/*
  simultaneous-music-iterator.cc -- implement Simultaneous_music_iterator

  source file of the GNU LilyPond music typesetter

  (c) 1997--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
*/

#include "simultaneous-music-iterator.hh"
#include "music.hh"
#include "context.hh"
#include "warn.hh"
#include "context-def.hh"

Simultaneous_music_iterator::Simultaneous_music_iterator ()
{
  create_separate_contexts_ = false;
  children_list_ = SCM_EOL;
}

void
Simultaneous_music_iterator::derived_mark () const
{
  scm_gc_mark (children_list_);
}

void
Simultaneous_music_iterator::derived_substitute (Context *f, Context *t)
{
  for (SCM s = children_list_; scm_is_pair (s); s = scm_cdr (s))
    unsmob_iterator (scm_car (s))->substitute_outlet (f, t);
}

void
Simultaneous_music_iterator::construct_children ()
{
  int j = 0;

  SCM i = get_music ()->get_property ("elements");

  children_list_ = SCM_EOL;
  SCM *tail = &children_list_;
  for (; scm_is_pair (i); i = scm_cdr (i), j++)
    {
      Music *mus = unsmob_music (scm_car (i));

      SCM scm_iter = get_static_get_iterator (mus);
      Music_iterator *mi = unsmob_iterator (scm_iter);

      /* if create_separate_contexts_ is set, create a new context with the
	 number number as name */

      SCM name = ly_symbol2scm (get_outlet ()->context_name ().c_str ());
      Context *t = (j && create_separate_contexts_)
	? get_outlet ()->find_create_context (name, to_string (j), SCM_EOL)
	: get_outlet ();

      if (!t)
	t = get_outlet ();

      mi->init_translator (mus, t);
      mi->construct_children ();

      if (mi->ok ())
	{
	  *tail = scm_cons (scm_iter, *tail);
	  tail = SCM_CDRLOC (*tail);
	}
      else
	mi->quit ();
    }
}

void
Simultaneous_music_iterator::process (Moment until)
{
  SCM *proc = &children_list_;
  while (scm_is_pair (*proc))
    {
      Music_iterator *i = unsmob_iterator (scm_car (*proc));
      if (i->run_always ()
	  || i->pending_moment () == until)
	i->process (until);
      if (!i->ok ())
	{
	  i->quit ();
	  *proc = scm_cdr (*proc);
	}
      else
	proc = SCM_CDRLOC (*proc);
    }
}

Moment
Simultaneous_music_iterator::pending_moment () const
{
  Moment next;
  next.set_infinite (1);

  for (SCM s = children_list_; scm_is_pair (s); s = scm_cdr (s))
    {
      Music_iterator *it = unsmob_iterator (scm_car (s));
      next = min (next, it->pending_moment ());
    }

  return next;
}

bool
Simultaneous_music_iterator::ok () const
{
  bool run_always_ok = false;
  for (SCM s = children_list_; scm_is_pair (s); s = scm_cdr (s))
    {
      Music_iterator *it = unsmob_iterator (scm_car (s));
      if (!it->run_always ())
	return true;
      else
	run_always_ok = run_always_ok || it->ok ();
    }
  return run_always_ok;
}

bool
Simultaneous_music_iterator::run_always () const
{
  for (SCM s = children_list_; scm_is_pair (s); s = scm_cdr (s))
    {
      Music_iterator *it = unsmob_iterator (scm_car (s));
      if (it->run_always ())
	return true;
    }
  return false;
}

Music_iterator *
Simultaneous_music_iterator::try_music_in_children (Music *m) const
{
  Music_iterator *b = 0;
  for (SCM s = children_list_; !b && scm_is_pair (s); s = scm_cdr (s))
    b = unsmob_iterator (scm_car (s))->try_music (m);
  return b;
}

void
Simultaneous_music_iterator::do_quit ()
{
  for (SCM s = children_list_; scm_is_pair (s); s = scm_cdr (s))
    unsmob_iterator (scm_car (s))->quit ();
}

IMPLEMENT_CTOR_CALLBACK (Simultaneous_music_iterator);
