parser.parse(response)) {

        qWarning("Error parsing bencode response from tracker: %s",

                 qPrintable(parser.errorString()));

        http.abort();

        return;

    }

    QMap<QByteArray, QVariant> dict = parser.dictionary();

    if (dict.contains("failure reason")) {

        // no other items are present

        emit failure(QString::fromUtf8(dict.value("failure reason").toByteArray()));

        return;

    }

    if (dict.contains("warning message")) {

        // continue processing

        emit warning(QString::fromUtf8(dict.value("warning message").toByteArray()));

    }

    if (dict.contains("tracker id")) {

        // store it

        trackerId = dict.value("tracker id").toByteArray();

    }

    if (dict.contains("interval")) {

        // Mandatory item

        if (requestIntervalTimer != -1)

            killTimer(requestIntervalTimer);

        requestIntervalTimer = startTimer(dict.value("interval").toInt() * 1000);

    }

    if (dict.contains("peers")) {

        // store it

        peers.clear();

        QVariant peerEntry = dict.value("peers");

        if (peerEntry.type() == QVariant::List) {

            QList<QVariant> peerTmp = peerEntry.toList();

            for (int i = 0; i < peerTmp.size(); ++i) {

                TorrentPeer tmp;

                QMap<QByteArray, QVariant> peer = qVariantValue<QMap<QByteArray, QVariant> >(peerTmp.at(i));

                tmp.id = QString::fromUtf8(peer.value("peer id").toByteArray());

                tmp.address.setAddress(QString::fromUtf8(peer.value("ip").toByteArray()));

                tmp.port = peer.value("port").toInt();

                peers << tmp;

            }

        } else {

            QByteArray peerTmp = peerEntry.toByteArray();

            for (int i = 0; i < peerTmp.size(); i += 6) {

                TorrentPeer tmp;

                uchar *data = (uchar *)peerTmp.constData() + i;

                tmp.port = (int(data[4]) << 8) + data[5];

                uint ipAddress = 0;

                ipAddress += uint(data[0]) << 24;

                ipAddress += uint(data[1]) << 16;

                ipAddress += uint(data[2]) << 8;

                ipAddress += uint(data[3]);

                tmp.address.setAddress(ipAddress);

                peers << tmp;

            }

        }

        emit peerListUpdated(peers);

    }

}