/*
  translator.cc -- implement Translator

  source file of the GNU LilyPond music typesetter

  (c) 1997--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
*/

#include "translator.hh"

#include "context-def.hh"
#include "dispatcher.hh"
#include "global-context.hh"
#include "international.hh"
#include "translator-group.hh"
#include "warn.hh"

#include "translator.icc"
#include "ly-smobs.icc"

Translator::~Translator ()
{
}

void
Translator::init ()
{
  must_be_last_ = false;
  self_scm_ = SCM_EOL;
  daddy_context_ = 0;
  smobify_self ();
}

void
Translator::process_music ()
{
}

void
Translator::process_acknowledged ()
{
}

Translator::Translator ()
{
  init ();
}

Translator::Translator (Translator const &src)
{
  init ();
  must_be_last_ = src.must_be_last_;
}

Moment
Translator::now_mom () const
{
  return daddy_context_->now_mom ();
}

Output_def *
Translator::get_output_def () const
{
  return daddy_context_->get_output_def ();
}

Translator_group *
Translator::get_daddy_translator () const
{
  return daddy_context_->implementation ();
}

void
Translator::protect_event (SCM ev)
{
  get_daddy_translator ()->protect_event (ev);
}

SCM
Translator::internal_get_property (SCM sym) const
{
  return daddy_context_->internal_get_property (sym);
}

void
Translator::stop_translation_timestep ()
{
}

/*
  this function is called once each moment, before any user
  information enters the translators.  (i.e. no \property or event has
  been processed yet.)
*/
void
Translator::start_translation_timestep ()
{
}

void
Translator::initialize ()
{
}

void
Translator::finalize ()
{
}

void
Translator::connect_to_context (Context *c)
{
  for (translator_listener_record *r = get_listener_list (); r; r=r->next_)
    c->events_below ()->add_listener (r->get_listener_ (this), r->event_class_);
}

void
Translator::disconnect_from_context (Context *c)
{
  for (translator_listener_record *r = get_listener_list (); r; r=r->next_)
    c->events_below ()->remove_listener (r->get_listener_ (this), r->event_class_);
}

static SCM listened_event_class_table;
void
ensure_listened_hash ()
{
  if (!listened_event_class_table)
    listened_event_class_table = scm_permanent_object (scm_c_make_hash_table (61));
}


LY_DEFINE (ly_get_listened_event_classes, "ly:get-listened-event-classes",
	   0, 0, 0, (),
	   "Returns a list of all event classes that some translator listens to.")
{
  ensure_listened_hash ();
  return ly_hash_table_keys (listened_event_class_table);
}

LY_DEFINE (ly_is_listened_event_class, "ly:is-listened-event-class",
	   1, 0, 0, (SCM sym),
	   "Is @var{sym} a listened event class?")
{
  ensure_listened_hash ();
  return scm_hashq_ref (listened_event_class_table, sym, SCM_BOOL_F);
}

void
add_listened_event_class (SCM sym)
{
  ensure_listened_hash ();
  scm_hashq_set_x (listened_event_class_table, sym, SCM_BOOL_T);
}


/*
  internally called once, statically, for each translator
  listener. Connects the name of an event class with a procedure that
  fetches the corresponding listener.

  The method should only be called from the macro
  IMPLEMENT_TRANSLATOR_LISTENER.
 */
void
Translator::add_translator_listener (translator_listener_record **listener_list,
				     translator_listener_record *r,
				     Listener (*get_listener) (void *), 
				     const char *ev_class)
{
  /* ev_class is the C++ identifier name. Convert to scm symbol */
  string name = string (ev_class);
  name = replace_all (name, '_', '-');
  name += "-event";
  
  SCM class_sym = scm_str2symbol (name.c_str ());
  
  add_listened_event_class (class_sym);

  r->event_class_ = class_sym;
  r->get_listener_ = get_listener;
  r->next_ = *listener_list;
  *listener_list = r;
}

/*
 Helps the individual static_translator_description methods of translators.
*/
SCM
Translator::static_translator_description (const char *grobs,
					   const char *desc,
					   translator_listener_record *listener_list,
					   const char *read, 
					   const char *write) const
{
  SCM static_properties = SCM_EOL;					

  static_properties = scm_acons (ly_symbol2scm ("grobs-created"),	
				 parse_symbol_list (grobs), static_properties);
  
  static_properties = scm_acons (ly_symbol2scm ("description"),	
				 scm_from_locale_string (desc), static_properties); 
  
