/*
  grob.cc -- implement Grob

  source file of the GNU LilyPond music typesetter

  (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
*/


#include <string.h>
#include <math.h>

#include "main.hh"
#include "input-smob.hh"
#include "warn.hh"
#include "group-interface.hh"
#include "misc.hh"
#include "paper-score.hh"
#include "stencil.hh"
#include "grob.hh"
#include "warn.hh"
#include "spanner.hh"
#include "system.hh"
#include "item.hh"
#include "stencil.hh"
#include "misc.hh"
#include "music.hh"
#include "item.hh"

#include "ly-smobs.icc"

/* TODO:

  - remove dynamic_cast<Spanner,Item> and put this code into respective
    subclass.  */

#define HASH_SIZE 3
#define INFINITY_MSG "Infinity or NaN encountered"

Grob::Grob (SCM basicprops)
{
  /* FIXME: default should be no callback.  */
  self_scm_ = SCM_EOL;
  pscore_= 0;
  status_ = 0;
  original_ = 0;
  immutable_property_alist_ =  basicprops;
  mutable_property_alist_ = SCM_EOL;

  /* We do smobify_self () as the first step.  Since the object lives
     on the heap, none of its SCM variables are protected from
     GC. After smobify_self (), they are.  */
  smobify_self ();

  SCM meta = get_property ("meta");
  if (ly_c_pair_p (meta))
    {
      SCM ifs = scm_assoc (ly_symbol2scm ("interfaces"), meta);

      /* Switch off interface checks for the moment.  */
      bool itc = internal_type_checking_global_b;
      internal_type_checking_global_b = false;
      internal_set_property (ly_symbol2scm ("interfaces"), ly_cdr (ifs));
      internal_type_checking_global_b = itc;
    }

  /* TODO:

    - destill this into a function, so we can re-init the immutable
      properties with a new BASICPROPS value after
      creation. Convenient eg. when using \override with
      StaffSymbol.  */

  char const*onames[] = {"X-offset-callbacks", "Y-offset-callbacks"};
  char const*xnames[] = {"X-extent", "Y-extent"};
  char const*enames[] = {"X-extent-callback", "Y-extent-callback"};

  for (int a = X_AXIS; a <= Y_AXIS; a++)
    {
      SCM l = get_property (onames[a]);

      if (scm_ilength (l) >=0)
	{
	  dim_cache_[a].offset_callbacks_ = l;
	  dim_cache_[a].offsets_left_ = scm_ilength (l);
	}
      else
	programming_error ("[XY]-offset-callbacks must be a list");

      SCM cb = get_property (enames[a]);
      SCM xt = get_property (xnames[a]);

      /* Should change default to empty?  */
      if (is_number_pair (xt))
	cb = xt;
      else if (cb != SCM_BOOL_F
	  && !ly_c_procedure_p (cb) && !ly_c_pair_p (cb)
	  && ly_c_procedure_p (get_property ("print-function")))
	cb = stencil_extent_proc;

      dim_cache_[a].dimension_ = cb;
    }
}

Grob::Grob (Grob const &s)
   : dim_cache_ (s.dim_cache_)
{
  original_ = (Grob*) &s;
  self_scm_ = SCM_EOL;

  immutable_property_alist_ = s.immutable_property_alist_;
  mutable_property_alist_ = SCM_EOL;

  /* No properties are copied.  That is the job of
     handle_broken_dependencies.  */
  status_ = s.status_;
  pscore_ = 0;

  smobify_self ();
}

Grob::~Grob ()
{
}

MAKE_SCHEME_CALLBACK (Grob, stencil_extent, 2);
SCM
Grob::stencil_extent (SCM element_smob, SCM scm_axis)
{
  Grob *s = unsmob_grob (element_smob);
  Axis a = (Axis) scm_to_int (scm_axis);

  Stencil *m = s->get_stencil ();
  Interval e;
  if (m)
    e = m->extent (a);
  return ly_interval2scm (e);
}


Interval
robust_relative_extent (Grob*me, Grob*refp, Axis a)
{
  Interval ext =  me->extent  (refp, a);
  if (ext.is_empty())
    {
      ext.add_point (me->relative_coordinate (refp, a));
    }

  return ext;      
}

Output_def *
Grob::get_paper () const
{
 return pscore_ ? pscore_->paper_ : 0;
}


/* Recursively track all dependencies of this Grob.  The status_ field
   is used as a mark-field.  It is marked with BUSY during execution
   of this function, and marked with FINAL when finished.

