/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
 * Copyright (c) 2014  Regents of the University of California,
 *                     Arizona Board of Regents,
 *                     Colorado State University,
 *                     University Pierre & Marie Curie, Sorbonne University,
 *                     Washington University in St. Louis,
 *                     Beijing Institute of Technology
 *
 * This file is part of NFD (Named Data Networking Forwarding Daemon).
 * See AUTHORS.md for complete list of NFD authors and contributors.
 *
 * NFD 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.
 *
 * NFD 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
 * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
 **/

#include "fib-manager.hpp"

#include "core/logger.hpp"
#include "table/fib.hpp"
#include "fw/forwarder.hpp"
#include "mgmt/internal-face.hpp"
#include "mgmt/app-face.hpp"

#include <ndn-cxx/encoding/tlv.hpp>

namespace nfd {

NFD_LOG_INIT("FibManager");

const Name FibManager::COMMAND_PREFIX = "/localhost/nfd/fib";

const size_t FibManager::COMMAND_UNSIGNED_NCOMPS =
  FibManager::COMMAND_PREFIX.size() +
  1 + // verb
  1;  // verb parameters

const size_t FibManager::COMMAND_SIGNED_NCOMPS =
  FibManager::COMMAND_UNSIGNED_NCOMPS +
  4; // (timestamp, nonce, signed info tlv, signature tlv)

const FibManager::SignedVerbAndProcessor FibManager::SIGNED_COMMAND_VERBS[] =
  {

    SignedVerbAndProcessor(
                           Name::Component("add-nexthop"),
                           &FibManager::addNextHop
                           ),

    SignedVerbAndProcessor(
                           Name::Component("remove-nexthop"),
                           &FibManager::removeNextHop
                           ),

  };

const FibManager::UnsignedVerbAndProcessor FibManager::UNSIGNED_COMMAND_VERBS[] =
  {
    UnsignedVerbAndProcessor(
                             Name::Component("list"),
                             &FibManager::listEntries
                             ),
  };

const Name FibManager::LIST_COMMAND_PREFIX("/localhost/nfd/fib/list");
const size_t FibManager::LIST_COMMAND_NCOMPS = LIST_COMMAND_PREFIX.size();


FibManager::FibManager(Fib& fib,
                       function<shared_ptr<Face>(FaceId)> getFace,
                       shared_ptr<InternalFace> face)
  : ManagerBase(face, FIB_PRIVILEGE)
  , m_managedFib(fib)
  , m_getFace(getFace)
  , m_fibEnumerationPublisher(fib, face, LIST_COMMAND_PREFIX)
  , m_signedVerbDispatch(SIGNED_COMMAND_VERBS,
                         SIGNED_COMMAND_VERBS +
                         (sizeof(SIGNED_COMMAND_VERBS) / sizeof(SignedVerbAndProcessor)))
  , m_unsignedVerbDispatch(UNSIGNED_COMMAND_VERBS,
                           UNSIGNED_COMMAND_VERBS +
                           (sizeof(UNSIGNED_COMMAND_VERBS) / sizeof(UnsignedVerbAndProcessor)))
{
  face->setInterestFilter("/localhost/nfd/fib",
                          bind(&FibManager::onFibRequest, this, _2));
}

FibManager::~FibManager()
{

}

void
FibManager::onFibRequest(const Interest& request)
{
  const Name& command = request.getName();
  const size_t commandNComps = command.size();
  const Name::Component& verb = command.get(COMMAND_PREFIX.size());

  UnsignedVerbDispatchTable::const_iterator unsignedVerbProcessor = m_unsignedVerbDispatch.find(verb);
  if (unsignedVerbProcessor != m_unsignedVerbDispatch.end())
    {
      NFD_LOG_DEBUG("command result: processing verb: " << verb);
      (unsignedVerbProcessor->second)(this, boost::cref(request));
    }
  else if (COMMAND_UNSIGNED_NCOMPS <= commandNComps &&
           commandNComps < COMMAND_SIGNED_NCOMPS)
    {
      NFD_LOG_DEBUG("command result: unsigned verb: " << command);
      sendResponse(command, 401, "Signature required");
    }
  else if (commandNComps < COMMAND_SIGNED_NCOMPS ||
           !COMMAND_PREFIX.isPrefixOf(command))
    {
      NFD_LOG_DEBUG("command result: malformed");
      sendResponse(command, 400, "Malformed command");
    }
  else
    {
      validate(request,
               bind(&FibManager::onValidatedFibRequest, this, _1),
               bind(&ManagerBase::onCommandValidationFailed, this, _1, _2));
    }
}

void
FibManager::onValidatedFibRequest(const shared_ptr<const Interest>& request)
{
  const Name& command = request->getName();
  const Name::Component& verb = command[COMMAND_PREFIX.size()];
  const Name::Component& parameterComponent = command[COMMAND_PREFIX.size() + 1];

