Run2ToRun3TrigNavConverterV2.cxx

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/*
  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
*/
 
#include <boost/functional/hash.hpp>
#include <GaudiKernel/StatusCode.h>
#include "AthLinks/ElementLinkVector.h"
#include "TrigConfHLTUtils/HLTUtils.h"
#include "TrigNavStructure/Types.h"
#include "xAODTrigger/TrigPassBitsContainer.h"
#include "AthenaKernel/ClassID_traits.h"
#include "TrigNavStructure/TriggerElement.h"
#include "Run2ToRun3TrigNavConverterV2.h"
#include "TrigCompositeUtils/ChainNameParser.h"
#include "TrigConfHLTData/HLTSequenceList.h"
#include "SpecialCases.h"
#include <limits>
#include <cstdint>
 
namespace TCU = TrigCompositeUtils;
 
// helper class
ConvProxy::ConvProxy(const HLT::TriggerElement *t) : te{t}
{
  teIDs.push_back(te->getId());
}
 
// find if proxy is a child of other proxies, also follows to children of the children etc...
bool ConvProxy::isChild(const ConvProxy* other ) const {
  for ( auto c: children ) {
    if (other == c)
      return true;
    if ( c->isChild(other) )
      return true;
  }
  return false;
}
 
bool ConvProxy::isParent(const ConvProxy* other ) const {
  for ( auto c: parents ) {
    if (other == c)
      return true;
    if ( c->isParent(other) )
      return true;
  }
  return false;
}
 
 
bool ConvProxy::mergeAllowed(const ConvProxy *other) const
{
  if (this == other)
    return false; // no merging with self
  // never merge children with parents
  if ( isChild(other) )
    return false;
  if ( isParent(other) )
    return false;
  return true;
}
 
void ConvProxy::merge(ConvProxy *other)
{
  if (other == this)
  {
    return;
  }
  // copy over chains
  runChains.insert(other->runChains.begin(), other->runChains.end());
  passChains.insert(other->passChains.begin(), other->passChains.end());
  teIDs.push_back(other->te->getId());
  /* the intention of the code below is following.
  Intial structure like is like this (the line is always bidirectional):
  P1 P2 P3 <- parents
   | | /
  T1 T2 <- "this" and "other"
   | |
  C1 C2 <- children
  1) Lets assume that the first proxies we treat are B1 & B2 ath they are mergable. The resulting structure should look like this:
  P1 P2 P3
   |/__/
  T1 T2
   |\
  C1 C2
 
  */
  auto add = [](ConvProxy *toadd, std::set<ConvProxy *> &coll)
  {
    if (std::find(coll.begin(), coll.end(), toadd) == coll.end())
    {
      coll.insert(toadd);
    }
  };
 
  auto remove = [](ConvProxy *torem, std::set<ConvProxy *> &coll)
  {
    auto place = std::find(coll.begin(), coll.end(), torem);
    if (place != coll.end())
    {
      coll.erase(place);
    }
  };
 
  // this is T <-> C connection
  for (auto otherChild : other->children)
  {
    add(otherChild, children);
    add(this, otherChild->parents);
  }
  // this is T <-> P connection rewiring
  for (auto otherParent : other->parents)
  {
    add(otherParent, parents);
    add(this, otherParent->children);
  }
 
  // now need to remove links back to the "other"
  for (auto otherParent : other->parents)
  {
    remove(other, otherParent->children);
  }
 
  for (auto otherChild : other->children)
  {
    remove(other, otherChild->parents);
  }
  other->children.clear();
  other->parents.clear();
}
 
std::string ConvProxy::description() const
{
  std::string ret;
  ret += " N parents: " + std::to_string(parents.size());
  ret += " N children: " + std::to_string(children.size());
  std::ostringstream os;
  for ( auto c: children )
    os << c << " ";
  ret += " ptrs: " + os.str();
  ret += " feaHash: " + std::to_string(feaHash);
  ret += " N run chains: " + std::to_string(runChains.size());
  return ret;
}
 
// the algorithm
Run2ToRun3TrigNavConverterV2::Run2ToRun3TrigNavConverterV2(const std::string &name, ISvcLocator *pSvcLocator) : AthReentrantAlgorithm(name, pSvcLocator)
{
}
 
Run2ToRun3TrigNavConverterV2::~Run2ToRun3TrigNavConverterV2()
{
}
 
StatusCode Run2ToRun3TrigNavConverterV2::initialize()
{
  ATH_CHECK(m_trigOutputNavKey.initialize());
  ATH_CHECK(m_tdt.empty() != m_trigNavKey.key().empty()); // either of the two has to be enabled but not both
  if (!m_tdt.empty())
  {
    ATH_CHECK(m_tdt.retrieve());
    ATH_MSG_INFO("Will use Trigger Navigation from TrigDecisionTool");
  }
  else
  {
    ATH_CHECK(m_trigNavKey.initialize(SG::AllowEmpty));
    ATH_MSG_INFO("Will use Trigger Navigation decoded from TrigNavigation object");
  }
 
  if (!m_chainsToSave.empty()) {
    ATH_MSG_DEBUG("Will only save features for these chains " << m_chainsToSave);
  }
 
  ATH_CHECK(m_configSvc.retrieve());
  ATH_CHECK(m_clidSvc.retrieve());
 
  // configured collections can be either just type name, or type#key
  // decoding takes this into account, if only the type is configured then empty string is places in the decoded lookup map
  // else CLID + a name is placed
 
  for (const auto &name : m_collectionsToSave)
  {
    std::string typeName = name;
    std::string collName;
    size_t delimeterIndex = name.find('#');
    if (delimeterIndex != std::string::npos)
    {
      typeName = name.substr(0, delimeterIndex);
      collName = name.substr(delimeterIndex + 1);
    }
    CLID id{0};
    ATH_CHECK(m_clidSvc->getIDOfTypeName(typeName, id));
    ATH_MSG_DEBUG("Will be linking collection type " << typeName << " name (empty==all) " << collName);
    if ( collName.empty() )
      m_collectionsToSaveDecoded[id]; // creates empty set
    else
      m_collectionsToSaveDecoded[id].insert(collName);
  }
 
  for (const auto &name : m_roisToSave)
  {
    m_setRoiName.push_back(name);
  }
 
  // sanity check, i.e. if there is at least one entry w/o the coll name no other entries are needed for a given clid
  for (auto [clid, keysSet] : m_collectionsToSaveDecoded)
  {
    if (keysSet.size() > 1 and keysSet.count("") != 0)
    {
      ATH_MSG_ERROR("Bad configuration for CLID " << clid << " requested saving of all (empty coll name configures) collections, yet there are also specific keys");
      return StatusCode::FAILURE;
    }
 
  }
 
  bool anyChainBad=false;
  for ( auto chain: m_chainsToSave ) {
    if ( chain.find('*') != std::string::npos or chain.find('|') != std::string::npos ) {
      ATH_MSG_ERROR("Supplied chain name: " << chain << " contains wildcard characters, this is not supported by the conversion tool");
      anyChainBad=true;
    }
  }
  if ( anyChainBad ) {
    ATH_MSG_ERROR("Supplied chain names contain wildcard characters, this is not supported by the conversion tool");
    return StatusCode::FAILURE;
  }
  if ( m_chainsToSave.empty() ) {
    ATH_MSG_INFO("No chains list supplied, the conversion will occur for all chains");
  }
 