  SCM list = SCM_EOL;
  for (; listener_list; listener_list = listener_list->next_)
    list = scm_cons (listener_list->event_class_, list);
  static_properties = scm_acons (ly_symbol2scm ("events-accepted"),
				 list, static_properties);
  
  static_properties = scm_acons (ly_symbol2scm ("properties-read"),	
				 parse_symbol_list (read), static_properties); 
  
  static_properties = scm_acons (ly_symbol2scm ("properties-written"), 
				 parse_symbol_list (write), static_properties); 
  
  return static_properties;						
}
  
/*
  SMOBS
*/
SCM
Translator::mark_smob (SCM sm)
{
  Translator *me = (Translator *) SCM_CELL_WORD_1 (sm);
  me->derived_mark ();
  return SCM_EOL;
}

Global_context *
Translator::get_global_context () const
{
  return daddy_context_->get_global_context ();
}

Context *
Translator::get_score_context () const
{
  return daddy_context_->get_score_context ();
}

IMPLEMENT_SMOBS (Translator);
IMPLEMENT_DEFAULT_EQUAL_P (Translator);
IMPLEMENT_TYPE_P (Translator, "ly:translator?");

bool
Translator::must_be_last () const
{
  return must_be_last_;
}

void
Translator::derived_mark () const
{
}

int
Translator::print_smob (SCM s, SCM port, scm_print_state *)
{
  Translator *me = (Translator *) SCM_CELL_WORD_1 (s);
  scm_puts ("#<Translator ", port);
  scm_puts (me->class_name (), port);
  scm_puts (" >", port);
  return 1;
}

void
add_acknowledger (Engraver_void_function_engraver_grob_info ptr,
		  char const *func_name,
		  vector<Acknowledge_information> *ack_array)
{
  Acknowledge_information inf;
  inf.function_ = ptr;

  string interface_name (func_name);

  interface_name = replace_all (interface_name, '_', '-');
  interface_name += "-interface";

  /*
    this is only called during program init, so safe to use scm_gc_protect_object ()
  */
  inf.symbol_ = scm_gc_protect_object (ly_symbol2scm (interface_name.c_str ()));
  ack_array->push_back (inf);
}

Engraver_void_function_engraver_grob_info
generic_get_acknowledger (SCM sym, vector<Acknowledge_information> const *ack_array)
{
  for (vsize i = 0; i < ack_array->size (); i++)
    {
      if (ack_array->at (i).symbol_ == sym)
	return ack_array->at (i).function_;
    }
  return 0;
}


Moment
get_event_length (Stream_event *e)
{
  Moment *m = unsmob_moment (e->get_property ("length"));
  if (m)
    return *m;
  else
    return Moment (0);
}

Moment
get_event_length (Stream_event *e, Moment now)
{
  Moment len = get_event_length (e);
  
  if (now.grace_part_)
    {
      len.grace_part_ = len.main_part_;
      len.main_part_ = Rational (0);
    }
  return len;
}

/*
  Helper, used through ASSIGN_EVENT_ONCE to throw warnings for
  simultaneous events. The helper is only useful in listen_* methods
  of translators.
*/
bool
internal_event_assignment (Stream_event **old_ev, Stream_event *new_ev, const char *function)
{
  if (*old_ev &&
      !to_boolean (scm_equal_p ((*old_ev)->self_scm (), 
			       new_ev->self_scm ())))
    {
      /* extract event class from function name */
      string ev_class = function;

      /* This assertion fails if EVENT_ASSIGNMENT was called outside a
	 translator listener. Don't do that. */
      const char *prefix = "listen_";
      assert (0 == ev_class.find (prefix));

      /* "listen_foo_bar" -> "foo-bar" */
      ev_class.erase (0, strlen (prefix));
      replace_all (ev_class, '_', '-');

      new_ev->origin ()->warning (_f ("Two simultaneous %s events, junking this one", ev_class.c_str ()));
      (*old_ev)->origin ()->warning (_f ("Previous %s event here", ev_class.c_str ()));
      return false;
    }
  else
    {
      *old_ev = new_ev;
      return true;
    }
}

ADD_TRANSLATOR (Translator,
		"Base class. Not instantiated.",
		"",
		"",
		"");