  SignedVerbDispatchTable::const_iterator verbProcessor = m_signedVerbDispatch.find(verb);
  if (verbProcessor != m_signedVerbDispatch.end())
    {
      ControlParameters parameters;
      if (!extractParameters(parameterComponent, parameters) || !parameters.hasFaceId())
        {
          NFD_LOG_DEBUG("command result: malformed verb: " << verb);
          sendResponse(command, 400, "Malformed command");
          return;
        }

      if (parameters.getFaceId() == 0)
        {
          parameters.setFaceId(request->getIncomingFaceId());
        }

      NFD_LOG_DEBUG("command result: processing verb: " << verb);
      ControlResponse response;
      (verbProcessor->second)(this, parameters, response);
      sendResponse(command, response);
    }
  else
    {
      NFD_LOG_DEBUG("command result: unsupported verb: " << verb);
      sendResponse(command, 501, "Unsupported command");
    }
}

void
FibManager::addNextHop(ControlParameters& parameters,
                       ControlResponse& response)
{
  ndn::nfd::FibAddNextHopCommand command;

  if (!validateParameters(command, parameters))
    {
      NFD_LOG_DEBUG("add-nexthop result: FAIL reason: malformed");
      setResponse(response, 400, "Malformed command");
      return;
    }

  const Name& prefix = parameters.getName();
  FaceId faceId = parameters.getFaceId();
  uint64_t cost = parameters.getCost();

  NFD_LOG_TRACE("add-nexthop prefix: " << prefix
                << " faceid: " << faceId
                << " cost: " << cost);

  shared_ptr<Face> nextHopFace = m_getFace(faceId);
  if (static_cast<bool>(nextHopFace))
    {
      shared_ptr<fib::Entry> entry = m_managedFib.insert(prefix).first;

      entry->addNextHop(nextHopFace, cost);

      NFD_LOG_DEBUG("add-nexthop result: OK"
                    << " prefix:" << prefix
                    << " faceid: " << faceId
                    << " cost: " << cost);

      setResponse(response, 200, "Success", parameters.wireEncode());
    }
  else
    {
      NFD_LOG_DEBUG("add-nexthop result: FAIL reason: unknown-faceid: " << faceId);
      setResponse(response, 410, "Face not found");
    }
}

void
FibManager::removeNextHop(ControlParameters& parameters,
                          ControlResponse& response)
{
  ndn::nfd::FibRemoveNextHopCommand command;
  if (!validateParameters(command, parameters))
    {
      NFD_LOG_DEBUG("remove-nexthop result: FAIL reason: malformed");
      setResponse(response, 400, "Malformed command");
      return;
    }

  NFD_LOG_TRACE("remove-nexthop prefix: " << parameters.getName()
                << " faceid: " << parameters.getFaceId());

  shared_ptr<Face> faceToRemove = m_getFace(parameters.getFaceId());
  if (static_cast<bool>(faceToRemove))
    {
      shared_ptr<fib::Entry> entry = m_managedFib.findExactMatch(parameters.getName());
      if (static_cast<bool>(entry))
        {
          entry->removeNextHop(faceToRemove);
          NFD_LOG_DEBUG("remove-nexthop result: OK prefix: " << parameters.getName()
                        << " faceid: " << parameters.getFaceId());

          if (!entry->hasNextHops())
            {
              m_managedFib.erase(*entry);
            }
        }
      else
        {
          NFD_LOG_DEBUG("remove-nexthop result: OK, but entry for face id "
                        << parameters.getFaceId() << " not found");
        }
    }
  else
    {
      NFD_LOG_DEBUG("remove-nexthop result: OK, but face id "
                    << parameters.getFaceId() << " not found");
    }

  setResponse(response, 200, "Success", parameters.wireEncode());
}

void
FibManager::listEntries(const Interest& request)
{
  const Name& command = request.getName();
  const size_t commandNComps = command.size();

  if (commandNComps < LIST_COMMAND_NCOMPS ||
      !LIST_COMMAND_PREFIX.isPrefixOf(command))
    {
      NFD_LOG_DEBUG("command result: malformed");
      sendResponse(command, 400, "Malformed command");
      return;
    }

  m_fibEnumerationPublisher.publish();
}

} // namespace nfd