  ATH_CHECK(m_clidSvc->getIDOfTypeName("TrigRoiDescriptor", m_roIDescriptorCLID));
  ATH_CHECK(m_clidSvc->getIDOfTypeName("TrigRoiDescriptorCollection", m_roIDescriptorCollectionCLID));
  ATH_CHECK(m_clidSvc->getIDOfTypeName("xAOD::TrigRingerRings", m_TrigRingerRingsCLID));
  ATH_CHECK(m_clidSvc->getIDOfTypeName("xAOD::TrigRingerRingsContainer", m_TrigRingerRingsContainerCLID));
  ATH_CHECK(m_clidSvc->getIDOfTypeName("xAOD::TrigEMCluster", m_TrigEMClusterCLID));
  ATH_CHECK(m_clidSvc->getIDOfTypeName("xAOD::TrigEMClusterContainer", m_TrigEMClusterContainerCLID));
  ATH_CHECK(m_clidSvc->getIDOfTypeName("xAOD::CaloCluster", m_CaloClusterCLID));
  ATH_CHECK(m_clidSvc->getIDOfTypeName("xAOD::CaloClusterContainer", m_CaloClusterContainerCLID));
  ATH_CHECK(m_clidSvc->getIDOfTypeName("xAOD::TrackParticleContainer", m_TrackParticleContainerCLID));
  ATH_CHECK(m_clidSvc->getIDOfTypeName("xAOD::TauTrackContainer", m_TauTrackContainerCLID));
 
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::finalize()
{
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::execute(const EventContext &context) const
{
  {
    // configuration reading could not be done before the event loop
    // it needs to be done only once though
    std::scoped_lock lock(m_configUpdateMutex);
    if (m_allTEIdsToChains.empty())
      ATH_CHECK(extractTECtoChainMapping(const_cast<TEIdToChainsMap_t &>(m_allTEIdsToChains), const_cast<TEIdToChainsMap_t &>(m_finalTEIdsToChains)));
  }
 
  ConvProxySet_t convProxies;
  HLT::StandaloneNavigation standaloneNav; // needed to keep TEs around, so it is out of the scope where it is filled and referenced
  const HLT::TrigNavStructure *run2NavigationPtr = nullptr;
  if (!m_trigNavKey.key().empty())
  {
    SG::ReadHandle navReadHandle(m_trigNavKey, context);
    ATH_CHECK(navReadHandle.isValid());
    standaloneNav.deserialize(navReadHandle->serialized());
    run2NavigationPtr = &standaloneNav;
  }
  else
  {
    run2NavigationPtr = m_tdt->ExperimentalAndExpertMethods().getNavigation();
  }
 
  ATH_CHECK(mirrorTEsStructure(convProxies, *run2NavigationPtr));
  // printProxies(convProxies, [](auto ){ return true;},
  //             {m_chainIdsPrinter});
 
  if (m_doSelfValidation)
    ATH_CHECK(allProxiesConnected(convProxies));
 
  ATH_CHECK(associateChainsToProxies(convProxies, m_allTEIdsToChains));
  // printProxies(convProxies, [](auto ){ return true;},
  //             {m_chainIdsPrinter});
 
  ATH_CHECK(cureUnassociatedProxies(convProxies));
  ATH_MSG_DEBUG("Proxies to chains mapping done");
 
  ATH_CHECK(removeTopologicalProxies(convProxies));
 
  if (not m_chainsToSave.empty())
  {
    ATH_CHECK(removeUnassociatedProxies(convProxies));
    printProxies(convProxies, [](auto ){ return true;},
            {m_chainIdsPrinter});
    ATH_MSG_DEBUG("Removed proxies to chains that are not converted, remaining number of elements " << convProxies.size());
  }
  if (m_doSelfValidation)
  {
    ATH_CHECK(allProxiesHaveChain(convProxies));
  }
  if (m_doCompression)
  {
    ATH_CHECK(doCompression(convProxies, *run2NavigationPtr));
    // printProxies(convProxies, [](auto ){ return true;},
    //         {m_chainIdsPrinter});
 
  }
 
  SG::WriteHandle<TrigCompositeUtils::DecisionContainer> outputNavigation = TrigCompositeUtils::createAndStore(m_trigOutputNavKey, context);
  auto decisionOutput = outputNavigation.ptr();
  TrigCompositeUtils::newDecisionIn(decisionOutput, TCU::summaryPassNodeName()); // we rely on the fact that the 1st element is the top
 
  if (m_doLinkFeatures)
  {
    ATH_CHECK(fillRelevantFeatures(convProxies, *run2NavigationPtr));
    ATH_CHECK(fillRelevantRois(convProxies, *run2NavigationPtr));
    ATH_CHECK(fillRelevantTracks(convProxies));
    ATH_MSG_DEBUG("Features to link found");
  }
 
  ATH_CHECK(createIMHNodes(convProxies, *decisionOutput, context));
  if (m_doSelfValidation)
  {
    ATH_CHECK(numberOfHNodesPerProxyNotExcessive(convProxies));
  }
 
  ATH_CHECK(createL1Nodes(convProxies, *decisionOutput, context));
  ATH_CHECK(linkFeaNode(convProxies, *decisionOutput, *run2NavigationPtr, context));
  ATH_CHECK(linkRoiNode(convProxies, *run2NavigationPtr));
  ATH_CHECK(linkTrkNode(convProxies, *run2NavigationPtr));
  ATH_CHECK(createSFNodes(convProxies, *decisionOutput, m_finalTEIdsToChains, context));
  ATH_CHECK(updateTerminusNode(*decisionOutput, context));
  ATH_MSG_DEBUG("Conversion done, from " << convProxies.size() << " elements to " << decisionOutput->size() << " elements");
 
  printProxies(convProxies, [](auto ){ return true;},
              {m_chainIdsPrinter, m_teIDPrinter});
  ATH_MSG_DEBUG("Resulting nodes");
  size_t index = 0;
  for ( auto o: *decisionOutput) {
    ATH_MSG_DEBUG("Index: " << index << " " << *o);
    index++;
  }
 
  // dispose temporaries
  for (auto proxy : convProxies)
  {
    delete proxy;
  }
 
  return StatusCode::SUCCESS;
}
 
size_t Run2ToRun3TrigNavConverterV2::is2LegTopoChain(const TrigConf::HLTChain* ptrChain) const {
  // chains of configs structure
  // A  B
  //  \/
  //  C
  // where C is the output TE of sequence consuming A & B
  // sometimes there are an additional leafs
  //  C
  //  |
  //  D
  if ( not std::regex_match(ptrChain->name(), SpecialCases::isTopo) ) return 0;
  size_t stepToConsider = 0;
  const size_t sigsSize = ptrChain->signatures().size();
  if ( sigsSize < 2 ) return 0;
  for ( size_t step = sigsSize-1; step > 1; step --) {
    if ( (ptrChain->signatures()[step-1])->outputTEs().size() == 2 and (ptrChain->signatures()[step])->outputTEs().size() == 1 )  {
      stepToConsider = step;
      break;
    }
  }
  if ( stepToConsider == 0 ) return 0; // not a topo
 
  //counting is right, need to see now if TEs are connected
  auto finalTE = (ptrChain->signatures()[stepToConsider])->outputTEs()[0];
  auto preFinalTEs = (ptrChain->signatures()[stepToConsider-1])->outputTEs();
 
  auto finalSeq =  m_configSvc->sequences().getSequence(finalTE->id());
  std::set<HLT::te_id_type> tesInSeq;
  std::set<HLT::te_id_type> tesInChain;
 
  for ( auto te: finalSeq->inputTEs()) {
     tesInSeq.insert(te->id());
  }
 
  for ( auto te: preFinalTEs) {
     tesInChain.insert(te->id());
  }
 
  if (tesInSeq == tesInChain)  {
    return stepToConsider;
  }
  return 0;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::extractTECtoChainMapping(TEIdToChainsMap_t &allTEs, TEIdToChainsMap_t &finalTEs) const
{
 
  ATH_CHECK(not m_configSvc->chains().empty());
 
  // obtain map output TE -> input TE via sequences
  for (auto ptrChain : m_configSvc->chains())
  {
    std::string chainName = ptrChain->name();
 
 
    if (not m_chainsToSave.empty())
    {
      auto found = std::find(m_chainsToSave.begin(), m_chainsToSave.end(), chainName);
      if (found == m_chainsToSave.end())
      {
        continue;
      }
    }
 
    if (std::regex_match(chainName, SpecialCases::bjetMuChain ))  {
      ATH_CHECK(bjetMuChainConfigDecoder(allTEs, finalTEs, ptrChain));
      continue;
    }
 
