/*   
  context.cc --  implement Context

  source file of the GNU LilyPond music typesetter

  (c) 2004 Han-Wen Nienhuys <hanwen@xs4all.nl>

*/

#include "translator-group.hh"
#include "context-def.hh"
#include "context.hh"
#include "warn.hh"
#include "output-def.hh"
#include "scm-hash.hh"
#include "main.hh"
#include "ly-smobs.icc"
#include "score-context.hh"

bool
Context::is_removable () const
{
  return context_list_ == SCM_EOL && ! iterator_count_ &&
	  !dynamic_cast<Score_context const*> (this)
    ;
}

void
Context::check_removal ()
{
  for (SCM p = context_list_; ly_c_pair_p (p); p = ly_cdr (p))
    {
      Context *trg =  unsmob_context (ly_car (p));

      trg->check_removal ();
      if (trg->is_removable ())
	{
	  recurse_over_translators (trg, &Translator::finalize, UP);
	  remove_context (trg);
	}
    }
}

Context::Context (Context const&)
{
  assert (false);
}

Scheme_hash_table*
Context::properties_dict () const
{
  return Scheme_hash_table::unsmob (properties_scm_);
}

void
Context::add_context (Context*t)
{
  SCM ts = t->self_scm ();
  context_list_ = ly_append2 (context_list_,
			      scm_cons (ts, SCM_EOL));
  
  t->daddy_context_ = this;
  if (!t->init_)
    {
      t->init_ = true;
      
      scm_gc_unprotect_object (ts);
      Context_def * td = unsmob_context_def (t->definition_);

      /*
	this can not move before add_context (), because \override
	operations require that we are in the hierarchy.
      */
      td->apply_default_property_operations (t);

      recurse_over_translators (t, &Translator::initialize, DOWN);
    }
}

Context::Context ()
{
  daddy_context_ = 0;
  init_ = false;
  aliases_ = SCM_EOL;
  iterator_count_  = 0;
  implementation_ = SCM_EOL;
  properties_scm_ = SCM_EOL;
  accepts_list_ = SCM_EOL;
  context_list_ = SCM_EOL;
  definition_ = SCM_EOL;
  
  smobify_self ();

  properties_scm_ = (new Scheme_hash_table)->self_scm ();
  scm_gc_unprotect_object (properties_scm_);
}



Context*
Context::find_create_context (SCM n, String id,
			      SCM operations)
{
  /*
    Don't create multiple score contexts.
   */
  if (dynamic_cast<Global_context*> (this)
      && dynamic_cast<Global_context*> (this)->get_score_context ())
    return get_score_context ()->find_create_context (n, id, operations);
    
  
  Context * existing = find_context_below (this, n,id);
  if (existing)
    return existing;

  if (n == ly_symbol2scm ("Bottom"))
    {
      Context* tg = get_default_interpreter ();
      tg->id_string_ = id;
      return tg;
    }

  /*
    TODO: use accepts_list_.
   */
  Link_array<Context_def> path
    = unsmob_context_def (definition_)->path_to_acceptable_context (n, get_output_def ());

  if (path.size ())
    {
      Context * current = this;

      // start at 1.  The first one (index 0) will be us.
      for (int i=0; i < path.size (); i++)
	{
	  SCM ops = (i == path.size () -1) ? operations : SCM_EOL;

	  Context * new_group
	    = path[i]->instantiate (ops);

	  if (i == path.size () -1)
	    {
	      new_group->id_string_ = id;
	    }

	  current->add_context (new_group);
	  apply_property_operations (new_group, ops);
	  
	  current = new_group;
	}

      return current;
    }

  /*
    Don't go up to Global_context, because global goes down to
    Score_context
   */
  Context *ret = 0;
  if (daddy_context_ && !dynamic_cast<Global_context*> (daddy_context_))
    ret = daddy_context_->find_create_context (n, id, operations);
  else
    {
      warning (_f ("Cannot find or create `%s' called `%s'",
		   ly_symbol2string (n).to_str0 (), id));
      ret =0;
    }
  return ret;
}

/*
  Default child context as a SCM string, or something else if there is
  none.
*/
SCM
Context::default_child_context_name () const
{
  return ly_c_pair_p (accepts_list_)
    ? ly_car (scm_last_pair (accepts_list_))
    : SCM_EOL;
}


bool
Context::is_bottom_context () const
{
  return !scm_is_symbol (default_child_context_name ());
}

Context*
Context::get_default_interpreter ()
{
  if (!is_bottom_context ())
    {
      SCM nm = default_child_context_name ();
      SCM st = find_context_def (get_output_def (), nm);

      Context_def *t = unsmob_context_def (st);
      if (!t)
	{
	  warning (_f ("can't find or create: `%s'", ly_symbol2string (nm).to_str0 ()));
	  t = unsmob_context_def (this->definition_);
	}
      Context *tg = t->instantiate (SCM_EOL);
      add_context (tg);
      if (!tg->is_bottom_context ())
	return tg->get_default_interpreter ();
      else
	return tg;
    }
  return this;
}

