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//
// G4DecayTable class implementation
//
// Author: H.Kurashige, 7 July 1996
// --------------------------------------------------------------------

#include "G4DecayTable.hh"

#include "Randomize.hh"
#include "globals.hh"

G4DecayTable::G4DecayTable()
{
  channels = new G4VDecayChannelVector;
}

G4DecayTable::~G4DecayTable()
{
  // remove and delete all contents
  for (const auto channel : *channels) {
    delete channel;
  }
  channels->clear();
  delete channels;
  channels = nullptr;
  parent = nullptr;
}

void G4DecayTable::Insert(G4VDecayChannel* aChannel)
{
  if (parent == nullptr) {
    parent = (G4ParticleDefinition*)(aChannel->GetParent());
  }
  if (parent != aChannel->GetParent()) {
#ifdef G4VERBOSE
    G4cout << " G4DecayTable::Insert :: bad G4VDecayChannel (mismatch parent) "
           << "       " << parent->GetParticleName()
           << " input:" << aChannel->GetParent()->GetParticleName() << G4endl;
#endif
  }
  else {
    G4double br = aChannel->GetBR();
    for (auto iCh = channels->cbegin(); iCh != channels->cend(); ++iCh) {
      if (br > (*iCh)->GetBR()) {
        channels->insert(iCh, aChannel);
        return;
      }
    }
    channels->push_back(aChannel);
  }
}

G4VDecayChannel* G4DecayTable::SelectADecayChannel(G4double parentMass)
{
  // check if contents exist
  if (channels->empty()) return nullptr;

  if (parentMass < 0.) parentMass = parent->GetPDGMass();

  G4double sumBR = 0.;
  for (const auto channel : *channels) {
    if (!(channel->IsOKWithParentMass(parentMass))) continue;
    sumBR += channel->GetBR();
  }
  if (sumBR <= 0.0) {
#ifdef G4VERBOSE
    G4cout << " G4DecayTable::SelectADecayChannel :: no possible DecayChannel"
           << "       " << parent->GetParticleName() << G4endl;
#endif
    return nullptr;
  }

  const std::size_t MAX_LOOP = 10000;
  for (std::size_t loop_counter = 0; loop_counter < MAX_LOOP; ++loop_counter) {
    G4double sum = 0.0;
    G4double br = sumBR * G4UniformRand();
    // select decay channel
    for (const auto channel : *channels) {
      sum += channel->GetBR();
      if (!(channel->IsOKWithParentMass(parentMass))) continue;
      if (br < sum) return channel;
    }
  }
  return nullptr;
}

void G4DecayTable::DumpInfo() const
{
  G4cout << "G4DecayTable:  " << parent->GetParticleName() << G4endl;
  G4int index = 0;
  for (const auto channel : *channels) {
    G4cout << index << ": ";
    channel->DumpInfo();
    index += 1;
  }
  G4cout << G4endl;
}