    // hack for etcut chains
    // if we ever need to generalise that it should be moved to separate function
    std::map<HLT::te_id_type, HLT::te_id_type> etcutReplacementTEs;
    auto etcutReplacement = [&etcutReplacementTEs](HLT::te_id_type in) { auto out = etcutReplacementTEs.find(in);  return (out == etcutReplacementTEs.end() ? in : out->second ); };
    if ( chainName.find("etcut") != std::string::npos ) {
      std::set<size_t> positionsOfEtCutLegs;
      // use heuristics to mention
      if( std::regex_match(chainName, SpecialCases::egammaDiEtcut) ) {
         ATH_MSG_DEBUG("EtCut chains hack, chain with two etcut legs ");
         positionsOfEtCutLegs.insert({0, 1});
      } else if ( std::regex_match(chainName, SpecialCases::egammaCombinedWithEtcut) ) {
         ATH_MSG_DEBUG("EtCut chains hack, egamma chain with second etcut leg ");
         positionsOfEtCutLegs.insert({1});
      } else if ( std::regex_match(chainName, SpecialCases::egammaEtcut) ) {
         ATH_MSG_DEBUG("EtCut chains hack, single leg egamma chain");
         positionsOfEtCutLegs.insert({0});
      }
 
      // pilot pass to fill the replacement map
      std::map<size_t, HLT::te_id_type> positionToDesiredIDmap;
      for (auto ptrHLTSignature : ptrChain->signatures()) {
        size_t position = 0;
        for (auto ptrHLTTE : ptrHLTSignature->outputTEs()) {
          if (positionsOfEtCutLegs.count(position) and positionToDesiredIDmap.find(position) != positionToDesiredIDmap.end() ) {
            etcutReplacementTEs[ptrHLTTE->id()] = positionToDesiredIDmap[position];
            ATH_MSG_DEBUG("EtCut chains hack, TE " << ptrHLTTE->name() << " will be replaced by: " << TrigConf::HLTUtils::hash2string(positionToDesiredIDmap[position]));
          } else {
            if ( ptrHLTTE->name().find("calocalib") != std::string::npos and positionsOfEtCutLegs.count(position) ) { // we have final TE for this leg
              positionToDesiredIDmap[position] =  ptrHLTTE->id();
            }
          }
          position++;
        }
      }
    }
 
    // chains with a single leg
    HLT::Identifier chainId = HLT::Identifier(chainName);
    ATH_MSG_DEBUG(" CHAIN name " << chainName << " CHAIN Id " << chainId);
    for (auto ptrHLTSignature : ptrChain->signatures()) {
      for (auto ptrHLTTE : ptrHLTSignature->outputTEs()) {
        unsigned int teId = etcutReplacement(ptrHLTTE->id());
        allTEs[teId].insert(chainId);
        if (ptrHLTSignature == ptrChain->signatures().back()) {
            finalTEs[teId].insert(chainId);
            ATH_MSG_DEBUG("TE will be used to mark final chain decision " << ptrHLTTE->name() << " chain " << chainName );
        }
      }
    }
    // chains with a multiple legs
    std::vector<int> multiplicities = ChainNameParser::multiplicities(chainName);
 
    // dirty hacks for failing chains parsing
    if(std::regex_match(chainName, SpecialCases::gammaXeChain))
      multiplicities={1,1};
 
    if ( multiplicities.size() > 1 ) {
      ATH_MSG_DEBUG(" this " << (is2LegTopoChain(ptrChain) ? "is": "is not") << " topological chain");
      // the chain structure (in terms of multiplicities) may change along the way
      // we'll assign legs only to these TEs of the steps that have identical multiplicity pattern
      // e.g. for the chain: HLT_2g25_loose_g20 the multiplicities are: [2, 1]
 
      // hack for HLT.*tau.*xe.* case
      if (std::regex_match(chainName, SpecialCases::tauXeChain)) {
          std::vector<size_t> mult_hack; // type mismatch with ChainNameParser::multiplicities
          if (multiplicities.size()==3) mult_hack={1,1};
          else if (multiplicities.size()==2) mult_hack={1};
          ptrChain->set_leg_multiplicities(mult_hack); // HLTChain needs vector<size_t>
      }
 
      // hack for mu2MunoL1Special
      if (std::regex_match(chainName, SpecialCases::mu2MunoL1Special)) {
          std::vector<size_t> mult_hack;
          if (multiplicities.size()==3) mult_hack={1,1};
          else if (multiplicities.size()==2) mult_hack={2}; // HLT_mu11_nomucomb_2mu4noL1_nscan03_L1MU11_2MU6
          ptrChain->set_leg_multiplicities(mult_hack);
      }
 
      ATH_MSG_DEBUG("CHAIN " << chainName << " needs legs: " << multiplicities );
      std::vector<unsigned int> teIdsLastHealthyStepIds;
 
      for (auto ptrHLTSignature : ptrChain->signatures())
        {
          std::vector<int> teCounts;
          std::vector<unsigned int> teIds;
          unsigned int lastSeenId = 0;
          for (auto ptrHLTTE : ptrHLTSignature->outputTEs())
          {
            if ( lastSeenId != ptrHLTTE->id()) {
              teCounts.push_back(1);
              teIds.push_back(ptrHLTTE->id());
            } else {
              teCounts.back()++;
            }
            lastSeenId = ptrHLTTE->id();
          }
 
          ATH_MSG_DEBUG("TE multiplicities seen in this step " << teCounts);
          bool multiplicityCounts = multiplicities == teCounts;
          // hack for HLT.*tau.*xe.* case
          if(std::regex_match(chainName, SpecialCases::tauXeChain)) multiplicityCounts = true;
          if ( multiplicityCounts ) {
            teIdsLastHealthyStepIds = teIds;
            ATH_MSG_DEBUG("There is a match, will assign chain leg IDs to TEs " << teCounts << " " << teIds);
            for ( size_t legNumber = 0; legNumber < teIds.size(); ++ legNumber){
              HLT::Identifier chainLegId = TrigCompositeUtils::createLegName(chainId, legNumber);
              allTEs[etcutReplacement(teIds[legNumber])].insert(chainLegId);
            }
          }
        }
        for ( size_t legNumber = 0; legNumber < teIdsLastHealthyStepIds.size(); ++ legNumber ) {
          HLT::Identifier chainLegId = TrigCompositeUtils::createLegName(chainId, legNumber);
 
          ATH_MSG_DEBUG("created leg id " << chainLegId << " that will replace TE ID " << etcutReplacement(teIdsLastHealthyStepIds[legNumber]));
          finalTEs[etcutReplacement(teIdsLastHealthyStepIds[legNumber])].insert(chainLegId);
        }
    }
  }
  ATH_MSG_DEBUG("Recognised " << allTEs.size() << " kinds of TEs and among them " << finalTEs.size() << " final types");
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::bjetMuChainConfigDecoder(TEIdToChainsMap_t &allTEs, TEIdToChainsMap_t &finalTEs, const TrigConf::HLTChain* ptrChain ) const {
  HLT::Identifier chainId = HLT::Identifier(ptrChain->name());
 
  std::vector<unsigned int> muons;
  std::vector<unsigned int> jets;
  bool switchedTojets =false;
  for (auto ptrHLTSignature : ptrChain->signatures()) {
    for (auto ptrHLTTE : ptrHLTSignature->outputTEs()) {
      if ( ptrHLTTE->name().find("_mu") == std::string::npos )  {
        switchedTojets = true; 
      }
 
      if ( switchedTojets)
        jets.push_back(ptrHLTTE->id());
      else
        muons.push_back(ptrHLTTE->id());
    }
  }
  ATH_CHECK(not muons.empty());
  ATH_CHECK(not jets.empty());
  std::reverse(std::begin(muons), std::end(muons));
  std::reverse(std::begin(jets), std::end(jets));
  finalTEs[muons[0]].insert(TrigCompositeUtils::createLegName(chainId, 0));
  finalTEs[muons[0]].insert(chainId);
  finalTEs[jets[0]].insert(TrigCompositeUtils::createLegName(chainId, 1));
  finalTEs[jets[0]].insert(chainId);
 
  for ( size_t index = 0; index < std::min(muons.size(), jets.size()); ++index)
    {
      allTEs[muons[index]].insert(TrigCompositeUtils::createLegName(chainId, 0));
      allTEs[muons[index]].insert(chainId);
      allTEs[jets[index]].insert(TrigCompositeUtils::createLegName(chainId, 1));
      allTEs[jets[index]].insert(chainId);
    }
  return StatusCode::SUCCESS;
}
 
