/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
 * Copyright (c) 2014-2016,  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,
 *                           The University of Memphis.
 *
 * 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 "table/fib.hpp"
#include "table/pit.hpp"
#include "table/measurements.hpp"
#include "tests/daemon/face/dummy-face.hpp"

#include "tests/test-common.hpp"

namespace nfd {
namespace fib {
namespace tests {

using namespace nfd::tests;

BOOST_AUTO_TEST_SUITE(Table)
BOOST_FIXTURE_TEST_SUITE(TestFib, BaseFixture)

BOOST_AUTO_TEST_CASE(FibEntry)
{
  Name prefix("ndn:/pxWhfFza");
  shared_ptr<Face> face1 = make_shared<DummyFace>();
  shared_ptr<Face> face2 = make_shared<DummyFace>();

  Entry entry(prefix);
  BOOST_CHECK_EQUAL(entry.getPrefix(), prefix);

  // []
  BOOST_CHECK_EQUAL(entry.getNextHops().size(), 0);

  entry.addNextHop(*face1, 20);
  // [(face1,20)]
  BOOST_CHECK_EQUAL(entry.getNextHops().size(), 1);
  BOOST_CHECK_EQUAL(&entry.getNextHops().begin()->getFace(), face1.get());
  BOOST_CHECK_EQUAL(entry.getNextHops().begin()->getCost(), 20);

  entry.addNextHop(*face1, 30);
  // [(face1,30)]
  BOOST_CHECK_EQUAL(entry.getNextHops().size(), 1);
  BOOST_CHECK_EQUAL(&entry.getNextHops().begin()->getFace(), face1.get());
  BOOST_CHECK_EQUAL(entry.getNextHops().begin()->getCost(), 30);

  entry.addNextHop(*face2, 40);
  // [(face1,30), (face2,40)]
  BOOST_CHECK_EQUAL(entry.getNextHops().size(), 2);
  {
    NextHopList::const_iterator it = entry.getNextHops().begin();
    BOOST_REQUIRE(it != entry.getNextHops().end());
    BOOST_CHECK_EQUAL(&it->getFace(), face1.get());
    BOOST_CHECK_EQUAL(it->getCost(), 30);

    ++it;
    BOOST_REQUIRE(it != entry.getNextHops().end());
    BOOST_CHECK_EQUAL(&it->getFace(), face2.get());
    BOOST_CHECK_EQUAL(it->getCost(), 40);

    ++it;
    BOOST_CHECK(it == entry.getNextHops().end());
  }

  entry.addNextHop(*face2, 10);
  // [(face2,10), (face1,30)]
  BOOST_CHECK_EQUAL(entry.getNextHops().size(), 2);
  {
    NextHopList::const_iterator it = entry.getNextHops().begin();
    BOOST_REQUIRE(it != entry.getNextHops().end());
    BOOST_CHECK_EQUAL(&it->getFace(), face2.get());
    BOOST_CHECK_EQUAL(it->getCost(), 10);

    ++it;
    BOOST_REQUIRE(it != entry.getNextHops().end());
    BOOST_CHECK_EQUAL(&it->getFace(), face1.get());
    BOOST_CHECK_EQUAL(it->getCost(), 30);

    ++it;
    BOOST_CHECK(it == entry.getNextHops().end());
  }

  entry.removeNextHop(*face1);
  // [(face2,10)]
  BOOST_CHECK_EQUAL(entry.getNextHops().size(), 1);
  BOOST_CHECK_EQUAL(entry.getNextHops().begin()->getFace().getId(), face2->getId());
  BOOST_CHECK_EQUAL(entry.getNextHops().begin()->getCost(), 10);

  entry.removeNextHop(*face1);
  // [(face2,10)]
  BOOST_CHECK_EQUAL(entry.getNextHops().size(), 1);
  BOOST_CHECK_EQUAL(entry.getNextHops().begin()->getFace().getId(), face2->getId());
  BOOST_CHECK_EQUAL(entry.getNextHops().begin()->getCost(), 10);

  entry.removeNextHop(*face2);
  // []
  BOOST_CHECK_EQUAL(entry.getNextHops().size(), 0);

  entry.removeNextHop(*face2);
  // []
  BOOST_CHECK_EQUAL(entry.getNextHops().size(), 0);
}

