/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
/*
 * Copyright (c) 2012-2022 University of California, Los Angeles
 *
 * This file is part of ChronoSync, synchronization library for distributed realtime
 * applications for NDN.
 *
 * ChronoSync 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.
 *
 * ChronoSync 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
 * ChronoSync, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "logic.hpp"
#include "detail/bzip2-helper.hpp"

#include "tests/boost-test.hpp"
#include "tests/identity-management-fixture.hpp"
#include "tests/unit-tests/dummy-forwarder.hpp"

#include <ndn-cxx/util/random.hpp>

namespace chronosync {
namespace test {

class Handler
{
public:
  Handler(ndn::Face& face, const Name& syncPrefix, const Name& userPrefix)
    : logic(face, syncPrefix, userPrefix,
            bind(&Handler::onUpdate, this, _1))
  {
  }

  void
  onUpdate(const std::vector<MissingDataInfo>& v)
  {
    for (size_t i = 0; i < v.size(); i++) {
      update(v[i].session, v[i].high, v[i].low);
    }
  }

  void
  update(const Name& p, const SeqNo& high, const SeqNo& low)
  {
    map[p] = high;
  }

  void
  updateSeqNo(const SeqNo& seqNo)
  {
    logic.updateSeqNo(seqNo);
  }

public:
  Logic logic;
  std::map<Name, SeqNo> map;
};

class LogicFixture : public ndn::tests::IdentityManagementTimeFixture
{
public:
  LogicFixture()
    : syncPrefix("/ndn/broadcast/sync")
    , fw(io, m_keyChain)
  {
    syncPrefix.appendVersion();
    userPrefix[0] = Name("/user0");
    userPrefix[1] = Name("/user1");
    userPrefix[2] = Name("/user2");
    userPrefix[3] = Name("/user3");
  }

public:
  Name syncPrefix;
  Name userPrefix[4];

  ndn::chronosync::DummyForwarder fw;
  // std::unique_ptr<DummyClientFace> faces[4];
  shared_ptr<Handler> handler[4];

  // size_t readInterestOffset[4];
  // size_t readDataOffset[4];
};

BOOST_FIXTURE_TEST_SUITE(LogicTests, LogicFixture)

static void
onUpdate(const std::vector<MissingDataInfo>&)
{
}

BOOST_AUTO_TEST_CASE(Constructor)
{
  Name syncPrefix("/ndn/broadcast/sync");
  Name userPrefix("/user");
  ndn::util::DummyClientFace face(io, {true, true});
  BOOST_REQUIRE_NO_THROW(Logic(face, syncPrefix, userPrefix, bind(onUpdate, _1)));
}

BOOST_AUTO_TEST_CASE(TwoBasic)
{
  handler[0] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[0]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[1] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[1]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[0]->updateSeqNo(1);

  advanceClocks(ndn::time::milliseconds(10), 100);

  BOOST_CHECK_EQUAL(handler[1]->map[handler[0]->logic.getSessionName()], 1);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[0]->updateSeqNo(2);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[0]->logic.getSessionName()], 2);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[1]->updateSeqNo(2);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[1]->logic.getSessionName()], 2);
}

BOOST_AUTO_TEST_CASE(ThreeBasic)
{
  handler[0] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[0]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[1] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[1]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[2] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[2]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[0]->updateSeqNo(1);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[0]->logic.getSessionName()], 1);
  BOOST_CHECK_EQUAL(handler[2]->map[handler[0]->logic.getSessionName()], 1);

  handler[1]->updateSeqNo(2);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[1]->logic.getSessionName()], 2);
  BOOST_CHECK_EQUAL(handler[2]->map[handler[1]->logic.getSessionName()], 2);

  handler[2]->updateSeqNo(4);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[2]->logic.getSessionName()], 4);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[2]->logic.getSessionName()], 4);
}

BOOST_AUTO_TEST_CASE(ResetRecover)
{
  handler[0] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[0]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[1] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[1]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[0]->updateSeqNo(1);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[0]->logic.getSessionName()], 1);

  handler[1]->updateSeqNo(2);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[1]->logic.getSessionName()], 2);

  advanceClocks(ndn::time::milliseconds(10), 100);
  handler[2] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[2]);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[2]->map[handler[0]->logic.getSessionName()], 1);
  BOOST_CHECK_EQUAL(handler[2]->map[handler[1]->logic.getSessionName()], 2);

  handler[2]->updateSeqNo(4);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[2]->logic.getSessionName()], 4);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[2]->logic.getSessionName()], 4);
}

