/**
  * @RDE_HEADER@
  * ImportHandler
  * $Id$
  * $HeadURL$
  * $Author$
  * Created by Astrid Müller, Christian Fröbel, SLSE, 2017-12-12
  */

#include "import_handler.h"
#include "exercise_handler.h"
#include <AssetManagement/asm.hpp>
#include <AssetManagement/asm_enums.hpp>
#include <AssetManagement/asm_dtc.h>
#include <ngldb/dbtransaction.h>
#include <QtGlobal>

using namespace AudioVideoManagement;

namespace
{

Database::AvmDeviceConfig toDb(const ExerciseContext &context, const AssetManagement::Asset &asset)
{
  Database::AvmDeviceConfig   deviceConfig;
  deviceConfig.context = context.toString();
  deviceConfig.type = QStringLiteral("IMPORT_VIDEO_CHANNEL");
  deviceConfig.name = QStringLiteral("ECRS");
  deviceConfig.controller = QString::fromStdString(asset.name());
  deviceConfig.definition = QStringLiteral("recording=ECRS@EXCAVS01");
  return deviceConfig;
}

} // anonymous namespace


namespace AudioVideoManagement
{

ImportHandler *ImportHandler::create(ExerciseHandler *exerciseHandler, DatabaseInterface *db, AssetManagement::Interface::Dtc *asmDtc)
{
  Q_ASSERT(exerciseHandler);

  ImportHandler   *newHandler = new ImportHandler(exerciseHandler->context(), db, asmDtc);

  connect(exerciseHandler, &ExerciseHandler::contextActivated, newHandler, &ImportHandler::onContextActivated);
  connect(exerciseHandler, &ExerciseHandler::contextDeactivated, newHandler, &ImportHandler::onContextDeactivated);
  connect(asmDtc, &AssetManagement::Interface::Dtc::assetChanged, newHandler, &ImportHandler::onAssetChanged);

  return newHandler;
}

ImportHandler::ImportHandler(const ExerciseContext &context, DatabaseInterface *db, AssetManagement::Interface::Dtc *asmDtc)
  : m_context(context)
  , m_db(db)
  , m_asmDtc(asmDtc)
{
  Q_ASSERT(db);
  Q_ASSERT(asmDtc);
}

void ImportHandler::onContextActivated()
{
  m_isActive = true;

  DBTransaction   transaction(m_db->database());

  // This can possibly cause a race condition. It can happen that for an asset we just retrieved
  // we immediatly get an onAssetChanged() notification with eAdded.
  auto   cb = [this] (const AssetManagement::Asset &asset) { onAssetChanged(asset, DataModification::eAdded); };
  m_asmDtc->assets(cb);

  transaction.commit();
}

void ImportHandler::onContextDeactivated()
{
  DBTransaction   transaction(m_db->database());

  for (const auto &idAndDeviceConfig: m_deviceConfigs)
    m_db->removeAvmDeviceConfig(idAndDeviceConfig.second.id);
  m_deviceConfigs.clear();

  transaction.commit();

  m_isActive = false;
}

void ImportHandler::onAssetChanged(const AssetManagement::Asset &asset, DataModification modType)
{
  if (!m_isActive)
    return;

  if (asset.assetTypeId() != AssetManagement::AssetType::Workstation)
    return;

  // Guard against a possible race condition, see comments in onContextActivated().
  auto   found = m_deviceConfigs.find(asset.id());
  if (found != m_deviceConfigs.end())
    return;

  switch (modType)
  {
  case DataModification::eAdded:
    addToDb(asset);
    break;

  case DataModification::eRemoved:
    // This is not a regular use case.
    // But it can happen when the services are stopped.
    removeFromDb(asset);
    break;

  case DataModification::eModified:
    // Assets are read-only.
    Q_ASSERT(false);
  }
}

void ImportHandler::addToDb(const AssetManagement::Asset &asset)
{
  Database::AvmDeviceConfig   newConfig = ::toDb(m_context, asset);
  m_db->insert(newConfig);
  auto   insertResult = m_deviceConfigs.insert({asset.id(), newConfig});
  Q_ASSERT(insertResult.second);
  emit avDbReloadNeeded();
}

void ImportHandler::removeFromDb(const AssetManagement::Asset &asset)
{
  auto   found = m_deviceConfigs.find(asset.id());
  Q_ASSERT(found != m_deviceConfigs.end());
  m_db->removeAvmDeviceConfig(found->second.id);
  m_deviceConfigs.erase(found);
  emit avDbReloadNeeded();
}

} // namespace AudioVideoManagement