/**
  * Block/unblock topics
  * $Id$
  * $HeadURL$
  * $Author$
  * Created by Christian Ehrlicher, SLSE, 2018-01-15
  */

#include "handler_locked_topics.h"
#include "main_handler.h"
#include "handler_operator.h"
#include <DDS/FTS/generic_fts_impl.h>
#include <DDS/DTS/generic_dts_impl.h>
#include <DDS/Core/function_reply_object.h>

#include <QMutableHashIterator>


namespace OperatorManagement
{
HandlerLockedTopics::HandlerLockedTopics(MainHandler &mainHandler,
                                         QObject *parent)
  : QObject(parent)
  , m_mainHandler(mainHandler)
  , m_logger(getLogger("HandlerLockedTopics"))
{}

bool HandlerLockedTopics::init()
{
  m_db = m_mainHandler.db();
  auto ddsConnector = m_mainHandler.dds()->ddsConnector();
  if (!m_db || !ddsConnector)
    return false;

  ddsConnector->initSubscriber();

  {
    m_ftsTryLockEntity.reset(ddsConnector->createFTS<FTS::TryLockEntity>());
    const auto cb = [this](const rti::core::SampleIdentity & cookie, const Core::TryLockEntityRequest & request)
    {
      this->onTryLockEntityRequest(cookie, request);
    };
    m_ftsTryLockEntity->setSubscriberCallback(cb);
  }

  {
    m_ftsTryUnlockEntity.reset(ddsConnector->createFTS<FTS::TryUnlockEntity>());
    const auto cb = [this](const rti::core::SampleIdentity & cookie, const Core::TryUnlockEntityRequest & request)
    {
      this->onTryUnlockEntityRequest(cookie, request);
    };
    m_ftsTryUnlockEntity->setSubscriberCallback(cb);
  }

  auto cbDatabase = [this](const Database::OpmLockedTopics & data)
  {
    DEBUG_LOG(m_logger) << "Locked topic from db: " << data.exerciseId.toInt() << ", " << data.workstationId
                        << ", " << data.operatorId << data.entityTypeName;
    m_lockedTopics.insert(Core::key(data.entityId, data.exerciseId.isNull() ? 0 : data.exerciseId.toInt(), data.entityTypeName), data);
  };
  m_db->selectByLocked(cbDatabase, true);

  m_dtsLockedEntity.reset(ddsConnector->createDTS<DTS::LockedEntityImpl>());

  return true;
}

static bool needsUnlock(int operatorId, int workstationId, const Database::OpmLockedTopics &data)
{
  // same operator -> check if other workstation
  if (operatorId == data.operatorId)
  {
    return true;    // NT, 18.09.20 remove. From former (crashed) session, independent from workstation

//    if (workstationId == 0) // logout
//      return true;
//    if (workstationId != data.workstationId)  // logged in on another workstation
//      return true;
//    return false;

  }
  // other operator on a workstation previously locked by another operator -> unlock
  if (workstationId != 0 && workstationId == data.workstationId)
    return true;

  return false;
}

void HandlerLockedTopics::operatorLoggedInOut(int operatorId, int workstationId)
{
  // check if there are stale locks (e.g. by crashing client) - then remove all of them - if there are any

  DEBUG_LOG(m_logger) << "operatorLoggedInOut: " << workstationId << ", " << operatorId;

  // Ueberall wurden - ohne erase wohlgemerkt - mutable Iteratoren verwendet. Nur hier - wo erase verwendet wurde - nicht! :')
  QMutableHashIterator<Core::key, Database::OpmLockedTopics> it(m_lockedTopics);

  while (it.hasNext())
  {
    const auto lockedTopic = it.next().value();

    DEBUG_LOG(m_logger) << "check if unlock: id=" << lockedTopic.id
                        << ", exId=" << lockedTopic.exerciseId.toInt()
                        << ", wsId=" << lockedTopic.workstationId
                        << ", opId=" << lockedTopic.operatorId;
    if (!needsUnlock(operatorId, workstationId, lockedTopic))
    {
      continue;
    }

