#include <RAT/Log.hh>
#include <RAT/DBCommandLoader.hh>
#include <RAT/MetaInformation.hh>
#include <RAT/DS/Entry.hh>
#include <RAT/DS/Run.hh>
#include <RAT/DS/DataNotFound.hh>
#include <RAT/DU/DSReader.hh>
#include <RAT/DU/Utility.hh>

using namespace RAT;
using namespace RAT::DU;

#include <TFile.h>
#include <TFileCollection.h>
#include <TList.h>
#include <THashList.h>

#include <string>

ClassImp( RAT::DU::DSReader )

DSReader::DSReader( const std::string& filename,
                    const bool useMeta )
  : fUseMeta(useMeta)
{
  string data = getenv("GLG4DATA");
  Log::Assert( data != "", "DSReader::DSReader: GLG4DATA is empty, where is the data?" );

  fT = new TChain("T");
  fRunT = new TChain("runT");
  Add( filename );

  fCurrentEntry = 0;
  fDS = new DS::Entry();
  fT->SetBranchAddress("ds", &fDS);
  fT->GetEntry( fCurrentEntry );

  fCurrentRun = 0;
  fRun = new DS::Run();
  fRunT->SetBranchAddress( "run", &fRun );
  fRunT->GetEntry( 0 );
  BeginOfRun();
}

DSReader::DSReader( const std::vector<std::string>& filenames,
                    const bool useMeta )
  : fUseMeta(useMeta)
{
  string data = getenv("GLG4DATA");
  Log::Assert( data != "", "DSReader::DSReader: GLG4DATA is empty, where is the data?" );

  fT = new TChain("T");
  fRunT = new TChain("runT");
  for( size_t iFile = 0; iFile < filenames.size(); iFile++ )
    Add( filenames[iFile] );

  fCurrentEntry = 0;
  fDS = new DS::Entry();
  fT->SetBranchAddress("ds", &fDS);
  fT->GetEntry( fCurrentEntry );

  fCurrentRun = 0;
  fRun = new DS::Run();
  fRunT->SetBranchAddress( "run", &fRun );
  fRunT->GetEntry( 0 );
  BeginOfRun();
}

DSReader::~DSReader()
{
  delete fT;
  delete fRunT;
  delete fRun;
  delete fDS;
}

void
DSReader::BeginOfRun()
{
  DB* db = DB::Get();
  db->BeginOfRun(*fRun);
  if (!fRun->GetMCFlag() || fRun->GetRunID() != 0) {
    db->LoadDefaultPlaneLocks();
  }
  try {
    db->Load( db->GetLink("DETECTOR")->GetS( "geo_file" ) );
    db->Load( db->GetLink("DETECTOR")->GetS( "pmt_info_file" ) );
  }
  catch(DBNotFoundError &e) {
    std::string msg = Form("%s : Attempting to fetch %s[%s].%s",
                           e.what(),
                           e.table.c_str(),
                           e.index.c_str(),
                           e.field.c_str());
    msg += "\n Hint: Be sure that RAT::DB loads a DETECTOR table with the appropriate geometry and PMT information.";
    Log::Die(msg);
  }
  Utility::Get()->BeginOfRun();
  db->EndOfBeginOfRun();
}

void
DSReader::Add( const std::string& filename )
{

  TFileCollection * col = new TFileCollection();
  col->Add(filename.c_str());
  //Assert that the list is bigger than 0
  Log::Assert(col->GetNFiles()>0, "DSReader::Add: File name/pattern yields no valid files!");

  // col will have already a consolidated list of existing files
  fT->AddFileInfoList(dynamic_cast<TList*>(col->GetList()));
  fRunT->AddFileInfoList(dynamic_cast<TList*>(col->GetList()));
  delete col;

  fTotalEntries = fT->GetEntries();
  fTotalRuns = fRunT->GetEntries();

  DB::Get()->AllowDanger();
  RAT::Log::ClearDBTraceMap();
  DB::Get()->Clear(); // Need some way not to clear defaults...
  DB::Get()->LoadDefaults();

  // Load the Meta information
  fT->GetFile()->GetObject("meta",fMeta);
  if(fMeta){
    MetaInformation::Get()->Initialise(fMeta);
  }
  else{
    warn<<"*** DSReader::Add: WARNING ***"<<newline;
    warn<<"* No meta information found in "<<filename<<": Creating new one."<<newline;
    warn<<"* This implies that the conditions under which this file was produced"<<newline;
    warn<<"* is unknown and the correct constants might NOT apply!"<<newline;
    warn<<"***********************************************************"<<newline;
    MetaInformation::Get()->Initialise();
  }
  if( fUseMeta ){ DBCommandLoader::LoadCommands( *fMeta ); }

}

const DS::Entry&
DSReader::GetEntry( const size_t entry )
{
  if( entry >= fTotalEntries )
    throw DS::DataNotFound( "DSReader", "GetEntry" );
  const unsigned int previousRun = GetRun().GetRunID();
  fT->GetEntry( entry );
  if( GetRun().GetRunID() != previousRun )
    BeginOfRun();
  return *fDS;
}

const DS::Run&
DSReader::GetRun()
{
  return GetRunByRunID( fDS->GetRunID() );
}

const DS::Run&
DSReader::GetRunByRunID( const unsigned int runID )
{
  if( runID == fRun->GetRunID() )
    return *fRun;
  for( size_t iRun = 0; iRun < GetRunCount(); iRun++ )
    {
      const DS::Run& run = GetRunByIndex( iRun );
      if( run.GetRunID() == runID )
        return run;
    }
  throw DS::DataNotFound( "DSReader", "GetRunByRunID" );
}

const DS::Run&
DSReader::GetRunByIndex( const size_t index )
{
  if( index >= fTotalRuns )
    throw DS::DataNotFound( "DSReader", "GetRunByIndex" );
  fRunT->GetEntry( index );
  return *fRun;
}