/home/breidi/Dropbox/libtia/src/tia/network/control_connection.cpp

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/*
    This file is part of the TOBI Interface A (TiA) library.

    Commercial Usage
    Licensees holding valid Graz University of Technology Commercial
    licenses may use this file in accordance with the Graz University
    of Technology Commercial License Agreement provided with the
    Software or, alternatively, in accordance with the terms contained in
    a written agreement between you and Graz University of Technology.

    --------------------------------------------------

    GNU Lesser General Public License Usage
    Alternatively, this file may be used under the terms of the GNU Lesser
    General Public License version 3.0 as published by the Free Software
    Foundation and appearing in the file lgpl.txt included in the
    packaging of this file.  Please review the following information to
    ensure the GNU General Public License version 3.0 requirements will be
    met: http://www.gnu.org/copyleft/lgpl.html.

    In case of GNU Lesser General Public License Usage ,the TiA library
    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 Lesser General Public License
    along with the TiA library. If not, see <http://www.gnu.org/licenses/>.

    Copyright 2010 Graz University of Technology
    Contact: TiA@tobi-project.org
*/

// Boost
#include <boost/thread.hpp>
#include <boost/bind.hpp>
#include <boost/iostreams/stream.hpp>

// local
#include "tia/constants.h"

#include "tia-private/config/control_message_decoder.h"
#include "tia-private/config/control_message_encoder.h"

#include "tia-private/network/control_connection.h"
#include "tia-private/network/control_connection_server.h"
#include "tia-private/network/tcp_data_server.h"
#include "tia-private/network/udp_data_server.h"

namespace tia
{
using std::cout;
using std::cerr;
using std::endl;
using std::istream;

using boost::uint16_t;
using boost::uint32_t;

//-----------------------------------------------------------------------------

ControlConnection::ControlConnection(boost::asio::io_service& io_service,
    const ConnectionID& id,
    ControlConnectionServer& ctl_conn_server,
    const TCPConnection::pointer& tcp_conn)
      : io_service_(io_service),
      connection_id_(id),
      ctl_conn_server_(ctl_conn_server),
      tcp_connection_(tcp_conn),
      msg_encoder_(0),
      msg_decoder_(0),
      state_(State_Connected),
      connection_type_(GetDataConnectionMsg::Tcp)
{
  input_buffer_   = new boost::asio::streambuf;
  output_buffer_  = new boost::asio::streambuf;

  msg_encoder_ = new ControlMsgEncoderXML;
  msg_decoder_ = new ControlMsgDecoderXML;

  config_msg_ = boost::shared_ptr<ConfigMsg>(new ConfigMsg);
  ctl_conn_server.getConfig(*config_msg_);
}

//-----------------------------------------------------------------------------

ControlConnection::~ControlConnection()
{
  delete input_buffer_;
  delete output_buffer_;
  delete msg_encoder_;
  delete msg_decoder_;
}

//-----------------------------------------------------------------------------

void ControlConnection::start()
{
  tcp_connection_->socket().async_read_some(input_buffer_->prepare(MAX_DATA_SIZE),
      boost::bind(&ControlConnection::handle_read, shared_from_this(),
        boost::asio::placeholders::error,
        boost::asio::placeholders::bytes_transferred));
}

//-----------------------------------------------------------------------------

void ControlConnection::handle_read(const boost::system::error_code& error,
    std::size_t bytes_transferred)
{
  if (error)
  {
    if (error != boost::asio::error::eof)
    {
      cerr << "ControlConnection::handle_read [Client @" << connection_id_.second << "]: "
           << "closing connection -- Error: "
           << "--> " << error.message() << endl;
    }

    close();
    return;
  }

  input_buffer_->commit(bytes_transferred);

  istream instream(input_buffer_);

  msg_decoder_->setInputStream(&instream);

  boost::shared_ptr<ControlMsg> msg(msg_decoder_->decodeMsg());

  if (msg != 0)
  {
    switch (msg->msgType())
    {
      case ControlMsg::KeepAlive:
      {
        // TODO:
        break;
      }