 
 
StatusCode Run2ToRun3TrigNavConverterV2::mirrorTEsStructure(ConvProxySet_t &convProxies, const HLT::TrigNavStructure &run2Nav) const
{
 
  // iterate over the TEs, for each make the ConvProxy and build connections
  std::map<const HLT::TriggerElement *, ConvProxy *> teToProxy;
  ATH_MSG_DEBUG("TrigNavStructure with " << run2Nav.getAllTEs().size() << " TEs acquired");
  for (auto te : run2Nav.getAllTEs())
  {
    // skip event seed node
    if (HLT::TrigNavStructure::isInitialNode(te))
      continue;
    auto proxy = new ConvProxy(te);
    convProxies.insert(proxy);
    teToProxy[te] = proxy;
    // add linking
    for (auto predecessor : HLT::TrigNavStructure::getDirectPredecessors(te))
    {
      ConvProxy *predecessorProxy = teToProxy[predecessor];
      if (predecessorProxy != nullptr)
      { // because we skip some
        proxy->parents.insert(predecessorProxy);
        predecessorProxy->children.insert(proxy);
      }
    }
  }
 
  if (m_doSelfValidation)
  {
    int counter = -1;
    for (auto proxy : convProxies)
    {
      counter++;
      ATH_MSG_DEBUG("Proxy " << counter << " " << proxy->description() << "ptr " << proxy);
      for (auto p : proxy->children)
        ATH_MSG_DEBUG("Child ptr " << p);
      for (auto p : proxy->parents)
        ATH_MSG_DEBUG("Parent ptr " << p);
 
      for (auto p : proxy->parents)
      {
        for (auto pp : p->parents)
        {
          if (pp == proxy)
          {
            ATH_MSG_WARNING("Weird, proxy is in parents list of parents");
          }
        }
      }
      for (auto c : proxy->children)
      {
        for (auto cc : c->children)
        {
          if (cc == proxy)
          {
            ATH_MSG_WARNING("Weird, proxy is in children list of children");
          }
        }
      }
    }
  }
 
  ATH_MSG_DEBUG("Created " << convProxies.size() << " proxy objects");
  return StatusCode::SUCCESS;
}
 
 
void Run2ToRun3TrigNavConverterV2::printProxies(const ConvProxySet_t& proxies,
                                                std::function<bool(const ConvProxy*)> selector,
                                                const std::vector<std::function<void(const ConvProxy*)>>& printers) const {
  ATH_MSG_DEBUG("Printing proxies");
  ATH_MSG_DEBUG("" );
  for ( auto p: proxies) {
    if ( selector(p) ){
      ATH_MSG_DEBUG("Proxy " << p->description() );
      for (auto& printer: printers) {
        printer(p);
      }
      ATH_MSG_DEBUG("" );
    }
  }
}
 
StatusCode Run2ToRun3TrigNavConverterV2::associateChainsToProxies(ConvProxySet_t &convProxies, const TEIdToChainsMap_t &allTEs) const
{
 
  for (auto &ptrConvProxy : convProxies)
  {
    auto teId = ptrConvProxy->te->getId();
    bool teActive = ptrConvProxy->te->getActiveState();
    auto iter = allTEs.find(teId);
    if (iter != allTEs.end())
    {
      ptrConvProxy->runChains.insert(iter->second.begin(), iter->second.end());
      if (teActive)
      {
        ptrConvProxy->passChains.insert(iter->second.begin(), iter->second.end());
      }
    }
 
    for (auto &objTeIdToChain : allTEs)
    {
      if (teId == objTeIdToChain.first)
      {
        for (auto &chainId : objTeIdToChain.second)
        {
          (ptrConvProxy->runChains).insert(chainId);
        }
        break;
      }
    }
  }
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::cureUnassociatedProxies(ConvProxySet_t &convProxies) const
{
  // propagate up (towards L1) chain IDs if they are not in proxies
  // technically each proxy looks at the children proxies and inserts from it all unseen chains
  // procedure is repeated until, no single proxy needs an update (tedious - we may be smarter in future)
 
  while (true)
  {
    size_t numberOfUpdates = 0;
    for (auto p : convProxies)
    {
      for (auto child : p->children)
      {
        size_t startSize = p->runChains.size();
        p->runChains.insert(std::begin(child->runChains), std::end(child->runChains));
 
        if (startSize != p->runChains.size())
        { // some chain needed to be inserted
          numberOfUpdates++;
          // if update was need, it means set of chains that passed need update as well
          p->passChains.insert(std::begin(child->runChains), std::end(child->runChains));
        }
      }
    }
    ATH_MSG_DEBUG("Needed to propagate chains from " << numberOfUpdates << " child(ren)");
    if (numberOfUpdates == 0)
    {
      break;
    }
  }
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::removeUnassociatedProxies(ConvProxySet_t &convProxies) const
{
  // remove proxies that have no chains
  for (auto i = std::begin(convProxies); i != std::end(convProxies);)
  {
    if ((*i)->runChains.empty())
    {
      ConvProxy *toDel = *i;
      // remove it from parents/children
      for (auto parent : toDel->parents)
      {
          parent->children.erase(toDel);
      }
      for (auto child : toDel->children)
      {
        child->parents.erase(toDel);
      }
      delete toDel;
      i = convProxies.erase(i);
    }
    else
    {
      ++i;
    }
  }
  ATH_MSG_DEBUG("After eliminating proxies not associated to chainsof intereset left with " << convProxies.size());
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::doCompression(ConvProxySet_t &convProxies, const HLT::TrigNavStructure &run2Nav) const
{
 
  ATH_CHECK(collapseFeaturesProxies(convProxies, run2Nav));
  ATH_CHECK(collapseFeaturelessProxies(convProxies));
  if (m_doSelfValidation)
  {
    ATH_CHECK(allProxiesHaveChain(convProxies));
    ATH_CHECK(allProxiesConnected(convProxies));
  }
  ATH_MSG_DEBUG("Compression done");
 
  return StatusCode::SUCCESS;
}
 
template <typename MAP>
StatusCode Run2ToRun3TrigNavConverterV2::collapseProxies(ConvProxySet_t &convProxies, MAP &keyToProxyMap) const
{
  // collapse proxies based on the mapping in the map argument(generic) and clean proxiesSet
  std::vector<ConvProxy *> todelete;
  for (auto &[key, proxies] : keyToProxyMap)
  {
    if (proxies.size() > 1)
    {
      ATH_MSG_DEBUG("Merging " << proxies.size() << " similar proxies");
      for (auto p : proxies)
      {
        if (p->mergeAllowed(*proxies.begin()))
        {
          (*proxies.begin())->merge(p);
          todelete.push_back(p);
        }
        // TODO consider scanning proxies another time if merge is not allowed, it may be allowed with other proxies here
      }
    }
  }
  for (auto proxy : todelete)
  {
    convProxies.erase(proxy);
    delete proxy;
  }
  // remove from proxies set all elements that are now unassociated (remember to delete after)
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::collapseFeaturesProxies(ConvProxySet_t &convProxies, const HLT::TrigNavStructure &run2Nav) const
{
 
  const size_t beforeCount = convProxies.size();
  std::map<uint64_t, ConvProxySet_t> feaToProxyMap;
  for (auto proxy : convProxies)
  {
    proxy->feaHash = feaToHash(proxy->te->getFeatureAccessHelpers(), proxy->te, run2Nav);
    if (proxy->feaHash != ConvProxy::MissingFEA)
      feaToProxyMap[proxy->feaHash].insert(proxy);
 