BOOST_AUTO_TEST_CASE(Insert_LongestPrefixMatch)
{
  NameTree nameTree;
  Fib fib(nameTree);

  // []
  BOOST_CHECK_EQUAL(fib.size(), 0);
  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch("/A").getPrefix(), "/"); // the empty entry

  std::pair<Entry*, bool> insertRes = fib.insert("/");
  BOOST_CHECK_EQUAL(insertRes.second, true);
  BOOST_REQUIRE(insertRes.first != nullptr);
  BOOST_CHECK_EQUAL(insertRes.first->getPrefix(), "/");
  // ['/']
  BOOST_CHECK_EQUAL(fib.size(), 1);

  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch("/A").getPrefix(), "/");

  insertRes = fib.insert("/A");
  BOOST_CHECK_EQUAL(insertRes.second, true);
  BOOST_REQUIRE(insertRes.first != nullptr);
  BOOST_CHECK_EQUAL(insertRes.first->getPrefix(), "/A");
  // ['/', '/A']
  BOOST_CHECK_EQUAL(fib.size(), 2);

  insertRes = fib.insert("/A");
  BOOST_CHECK_EQUAL(insertRes.second, false);
  BOOST_REQUIRE(insertRes.first != nullptr);
  BOOST_CHECK_EQUAL(insertRes.first->getPrefix(), "/A");
  // ['/', '/A']
  BOOST_CHECK_EQUAL(fib.size(), 2);

  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch("/A").getPrefix(), "/A");

  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch("/A/B/C/D").getPrefix(), "/A");

  insertRes = fib.insert("/A/B/C");
  BOOST_CHECK_EQUAL(insertRes.second, true);
  BOOST_REQUIRE(insertRes.first != nullptr);
  BOOST_CHECK_EQUAL(insertRes.first->getPrefix(), "/A/B/C");
  // ['/', '/A', '/A/B/C']
  BOOST_CHECK_EQUAL(fib.size(), 3);

  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch("/A").getPrefix(), "/A");
  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch("/A/B").getPrefix(), "/A");
  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch("/A/B/C/D").getPrefix(), "/A/B/C");
  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch("/E").getPrefix(), "/");
}

BOOST_AUTO_TEST_CASE(LongestPrefixMatchWithPitEntry)
{
  NameTree nameTree;
  Fib fib(nameTree);

  shared_ptr<Data> dataABC = makeData("/A/B/C");
  Name fullNameABC = dataABC->getFullName();
  shared_ptr<Data> dataADE = makeData("/A/D/E");
  Name fullNameADE = dataADE->getFullName();
  fib.insert("/A");
  fib.insert(fullNameABC);

  Pit pit(nameTree);
  shared_ptr<Interest> interestAB = makeInterest("/A/B");
  shared_ptr<pit::Entry> pitAB = pit.insert(*interestAB).first;
  shared_ptr<Interest> interestABC = makeInterest(fullNameABC);
  shared_ptr<pit::Entry> pitABC = pit.insert(*interestABC).first;
  shared_ptr<Interest> interestADE = makeInterest(fullNameADE);
  shared_ptr<pit::Entry> pitADE = pit.insert(*interestADE).first;

  size_t nNameTreeEntriesBefore = nameTree.size();

  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch(*pitAB).getPrefix(), "/A");
  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch(*pitABC).getPrefix(), fullNameABC);
  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch(*pitADE).getPrefix(), "/A");

  BOOST_CHECK_EQUAL(nameTree.size(), nNameTreeEntriesBefore);
}

BOOST_AUTO_TEST_CASE(LongestPrefixMatchWithMeasurementsEntry)
{
  NameTree nameTree;
  Fib fib(nameTree);

  fib.insert("/A");
  fib.insert("/A/B/C");