      case ControlMsg::GetConfig:
      {
        cout << "Client @" << connection_id_.second
             << " requests config" << endl;

        sendMsg(*config_msg_);

        break;
      }

      case ControlMsg::GetDataConnection:
      {
        #ifdef DEBUG
          cout << "ControlConnection::handle_read [Client @" << connection_id_.second << "]: "
               << "Got Request 'GetDataConnection'" << endl;
        #endif

        if (state_ == State_TransmissionStarted)
        {
          cout << "ControlConnection::handle_read [Client @" << connection_id_.second << "]: "
               << "request 'GetDataConnection' failed - "
                  "not allowed while transmission is running" << endl;
          sendMsg(ReplyMsg::error());
          break;
        }

        if (connection_type_ == GetDataConnectionMsg::Tcp &&
            (state_ == State_AllocatedDataConnection ||
             state_ == State_TransmissionStopped       ))
        {
          ctl_conn_server_.tcpDataServer()->removeConnection(tcp_data_server_local_endpoint_);
        }

        boost::shared_ptr<GetDataConnectionMsg> get_data_conn_msg =
            boost::static_pointer_cast<GetDataConnectionMsg>(msg);

        connection_type_ = get_data_conn_msg->connectionType();

        DataConnectionMsg data_conn_msg;

        switch (connection_type_)
        {
          case GetDataConnectionMsg::Udp:
          {
            boost::asio::ip::udp::endpoint endpoint =
                ctl_conn_server_.udpDataServer()->destination();

            data_conn_msg.setPort(endpoint.port());

            cout << "Client @" << connection_id_.second
                 << " requests UDP data broadcast - allocating port "
                 << endpoint.port() << endl;
            break;
          }
          case GetDataConnectionMsg::Tcp:
          {
            tcp_data_server_local_endpoint_ = ctl_conn_server_.tcpDataServer()->addConnection();

            data_conn_msg.setPort(tcp_data_server_local_endpoint_.port());

            cout << "Client @" << connection_id_.second
                 << " requests TCP data connection - allocating port "
                 << tcp_data_server_local_endpoint_.port() << endl;

            break;
          }
        }

        if (state_ == State_Connected)
        {
          state_ = State_AllocatedDataConnection;
        }

        sendMsg(data_conn_msg);

        break;
      }

      case ControlMsg::StartTransmission:
      {
        cout << "Client @" << connection_id_.second
             << " requests data transmission start." << endl;

        if (state_ == State_Connected)
        {
          cout << "ControlConnection::handle_read [Client @" << connection_id_.second << "]: "
               << "request 'StartTransmission' failed - cannot start transmission before "
               << "data connection has been requested." << endl;

          sendMsg(ReplyMsg::error());
          break;
        }

        if (state_ == State_TransmissionStarted)
        {
          cout << "ControlConnection::handle_read [Client @" << connection_id_.second << "]: "
               << "request 'StartTransmission' failed - transmission is already running." << endl;

          sendMsg(ReplyMsg::error());
          break;
        }

        switch (connection_type_)
        {
          case GetDataConnectionMsg::Udp:
          {
            ctl_conn_server_.udpDataServer()->incClientCount();
            break;
          }
          case GetDataConnectionMsg::Tcp:
          {
            ctl_conn_server_.tcpDataServer()->enableTransmission(
                tcp_data_server_local_endpoint_, true);
            break;
          }
        }

        sendMsg(ReplyMsg::ok());

        state_ = State_TransmissionStarted;

        break;
      }

      case ControlMsg::StopTransmission:
      {
        cout << "Client @" << connection_id_.second
             << " requests data transmission stop." << endl;

        if (state_ == State_Connected)
        {
          cout << "ControlConnection::handle_read [Client @" << connection_id_.second << "]: "
               << "request 'StopTransmission' failed - cannot stop transmission if  "
               << "data connection has never been requested." << endl;

          sendMsg(ReplyMsg::error());
          break;
        }

        if (state_ == State_TransmissionStopped)
        {
          cout << "ControlConnection::handle_read [Client @" << connection_id_.second << "]: "
               << "request 'StopTransmission' failed - transmission is not running."
               << endl;
          sendMsg(ReplyMsg::error());
          break;
        }

