/***************************************************************************
 *   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.             *
 ***************************************************************************/
#ifndef BTTRACKER_H
#define BTTRACKER_H

#include <QTimer>
#include <QUrl>

#include <util/sha1hash.h>
#include <interfaces/peersource.h>
#include <interfaces/trackerinterface.h>
#include <peer/peerid.h>
#include <ktorrent_export.h>

class QUrl;

namespace bt
{
/**
    Interface used by the Tracker to obtain the data it needs to know
    when announcing.
*/
class KTORRENT_EXPORT TrackerDataSource
{
public:
    virtual ~TrackerDataSource() {}

    virtual Uint64 bytesDownloaded() const = 0;
    virtual Uint64 bytesUploaded() const = 0;
    virtual Uint64 bytesLeft() const = 0;
    virtual const SHA1Hash & infoHash() const = 0;
    virtual bool isPartialSeed() const = 0;
};

/**
 * Base class for all tracker classes.
*/
class KTORRENT_EXPORT Tracker : public PeerSource, public TrackerInterface
{
    Q_OBJECT
public:
    Tracker(const QUrl &url, TrackerDataSource* tds, const PeerID & id, int tier);
    ~Tracker() override;

    /**
     * Set the custom IP
     * @param str
     */
    static void setCustomIP(const QString & str);

    /// get the tracker url
    QUrl trackerURL() const
    {
        return url;
    }

    /**
     * Delete the tracker in ms milliseconds, or when the stopDone signal is emitted.
     * @param ms Number of ms to wait
     */
    void timedDelete(int ms);

    /**
     * Get the number of failed attempts to reach a tracker.
     * @return The number of failed attempts
     */
    virtual Uint32 failureCount() const = 0;

    /**
     * Do a tracker scrape to get more accurate stats about a torrent.
     * Does nothing if the tracker does not support this.
     */
    virtual void scrape() = 0;

    /// Get the trackers tier
    int getTier() const
    {
        return tier;
    }

    /// Get the custom ip to use, null if none is set
    static QString getCustomIP();

    /// Handle a failure
    void handleFailure();
protected:
    /// Reset the tracker stats
    void resetTrackerStats();

    /// Calculates the bytes downloaded to send with the request
    Uint64 bytesDownloaded() const;

    /// Calculates the bytes uploaded to send with the request
    Uint64 bytesUploaded() const;

    /// Emit the failure signal, and set the error
    void failed(const QString & err);

public:
    void manualUpdate() override = 0;

Q_SIGNALS:
    /**
     * Emitted when an error happens.
     * @param failure_reason The reason why we couldn't reach the tracker
     */
    void requestFailed(const QString & failure_reason);

    /**
     * Emitted when a stop is done.
     */
    void stopDone();

    /**
     * Emitted when a request to the tracker succeeded
     */
    void requestOK();

    /**
     * A request to the tracker has been started.
     */
    void requestPending();

    /**
     * Emitted when a scrape has finished
     * */
    void scrapeDone();

protected:
    int tier;
    PeerID peer_id;
    TrackerDataSource* tds;
    Uint32 key;
    QTimer reannounce_timer;
    Uint64 bytes_downloaded_at_start;
    Uint64 bytes_uploaded_at_start;
};
}

#endif