    DEBUG_LOG(m_logger) << "Unlocking topic: id=" << lockedTopic.id
                        << ", exId=" << lockedTopic.exerciseId.toInt()
                        << ", wsId=" << lockedTopic.workstationId
                        << ", opId=" << lockedTopic.operatorId;
    unlockInDb(lockedTopic);
    removeLockedEntity(lockedTopic.id);
    it.remove();
  }
}

void HandlerLockedTopics::onTryLockEntityRequest(const rti::core::SampleIdentity &cookie,
                                                 const Core::TryLockEntityRequest &request)
{
  if (m_logger.isDebugEnabled())
    dumpLockedTopics(__LINE__);

  auto ret = tryLock(request);
  if (!ret.errorString().empty())
  {
    WARNING_LOG(m_logger) << Core::FunctionReplyObject(ret.FunctionReply::id(), ret.errorString(), ret.errorParams()).translated() << " - " << request;
  }
  else if (ret.alreadyLocked())
  {
    WARNING_LOG(m_logger) << "onTryLockEntityRequest failed because the topic was already locked by ws " << ret.alreadyLocked().get().workstationName() << " and op " << ret.alreadyLocked().get().operatorName() <<  " - " << request;
  }
  m_ftsTryLockEntity->sendReply(cookie, ret);

  if (m_logger.isDebugEnabled())
    dumpLockedTopics(__LINE__);
}

Core::TryLockEntityReply lockErrorReply(const long topicId, const std::string &msg)
{
  return Core::TryLockEntityReply(-1, msg, { std::to_string(topicId) }, {}, {});
}

Core::TryLockEntityReply lockAlreadyLockedReply(const std::string &ws, const QString &op)
{
  return Core::TryLockEntityReply(-1, {}, {},{}, Core::LockEntityError(ws, op.toStdString()));
}

Core::TryLockEntityReply lockSuccessReply(const Database::OpmLockedTopics &dbStruct)
{
  return Core::TryLockEntityReply(dbStruct.id, {}, {}, {}, {});
}

Core::TryLockEntityReply HandlerLockedTopics::tryLock(const Core::TryLockEntityRequest &request)
{
  DEBUG_LOG(m_logger) << "tryLock : " << request;

  const auto topicId = request.entityId();

  const Core::key k(request.entityId(), request.exerciseId(), QString::fromStdString(request.entityTypeName()));
  Database::OpmLockedTopics dbStruct(toDb(request));
  auto it = m_lockedTopics.constFind(k);
  if (it == m_lockedTopics.constEnd())
  {
    // noch nicht vorhanden -> add
    dbStruct.timeStampLock = QDateTime::currentMSecsSinceEpoch();
    if (!m_db->insert(dbStruct))
    {
      return lockErrorReply(topicId, tr_lts("dds", "Failed to lock element with id %1 in database"));
    }

    m_lockedTopics.insert(k, dbStruct);
    Core::LockedEntity lckEntity(request.operatorId(), request.workstationId(),
                                 request.exerciseId(), request.entityId(),
                                 request.entityTypeName(),  dbStruct.id);
    publishLockedEntity(lckEntity);
    return lockSuccessReply(dbStruct);
  }

  // NOTE: don't check if there is already a lock for that exact same key (same op, ws, topic, ...): Reason: Szenario: in 2 sitmaps "Exercise Purpose" aufschalten... 2. Dlg muss gelockt werden !!!

  // already locked by another user
  const Database::OpmLockedTopics &data = *it;
  const auto opName = m_mainHandler.getHandlerOperator()->operatorNameById(data.operatorId);
  const auto wsName = m_mainHandler.dds()->dtcAsm()->asset(data.workstationId).name();

  return lockAlreadyLockedReply(wsName, opName);
}

//Core::TryLockEntityReply HandlerLockedTopics::tryLockModify(const Core::TryLockEntityRequest &request)
//{
//  DEBUG_LOG(m_logger) << "tryLockModify: " << request;

//  const auto lockEntityId = request.id();

//  // requestedKey == new key
//  const Core::key requestedKey(request.entityId(), request.exerciseId(), QString::fromStdString(request.entityTypeName()));

//  // is requested topic already locked?
//  {
//    auto it = m_lockedTopics.constFind(requestedKey);
//    if (it != m_lockedTopics.constEnd())
//    {
//      // vorhanden -> locked by another user/dlg
//      // or be me??? (locked by this dialog instance / topicId ?
//      const Database::OpmLockedTopics &data = it.value();
//      if (lockEntityId != data.id)
//      {
//        // vorhanden and locked by another user/dlg:
//        // "release" my *former* lock:
//        removeReleaseOutdatedLock(lockEntityId);

