/*
  engraver-group-engraver.cc -- implement Engraver_group_engraver

  source file of the GNU LilyPond music typesetter

  (c) 1997--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
*/

#include "engraver-group-engraver.hh"

#include "flower-proto.hh"
#include "warn.hh"
#include "paper-score.hh"
#include "grob.hh"
#include "context.hh"

void
Engraver_group_engraver::announce_grob (Grob_info info)
{
  announce_infos_.push (info);
  get_daddy_engraver ()->announce_grob (info);
}

SCM find_acknowledge_engravers (SCM gravlist, SCM meta);
SCM find_accept_engravers (SCM gravlist, SCM music_descr);

void
Engraver_group_engraver::acknowledge_grobs ()
{
  if (!announce_infos_.size ())
    return;

  SCM tab = get_property ("acknowledgeHashTable");
  SCM name_sym = ly_symbol2scm ("name");
  SCM meta_sym = ly_symbol2scm ("meta");

  for (int j = 0; j < announce_infos_.size (); j++)
    {
      Grob_info info = announce_infos_[j];

      SCM meta = info.grob ()->internal_get_property (meta_sym);
      SCM nm = scm_assoc (name_sym, meta);
      if (scm_is_pair (nm))
	nm = scm_cdr (nm);
      else
	{
	  /*
	    it's tempting to put an assert for
	    immutable_property_alist_ == '(), but in fact, some
	    engravers (clef-engraver) add some more information to the
	    immutable_property_alist_ (after it has been '()-ed).

	    We ignore the grob anyway. He who has no name, shall not
	    be helped.  */

	  continue;
	}

      SCM acklist = scm_hashq_ref (tab, nm, SCM_UNDEFINED);
      if (acklist == SCM_BOOL_F)
	{
	  acklist = find_acknowledge_engravers (scm_cons (self_scm (), get_simple_trans_list ()), meta);
	  scm_hashq_set_x (tab, nm, acklist);
	}

      for (SCM p = acklist; scm_is_pair (p); p = scm_cdr (p))
	{
	  Translator *t = unsmob_translator (scm_car (p));
	  Engraver *eng = dynamic_cast<Engraver *> (t);
	  if (eng && eng != info.origin_translator ())
	    eng->acknowledge_grob (info);
	}
    }
}

/*
  Ugh. This is slightly expensive. We could/should cache the value of
  the group count?
*/
int
Engraver_group_engraver::pending_grob_count () const
{
  int count = announce_infos_.size ();
  for (SCM s = context ()->children_contexts ();
       scm_is_pair (s); s = scm_cdr (s))
    {
      Context *c = unsmob_context (scm_car (s));
      Engraver_group_engraver *group
	= dynamic_cast<Engraver_group_engraver *> (c->implementation ());

      if (group)
	count += group->pending_grob_count ();
    }
  return count;
}

void
Engraver_group_engraver::do_announces ()
{
  do
    {
      for (SCM s = context ()->children_contexts ();
	   scm_is_pair (s); s = scm_cdr (s))
	{
	  Context *c = unsmob_context (scm_car (s));
	  Engraver_group_engraver *group
	    = dynamic_cast<Engraver_group_engraver *> (c->implementation ());
	  if (group)
	    group->do_announces ();
	}

      while (1)
	{
	  engraver_each (get_simple_trans_list (),
			 &Engraver::process_acknowledged_grobs);

	  if (announce_infos_.size () == 0)
	    break;

	  acknowledge_grobs ();
	  announce_infos_.clear ();
	}
    }
  while (pending_grob_count () > 0);
}

void
Engraver_group_engraver::initialize ()
{
  SCM tab = scm_make_vector (scm_int2num (61), SCM_BOOL_F);
  context ()->set_property ("acknowledgeHashTable", tab);

  Translator_group::initialize ();
}

Engraver_group_engraver::Engraver_group_engraver () {}

ADD_TRANSLATOR (Engraver_group_engraver,
		/* descr */ "A group of engravers taken together",
		/* creats*/ "",
		/* accepts */ "",
		/* acks  */ "",
		/* reads */ "",
		/* write */ "");

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

bool
engraver_valid (Translator *tr, SCM ifaces)
{
  SCM ack_ifs = scm_assoc (ly_symbol2scm ("interfaces-acked"), tr->translator_description ());
  ack_ifs = scm_cdr (ack_ifs);
  for (SCM s = ifaces; scm_is_pair (s); s = scm_cdr (s))
    if (scm_c_memq (scm_car (s), ack_ifs) != SCM_BOOL_F)
      return true;
  return false;
}

SCM
find_acknowledge_engravers (SCM gravlist, SCM meta_alist)
{
  SCM ifaces = scm_cdr (scm_assoc (ly_symbol2scm ("interfaces"), meta_alist));

  SCM l = SCM_EOL;
  for (SCM s = gravlist; scm_is_pair (s); s = scm_cdr (s))
    {
      Translator *tr = unsmob_translator (scm_car (s));
      if (engraver_valid (tr, ifaces))
	l = scm_cons (tr->self_scm (), l);
    }
  l = scm_reverse_x (l, SCM_EOL);

  return l;
}

/* c&p engraver-group.cc */
void
recurse_down_engravers (Context *c, Engraver_method ptr, bool context_first)
{
  Engraver_group_engraver *tg
    = dynamic_cast<Engraver_group_engraver *> (c->implementation ());

  if (!context_first)
    {
      engraver_each (tg->get_simple_trans_list (),
		     ptr);

      (tg->*ptr) ();
    }

  for (SCM s = c->children_contexts (); scm_is_pair (s);
       s = scm_cdr (s))
    {
      recurse_down_engravers (unsmob_context (scm_car (s)), ptr, context_first);
    }

  if (context_first)
    {
      engraver_each (tg->get_simple_trans_list (),
		     ptr);
      (tg->*ptr) ();
    }
}

void
engraver_each (SCM list, Engraver_method method)
{
  for (SCM p = list; scm_is_pair (p); p = scm_cdr (p))
    {
      Engraver *e = dynamic_cast<Engraver *> (unsmob_translator (scm_car (p)));
      if (e)
	(e->*method) ();
    }
}
