/*
 * Project: MoleCuilder
 * Description: creates and alters molecular systems
 * Copyright (C)  2011 University of Bonn. All rights reserved.
 * Please see the LICENSE file or "Copyright notice" in builder.cpp for details.
 */

/*
 * \file FragmentWorker.cpp
 *
 * This file strongly follows the Serialization example from the boost::asio
 * library (see client.cpp).
 *
 *  Created on: Nov 18, 2011
 *      Author: heber
 */

// include config.h
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

// boost asio needs specific operator new
#include <boost/asio.hpp>

#include "CodePatterns/MemDebug.hpp"

#include <boost/bind.hpp>
#include <iostream>
#include <vector>
#include "Connection.hpp" // Must come before boost/serialization headers.
#include <boost/serialization/vector.hpp>
#include "CodePatterns/Info.hpp"
#include "CodePatterns/Log.hpp"
#include "Jobs/FragmentJob.hpp"
#include "FragmentResult.hpp"
#include "FragmentWorker.hpp"

FragmentResult FragmentWorker::EmptyResult(JobId::NoJob, std::string("EmptyResult"));

/// Constructor starts the asynchronous connect operation.
FragmentWorker::FragmentWorker(
    boost::asio::io_service& io_service,
    const std::string& host,
    const std::string& service) :
  connection_(io_service),
  result(JobId::IllegalJob),
  Exitflag(OkFlag)
{
    Info info(__FUNCTION__);
  // Resolve the host name into an IP address.
  boost::asio::ip::tcp::resolver resolver(io_service);
  boost::asio::ip::tcp::resolver::query query(host, service);
  boost::asio::ip::tcp::resolver::iterator endpoint_iterator =
    resolver.resolve(query);
  boost::asio::ip::tcp::endpoint endpoint = *endpoint_iterator;

  // Start an asynchronous connect operation.
  std::cout << "Connecting to endpoint " << endpoint << std::endl;
  connection_.socket().async_connect(endpoint,
    boost::bind(&FragmentWorker::handle_connect, this,
      boost::asio::placeholders::error, ++endpoint_iterator));
}

/// Handle completion of a connect operation.
void FragmentWorker::handle_connect(const boost::system::error_code& e,
    boost::asio::ip::tcp::resolver::iterator endpoint_iterator)
{
  Info info(__FUNCTION__);
  if (!e)
  {
    // Successfully established connection. Start operation to read the list
    // of jobs. The connection::async_read() function will automatically
    // decode the data that is read from the underlying socket.
    LOG(1, "INFO: Receiving a job ...");
    connection_.async_read(job,
      boost::bind(&FragmentWorker::handle_ReceiveJob, this,
      boost::asio::placeholders::error));
  } else if (endpoint_iterator != boost::asio::ip::tcp::resolver::iterator()) {
    // Try the next endpoint.
    connection_.socket().close();
    boost::asio::ip::tcp::endpoint endpoint = *endpoint_iterator;
    connection_.socket().async_connect(endpoint,
      boost::bind(&FragmentWorker::handle_connect, this,
      boost::asio::placeholders::error, ++endpoint_iterator));
  } else {
    // An error occurred. Log it and return. Since we are not starting a new
    // operation the io_service will run out of work to do and the client will
    // exit.
    Exitflag = ErrorFlag;
    ELOG(1, e.message());
  }
}

/// Callback function when job has been received.
void FragmentWorker::handle_ReceiveJob(const boost::system::error_code& e)
{
  Info info(__FUNCTION__);
  if (!e)
  {
    LOG(1, "INFO: Received job #" << job->getId() << ".");
    if (job->getId() != JobId::NoJob) {
      // Print out the data that was received.
      std::cout << "Job output: " << job->outputfile << "\n";
      std::cout << "Job id: " << job->getId() << "\n";

      // do something .. right now: wait
      LOG(1, "INFO: Calculating job #" << job->getId() << " ...");
      FragmentResult result(job->Work());

      // write the result to the server
      LOG(1, "INFO: Sending result for job #" << job->getId() << " ...");
      connection_.async_write(result,
        boost::bind(&FragmentWorker::handle_SendResult, this,
        boost::asio::placeholders::error));

    } else {
      std::cout << "The server has no job for me." << std::endl;
      // send out empty result
      LOG(1, "INFO: Sending empty result ...");
      connection_.async_write(EmptyResult,
        boost::bind(&FragmentWorker::handle_SendResult, this,
        boost::asio::placeholders::error));
      Exitflag = NoJobFlag;
    }
  }
  else
  {
    // An error occurred.
    Exitflag = ErrorFlag;
    ELOG(1, e.message());
  }

  // Since we are not starting a new operation the io_service will run out of
  // work to do and the client will exit.
}

/// Callback function when result has been sent.
void FragmentWorker::handle_SendResult(const boost::system::error_code& e)
{
  Info info(__FUNCTION__);
  // Nothing to do.
  LOG(1, "INFO: Job #" << job->getId() << " calculated and sent.");
  // erase job
  job = FragmentJob::ptr(new FragmentJob());
}