/*
  PROPERTIES
 */
Context*
Context::where_defined (SCM sym) const
{
  if (properties_dict ()->contains (sym))
    {
      return (Context*)this;
    }

  return (daddy_context_) ? daddy_context_->where_defined (sym) : 0;
}

/*
  return SCM_EOL when not found.
*/
SCM
Context::internal_get_property (SCM sym) const
{
  SCM val =SCM_EOL;
  if (properties_dict ()->try_retrieve (sym, &val))
    return val;

  if (daddy_context_)
    return daddy_context_->internal_get_property (sym);
  
  return val;
}

bool
Context::is_alias (SCM sym) const
{
  if (sym == ly_symbol2scm ("Bottom")
      && !ly_c_pair_p (accepts_list_))
    return true;
  if (sym == unsmob_context_def (definition_)->get_context_name ())
    return true;
  
  return scm_c_memq (sym, aliases_) != SCM_BOOL_F;
}

void
Context::add_alias (SCM sym)
{
  aliases_ = scm_cons (sym, aliases_);
}



void
Context::internal_set_property (SCM sym, SCM val)
{
#ifndef NDEBUG
  if (internal_type_checking_global_b)
    assert (type_check_assignment (sym, val, ly_symbol2scm ("translation-type?")));
#endif
  
  properties_dict ()->set (sym, val);
}

/*
  TODO: look up to check whether we have inherited var? 
 */
void
Context::unset_property (SCM sym)
{
  properties_dict ()->remove (sym);
}

/**
   Remove a context from the hierarchy.
 */
Context *
Context::remove_context (Context*trans)
{
  assert (trans);

  context_list_ = scm_delq_x (trans->self_scm (), context_list_);
  trans->daddy_context_ = 0;
  return trans;
}

/*
  ID == "" means accept any ID.
 */
Context *
find_context_below (Context * where,
		    SCM type, String id)
{
  if (where->is_alias (type))
    {
      if (id == "" || where->id_string () == id)
	return where;
    }
  
  Context * found = 0;
  for (SCM s = where->children_contexts ();
       !found && ly_c_pair_p (s); s = ly_cdr (s))
    {
      Context * tr = unsmob_context (ly_car (s));

      found = find_context_below (tr, type, id);
    }

  return found; 
}

SCM
Context::properties_as_alist () const
{
  return properties_dict ()->to_alist ();
}

String
Context::context_name () const
{
  Context_def * td = unsmob_context_def (definition_ );
  return ly_symbol2string (td->get_context_name ());
}


Score_context*
Context::get_score_context () const
{
  if (Score_context *sc =dynamic_cast<Score_context*> ((Context*)this))
    return sc;
  else if (daddy_context_)
    return daddy_context_->get_score_context ();
  else
    return 0;
}

Output_def *
Context::get_output_def () const
{
  return  (daddy_context_)
    ? daddy_context_->get_output_def () : 0;
}

Context::~Context ()
{
  
}

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

int
Context::print_smob (SCM s, SCM port, scm_print_state *)
{
  Context *sc = (Context *) ly_cdr (s);
     
  scm_puts ("#<", port);
  scm_puts (classname (sc), port);
  if (Context_def *d=unsmob_context_def (sc->definition_))
    {
      scm_puts (" ", port);
      scm_display (d->get_context_name (), port);
    }

  if (Context *td=dynamic_cast<Context *> (sc))
    {
      scm_puts ("=", port);
      scm_puts (td->id_string_.to_str0 (), port);
    }
  

  scm_puts (" ", port);

  scm_display (sc->context_list_, port);
  scm_puts (" >", port);
  
  return 1;
}

SCM
Context::mark_smob (SCM sm)
{
  Context * me = (Context*) SCM_CELL_WORD_1 (sm);
  
  scm_gc_mark (me->context_list_);
  scm_gc_mark (me->aliases_);
  scm_gc_mark (me->definition_);  
  scm_gc_mark (me->properties_scm_);  
  scm_gc_mark (me->accepts_list_);
  scm_gc_mark (me->implementation_);

  return me->properties_scm_;
}

IMPLEMENT_SMOBS (Context);
IMPLEMENT_DEFAULT_EQUAL_P (Context);
IMPLEMENT_TYPE_P (Context,"ly:context?");

bool
Context::try_music (Music* m)
{
  Translator*  t = implementation ();
  if (!t)
    return false;
  
  bool b = t->try_music (m);
  if (!b && daddy_context_)
    b = daddy_context_->try_music (m);

  return b;
}


Global_context*
Context::get_global_context () const
{
  if (dynamic_cast<Global_context *>((Context*) this))
    return dynamic_cast<Global_context *> ((Context*) this);

  if (daddy_context_)
    return daddy_context_->get_global_context ();

  programming_error ("No Global context!");
  return 0;
}

Context*
Context::get_parent_context () const
{
  return daddy_context_;
}

Translator_group*
Context::implementation () const
{
  return dynamic_cast<Translator_group*> (unsmob_translator (implementation_));
}
