/*
 * libjingle
 * Copyright 2004--2005, Google Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef TALK_BASE_NETWORK_H_
#define TALK_BASE_NETWORK_H_

#include <deque>
#include <map>
#include <string>
#include <vector>

#include "talk/base/basictypes.h"
#include "talk/base/ipaddress.h"
#include "talk/base/messagehandler.h"
#include "talk/base/sigslot.h"

namespace talk_base {

class Network;
class NetworkSession;
class Thread;

// Generic network manager interface. It provides list of local
// networks.
class NetworkManager {
 public:
  typedef std::vector<Network*> NetworkList;

  NetworkManager();
  virtual ~NetworkManager();

  // Called when network list is updated.
  sigslot::signal0<> SignalNetworksChanged;

  // Indicates a failure when getting list of network interfaces.
  sigslot::signal0<> SignalError;

  // Start/Stop monitoring of network interfaces
  // list. SignalNetworksChanged or SignalError is emitted immidiately
  // after StartUpdating() is called. After that SignalNetworksChanged
  // is emitted wheneven list of networks changes.
  virtual void StartUpdating() = 0;
  virtual void StopUpdating() = 0;

  // Returns the current list of networks available on this machine.
  // UpdateNetworks() must be called before this method is called.
  // It makes sure that repeated calls return the same object for a
  // given network, so that quality is tracked appropriately. Does not
  // include ignored networks.
  virtual void GetNetworks(NetworkList* networks) const = 0;
};

// Base class for NetworkManager implementations.
class NetworkManagerBase : public NetworkManager {
 public:
  NetworkManagerBase();
  virtual ~NetworkManagerBase();

  virtual void GetNetworks(std::vector<Network*>* networks) const;

 protected:
  // Updates |networks_| with the networks listed in |list|. If
  // |network_map_| already has a Network object for a network listed
  // in the |list| then it is reused. Accept ownership of the Network
  // objects in the |list|. SignalNetworkListUpdated is emitted if
  // there is a change in network configuration or
  // |force_notification| is set to true.
  void MergeNetworkList(const NetworkList& list, bool force_notification);

 private:
  typedef std::map<std::string, Network*> NetworkMap;

  void DoUpdateNetworks();

  NetworkList networks_;
  NetworkMap networks_map_;
};

// Basic implementation of the NetworkManager interface that gets list
// of networks using OS APIs.
class BasicNetworkManager : public NetworkManagerBase,
                            public MessageHandler {
 public:
  BasicNetworkManager();
  virtual ~BasicNetworkManager();

  virtual void StartUpdating();
  virtual void StopUpdating();

  // Logs the available networks.
  static void DumpNetworks(bool include_ignored);

  // MessageHandler interface.
  virtual void OnMessage(Message* msg);

 protected:
  // Creates a network object for each network available on the machine.
  static bool CreateNetworks(bool include_ignored, NetworkList* networks);
  // Determines if a network should be ignored.
  static bool IsIgnoredNetwork(const Network& network);

 private:
  friend class NetworkTest;

  void DoUpdateNetworks();

  Thread* thread_;
  bool started_;
  bool sent_first_update_;
};

// Represents a Unix-type network interface, with a name and single address.
class Network {
 public:
  Network() : ip_(INADDR_ANY) {}

  Network(const std::string& name, const std::string& description,
          const IPAddress& ip);

  // Returns the index of this network.  This is considered the primary key
  // that identifies each network.
  const std::string& name() const { return name_; }

  // Returns the OS-assigned name for this network. This is useful for
  // debugging but should not be sent over the wire (for privacy reasons).
  const std::string& description() const { return description_; }

  // Identifies the current IP address used by this network.
  const IPAddress& ip() const { return ip_; }
  void set_ip(const IPAddress& ip) { ip_ = ip; }

  // Indicates whether this network should be ignored, perhaps because
  // the IP is 0, or the interface is one we know is invalid.
  bool ignored() const { return ignored_; }
  void set_ignored(bool ignored) { ignored_ = ignored; }

  // Debugging description of this network
  std::string ToString() const;

 private:
  typedef std::vector<NetworkSession*> SessionList;

  std::string name_;
  std::string description_;
  IPAddress ip_;
  bool ignored_;
  SessionList sessions_;
  double uniform_numerator_;
  double uniform_denominator_;
  double exponential_numerator_;
  double exponential_denominator_;

  friend class NetworkManager;
};

}  // namespace talk_base

#endif  // TALK_BASE_NETWORK_H_