  Measurements measurements(nameTree);
  shared_ptr<measurements::Entry> mAB = measurements.get("/A/B");
  shared_ptr<measurements::Entry> mABCD = measurements.get("/A/B/C/D");

  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch(*mAB).getPrefix(), "/A");
  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch(*mABCD).getPrefix(), "/A/B/C");
}

BOOST_AUTO_TEST_CASE(RemoveNextHopFromAllEntries)
{
  shared_ptr<Face> face1 = make_shared<DummyFace>();
  shared_ptr<Face> face2 = make_shared<DummyFace>();

  NameTree nameTree;
  Fib fib(nameTree);
  // {}

  Entry* entryA = fib.insert("/A").first;
  entryA->addNextHop(*face1, 0);
  entryA->addNextHop(*face2, 0);
  // {'/A':[1,2]}

  Entry* entryB = fib.insert("/B").first;
  entryB->addNextHop(*face1, 0);
  // {'/A':[1,2], '/B':[1]}
  BOOST_CHECK_EQUAL(fib.size(), 2);

  Entry* entryC = fib.insert("/C").first;
  entryC->addNextHop(*face2, 1);
  // {'/A':[1,2], '/B':[1], '/C':[2]}
  BOOST_CHECK_EQUAL(fib.size(), 3);

  Entry* entryB1 = fib.insert("/B/1").first;
  entryB1->addNextHop(*face1, 0);
  // {'/A':[1,2], '/B':[1], '/B/1':[1], '/C':[2]}
  BOOST_CHECK_EQUAL(fib.size(), 4);

  Entry* entryB12 = fib.insert("/B/1/2").first;
  entryB12->addNextHop(*face1, 0);
  // {'/A':[1,2], '/B':[1], '/B/1':[1], '/B/1/2':[1], '/C':[2]}
  BOOST_CHECK_EQUAL(fib.size(), 5);

  /////////////

  fib.removeNextHopFromAllEntries(*face1);
  // {'/A':[2], '/C':[2]}
  BOOST_CHECK_EQUAL(fib.size(), 2);

  const Entry& foundA = fib.findLongestPrefixMatch("/A");
  BOOST_CHECK_EQUAL(foundA.getPrefix(), "/A");
  const NextHopList& nexthopsA = foundA.getNextHops();
  BOOST_CHECK_EQUAL(nexthopsA.size(), 1);
  BOOST_CHECK_EQUAL(&nexthopsA.begin()->getFace(), face2.get());

  BOOST_CHECK_EQUAL(fib.findLongestPrefixMatch("/B").getPrefix(), "/");
}

BOOST_AUTO_TEST_CASE(RemoveNextHopFromManyEntries)
{
  NameTree nameTree(16);
  Fib fib(nameTree);
  shared_ptr<Face> face1 = make_shared<DummyFace>();

  for (uint64_t i = 0; i < 300; ++i) {
    Entry* entry = fib.insert(Name("/P").appendVersion(i)).first;
    entry->addNextHop(*face1, 0);
  }
  BOOST_CHECK_EQUAL(fib.size(), 300);

  fib.removeNextHopFromAllEntries(*face1);
  BOOST_CHECK_EQUAL(fib.size(), 0);
}

void
validateFindExactMatch(Fib& fib, const Name& target)
{
  const Entry* entry = fib.findExactMatch(target);
  BOOST_REQUIRE_MESSAGE(entry != nullptr, "No entry found for " << target);
  BOOST_CHECK_EQUAL(entry->getPrefix(), target);
}

void
validateNoExactMatch(Fib& fib, const Name& target)
{
  const Entry* entry = fib.findExactMatch(target);
  BOOST_CHECK_MESSAGE(entry == nullptr,
                      "Found unexpected entry for " << target);
}

