//
// Description:
//      Fucking draw the shit.
//
// Environment:
//      Software developed for FOPI GEM-TPC
//
// Author List:
//      Felix Boehmer    TUM   (original author)
//
//
//-----------------------------------------------------------

#include "FopiEventDisplayTask.h"
#include "GenfitDisplay.h"
#include "TClonesArray.h"
#include "FairRun.h"
#include "FairRuntimeDb.h"
#include "FairRootManager.h"
#include "TGeoShape.h"
#include "TGeoMatrix.h"
#include "TGeoTube.h"
#include "TEveGeoShape.h"
#include "TEveStraightLineSet.h"



#include "TpcDigiPar.h"

#include "GFTrack.h"
#include "CdcTrack.h"

#include <cstdio>

ClassImp(FopiEventDisplayTask)

FopiEventDisplayTask::FopiEventDisplayTask() 
  :
  fOptions(""),
  fCdcCircleBranchName("CdcTrack")
{;}



InitStatus
FopiEventDisplayTask::Init()
{
  //Get ROOT Manager
  FairRootManager* ioman= FairRootManager::Instance();
  
  if(ioman==0)
    {
      Error("FopiEventDisplayTask::Init","RootManager not instantiated!");
      return kERROR;
    }
  
  
  fGFTrackArray=(TClonesArray*) ioman->GetObject(fGFTrackBranchName);
  
  if(fGFTrackArray==0)
    {
      Error("FopiEventDisplayTask::Init","CDC GFTrack-array not found!");
      return kERROR;
    }

  fCdcCircleArray=(TClonesArray*) ioman->GetObject(fCdcCircleBranchName);
  
  if(fCdcCircleArray==0)
    {
      Error("FopiEventDisplayTask::Init","CDC CdcCircle-array not found!");
      return kERROR;
    }

  fDisplay = GenfitDisplay::getInstance();
  fDisplay->setOptions(fOptions.Data());
 
  return kSUCCESS;
}


void
FopiEventDisplayTask::SetParContainers() {

  std::cout<<"FopiEventDisplayTask::SetParContainers"<<std::endl;
  std::cout.flush();
  
  // Get run and runtime database
  FairRun* run = FairRun::Instance();
  if ( ! run ) Fatal("SetParContainers", "No analysis run");

  FairRuntimeDb* db = run->GetRuntimeDb();
  if ( ! db ) Fatal("SetParContainers", "No runtime database");

  // Get Tpc digitisation parameter container
  fPar= (TpcDigiPar*) db->getContainer("TpcDigiPar");
  if (! fPar ) Fatal("SetParContainers", "TpcDigiPar not found");

}


void
FopiEventDisplayTask::Exec(Option_t* opt)
{
  std::vector<GFTrack*> tracklist;
  for(unsigned int it=0; it<fGFTrackArray->GetEntriesFast(); it++) {
    GFTrack* track = (GFTrack*) fGFTrackArray->At(it);
    tracklist.push_back(track);
  }
  fDisplay->addEvent(tracklist);


  std::vector<TEveGeoShape*> shapes;
  std::vector<TEveStraightLineSet*> lines;
  
  for(unsigned int is=0; is<fCdcCircleArray->GetEntriesFast(); is++) {
    CdcTrack* track = (CdcTrack*)fCdcCircleArray->At(is);
    double charge = track->GetCharge();
    double rad = std::fabs(track->GetRadius());
    double mx = track->GetMx();
    double my = track->GetMy();
        
    double theta = 0.5*TMath::Pi()-track->GetTheta();  //radians
    
    TString name("cdc_track");
    
    TEveStraightLineSet* lineset = new TEveStraightLineSet(name.Data());
    lineset->SetLineColor(kTeal+3);
    lineset->SetLineWidth(2.);
    //vector from circle center to origin:
    TVector3 start(mx,my,0.);
    double steplength = 0.4;  //
    double d_alpha = steplength/rad;
    
    double totrot = 0.;
    //pointing to the track points: 
    TVector3 target = -1.*start;
    target.SetMag(rad);
    target.SetZ(track->GetZ0());
    TVector3 target0 = target;    
    TVector3 pos = target+start; //real position on the track
    while(pos.Perp() < 100 && totrot < TMath::Pi()) {
      //todo: check for charge -> determine rotation sense
      TEveVector lastPoint(pos.X(),pos.Y(),pos.Z());
      //move to the next point:
      if(charge<0.)
	target.RotateZ(d_alpha);
      else 
	target.RotateZ(-d_alpha);
      
      double dz = steplength * TMath::Tan(theta);
      target.SetZ(target.Z() + dz);
      pos = target + start;
      totrot += d_alpha;

      TEveVector newPoint(pos.X(),pos.Y(),pos.Z());
      lineset->AddLine(lastPoint,newPoint);
    }
    std::cout<<"   adding CDC track around ("<<mx<<","<<my
    	     <<") with radius "<<rad<<std::endl;
    lines.push_back(lineset);
    
 
   
    
  }

 
  
  fDisplay->addShapes(shapes);
  fDisplay->addLines(lines);

}