/*   
     new-chord-tremolo-engraver.cc --  implement Chord_tremolo_engraver
  
     source file of the GNU LilyPond music typesetter
  
     (c) 2000--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
  
*/

#include "engraver.hh"
#include "beam.hh"
#include "repeated-music.hh"
#include "stem.hh"
#include "rhythmic-head.hh"
#include "engraver-group-engraver.hh"
#include "event.hh"
#include "warn.hh"
#include "misc.hh"
#include "note-head.hh"
#include "spanner.hh"
#include "item.hh"
#include "chord-tremolo-iterator.hh"
#include "stem-tremolo.hh"
#include "music-list.hh"
#include "math.h"           // ceil

/**

This acknowledges repeated music with "tremolo" style.  It typesets
a beam.

TODO:

- perhaps use engraver this to steer other engravers? That would
create dependencies between engravers, which is bad.

- create dots if appropriate.

- create TremoloBeam iso Beam?

*/
class Chord_tremolo_engraver : public Engraver
{
  void typeset_beam ();
  TRANSLATOR_DECLARATIONS (Chord_tremolo_engraver);
protected:
  Repeated_music * repeat_;

  /// moment (global time) where beam started.
  Moment start_mom_;
  Moment stop_mom_;
  int flags_ ;
  int total_duration_flags_;
  
  /// location  within measure where beam started.
  Moment beam_start_location_;

  bool sequential_body_b_;
  Spanner * beam_;
  Spanner * finished_beam_;
  Item * stem_tremolo_;
protected:
  virtual void finalize ();
  virtual bool try_music (Music*);
  virtual void acknowledge_grob (Grob_info);
  virtual void stop_translation_timestep ();
  virtual void start_translation_timestep ();
  virtual void process_music ();
};

Chord_tremolo_engraver::Chord_tremolo_engraver ()
{
  beam_  = finished_beam_ = 0;
  repeat_ =0;
  flags_ = 0;
  stem_tremolo_ = 0;
  sequential_body_b_ = false;
}

bool
Chord_tremolo_engraver::try_music (Music * m)
{
  Repeated_music * rp = dynamic_cast<Repeated_music*> (m);
  if (rp
      && rp->get_property ("iterator-ctor") == Chord_tremolo_iterator::constructor_proc
      && !repeat_) 
    {
      Moment l = rp->get_length ();
      repeat_ = rp;
      start_mom_ = now_mom ();
      stop_mom_ = start_mom_ + l;

      Sequential_music * seq = dynamic_cast<Sequential_music*> (rp->body ());
      sequential_body_b_ = seq;

      int elt_count = seq ? scm_ilength (seq-> music_list ()) : 1;

      if (seq && elt_count != 2)
	{
	  rp->origin ()->warning (_f ("Chord tremolo with %d elements. Must have two elements.", elt_count));
	}

      if (elt_count <= 0)
	elt_count = 1;
	  
      Rational total_dur = l.main_part_;
      Rational note_dur = total_dur / Rational (elt_count * repeat_->repeat_count ());

      total_duration_flags_ = 0 >? (intlog2 (total_dur.den ()) - 2);
      
      flags_ = intlog2 (note_dur.den ()) -2 ;
      
      return true;
    }

  return false;
}

void
Chord_tremolo_engraver::process_music ()
{
  if (repeat_ && sequential_body_b_ && !beam_)
    {
      beam_ = make_spanner ("Beam", repeat_->self_scm ());
      beam_->set_property ("chord-tremolo", SCM_BOOL_T);

      beam_start_location_ = robust_scm2moment (get_property ("measurePosition"), Moment (0));
    }
}

void
Chord_tremolo_engraver::finalize ()
{
  typeset_beam ();
  if (beam_)
    {
      repeat_->origin ()->warning (_ ("unterminated chord tremolo"));
      beam_->suicide ();
    }
}

void
Chord_tremolo_engraver::typeset_beam ()
{
  finished_beam_ = 0;
}

void
Chord_tremolo_engraver::acknowledge_grob (Grob_info info)
{
  if (beam_ && Stem::has_interface (info.grob_))
    {
      Grob * s = info.grob_;

      if (start_mom_ == now_mom ())
	Stem::set_beaming (s, flags_, RIGHT);
      else
	Stem::set_beaming (s, flags_, LEFT);
	  
      if (Stem::duration_log (s) != 1)
	{
	  beam_->set_property ("gap-count", scm_int2num (flags_ - total_duration_flags_));
	}

      if (info.music_cause ()->is_mus_type ("rhythmic-event"))
	{
	  Beam::add_stem (beam_, s);
	}
      else
	{
	  String s = _ ("stem must have Rhythmic structure");
	  if (info.music_cause ())
	    info.music_cause ()->origin ()->warning (s);
	  else
	    ::warning (s);
	}
    }
  else if (repeat_ &&
	   flags_ && !sequential_body_b_ && Stem::has_interface (info.grob_))
    {
      stem_tremolo_ = make_item ("StemTremolo", repeat_->self_scm ());
      stem_tremolo_->set_property ("flag-count",
				   scm_int2num (flags_));
      stem_tremolo_->set_property ("stem",
				   info.grob_->self_scm ());
      stem_tremolo_->set_parent (info.grob_, X_AXIS);
    }
}


void
Chord_tremolo_engraver::start_translation_timestep ()
{
  if (beam_ && stop_mom_ == now_mom ())
    {
      finished_beam_ = beam_;
      repeat_ = 0;
      beam_ = 0;
    }
}


void
Chord_tremolo_engraver::stop_translation_timestep ()
{
  if (stem_tremolo_)
    {
      repeat_ = 0;
      if (beam_)
	programming_error ("Huh, beam and stem tremolo?");
      stem_tremolo_ = 0;
    }

  typeset_beam ();
}



ENTER_DESCRIPTION (Chord_tremolo_engraver,
/* descr */       "Generates beams for  tremolo repeats.",
/* creats*/       "Beam",
/* accepts */     "repeated-music",
/* acks  */      "stem-interface note-head-interface",
/* reads */       "",
/* write */       "");