BOOST_AUTO_TEST_CASE(ExactMatch)
{
  NameTree nameTree;
  Fib fib(nameTree);
  fib.insert("/A");
  fib.insert("/A/B");
  fib.insert("/A/B/C");

  validateFindExactMatch(fib, "/A");
  validateFindExactMatch(fib, "/A/B");
  validateFindExactMatch(fib, "/A/B/C");

  validateNoExactMatch(fib, "/");
  validateNoExactMatch(fib, "/does/not/exist");
}

BOOST_AUTO_TEST_CASE(ExactMatchGap)
{
  NameTree nameTree;
  Fib fib(nameTree);
  fib.insert("/X");
  fib.insert("/X/Y/Z");

  validateNoExactMatch(fib, "/X/Y");
}

BOOST_AUTO_TEST_CASE(ExactMatchEmpty)
{
  NameTree nameTree;
  Fib fib(nameTree);
  validateNoExactMatch(fib, "/");
  validateNoExactMatch(fib, "/nothing/here");
}

void
validateErase(Fib& fib, const Name& target)
{
  fib.erase(target);

  const Entry* entry = fib.findExactMatch(target);
  BOOST_CHECK_MESSAGE(entry == nullptr, "Found \"removed\" entry for " << target);
}

BOOST_AUTO_TEST_CASE(Erase)
{
  NameTree nameTree;
  Fib fib(nameTree);
  fib.insert("/");
  fib.insert("/A");
  fib.insert("/A/B");
  fib.insert("/A/B/C");

  // check if we remove the right thing and leave
  // everything else alone

  validateErase(fib, "/A/B");
  validateFindExactMatch(fib, "/A");
  validateFindExactMatch(fib, "/A/B/C");
  validateFindExactMatch(fib, "/");

  validateErase(fib, "/A/B/C");
  validateFindExactMatch(fib, "/A");
  validateFindExactMatch(fib, "/");

  validateErase(fib, "/A");
  validateFindExactMatch(fib, "/");

  validateErase(fib, "/");
  validateNoExactMatch(fib, "/");
}

BOOST_AUTO_TEST_CASE(EraseGap)
{
  NameTree nameTree;
  Fib fib(nameTree);
  fib.insert("/X");
  fib.insert("/X/Y/Z");

  fib.erase("/X/Y"); //should do nothing
  validateFindExactMatch(fib, "/X");
  validateFindExactMatch(fib, "/X/Y/Z");
}

BOOST_AUTO_TEST_CASE(EraseEmpty)
{
  NameTree nameTree;
  Fib fib(nameTree);

  BOOST_CHECK_NO_THROW(fib.erase("/does/not/exist"));
  validateErase(fib, "/");
  BOOST_CHECK_NO_THROW(fib.erase("/still/does/not/exist"));
}

BOOST_AUTO_TEST_CASE(EraseNameTreeEntry)
{
  NameTree nameTree;
  Fib fib(nameTree);
  size_t nNameTreeEntriesBefore = nameTree.size();

  fib.insert("/A/B/C");
  fib.erase("/A/B/C");
  BOOST_CHECK_EQUAL(nameTree.size(), nNameTreeEntriesBefore);
}

BOOST_AUTO_TEST_CASE(Iterator)
{
  NameTree nameTree;
  Fib fib(nameTree);
  Name nameA("/A");
  Name nameAB("/A/B");
  Name nameABC("/A/B/C");
  Name nameRoot("/");

  fib.insert(nameA);
  fib.insert(nameAB);
  fib.insert(nameABC);
  fib.insert(nameRoot);

  std::set<Name> expected{nameA, nameAB, nameABC, nameRoot};

  for (Fib::const_iterator it = fib.begin(); it != fib.end(); it++) {
    bool isInSet = expected.find(it->getPrefix()) != expected.end();
    BOOST_CHECK(isInSet);
    expected.erase(it->getPrefix());
  }

  BOOST_CHECK_EQUAL(expected.size(), 0);
}

BOOST_AUTO_TEST_SUITE_END() // TestFib
BOOST_AUTO_TEST_SUITE_END() // Table

} // namespace tests
} // namespace fib
} // namespace nfd