    ATH_MSG_VERBOSE("TE " << TrigConf::HLTUtils::hash2string(proxy->te->getId()) << " FEA hash " << proxy->feaHash);
    for (const HLT::TriggerElement::FeatureAccessHelper& fea : proxy->te->getFeatureAccessHelpers())
    {
      ATH_MSG_VERBOSE("FEA: " << fea);
    }
  }
 
  for (auto [feaHash, proxies] : feaToProxyMap)
  {
    auto first = *proxies.begin();
    for (auto p : proxies)
    {
      if (filterFEAs(first->te->getFeatureAccessHelpers(), run2Nav) !=
                        filterFEAs(p->te->getFeatureAccessHelpers(), run2Nav))
      {
        ATH_MSG_ERROR("Proxies grouped by FEA hash have actually distinct features (specific FEAs are different)");
        for (auto id: p->passChains ) ATH_MSG_ERROR("... chain id for this proxy " << id);
        ATH_MSG_ERROR(".... TE id of this proxy: " << TrigConf::HLTUtils::hash2string(p->te->getId()));
        for ( auto fea: first->te->getFeatureAccessHelpers() ) {
          ATH_MSG_ERROR("FEA1 " << fea);
        }
        for ( auto fea: p->te->getFeatureAccessHelpers() ) {
          ATH_MSG_ERROR("FEA2 " << fea);
        }
 
        return StatusCode::FAILURE;
      }
    }
  }
 
 
  ATH_CHECK(collapseProxies(convProxies, feaToProxyMap));
  ATH_MSG_DEBUG("Proxies with features collapsing reduces size from " << beforeCount << " to " << convProxies.size());
 
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::collapseFeaturelessProxies(ConvProxySet_t &convProxies) const
{
  // merge proxies bases on the parent child relation (this has to run after feature based collapsing)
  struct ParentChildCharacteristics
  {
    ConvProxy *parent = nullptr;
    ConvProxy *child = nullptr;
    size_t distanceFromParent = 0;
    bool operator<(const ParentChildCharacteristics &rhs) const
    {
      if (parent != rhs.parent)
        return parent < rhs.parent;
      if (child != rhs.child)
        return child < rhs.child;
      return distanceFromParent < rhs.distanceFromParent;
    }
  };
  const size_t beforeCount = convProxies.size();
  std::map<ParentChildCharacteristics, ConvProxySet_t> groupedProxies;
  for (auto proxy : convProxies)
  {
    if (proxy->feaHash == ConvProxy::MissingFEA)
    {
      ATH_MSG_VERBOSE("Featureless proxy to deal with: " << proxy->description());
      /* the canonical case
        merged parent
         / |  | \
        C1 C2 C3 C4 <-- proxies to merge
         \ |  | /
        merged child
      */
      auto hasSomeFeatures = [](const ConvProxy* p){ return p->feaHash != ConvProxy::MissingFEA; };
      if (proxy->children.size() == 1 and
          std::all_of(proxy->children.begin(), proxy->children.end(), hasSomeFeatures ) and
          proxy->parents.size() == 1 and
          std::all_of(proxy->parents.begin(), proxy->parents.end(), hasSomeFeatures )
          )
      {
        ATH_MSG_VERBOSE("Proxy to possibly merge: " << proxy->description());
        groupedProxies[{*(proxy->parents.begin()), *(proxy->children.begin()), 0}].insert(proxy);
        // TODO expand it to cover longer featureless sequences
      }
      else
      {
        ATH_MSG_VERBOSE("Featureless proxy in noncanonical situation " << proxy->description());
        ATH_MSG_VERBOSE("parents ");
        for (auto pp : proxy->parents)
        {
          ATH_MSG_VERBOSE(pp->description());
        }
        ATH_MSG_VERBOSE("children ");
        for (auto cp : proxy->children)
        {
          ATH_MSG_VERBOSE(cp->description());
        }
      }
    }
  }
 
  ATH_CHECK(collapseProxies(convProxies, groupedProxies));
  ATH_MSG_DEBUG("Proxies without features collapsing reduces size from " << beforeCount << " to " << convProxies.size());
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::removeTopologicalProxies(ConvProxySet_t & convProxies) const
{
 for (auto i = std::begin(convProxies); i != std::end(convProxies);)
  {
    if ((*i)->parents.size() > 1)
    {
      ConvProxy *toDel = *i;
      // remove it from parents/children
      for (auto parent : toDel->parents)
      {
          parent->children.erase(toDel);
      }
      for (auto child : toDel->children)
      {
        child->parents.erase(toDel);
      }
      delete toDel;
      i = convProxies.erase(i);
    }
    else
    {
      ++i;
    }
  }
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::fillRelevantFeatures(ConvProxySet_t &convProxies, const HLT::TrigNavStructure &run2Nav) const
{
  // from all FEAs of the associated TE pick those objects that are to be linked
  for (auto &proxy : convProxies)
  {
    if (proxy->te != nullptr)
    {
 
      for (const HLT::TriggerElement::FeatureAccessHelper& helper : proxy->te->getFeatureAccessHelpers())
      {
        auto [sgKey, sgCLID, sgName] = getSgKey(run2Nav, helper);
        if (sgKey != 0)
        {
          if (feaToSave(helper, sgName))
          {
            proxy->features.push_back(helper);
          }
        }
      }
    }
  }
 
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::fillRelevantRois(ConvProxySet_t &convProxies, const HLT::TrigNavStructure &run2Nav) const
{
 
  // ordered_sorter
  auto ordered_sorter = [&setRoiName = std::as_const(m_setRoiName)](const std::string &left, const std::string &right) -> bool
  {
    return std::find(cbegin(setRoiName), cend(setRoiName), left) < std::find(cbegin(setRoiName), cend(setRoiName), right);
  };
 
  std::map<std::string, HLT::TriggerElement::FeatureAccessHelper, decltype(ordered_sorter)> mp(ordered_sorter);
 
  for (auto &proxy : convProxies)
  {
    // TODO need check & handling of case when there is more RoIs, now overwriting
    if (HLT::TrigNavStructure::getRoINodes(proxy->te).size() > 1)
      ATH_MSG_DEBUG("Several RoIs pointing to a proxy, taking latest one for now");
 
    mp.clear();
 
    for (const HLT::TriggerElement::FeatureAccessHelper& helper : proxy->te->getFeatureAccessHelpers())
    {
      auto [sgKey, sgCLID, sgName] = getSgKey(run2Nav, helper);
      if (std::find(m_setRoiName.begin(), m_setRoiName.end(), sgName) == m_setRoiName.end())
      {
        // do not filter continue;
        continue;
      }
      mp[sgName] = helper;
    }
 
    std::transform(cbegin(mp), cend(mp), back_inserter(proxy->rois),
                   [](const std::map<std::string, HLT::TriggerElement::FeatureAccessHelper>::value_type &p)
                   { return p.second; });
  }
 
  // roiPropagator
  std::set<const ConvProxy*>  visited;
  std::function<void(std::set<ConvProxy *> &, const std::vector<HLT::TriggerElement::FeatureAccessHelper> &)>
   roiPropagator = [&](std::set<ConvProxy *> &convProxyChildren, const std::vector<HLT::TriggerElement::FeatureAccessHelper> &roiParent)
  {
    for (auto &proxyChild : convProxyChildren)
    {
      if ( visited.count(proxyChild) == 1 ) {
        continue;
      }
      visited.insert(proxyChild);
      if (proxyChild->rois.empty())
      { // no roi update, copy from parent
        proxyChild->rois = roiParent;
        if (proxyChild->children.empty() == false)
        {
          roiPropagator(proxyChild->children, roiParent);
        }
      }
    }
  };
 
  for (auto &proxy : convProxies)
  {
    roiPropagator(proxy->children, proxy->rois);
  }
 