BOOST_AUTO_TEST_CASE(RecoverConflict)
{
  handler[0] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[0]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[1] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[1]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[2] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[2]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[0]->updateSeqNo(1);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[0]->logic.getSessionName()], 1);
  BOOST_CHECK_EQUAL(handler[2]->map[handler[0]->logic.getSessionName()], 1);

  handler[1]->updateSeqNo(2);
  handler[2]->updateSeqNo(4);

  advanceClocks(ndn::time::milliseconds(50), 100);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[1]->logic.getSessionName()], 2);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[2]->logic.getSessionName()], 4);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[2]->logic.getSessionName()], 4);
  BOOST_CHECK_EQUAL(handler[2]->map[handler[1]->logic.getSessionName()], 2);
}

BOOST_AUTO_TEST_CASE(PartitionRecover)
{
  handler[0] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[0]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[1] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[1]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[2] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[2]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[3] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[3]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[0]->updateSeqNo(1);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[0]->logic.getSessionName()], 1);
  BOOST_CHECK_EQUAL(handler[2]->map[handler[0]->logic.getSessionName()], 1);
  BOOST_CHECK_EQUAL(handler[3]->map[handler[0]->logic.getSessionName()], 1);

  handler[2]->updateSeqNo(2);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[2]->logic.getSessionName()], 2);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[2]->logic.getSessionName()], 2);
  BOOST_CHECK_EQUAL(handler[3]->map[handler[2]->logic.getSessionName()], 2);

  // Network Partition start

  handler[1]->updateSeqNo(3);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[1]->logic.getSessionName()], 3);
  handler[2]->map[handler[1]->logic.getSessionName()] = 0;
  handler[3]->map[handler[1]->logic.getSessionName()] = 0;

  handler[3]->updateSeqNo(4);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[2]->map[handler[3]->logic.getSessionName()], 4);
  handler[0]->map[handler[3]->logic.getSessionName()] = 0;
  handler[1]->map[handler[3]->logic.getSessionName()] = 0;

  // Network partition over

  handler[0]->updateSeqNo(5);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[0]->logic.getSessionName()], 5);
  BOOST_CHECK_EQUAL(handler[2]->map[handler[0]->logic.getSessionName()], 5);
  BOOST_CHECK_EQUAL(handler[3]->map[handler[0]->logic.getSessionName()], 5);

  handler[2]->updateSeqNo(6);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[2]->logic.getSessionName()], 6);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[2]->logic.getSessionName()], 6);
  BOOST_CHECK_EQUAL(handler[3]->map[handler[2]->logic.getSessionName()], 6);
}

BOOST_AUTO_TEST_CASE(MultipleUserUnderOneLogic)
{
  handler[0] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[0]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[1] = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[2]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[0]->logic.addUserNode(userPrefix[1]);

  advanceClocks(ndn::time::milliseconds(10), 100);

  handler[0]->updateSeqNo(1);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[0]->logic.getSessionName()], 1);

  handler[0]->logic.updateSeqNo(2, userPrefix[1]);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[1]->map[handler[0]->logic.getSessionName(userPrefix[1])], 2);

  handler[1]->updateSeqNo(4);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(handler[0]->map[handler[1]->logic.getSessionName()], 4);

  handler[0]->logic.removeUserNode(userPrefix[0]);

  advanceClocks(ndn::time::milliseconds(50), 100);
  BOOST_CHECK_EQUAL(handler[1]->logic.getSessionNames().size(), 2);
}

BOOST_AUTO_TEST_CASE(CancelOutstandingEvents)
{
  auto h1 = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[0]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  auto h2 = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[1]);
  advanceClocks(ndn::time::milliseconds(10), 100);

  h1->updateSeqNo(1);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(h2->map[h1->logic.getSessionName()], 1);

  h2->updateSeqNo(2);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(h1->map[h2->logic.getSessionName()], 2);

  advanceClocks(ndn::time::milliseconds(10), 100);
  auto h3 = make_shared<Handler>(fw.addFace(), syncPrefix, userPrefix[2]);
  // Bringing this handler online later causes recovery interests to
  // be sent -- h3 has no record of any digests

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(h3->map[h1->logic.getSessionName()], 1);
  BOOST_CHECK_EQUAL(h3->map[h2->logic.getSessionName()], 2);

  h3->updateSeqNo(4);

  advanceClocks(ndn::time::milliseconds(10), 100);
  BOOST_CHECK_EQUAL(h2->map[h3->logic.getSessionName()], 4);
  BOOST_CHECK_EQUAL(h1->map[h3->logic.getSessionName()], 4);

  h1.reset();

