// AddFitter.cpp

#include "AddFitter.h"
#include <iostream>
#include <cassert>
#include "trfutil/trfstream.h"
#include "trfbase/Surface.h"
#include "trfbase/ETrack.h"
#include "HTrack.h"

using std::cout;
using std::endl;

using trf::HitPtr;
using trf::ETrack;
using trf::HTrack;
using trf::AddFitter;

//**********************************************************************
// Free functions.
//**********************************************************************

namespace {

ObjPtr create(const ObjData& data) {
  return ObjPtr(0);
}

}

//**********************************************************************
// Member functions.
//**********************************************************************

// constructor

AddFitter::AddFitter()
: _base_add_hit(false), _base_add_hit_fit(false) { }

//**********************************************************************

// destructor

AddFitter::~AddFitter() { }

//**********************************************************************

// Return the creator.

ObjCreator AddFitter::get_creator() {
  return create;
}

//**********************************************************************

// Add a hit to an ETrack.
// Default is call add_hit_fit_with_record(tre,chsq,phit,0);
// If neither method is overriden, the fit fails.

int AddFitter::
add_hit_fit(ETrack& tre, double& chsq, const HitPtr& phit) const {
  // Check that we are not stuck in a loop because subclass has failed
  // to implement either ETrack method.
  if ( _base_add_hit_fit ) {
    cout << *this << endl;
    assert(false);
    return 1;
  }
  _base_add_hit_fit = true;
  int stat = add_hit_fit_with_record(tre,chsq,phit,0);
  _base_add_hit_fit = false;
  return stat;
}

//**********************************************************************

// Add a hit to an ETrack with a cut record.
// Default is call add_hit_fit(tre,chsq,phit);

int AddFitter::
add_hit_fit_with_record(ETrack& tre, double& chsq, const HitPtr& phit,
                        CutRecord* prec) const {
  return add_hit_fit(tre,chsq,phit);
}

//**********************************************************************

// add hit to an HTrack

int AddFitter::add_hit(HTrack& trh, const HitPtr& phit) const {
  _base_add_hit = true;
  int stat = add_hit_with_record(trh,phit,0);
  _base_add_hit = false;
  return stat;
}

//**********************************************************************

// Default method to add a hit to an HTrack.
//
// If subclass has implemented add_hit(trh,phit) const, then we use it.
// If not, call add_hit_fit_with_record(tre,chsq,phit,prec).

int AddFitter::add_hit_with_record(
HTrack& trh, const HitPtr& phit, CutRecord* prec) const {

  // Define the return status.
  int stat = 0;

  // If we have not already done so, try add_hit(trh,phit).
  if ( ! _base_add_hit ) {
    stat = add_hit(trh,phit);

  // Otherwise try add_hit_fit_with_record(tre,chsq,phit,prec).
  } else {

    // Fetch the starting fit and chi-square.
    ETrack tre = trh.get_track();
    double chsq = trh.get_chi_square();

    // check the track and hit are at the same surface
    const Surface& tsrf = *tre.get_surface();
    const Surface& hsrf = phit->get_surface();
    assert ( tsrf.pure_equal(hsrf) );
    if ( ! tsrf.pure_equal(hsrf) ) return -1;

    // Check the track is fully fit before adding hit.
    // Unless this is the first hit.
    if ( trh.get_hits().size() ) {
      assert( trh.is_fit() );
      if ( ! trh.is_fit() ) return -2;
    }

    // Fit with the new point; exit if error occurs.
    int stat = this->add_hit_fit_with_record(tre,chsq,phit,prec);
    if ( stat ) return stat;

    // Update the track with the new fit and hit.
    trh.add_hit(phit);
    trh.set_fit(tre,chsq);

  }

  return stat;

}

//**********************************************************************