/* <!-- 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 --> */
#ifndef D_PEER_STORAGE_H
#define D_PEER_STORAGE_H

#include "common.h"

#include <deque>
#include <vector>
#include <set>
#include <memory>

#include "TransferStat.h"
#include "Command.h"
#include "a2functional.h"

namespace aria2 {

class Peer;

typedef std::set<std::shared_ptr<Peer>, RefLess<Peer>> PeerSet;

class PeerStorage {
public:
  virtual ~PeerStorage() = default;

  /**
   * Adds new peer to the internal peer list.
   * If the peer is added successfully, returns true. Otherwise returns false.
   */
  virtual bool addPeer(const std::shared_ptr<Peer>& peer) = 0;

  /**
   * Adds all peers in peers to internal peer list.
   */
  virtual void addPeer(const std::vector<std::shared_ptr<Peer>>& peers) = 0;

  /**
   * Adds new peer, and checkout it atomically.
   */
  virtual std::shared_ptr<Peer>
  addAndCheckoutPeer(const std::shared_ptr<Peer>& peer, cuid_t cuid) = 0;

  /**
   * Returns the number of peers, including used and unused ones.
   */
  virtual size_t countAllPeer() const = 0;

  /**
   * Returns internal dropped peer list.
   */
  virtual const std::deque<std::shared_ptr<Peer>>& getDroppedPeers() = 0;

  /**
   * Returns true if at least one unused peer exists.
   * Otherwise returns false.
   */
  virtual bool isPeerAvailable() = 0;

  /**
   * Returns used peer set.
   */
  virtual const PeerSet& getUsedPeers() = 0;

  /**
   * Returns true if peer with ipaddr should be ignored because, for
   * example, it sends bad data.
   */
  virtual bool isBadPeer(const std::string& ipaddr) = 0;

  /**
   * Adds peer with ipaddr in bad peer set.
   */
  virtual void addBadPeer(const std::string& ipaddr) = 0;

  /**
   * Moves first peer in unused peer list to used peer set and calls
   * Peer::usedBy(cuid). If there is no peer available, returns
   * std::shared_ptr<Peer>().
   */
  virtual std::shared_ptr<Peer> checkoutPeer(cuid_t cuid) = 0;

  /**
   * Tells PeerStorage object that peer is no longer used in the session.
   */
  virtual void returnPeer(const std::shared_ptr<Peer>& peer) = 0;

  virtual bool chokeRoundIntervalElapsed() = 0;

  virtual void executeChoke() = 0;
};

} // namespace aria2

#endif // D_PEER_STORAGE_H