  BOOST_CHECK_NE(io.poll(), 0); // some cancel events handlers are expected
  advanceClocks(ndn::time::minutes(1), 60); // should not crash

  h2.reset();
  h3.reset();

  BOOST_CHECK_NE(io.poll(), 0); // some cancel events handlers are expected
  fw.removeFaces();
  while (io.poll() != 0); // execute all other ready events that may have been scheduled

  steadyClock->advance(ndn::time::hours(1));
  systemClock->advance(ndn::time::hours(1));

  BOOST_CHECK_EQUAL(io.poll(), 0); // no delayed handlers are expected
  BOOST_CHECK_EQUAL(io.stopped(), true); // io_service expected to be stopped
}

BOOST_FIXTURE_TEST_CASE(TrimState, ndn::tests::IdentityManagementTimeFixture)
{
  Name syncPrefix("/ndn/broadcast/sync");
  Name userPrefix("/user");
  ndn::util::DummyClientFace face;
  Logic logic(face, syncPrefix, userPrefix, bind(onUpdate, _1));

  State state;
  for (size_t i = 0; i != 100; ++i) {
    state.update(Name("/to/trim").appendNumber(i), 42);
  }

  State partial;
  logic.trimState(partial, state, 1);
  BOOST_CHECK_EQUAL(partial.getLeaves().size(), 99);

  logic.trimState(partial, state, 100);
  BOOST_CHECK_EQUAL(partial.getLeaves().size(), 1);

  logic.trimState(partial, state, 101);
  BOOST_CHECK_EQUAL(partial.getLeaves().size(), 1);

  logic.trimState(partial, state, 42);
  BOOST_CHECK_EQUAL(partial.getLeaves().size(), 58);
}

BOOST_FIXTURE_TEST_CASE(VeryLargeState, ndn::tests::IdentityManagementTimeFixture)
{
  addIdentity("/bla");
  Name syncPrefix("/ndn/broadcast/sync");
  Name userPrefix("/user");
  ndn::util::DummyClientFace face;
  Logic logic(face, syncPrefix, userPrefix, bind(onUpdate, _1));

  State state;
  for (size_t i = 0; i < 50000 && bzip2::compress(reinterpret_cast<const char*>(state.wireEncode().data()),
                                                  state.wireEncode().size())->size() < ndn::MAX_NDN_PACKET_SIZE;
       i += 10) {
    Name prefix("/to/trim");
    prefix.appendNumber(i);
    for (size_t j = 0; j != 20; ++j) {
      prefix.appendNumber(ndn::random::generateWord32());
    }
    state.update(prefix, ndn::random::generateWord32());
  }
  BOOST_TEST_MESSAGE("Got state with " << state.getLeaves().size() << " leaves");

  auto data = logic.encodeSyncReply(userPrefix, "/fake/prefix/of/interest", state);
  BOOST_CHECK_LE(data.wireEncode().size(), ndn::MAX_NDN_PACKET_SIZE);
}

class MaxPacketCustomizationFixture
{
public:
  MaxPacketCustomizationFixture()
  {
    if (getenv("CHRONOSYNC_MAX_PACKET_SIZE") != nullptr) {
      oldSize = std::string(getenv("CHRONOSYNC_MAX_PACKET_SIZE"));
      unsetenv("CHRONOSYNC_MAX_PACKET_SIZE");
    }
  }

  ~MaxPacketCustomizationFixture()
  {
    unsetenv("CHRONOSYNC_MAX_PACKET_SIZE");
    if (oldSize) {
      setenv("CHRONOSYNC_MAX_PACKET_SIZE", oldSize->c_str(), 1);
    }
  }

private:
  ndn::optional<std::string> oldSize;
};

BOOST_FIXTURE_TEST_CASE(MaxPacketCustomization, MaxPacketCustomizationFixture)
{
  BOOST_CHECK_EQUAL(getMaxPacketLimit(), ndn::MAX_NDN_PACKET_SIZE);

  setenv("CHRONOSYNC_MAX_PACKET_SIZE", "1500", 1);
  BOOST_CHECK_EQUAL(getMaxPacketLimit(), 1500);

  setenv("CHRONOSYNC_MAX_PACKET_SIZE", ndn::to_string(ndn::MAX_NDN_PACKET_SIZE * 100).c_str(), 1);
  BOOST_CHECK_EQUAL(getMaxPacketLimit(), ndn::MAX_NDN_PACKET_SIZE);

  setenv("CHRONOSYNC_MAX_PACKET_SIZE", "1", 1);
  BOOST_CHECK_EQUAL(getMaxPacketLimit(), 500);
}

BOOST_AUTO_TEST_SUITE_END()

} // namespace test
} // namespace chronosync