        switch (connection_type_)
        {
          case GetDataConnectionMsg::Udp:
          {
            ctl_conn_server_.udpDataServer()->decClientCount();
            break;
          }
          case GetDataConnectionMsg::Tcp:
          {
            ctl_conn_server_.tcpDataServer()->enableTransmission(
                tcp_data_server_local_endpoint_, false);
            break;
          }
        }

        sendMsg(ReplyMsg::ok());

        state_ = State_TransmissionStopped;

        break;
      }

      default:
      {
        cout << "ControlConnection::handle_read [Client @" << connection_id_.second << "]: "
             << "unsupported request type (" << msg->msgType() << ") - ignoring request."
             << endl;
        break;
      }
    }

    // Read next message
    tcp_connection_->socket().async_read_some(input_buffer_->prepare(MAX_DATA_SIZE),
        boost::bind(&ControlConnection::handle_read, shared_from_this(),
          boost::asio::placeholders::error,
          boost::asio::placeholders::bytes_transferred));
  }
  else
    close ();
}

//-----------------------------------------------------------------------------

void ControlConnection::sendMsg(const ControlMsg& msg)
{
#ifdef DEBUG
  cout << "ControlConnection::sendMsg [Client @" << connection_id_.second << "]" << endl;
#endif

  std::ostream ostream(output_buffer_);
  msg.writeMsg(*msg_encoder_, ostream);

#ifdef DEBUG
  {
    cout << "ControlConnection::sendMsg [Client @" << connection_id_.second << "]" << endl;
    cout << "-----------" << endl;

    std::stringstream sstream;
    msg.writeMsg(*msg_encoder_, sstream);

    cout << sstream.str() << endl;

    cout << "-----------" << endl;
  }
#endif

  boost::asio::async_write(tcp_connection_->socket(), output_buffer_->data(),
      boost::bind(&ControlConnection::handle_write, shared_from_this(),
        boost::asio::placeholders::error, output_buffer_->size()));
}

//-----------------------------------------------------------------------------

void ControlConnection::close()
{

#ifdef DEBUG
  cout << "ControlConnection::close [Client @" << connection_id_.second << "]" << endl;
#endif

  // Initiate graceful connection closure.
  boost::system::error_code ignored_ec;
  tcp_connection_->socket().shutdown(boost::asio::ip::tcp::socket::shutdown_both, ignored_ec);

  tcp_connection_->socket().close();

  switch (connection_type_)
  {
    case GetDataConnectionMsg::Udp:
    {
      if (state_ == State_TransmissionStarted) ctl_conn_server_.udpDataServer()->decClientCount();
      break;
    }
    case GetDataConnectionMsg::Tcp:
    {
      if (state_ == State_AllocatedDataConnection ||
          state_ == State_TransmissionStarted     ||
          state_ == State_TransmissionStopped)
      {
        ctl_conn_server_.tcpDataServer()->removeConnection(tcp_data_server_local_endpoint_);
      }

      break;
    }
  }

  state_ = State_ConnectionClosed;

  ctl_conn_server_.clientHasDisconnected(connection_id_);
}

//-----------------------------------------------------------------------------

void ControlConnection::handle_write(const boost::system::error_code& error,
                                     std::size_t bytes_transferred)
{
#ifdef DEBUG
  cout << "ControlConnection::handle_write [Client @" << connection_id_.second << "]" << endl;
#endif

  if (error)
  {
    cerr << "ControlConnection::handle_write [Client@" << connection_id_.second << "]: "
         << "error during write - closing connection."
         << "--> " << error.message() << endl;
    close();

    // No new asynchronous operations are started. This means that all shared_ptr
    // references to the connection object will disappear and the object will be
    // destroyed automatically after this handler returns. The connection class's
    // destructor closes the socket.
    return;
  }

  // Consume whole input sequence
  output_buffer_->consume(bytes_transferred);
}

//-----------------------------------------------------------------------------

} // Namespace tobiss

// End Of File