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::fillRelevantTracks(ConvProxySet_t &convProxies) const
{
  for (auto &proxy : convProxies)
  {
    for (const HLT::TriggerElement::FeatureAccessHelper& helper : proxy->te->getFeatureAccessHelpers())
    {
      if (helper.getCLID() == m_TrackParticleContainerCLID || helper.getCLID() == m_TauTrackContainerCLID)
      {
        proxy->tracks.push_back(helper);
      }
    }
  }
 
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::createIMHNodes(ConvProxySet_t &convProxies, xAOD::TrigCompositeContainer &decisions, const EventContext &context) const
{
  for (auto &proxy : convProxies)
  {
    proxy->imNode = TrigCompositeUtils::newDecisionIn(&decisions, TrigCompositeUtils::inputMakerNodeName()); // IM
    for (auto chainId : proxy->runChains)
    {
      TrigCompositeUtils::addDecisionID(chainId, proxy->imNode);
    }
    proxy->hNode.push_back(TrigCompositeUtils::newDecisionIn(&decisions, TrigCompositeUtils::hypoAlgNodeName())); // H
    for (auto chainId : proxy->passChains)
    {
      TrigCompositeUtils::addDecisionID(chainId, proxy->hNode.back());
    }
 
    TrigCompositeUtils::linkToPrevious(proxy->hNode.front(), proxy->imNode, context); // H low IM up
  }
  // connecting current IM to all Hs in parent proxies
  for (auto &proxy : convProxies)
  {
    for (auto &parentProxy : proxy->parents)
    {
      TrigCompositeUtils::linkToPrevious(proxy->imNode, parentProxy->hNode.front(), context); // IM low H up (in parent)
    }
  }
  ATH_MSG_DEBUG("IM & H nodes made, output nav elements " << decisions.size());
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::createSFNodes(const ConvProxySet_t &convProxies, xAOD::TrigCompositeContainer &decisions,
                                                       const TEIdToChainsMap_t &terminalIds, const EventContext &context) const
{
  // make node & link it properly
  auto makeSingleSFNode = [&decisions, &context](auto lastDecisionNode, auto chainIds, TrigCompositeUtils::DecisionID idStore = 0)
  {
    auto sfNode = TrigCompositeUtils::newDecisionIn(&decisions);
    sfNode->setName("SF");
    TrigCompositeUtils::linkToPrevious(decisions.at(0), sfNode, context);
    TrigCompositeUtils::linkToPrevious(sfNode, lastDecisionNode, context);
    for (auto chainId : chainIds)
    {
      if (idStore == 0)
    {
      TrigCompositeUtils::addDecisionID(chainId, sfNode);
      TrigCompositeUtils::addDecisionID(chainId, decisions.at(0));
    }
      else if (chainId.numeric() == idStore)
      {
        TrigCompositeUtils::addDecisionID(chainId, sfNode);
        TrigCompositeUtils::addDecisionID(chainId, decisions.at(0));
      }
    }
    return sfNode;
  };
  auto makeSFNodes = [makeSingleSFNode](auto proxy, TrigCompositeUtils::DecisionID idToStore = 0)
  {
      if (proxy->hNode.empty())
      { // nothing has passed, so link to the IM node
        // TODO make sure it needs to be done like that
        makeSingleSFNode(proxy->imNode, proxy->runChains, idToStore);
      }
      else
      {
        // makeSFNode(proxy->hNode[0], TCU::decisionIDs(proxy->hNode[0])); // not using passChains as there may be additional filtering
        for (auto &hNode : proxy->hNode)
        {
          makeSingleSFNode(hNode, proxy->passChains, idToStore); // using passChains
        }
      }
  };
 
  for (auto proxy : convProxies)
  {
    // associate terminal nodes to filter nodes,
    if (proxy->children.empty())
    { // the H modes are terminal
      makeSFNodes(proxy);
    }
    else
    {
      // likely need more iterations
      // nonterminal nodes that are nevertheless terminal for a given chain
      std::vector<TCU::DecisionID> toRetain;
      for (auto teId : proxy->teIDs)
      {
        auto whereInMap = terminalIds.find(teId);
        if (whereInMap != terminalIds.end())
        {
          toRetain.insert(toRetain.end(), whereInMap->second.begin(), whereInMap->second.end());
        }
      }
      for (auto chainIdstore : toRetain)
      {
        makeSFNodes(proxy, chainIdstore);
      }
    }
  }
  // associate all nodes designated as final one with the filter nodes
 
  ATH_MSG_DEBUG("SF nodes made, output nav elements " << decisions.size());
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::updateTerminusNode(xAOD::TrigCompositeContainer &decisions, const EventContext &) const
{
  // Check that only ChainIDs (not LegIDs) are present in the terminus "HLTPassRaw" node.
  // Check that only chains which pass the event are included.
  TCU::Decision* terminus = decisions.at(0);
  ATH_CHECK( terminus->name() == TCU::summaryPassNodeName() );
  TCU::DecisionIDContainer currentIDs;
  TCU::DecisionIDContainer filteredIDs;
  TCU::decisionIDs(terminus, currentIDs); // Extract, std::vector -> std::set
  for (const TCU::DecisionID id : currentIDs)
  {
    const TCU::DecisionID idToCheck = ( TCU::isLegId(id) ? TCU::getIDFromLeg( HLT::Identifier(id) ).numeric() : id );
    const std::string chainName = HLT::Identifier(idToCheck).name();
    // Sanity check
    if (!m_chainsToSave.empty())
    {
      if (std::find(m_chainsToSave.begin(), m_chainsToSave.end(), chainName) == m_chainsToSave.end())
      {
        ATH_MSG_ERROR("Navigation information for chain " << chainName << " in "
          << TCU::summaryPassNodeName() << " but this chain wasn't on the list of chains to save");
        return StatusCode::FAILURE;
      }
    }
    if (m_tdt->isPassed(chainName))
    {
      filteredIDs.insert(idToCheck);
    }
  }
  terminus->setDecisions( std::vector<TCU::DecisionID>() ); // decisions.clear(), but via the xAOD setter function
  TCU::insertDecisionIDs(filteredIDs, terminus); // Insert, std::set -> std::vector
  ATH_MSG_VERBOSE("After filtering out leg IDs and checking isPassed, "
    "the terminus node goes from " << currentIDs.size() << " to " << filteredIDs.size() << " chain IDs.");
  if (msgLvl(MSG::VERBOSE))
  {
    for (const TCU::DecisionID id : filteredIDs)
    {
      ATH_MSG_VERBOSE(" -- Retained passing ID: " << HLT::Identifier(id));
    }
  }
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::createL1Nodes(const ConvProxySet_t &convProxies, xAOD::TrigCompositeContainer &decisions,
                                                       const EventContext &context) const
{
 
  auto makeL1Node = [&decisions, &context](auto firstDecisionNode, auto chainIds)
  {
    auto L1Node = TrigCompositeUtils::newDecisionIn(&decisions);
    L1Node->setName(TrigCompositeUtils::hltSeedingNodeName()); // L1
    for (auto chainId : chainIds)
    {
      TrigCompositeUtils::addDecisionID(chainId, L1Node);
    }
    TrigCompositeUtils::linkToPrevious(firstDecisionNode, L1Node, context); // IM -> L1
 
    return L1Node;
  };
 
  for (auto &proxy : convProxies)
  {
    // associate initial node to filter nodes,
    if (proxy->parents.empty())
    {                                                                             // the IM node is initial
      proxy->l1Node = makeL1Node(proxy->imNode, TCU::decisionIDs(proxy->imNode)); // not using passChains as there may be additional filtering
    }
  }
 