//        const auto opName = m_mainHandler->getHandlerOperator()->operatorNameById(data.operatorId);
//        const auto wsName = m_mainHandler->dds()->dtcAsm()->asset(data.workstationId).name();

//        return lockAlreadyLockedReply(wsName, opName);
//      }
//    }
//  }

//  // not already lock -> 'update' the entry:
//  //
//  // 1) DB-Update
//  //
//  Database::OpmLockedTopics dbStruct(toDb(request));
//  dbStruct.id = lockEntityId;      // to enable dbUpdate :-)
//  dbStruct.timeStampLock = QDateTime::currentMSecsSinceEpoch();

//  if (!m_db->update(dbStruct))
//  {
//    return lockErrorReply(lockEntityId, tr_lts("dds", "Failed to update lock entity (%1) in database"));
//  }

//  //
//  // 2) DDS-Update
//  //
//  Core::LockedEntity lckEntity(request.operatorId(), request.workstationId(),
//                               request.exerciseId(), request.entityId(),
//                               request.entityTypeName(), dbStruct.id);
//  publishLockedEntity(lckEntity);


//  //
//  // 3) QHash-Update
//  //

//  // update both: key and value!!! by removing the key-value-pair with topicId ...
//  {
//    auto lockedTopicIt = std::find_if(m_lockedTopics.constBegin(), m_lockedTopics.constEnd(),
//                                      [&lockEntityId](const Database::OpmLockedTopics &lockedTopic)
//    {
//      return (lockEntityId == lockedTopic.id);
//    });

//    if (lockedTopicIt == m_lockedTopics.constEnd())
//    {
//      return lockErrorReply(lockEntityId, tr_lts("dds", "Failed to update lock entity (%1) on the heap"));
//    }

//    const Database::OpmLockedTopics &lockedTopic = *lockedTopicIt;
//    DEBUG_LOG(m_logger) << LOGFUNCTION << ": locked topic id " << lockedTopic.id;
//    // ... and then reinserting the updated lock entity (as the id has now changed) - while the key (op, ws, exc, topic id) stays the same!
//    m_lockedTopics[requestedKey] = dbStruct;
//  }

//  return lockSuccessReply(dbStruct); // success
//}

//bool HandlerLockedTopics::removeReleaseOutdatedLock(const int lockEntityId)
//{
//  DEBUG_LOG(m_logger) << "removeReleaseOutdatedLock: lockEntityId = " << lockEntityId;

//  auto lockedTopicIt = std::find_if(m_lockedTopics.constBegin(), m_lockedTopics.constEnd(),
//                                    [&lockEntityId](const Database::OpmLockedTopics &lockedTopic)
//  {
//    return (lockEntityId == lockedTopic.id);
//  });

//  if (lockedTopicIt == m_lockedTopics.constEnd())
//  {
//    ERROR_LOG(m_logger) << LOGFUNCTION << ": Failed to release outdated lock as lock entity id ("<<lockedTopicIt<<") was not found!";
//    Q_ASSERT(false);
//    return false;
//  }

//  const Database::OpmLockedTopics &lockedTopic = *lockedTopicIt;
//  DEBUG_LOG(m_logger) << LOGFUNCTION << ": found lock entity " << lockEntityId;

//  unlockInDb(lockedTopic);
//  removeLockedEntity(lockEntityId);

//  m_lockedTopics.erase(lockedTopicIt);

