/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2016-2017, Regents of the University of California,
 *                          Colorado State University,
 *                          University Pierre & Marie Curie, Sorbonne University.
 *
 * This file is part of ndn-tools (Named Data Networking Essential Tools).
 * See AUTHORS.md for complete list of ndn-tools authors and contributors.
 *
 * ndn-tools 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 3 of the License, or (at your option) any later version.
 *
 * ndn-tools 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
 * ndn-tools, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
 *
 * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
 *
 * @author Wentao Shang
 * @author Steve DiBenedetto
 * @author Andrea Tosatto
 * @author Davide Pesavento
 * @author Weiwei Liu
 * @author Klaus Schneider
 */

#include "aimd-statistics-collector.hpp"
#include "aimd-rtt-estimator.hpp"
#include "consumer.hpp"
#include "discover-version-fixed.hpp"
#include "discover-version-iterative.hpp"
#include "pipeline-interests-aimd.hpp"
#include "pipeline-interests-fixed-window.hpp"
#include "options.hpp"
#include "core/version.hpp"

#include <fstream>
#include <ndn-cxx/security/validator-null.hpp>

namespace ndn {
namespace chunks {

static int
main(int argc, char** argv)
{
  std::string programName(argv[0]);
  Options options;
  std::string discoverType("iterative");
  std::string pipelineType("fixed");
  size_t maxPipelineSize(1);
  int maxRetriesAfterVersionFound(0);
  int64_t discoveryTimeoutMs(300);
  std::string uri;

  // congestion control parameters, CWA refers to conservative window adaptation,
  // i.e. only reduce window size at most once per RTT
  bool disableCwa(false), resetCwndToInit(false);
  double aiStep(1.0), mdCoef(0.5), alpha(0.125), beta(0.25),
         minRto(200.0), maxRto(4000.0);
  int initCwnd(1), initSsthresh(std::numeric_limits<int>::max()), k(4);
  std::string cwndPath, rttPath;

  namespace po = boost::program_options;
  po::options_description basicDesc("Basic Options");
  basicDesc.add_options()
    ("help,h",      "print this help message and exit")
    ("discover-version,d", po::value<std::string>(&discoverType)->default_value(discoverType),
                            "version discovery algorithm to use; valid values are: 'fixed', 'iterative'")
    ("pipeline-type,p", po::value<std::string>(&pipelineType)->default_value(pipelineType),
                         "type of Interest pipeline to use; valid values are: 'fixed', 'aimd'")
    ("fresh,f",     po::bool_switch(&options.mustBeFresh), "only return fresh content")
    ("lifetime,l",  po::value<int64_t>()->default_value(options.interestLifetime.count()),
                    "lifetime of expressed Interests, in milliseconds")
    ("retries,r",   po::value<int>(&options.maxRetriesOnTimeoutOrNack)->default_value(options.maxRetriesOnTimeoutOrNack),
                    "maximum number of retries in case of Nack or timeout (-1 = no limit)")
    ("verbose,v",   po::bool_switch(&options.isVerbose), "turn on verbose output")
    ("version,V",   "print program version and exit")
    ;

  po::options_description iterDiscoveryDesc("Iterative version discovery options");
  iterDiscoveryDesc.add_options()
    ("retries-iterative,i", po::value<int>(&maxRetriesAfterVersionFound)->default_value(maxRetriesAfterVersionFound),
                            "number of timeouts that have to occur in order to confirm a discovered Data "
                            "version as the latest one")
    ("discovery-timeout,t", po::value<int64_t>(&discoveryTimeoutMs)->default_value(discoveryTimeoutMs),
                            "discovery timeout (in milliseconds)")
    ;

  po::options_description fixedPipeDesc("Fixed pipeline options");
  fixedPipeDesc.add_options()
    ("pipeline-size,s", po::value<size_t>(&maxPipelineSize)->default_value(maxPipelineSize),
                        "size of the Interest pipeline")
    ;