  ATH_MSG_DEBUG("L1 nodes made, output nav elements ");
  return StatusCode::SUCCESS;
}
 
std::size_t Run2ToRun3TrigNavConverterV2::getFeaSize(const ConvProxy &proxy) const
{
  size_t feaCount{0};
  if (proxy.features.empty())
  { // no features
    ++feaCount;
  }
  for (const auto &fea : proxy.features)
  {
    if (fea.getIndex().objectsBegin() == fea.getIndex().objectsEnd())
    {
      ++feaCount;
    }
    for (auto n = fea.getIndex().objectsBegin(); n < fea.getIndex().objectsEnd(); ++n)
    {
      ++feaCount;
    }
  }
  // 1 means a deafult H node created is enough, no need to expand H nodes
  return feaCount;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::linkFeaNode(ConvProxySet_t &convProxies, xAOD::TrigCompositeContainer &decisions, const HLT::TrigNavStructure &run2Nav, const EventContext &context) const
{
  // from all FEAs of the associated TE pick those objects that are to be linked
  for (const auto &proxy : convProxies)
  {
    auto [bestFeaIdx, bestObjIdx] = getHighestPtObject(*proxy, run2Nav);
 
    auto feaN = getFeaSize(*proxy);
    if (feaN > 1)
    { // expand for more H nodes and connect them
      while (--feaN)
      {
        proxy->hNode.push_back(TrigCompositeUtils::newDecisionIn(&decisions, TrigCompositeUtils::hypoAlgNodeName())); // H
        for (auto chainId : proxy->passChains) // adding hash values of active chains to expanded H nodes
         {
            TrigCompositeUtils::addDecisionID(chainId, proxy->hNode.back());
         }
        // connecting to upeer IM node
        TrigCompositeUtils::linkToPrevious(proxy->hNode.back(), proxy->imNode, context); // H low IM up
        // connecting created H to IM in children proxies
        for (auto &childProxy : proxy->children)
        {
          TrigCompositeUtils::linkToPrevious(childProxy->imNode, proxy->hNode.back(), context); // IM child H up (just created))
        }
      }
    }
 
    if (proxy->features.empty())
    { // no features attached, self link
      ElementLink<xAOD::TrigCompositeContainer> linkToSelf = TrigCompositeUtils::decisionToElementLink(proxy->hNode.front(), context);
      proxy->hNode.front()->setObjectLink<xAOD::TrigCompositeContainer>(TrigCompositeUtils::featureString(), linkToSelf);
    }
 
    auto hNodeIter = proxy->hNode.begin();
    for (std::size_t feaIdx = 0; feaIdx < proxy->features.size(); ++feaIdx)
    {
      auto &fea = proxy->features[feaIdx];
      auto [sgKey, sgCLID, sgName] = getSgKey(run2Nav, fea);
      // link to itself when lined collection has size 0
      if (fea.getIndex().objectsBegin() == fea.getIndex().objectsEnd())
      {
        ElementLink<xAOD::TrigCompositeContainer> linkToSelf = TrigCompositeUtils::decisionToElementLink(*hNodeIter, context);
        (*hNodeIter)->setObjectLink<xAOD::TrigCompositeContainer>(TrigCompositeUtils::featureString(), linkToSelf);
        ++hNodeIter;
      }
      for (auto n = fea.getIndex().objectsBegin(); n < fea.getIndex().objectsEnd(); ++n)
      {
        // connecting feature or subfeature
        const std::string& linkName = (feaIdx == bestFeaIdx && n == bestObjIdx) ?
                                       TrigCompositeUtils::featureString() : "subfeature";
        (*hNodeIter)->typelessSetObjectLink(linkName, sgKey, sgCLID, n, n + 1);
        ++hNodeIter;
      }
    }
  }
 
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::linkRoiNode(ConvProxySet_t &convProxies, const HLT::TrigNavStructure &run2Nav) const
{
  // from all Rois of the associated TE pick those objects that are to be linked
  for (auto &proxy : convProxies)
  {
    for (auto &roi : proxy->rois)
    {
      auto [sgKey, sgCLID, sgName] = getSgKey(run2Nav, roi);
      if (proxy->l1Node)
      {
        proxy->l1Node->typelessSetObjectLink(TrigCompositeUtils::initialRoIString(), sgKey, sgCLID, roi.getIndex().objectsBegin());
      }
      if (proxy->rois.empty() == false)
      {
        proxy->imNode->typelessSetObjectLink(TrigCompositeUtils::roiString(), sgKey, sgCLID, roi.getIndex().objectsBegin());
      }
    }
  }
 
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::linkTrkNode(ConvProxySet_t &convProxies, const HLT::TrigNavStructure &run2Nav) const
{
  for (auto &proxy : convProxies)
  {
    for (auto &trk : proxy->tracks)
    {
      if (proxy->imNode->hasObjectLink(TrigCompositeUtils::roiString()))
      {
        try
        {
          ElementLink<TrigRoiDescriptorCollection> ROIElementLink = proxy->imNode->objectLink<TrigRoiDescriptorCollection>(TrigCompositeUtils::roiString());
          if (ROIElementLink.isValid())
          {
            SG::AuxElement::Decorator<ElementLink<TrigRoiDescriptorCollection>> viewBookkeeper("viewIndex");
            auto [sgKey, sgCLID, sgName] = getSgKey(run2Nav, trk);
            if (sgCLID == m_TrackParticleContainerCLID || sgCLID == m_TauTrackContainerCLID)
            {
              const char *tName = sgCLID == m_TrackParticleContainerCLID ? "TEMP_TRACKS" : "TEMP_TAU_TRACKS";
              auto d = std::make_unique<TrigCompositeUtils::Decision>();
              d->makePrivateStore();
              d->typelessSetObjectLink(tName, sgKey, sgCLID, trk.getIndex().objectsBegin());
              if (sgCLID == m_TrackParticleContainerCLID)
              {
                for (const ElementLink<xAOD::TrackParticleContainer> &track : d->objectCollectionLinks<xAOD::TrackParticleContainer>(tName))
                {
                  if (track.isValid())
                  {
                    const xAOD::TrackParticle *t = *track;
                    viewBookkeeper(*t) = ROIElementLink;
                  }
                }
              }
              if (m_includeTauTrackFeatures == false && sgCLID == m_TauTrackContainerCLID)
              {
                for (const ElementLink<xAOD::TauTrackContainer> &track : d->objectCollectionLinks<xAOD::TauTrackContainer>(tName))
                {
                  if (track.isValid())
                  {
                    const xAOD::TauTrack_v1 *t = *track;
                    viewBookkeeper(*t) = ROIElementLink;
                  }
                }
              }
            }
          }
        } catch (SG::ExcBadForwardLink&) {
          ATH_MSG_WARNING("Unable to create an ElementLink into a container with no entries");
        }
      }
    }
  }
 
  return StatusCode::SUCCESS;
}
 
// does not need to be a method, so kept as local
bool feaToSkip(const HLT::TriggerElement::FeatureAccessHelper &fea)
{
  CLID thePassBitsCLID = ClassID_traits<xAOD::TrigPassBits>::ID();
  CLID thePassBitsContCLID = ClassID_traits<xAOD::TrigPassBitsContainer>::ID();
 
  return fea.getCLID() == thePassBitsCLID or fea.getCLID() == thePassBitsContCLID;
}
 
std::vector<HLT::TriggerElement::FeatureAccessHelper> Run2ToRun3TrigNavConverterV2::filterFEAs(const std::vector<HLT::TriggerElement::FeatureAccessHelper> &feaVector, const HLT::TrigNavStructure &navigationDecoder) const {
  std::vector<HLT::TriggerElement::FeatureAccessHelper> out;
  for (auto fea : feaVector)
  {
    if (feaToSkip(fea))
    {
      ATH_MSG_VERBOSE("Skipping in FEA hash calculation");
      continue;
    }
 
    auto [sgKey, sgCLID, sgName] = getSgKey(navigationDecoder, fea);
 