//  return true;
//}

void HandlerLockedTopics::onTryUnlockEntityRequest(const rti::core::SampleIdentity &cookie,
                                                   const Core::TryUnlockEntityRequest &request)
{
  if (m_logger.isDebugEnabled())
    dumpLockedTopics(__LINE__);

  auto ret = tryUnlock(request);
  if (!ret.errorString().empty())
  {
    WARNING_LOG(m_logger) << Core::FunctionReplyObject(ret.FunctionReply::id(), ret.errorString(), ret.errorParams()).translated() << " - " << request;
  }
  m_ftsTryUnlockEntity->sendReply(cookie, ret);

  if (m_logger.isDebugEnabled())
    dumpLockedTopics(__LINE__);
}

Core::FunctionReply HandlerLockedTopics::tryUnlock(const Core::TryUnlockEntityRequest &request)
{
  DEBUG_LOG(m_logger) << "tryUnlock: " << request;

  const auto lockEntityId = request.id();

  auto lockedTopicIt = std::find_if(m_lockedTopics.constBegin(), m_lockedTopics.constEnd(),
                                    [lockEntityId](const Database::OpmLockedTopics &lockedTopic)
  {
    return (lockEntityId == lockedTopic.id);
  });

  if (lockedTopicIt == m_lockedTopics.constEnd())
  {
    // nicht vorhanden => unlock nicht möglich
    return Core::FunctionReply(-1, tr_lts("dds", "Failed to unlock unknown lock with id %1."), {}, { std::to_string(lockEntityId) });
  }

  // found => unlock
  const Database::OpmLockedTopics &lockedTopic = *lockedTopicIt;
  unlockInDb(lockedTopic);
  removeLockedEntity(lockedTopic.id);
  m_lockedTopics.erase(lockedTopicIt);
  return Core::FunctionReply(); // success!
}

void HandlerLockedTopics::unlockInDb(const Database::OpmLockedTopics &data)
{
  Database::OpmLockedTopics dbStruct(data);
  dbStruct.locked = false;
  dbStruct.timeStampUnlock = QDateTime::currentMSecsSinceEpoch();
  m_db->update(dbStruct);
}

Database::OpmLockedTopics HandlerLockedTopics::toDb(const Core::LockedEntityBase &request)
{
  Database::OpmLockedTopics ret;
  ret.locked = true;
  ret.entityId = request.entityId();
  ret.entityTypeName = QString::fromStdString(request.entityTypeName());
  ret.operatorId = request.operatorId();
  ret.workstationId = request.workstationId();
  ret.exerciseId = request.exerciseId() ? QVariant(request.exerciseId()) : QVariant();
  return ret;
}

bool HandlerLockedTopics::publishLockedEntity(const Core::LockedEntity &entity)
{
  if (m_dtsLockedEntity)
  {
    m_dtsLockedEntity->write(entity);
    return true;
  }
  ERROR_LOG(m_logger) << "Publishing LockedEntity " << entity.id() << " failed: DTS not available!";
  return false;
}

bool HandlerLockedTopics::removeLockedEntity(int64_t id)
{
  Core::LockedEntity entity;
  entity.id(id);
  if (m_dtsLockedEntity)
  {
    m_dtsLockedEntity->remove(entity);
    return true;
  }
  ERROR_LOG(m_logger) << "Removing LockedEntity " << entity.id() << " failed: DTS not available!";
  return false;
}

//Core::key HandlerLockedTopics::topicIdToKey(long id)
//{
//  QHashIterator<Core::key, Database::OpmLockedTopics> it (m_lockedTopics);

//  while (it.hasNext())
//  {
//    it.next();
//    const Database::OpmLockedTopics &topicRef = it.value();
//    if (topicRef.id == id)
//    {
//      return it.key();
//    }
//  } // while (it.hasNext())

//  return {};
//}

void HandlerLockedTopics::dumpLockedTopics(int line)
{
  QHashIterator<Core::key, Database::OpmLockedTopics> it (m_lockedTopics);

  INFO_LOG(m_logger)  << " dump m_lockedTopics, START size= " << m_lockedTopics.size()
                        << " (callerline=" << line << ")";
  while (it.hasNext())
  {
    it.next();
    const Core::key &keyRef = it.key();
    const Database::OpmLockedTopics &valRef = it.value();
    INFO_LOG(m_logger) << " entityTypeName=" << keyRef.entityTypeName << "'"
                       << ", entityId=" << keyRef.entityId
                       << ", exerciseId=" << keyRef.exerciseId
                       << " - eTN=" << valRef.entityTypeName
                       << ", entityId=" << valRef.entityId
                       << ", exId=" << valRef.exerciseId.toInt()
                       << ", opId=" << valRef.operatorId;
  }
  INFO_LOG(m_logger)  << " dump m_lockedTopics, END   size= " << m_lockedTopics.size();
}

} // namespace