  po::options_description aimdPipeDesc("AIMD pipeline options");
  aimdPipeDesc.add_options()
    ("aimd-debug-cwnd", po::value<std::string>(&cwndPath),
                        "log file for AIMD cwnd statistics")
    ("aimd-debug-rtt", po::value<std::string>(&rttPath),
                       "log file for AIMD rtt statistics")
    ("aimd-disable-cwa", po::bool_switch(&disableCwa),
                         "disable Conservative Window Adaptation, "
                         "i.e. reduce window on each timeout (instead of at most once per RTT)")
    ("aimd-reset-cwnd-to-init", po::bool_switch(&resetCwndToInit),
                                "reset cwnd to initial cwnd when loss event occurs, default is "
                                "resetting to ssthresh")
    ("aimd-initial-cwnd",       po::value<int>(&initCwnd)->default_value(initCwnd),
                                "initial cwnd")
    ("aimd-initial-ssthresh",   po::value<int>(&initSsthresh),
                                "initial slow start threshold (defaults to infinity)")
    ("aimd-aistep",    po::value<double>(&aiStep)->default_value(aiStep),
                       "additive-increase step")
    ("aimd-mdcoef",    po::value<double>(&mdCoef)->default_value(mdCoef),
                       "multiplicative-decrease coefficient")
    ("aimd-rto-alpha", po::value<double>(&alpha)->default_value(alpha),
                       "alpha value for rto calculation")
    ("aimd-rto-beta",  po::value<double>(&beta)->default_value(beta),
                       "beta value for rto calculation")
    ("aimd-rto-k",     po::value<int>(&k)->default_value(k),
                       "k value for rto calculation")
    ("aimd-rto-min",   po::value<double>(&minRto)->default_value(minRto),
                       "min rto value in milliseconds")
    ("aimd-rto-max",   po::value<double>(&maxRto)->default_value(maxRto),
                       "max rto value in milliseconds")
    ;

  po::options_description visibleDesc;
  visibleDesc.add(basicDesc).add(iterDiscoveryDesc).add(fixedPipeDesc).add(aimdPipeDesc);

  po::options_description hiddenDesc;
  hiddenDesc.add_options()
    ("ndn-name,n", po::value<std::string>(&uri), "NDN name of the requested content");

  po::positional_options_description p;
  p.add("ndn-name", -1);

  po::options_description optDesc;
  optDesc.add(visibleDesc).add(hiddenDesc);

  po::variables_map vm;
  try {
    po::store(po::command_line_parser(argc, argv).options(optDesc).positional(p).run(), vm);
    po::notify(vm);
  }
  catch (const po::error& e) {
    std::cerr << "ERROR: " << e.what() << std::endl;
    return 2;
  }
  catch (const boost::bad_any_cast& e) {
    std::cerr << "ERROR: " << e.what() << std::endl;
    return 2;
  }

  if (vm.count("help") > 0) {
    std::cout << "Usage: " << programName << " [options] ndn:/name" << std::endl;
    std::cout << visibleDesc;
    return 0;
  }

  if (vm.count("version") > 0) {
    std::cout << "ndncatchunks " << tools::VERSION << std::endl;
    return 0;
  }

  if (vm.count("ndn-name") == 0) {
    std::cerr << "Usage: " << programName << " [options] ndn:/name" << std::endl;
    std::cerr << visibleDesc;
    return 2;
  }

  Name prefix(uri);
  if (discoverType == "fixed" && (prefix.empty() || !prefix[-1].isVersion())) {
    std::cerr << "ERROR: The specified name must contain a version component when using "
                 "fixed version discovery" << std::endl;
    return 2;
  }

  if (maxPipelineSize < 1 || maxPipelineSize > 1024) {
    std::cerr << "ERROR: pipeline size must be between 1 and 1024" << std::endl;
    return 2;
  }

  if (options.maxRetriesOnTimeoutOrNack < -1 || options.maxRetriesOnTimeoutOrNack > 1024) {
    std::cerr << "ERROR: retries value must be between -1 and 1024" << std::endl;
    return 2;
  }

  if (maxRetriesAfterVersionFound < 0 || maxRetriesAfterVersionFound > 1024) {
    std::cerr << "ERROR: retries iterative value must be between 0 and 1024" << std::endl;
    return 2;
  }

  if (discoveryTimeoutMs < 0) {
    std::cerr << "ERROR: timeout cannot be negative" << std::endl;
    return 2;
  }

