/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
 * Copyright (C) 2014 Named Data Networking Project
 * See COPYING for copyright and distribution information.
 */

#ifndef NFD_FACE_UDP_FACTORY_HPP
#define NFD_FACE_UDP_FACTORY_HPP

#include "protocol-factory.hpp"
#include "udp-channel.hpp"
#include "multicast-udp-face.hpp"


namespace nfd {

// @todo The multicast support for ipv6 must be implemented

class UdpFactory : public ProtocolFactory
{
public:
  /**
   * \brief Exception of UdpFactory
   */
  struct Error : public ProtocolFactory::Error
  {
    Error(const std::string& what) : ProtocolFactory::Error(what) {}
  };
  
  explicit
  UdpFactory(const std::string& defaultPort = "6363");

  /**
   * \brief Create UDP-based channel using udp::Endpoint
   *
   * udp::Endpoint is really an alias for boost::asio::ip::udp::endpoint.
   *
   * If this method called twice with the same endpoint, only one channel
   * will be created.  The second call will just retrieve the existing
   * channel.
   *
   * If a multicast face is already active on the same local endpoint,
   * the creation fails and an exception is thrown
   *
   * Once a face is created, if it doesn't send/receive anything for
   * a period of time equal to timeout, it will be destroyed
   * @todo this funcionality has to be implemented
   *
   * \returns always a valid pointer to a UdpChannel object, an exception
   *          is thrown if it cannot be created.
   *
   * \throws UdpFactory::Error
   *
   * \see http://www.boost.org/doc/libs/1_42_0/doc/html/boost_asio/reference/ip__udp/endpoint.html
   *      for details on ways to create udp::Endpoint
   */
  shared_ptr<UdpChannel>
  createChannel(const udp::Endpoint& localEndpoint,
         const time::Duration& timeout = time::seconds(600));

  /**
   * \brief Create UDP-based channel using specified host and port number
   *
   * This method will attempt to resolve the provided host and port numbers
   * and will throw UdpFactory::Error when channel cannot be created.
   *
   * Note that this call will **BLOCK** until resolution is done or failed.
   *
   * If localHost is a IPv6 address of a specific device, it must be in the form: 
   * ip address%interface name
   * Example: fe80::5e96:9dff:fe7d:9c8d%en1
   * Otherwise, you can use :: 
   *
   * Once a face is created, if it doesn't send/receive anything for
   * a period of time equal to timeout, it will be destroyed
   * @todo this funcionality has to be implemented
   *
   * \throws UdpChannel::Error if the bind on the socket fails
   * \throws UdpFactory::Error
   */
  shared_ptr<UdpChannel>
  createChannel(const std::string& localHost,
         const std::string& localPort,
         const time::Duration& timeout = time::seconds(600));

  /**
   * \brief Create MulticastUdpFace using udp::Endpoint
   *
   * udp::Endpoint is really an alias for boost::asio::ip::udp::endpoint.
   *
   * The face will join the multicast group
   *
   * If this method called twice with the same endpoint and group, only one face
   * will be created.  The second call will just retrieve the existing
   * channel.
   *
   * If an unicast face is already active on the same local NIC and port, the
   * creation fails and an exception is thrown
   *
   * \returns always a valid pointer to a MulticastUdpFace object, an exception
   *          is thrown if it cannot be created. 
   *
   * \throws UdpFactory::Error
   *
   * \see http://www.boost.org/doc/libs/1_42_0/doc/html/boost_asio/reference/ip__udp/endpoint.html
   *      for details on ways to create udp::Endpoint
   */
  shared_ptr<MulticastUdpFace>
  createMulticastFace(const udp::Endpoint& localEndpoint,
                      const udp::Endpoint& multicastEndpoint);
  
  shared_ptr<MulticastUdpFace>
  createMulticastFace(const std::string& localIp,
                      const std::string& multicastIp,
                      const std::string& multicastPort);
  
  // from Factory
  virtual void
  createFace(const FaceUri& uri,
             const FaceCreatedCallback& onCreated,
             const FaceConnectFailedCallback& onConnectFailed);

protected:
  typedef std::map< udp::Endpoint, shared_ptr<MulticastUdpFace> > MulticastFaceMap;

  /**
   * \brief Keeps tracking of the MulticastUdpFace created
   */
  MulticastFaceMap m_multicastFaces;

private:
  void
  afterFaceFailed(udp::Endpoint& endpoint);
    
  /**
   * \brief Look up UdpChannel using specified local endpoint
   *
   * \returns shared pointer to the existing UdpChannel object
   *          or empty shared pointer when such channel does not exist
   *
   * \throws never
   */
  shared_ptr<UdpChannel>
  findChannel(const udp::Endpoint& localEndpoint);
  
  
  /**
   * \brief Look up multicast UdpFace using specified local endpoint
   *
   * \returns shared pointer to the existing multicast MulticastUdpFace object
   *          or empty shared pointer when such face does not exist
   *
   * \throws never
   */
  shared_ptr<MulticastUdpFace>
  findMulticastFace(const udp::Endpoint& localEndpoint);
  
  void
  continueCreateFaceAfterResolve(const udp::Endpoint& endpoint,
                                 const FaceCreatedCallback& onCreated,
                                 const FaceConnectFailedCallback& onConnectFailed);
  
  typedef std::map< udp::Endpoint, shared_ptr<UdpChannel> > ChannelMap;
  ChannelMap m_channels;
  
  std::string m_defaultPort;
};

} // namespace nfd

#endif // NFD_FACE_UDP_FACTORY_HPP