    if (sgKey == 0)
    {
      ATH_MSG_VERBOSE("Skipping unrecorded (missing in SG) FEA hash calculation - name in SG: " << sgName << " FEA " << fea);
      continue;
    }
    out.push_back(fea);
  }
  return out;
}
 
uint64_t Run2ToRun3TrigNavConverterV2::feaToHash(const std::vector<HLT::TriggerElement::FeatureAccessHelper> &feaVector, const HLT::TriggerElement *te_ptr, const HLT::TrigNavStructure &navigationDecoder) const
{
  // FEA vectors hashing
  ATH_MSG_VERBOSE("Calculating FEA hash");
  uint64_t hash = 0;
  for (auto fea : filterFEAs(feaVector, navigationDecoder))
  {
    ATH_MSG_VERBOSE("Including FEA in hash CLID: " << fea.getCLID() << " te Id: " << te_ptr->getId());
    boost::hash_combine(hash, fea.getCLID());
    boost::hash_combine(hash, fea.getIndex().subTypeIndex());
    boost::hash_combine(hash, fea.getIndex().objectsBegin());
    boost::hash_combine(hash, fea.getIndex().objectsEnd());
  }
  // Include the originating TE identifier and pointer to ensure that
  // navigation elements stemming from different Trigger Elements do not
  // collapse into a single proxy even if their features are otherwise
  // identical. The TE ID alone is not sufficient, as multiple clones of the
  // same TE share the ID, so we also add the pointer value to the hash.
  boost::hash_combine(hash, te_ptr->getId());
  boost::hash_combine(hash, reinterpret_cast<std::uintptr_t>(te_ptr));
  ATH_MSG_VERBOSE("Obtained FEA hash " << hash);
  return hash;
}
 
bool Run2ToRun3TrigNavConverterV2::feaToSave(const HLT::TriggerElement::FeatureAccessHelper &fea, const std::string& sgName) const
{
  auto iter = m_collectionsToSaveDecoded.find(fea.getCLID());
  if (iter != m_collectionsToSaveDecoded.end())
  {
    if ( iter->second.empty() )
      return true; // feature accepted for saving
    ATH_MSG_DEBUG("fea to save CLID: " << fea.getCLID() << ", sgName: " << sgName << " " <<iter->second.size() << " " << iter->second.empty() );
    return iter->second.contains(sgName);
  }
 
  return false;
}
 
 
 
bool Run2ToRun3TrigNavConverterV2::roiToSave(const HLT::TrigNavStructure &run2Nav, const HLT::TriggerElement::FeatureAccessHelper &roi) const
{
  auto [sgKey, sgCLID, sgName] = getSgKey(run2Nav, roi);
  if (std::find(m_setRoiName.begin(), m_setRoiName.end(), sgName) != m_setRoiName.end())
  {
    return true;
  }
 
  return false;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::allProxiesHaveChain(const ConvProxySet_t &proxies) const
{
  for (auto p : proxies)
  {
    if (p->runChains.empty())
    {
      ATH_MSG_ERROR("Proxy with no chains");
      return StatusCode::FAILURE;
    }
  }
  ATH_MSG_DEBUG("CHECK OK, no proxies w/o a chain");
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::allProxiesConnected(const ConvProxySet_t &proxies) const
{
  for (auto p : proxies)
  {
    if (p->children.empty() and p->parents.empty() and not p->runChains.empty())
    {
      ATH_MSG_ERROR("Orphanted proxy N chains run:" << p->runChains.size());
      return StatusCode::FAILURE;
    }
  }
  ATH_MSG_DEBUG("CHECK OK, no orphanted proxies");
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::numberOfHNodesPerProxyNotExcessive(const ConvProxySet_t &) const
{
  ATH_MSG_DEBUG("CHECK OK, no excessive number of H nodes per proxy");
  return StatusCode::SUCCESS;
}
 
StatusCode Run2ToRun3TrigNavConverterV2::noUnconnectedHNodes(const xAOD::TrigCompositeContainer &decisions) const
{
  // build map of all links to H nodes from IMs and FS
  std::set<const TrigCompositeUtils::Decision *> linkedHNodes;
  for (auto d : decisions)
  {
    if (d->name() == "IM" or d->name() == "FS")
    {
      for (auto el : TCU::getLinkToPrevious(d))
      {
        linkedHNodes.insert(*el); // dereferences to bare pointer
      }
    }
  }
  for (auto d : decisions)
  {
    if (d->name() == "H")
    {
      if (linkedHNodes.count(d) == 0)
      {
        ATH_MSG_ERROR("Orphaned H node");
        return StatusCode::FAILURE;
      }
    }
  }
  ATH_MSG_DEBUG("CHECK OK, all H modes are connected");
 
  return StatusCode::SUCCESS;
}
 
std::tuple<uint32_t, CLID, std::string> Run2ToRun3TrigNavConverterV2::getSgKey(const HLT::TrigNavStructure &navigationDecoder, const HLT::TriggerElement::FeatureAccessHelper &helper) const
{
  const std::string hltLabel = navigationDecoder.label(helper.getCLID(), helper.getIndex().subTypeIndex());
 
  const CLID saveCLID = [&](const CLID &clid)
  {
    if (clid == m_roIDescriptorCLID)
      return m_roIDescriptorCollectionCLID;
    if (clid == m_TrigEMClusterCLID)
      return m_TrigEMClusterContainerCLID;
    if (clid == m_TrigRingerRingsCLID)
      return m_TrigRingerRingsContainerCLID;
    return clid;
  }(helper.getCLID());
 
  std::string type_name;
  if (m_clidSvc->getTypeNameOfID(saveCLID, type_name).isFailure())
  {
    return {0, 0, ""};
  }
 
  const auto sgStringKey = HLTNavDetails::formatSGkey("HLT", type_name, hltLabel);
  const bool isAvailable = evtStore()->contains(saveCLID, sgStringKey);
  ATH_MSG_DEBUG(" Objects presence " << helper << " " << sgStringKey << (isAvailable ? " present" : " absent"));
  if (!isAvailable)
  {
    return {0, saveCLID, ""};
  }
 
  return {evtStore()->stringToKey(sgStringKey, saveCLID), saveCLID, hltLabel}; // sgKey, sgCLID, sgName
}
 
std::pair<std::size_t, std::size_t> Run2ToRun3TrigNavConverterV2::getHighestPtObject(
    const ConvProxy& proxy, const HLT::TrigNavStructure& run2Nav) const
{
  std::size_t bestFea = std::numeric_limits<std::size_t>::max();
  std::size_t bestObj = 0;
  float bestPt = -1.0;
 
  for (std::size_t i = 0; i < proxy.features.size(); ++i) {
    const auto& fea = proxy.features[i];
    auto [sgKey, sgCLID, sgName] = getSgKey(run2Nav, fea);
    if (!feaToSave(fea, sgName)) {
      continue;
    }
    if (sgKey == 0) continue;
    const std::string* keyStr = evtStore()->keyToString(sgKey, sgCLID);
    if (!keyStr) continue;
    const xAOD::IParticleContainer* cont = nullptr;
    if (evtStore()->retrieve(cont, *keyStr).isFailure()) continue;
    for (auto n = fea.getIndex().objectsBegin(); n < fea.getIndex().objectsEnd(); ++n) {
      if (n >= cont->size()) continue;
      const xAOD::IParticle* p = (*cont)[n];
      if (!p) continue;
      if (p->pt() > bestPt) {
        bestPt = p->pt();
        bestFea = i;
        bestObj = n;
      }
    }
  }
  if (bestFea == std::numeric_limits<std::size_t>::max()) {
    for (std::size_t i = 0; i < proxy.features.size(); ++i) {
      auto [sgKey, sgCLID, sgName] = getSgKey(run2Nav, proxy.features[i]);
      if (!feaToSave(proxy.features[i], sgName)) continue;
      bestFea = i;
      bestObj = proxy.features[i].getIndex().objectsBegin();
      break;
    }
  }
  return {bestFea, bestObj};
}