  if (vm["lifetime"].as<int64_t>() < 0) {
    std::cerr << "ERROR: lifetime cannot be negative" << std::endl;
    return 2;
  }

  options.interestLifetime = time::milliseconds(vm["lifetime"].as<int64_t>());

  try {
    Face face;

    unique_ptr<DiscoverVersion> discover;
    if (discoverType == "fixed") {
      discover = make_unique<DiscoverVersionFixed>(prefix, face, options);
    }
    else if (discoverType == "iterative") {
      DiscoverVersionIterative::Options optionsIterative(options);
      optionsIterative.maxRetriesAfterVersionFound = maxRetriesAfterVersionFound;
      optionsIterative.discoveryTimeout = time::milliseconds(discoveryTimeoutMs);
      discover = make_unique<DiscoverVersionIterative>(prefix, face, optionsIterative);
    }
    else {
      std::cerr << "ERROR: discover version type not valid" << std::endl;
      return 2;
    }

    unique_ptr<PipelineInterests> pipeline;
    unique_ptr<aimd::StatisticsCollector> statsCollector;
    unique_ptr<aimd::RttEstimator> rttEstimator;
    std::ofstream statsFileCwnd;
    std::ofstream statsFileRtt;

    if (pipelineType == "fixed") {
      PipelineInterestsFixedWindow::Options optionsPipeline(options);
      optionsPipeline.maxPipelineSize = maxPipelineSize;
      pipeline = make_unique<PipelineInterestsFixedWindow>(face, optionsPipeline);
    }
    else if (pipelineType == "aimd") {
      aimd::RttEstimator::Options optionsRttEst;
      optionsRttEst.isVerbose = options.isVerbose;
      optionsRttEst.alpha = alpha;
      optionsRttEst.beta = beta;
      optionsRttEst.k = k;
      optionsRttEst.minRto = aimd::Milliseconds(minRto);
      optionsRttEst.maxRto = aimd::Milliseconds(maxRto);

      rttEstimator = make_unique<aimd::RttEstimator>(optionsRttEst);

      PipelineInterestsAimd::Options optionsPipeline(options);
      optionsPipeline.disableCwa = disableCwa;
      optionsPipeline.resetCwndToInit = resetCwndToInit;
      optionsPipeline.initCwnd = static_cast<double>(initCwnd);
      optionsPipeline.initSsthresh = static_cast<double>(initSsthresh);
      optionsPipeline.aiStep = aiStep;
      optionsPipeline.mdCoef = mdCoef;

      auto aimdPipeline = make_unique<PipelineInterestsAimd>(face, *rttEstimator, optionsPipeline);

      if (!cwndPath.empty() || !rttPath.empty()) {
        if (!cwndPath.empty()) {
          statsFileCwnd.open(cwndPath);
          if (statsFileCwnd.fail()) {
            std::cerr << "ERROR: failed to open " << cwndPath << std::endl;
            return 4;
          }
        }
        if (!rttPath.empty()) {
          statsFileRtt.open(rttPath);
          if (statsFileRtt.fail()) {
            std::cerr << "ERROR: failed to open " << rttPath << std::endl;
            return 4;
          }
        }
        statsCollector = make_unique<aimd::StatisticsCollector>(*aimdPipeline, *rttEstimator,
                                                                statsFileCwnd, statsFileRtt);
      }

      pipeline = std::move(aimdPipeline);
    }
    else {
      std::cerr << "ERROR: Interest pipeline type not valid" << std::endl;
      return 2;
    }

    Consumer consumer(security::v2::getAcceptAllValidator(), options.isVerbose);

    BOOST_ASSERT(discover != nullptr);
    BOOST_ASSERT(pipeline != nullptr);
    consumer.run(std::move(discover), std::move(pipeline));
    face.processEvents();
  }
  catch (const Consumer::ApplicationNackError& e) {
    std::cerr << "ERROR: " << e.what() << std::endl;
    return 3;
  }
  catch (const std::exception& e) {
    std::cerr << "ERROR: " << e.what() << std::endl;
    return 1;
  }

  return 0;
}

} // namespace chunks
} // namespace ndn

int
main(int argc, char** argv)
{
  return ndn::chunks::main(argc, argv);
}