/*
  This file is part of LilyPond, the GNU music typesetter.

  Copyright (C) 1997--2020 Han-Wen Nienhuys <hanwen@xs4all.nl>

  LilyPond is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  LilyPond is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "engraver.hh"
#include "note-column.hh"
#include "note-collision.hh"
#include "axis-group-interface.hh"
#include "item.hh"

#include "translator.icc"

using std::vector;

class Collision_engraver : public Engraver
{
  Item *col_;
  vector<Grob *> note_columns_;

protected:
  void acknowledge_note_column (Grob_info);
  void process_acknowledged ();
  void stop_translation_timestep ();
public:
  TRANSLATOR_DECLARATIONS (Collision_engraver);
};

void
Collision_engraver::process_acknowledged ()
{
  if (col_ || note_columns_.size () < 2)
    return;
  if (!col_)
    col_ = make_item ("NoteCollision", SCM_EOL);

  for (vsize i = 0; i < note_columns_.size (); i++)
    Note_collision_interface::add_column (col_, note_columns_[i]);
}

void
Collision_engraver::acknowledge_note_column (Grob_info i)
{
  if (has_interface<Note_column> (i.grob ()))
    {
      /*should check Y axis? */
      if (Note_column::has_rests (i.grob ()) || i.grob ()->get_x_parent ())
        return;

      if (from_scm<bool> (get_property (i.grob (), "ignore-collision")))
        return;

      note_columns_.push_back (i.grob ());
    }
}

void
Collision_engraver::stop_translation_timestep ()
{
  col_ = 0;
  note_columns_.clear ();
}

Collision_engraver::Collision_engraver (Context *c)
  : Engraver (c)
{
  col_ = 0;
}

void
Collision_engraver::boot ()
{
  ADD_ACKNOWLEDGER (Collision_engraver, note_column);
}

ADD_TRANSLATOR (Collision_engraver,
                /* doc */
                "Collect @code{NoteColumns}, and as soon as there are two or"
                " more, put them in a @code{NoteCollision} object.",

                /* create */
                "NoteCollision ",

                /* read */
                "",

                /* write */
                ""
               );
