/**
 *  \file BallMover.cpp  \brief A modifier which perturbs a discrete variable.
 *
 *  Copyright 2007-2010 IMP Inventors. All rights reserved.
 *
 */

#include <IMP/core/IncrementalBallMover.h>
#include <IMP/core/XYZ.h>
#include <IMP/algebra/vector_generators.h>
#include <boost/random/uniform_real.hpp>
#include <algorithm>

IMPCORE_BEGIN_NAMESPACE

IncrementalBallMover::IncrementalBallMover(SingletonContainer *sc,
                                           unsigned int n,
                                           Float radius): sc_(sc),
                                                          n_(n),
                                                          radius_(radius),
                                                          moved_(n_)
{
}

void IncrementalBallMover::propose_move(Float /*size*/) {
  // damnit, why didn't these functions make it into the standard
  /*std::random_sample(sc_->particles_begin(), sc_->particles_end(),
    moved_.begin(), moved_.end());*/
  IMP_CHECK_OBJECT(sc_);
  IMP_CHECK_OBJECT(this);
  IMP_OBJECT_LOG;
  ParticlesTemp pts(sc_->get_particles());
  std::random_shuffle(pts.begin(), pts.end());
  for (unsigned int i=0;
       i< std::min(n_, static_cast<unsigned int>(pts.size())); ++i) {
    moved_[i]= pts[i];
    XYZ d(moved_[i]);
    IMP_USAGE_CHECK(d.get_coordinates_are_optimized(),
                    "Particles passed to IncrementalBallMover must have "
                    << "optimized cartesian coordinates. "
                    << moved_[i]->get_name() << " does not.");
    d.set_coordinates(algebra::get_random_vector_in<3>
                      (algebra::Sphere3D(d.get_coordinates(),
                                         radius_)));
    IMP_LOG(VERBOSE, "Proposing move of particle " << d->get_name()
            << " to " << d.get_coordinates() << std::endl);
  }
}


void IncrementalBallMover::accept_move() {
}

void IncrementalBallMover::reject_move() {
  for (unsigned int i=0; i< n_; ++i) {
    XYZ od(moved_[i]->get_prechange_particle());
    XYZ cd(moved_[i]);
    cd.set_coordinates(od.get_coordinates());
  }
}


void IncrementalBallMover::do_show(std::ostream &out) const {
  out << "on " << *sc_ << std::endl;
}

IMPCORE_END_NAMESPACE