   FUNCPTR is the function to call to update this element.  */
void
Grob::calculate_dependencies (int final, int busy, SCM funcname)
{
  if (status_ >= final)
    return;

  if (status_ == busy)
    {
      programming_error ("Element is busy, come back later");
      return;
    }

  status_ = busy;

  for (SCM d = get_property ("dependencies"); ly_c_pair_p (d);
       d = ly_cdr (d))
    unsmob_grob (ly_car (d))->calculate_dependencies (final, busy, funcname);

  SCM proc = internal_get_property (funcname);
  if (ly_c_procedure_p (proc))
    scm_call_1 (proc, this->self_scm ());

  status_ = final;
}

Stencil *
Grob::get_stencil ()  const
{
  if (!is_live ())
    return 0;

  SCM stil = get_property ("stencil");
  if (unsmob_stencil (stil))
    return unsmob_stencil (stil);

  stil = get_uncached_stencil ();

  if (is_live ())
    {
      Grob *me = (Grob*) this;
      me->set_property ("stencil", stil);
    }

  return unsmob_stencil (stil);
}

SCM
Grob::get_uncached_stencil () const
{
  SCM proc = get_property ("print-function");

  SCM  stil = SCM_EOL;
  if (ly_c_procedure_p (proc))
    stil = scm_apply_0 (proc, scm_list_n (this->self_scm (), SCM_UNDEFINED));

  if (Stencil *m = unsmob_stencil (stil))
     {
      if (to_boolean (get_property ("transparent")))
	stil = Stencil (m->extent_box (), SCM_EOL).smobbed_copy ();
      else
	{
	  SCM expr = scm_list_3 (ly_symbol2scm ("grob-cause"), self_scm(),
				 m->expr ());
	  stil = Stencil (m->extent_box (),expr). smobbed_copy ();
	}
     }

  return stil;
}

/*
  VIRTUAL STUBS

 */
void
Grob::do_break_processing ()
{
}

System *
Grob::get_system () const
{
  return 0;
}

void
Grob::add_dependency (Grob *e)
{
  if (e)
    Pointer_group_interface::add_grob (this, ly_symbol2scm ("dependencies"),
				       e);
  else
    programming_error ("Null dependency added");
}

void
Grob::handle_broken_dependencies ()
{
  Spanner *sp = dynamic_cast<Spanner*> (this);
  if (original_ && sp)
    return;

  if (sp)
    /* THIS, SP is the original spanner.  We use a special function
       because some Spanners have enormously long lists in their
       properties, and a special function fixes FOO  */
    for (SCM s = mutable_property_alist_; ly_c_pair_p (s); s = ly_cdr (s))
      sp->substitute_one_mutable_property (ly_caar (s), ly_cdar (s));

  System *system = get_system ();

  if (is_live ()
      && system && common_refpoint (system, X_AXIS)
      && common_refpoint (system, Y_AXIS))
    substitute_mutable_properties (system
				   ? system->self_scm () : SCM_UNDEFINED,
				   mutable_property_alist_);
  else if (dynamic_cast <System*> (this))
    substitute_mutable_properties (SCM_UNDEFINED, mutable_property_alist_);
  else
    /* THIS element is `invalid'; it has been removed from all
       dependencies, so let's junk the element itself.

       Do not do this for System, since that would remove references
       to the originals of score-grobs, which get then GC'd (a bad
       thing).  */
    suicide ();
}

/* Note that we still want references to this element to be
   rearranged, and not silently thrown away, so we keep pointers like
   {broken_into_{drul, array}, original}
*/
void
Grob::suicide ()
{
  if (!is_live ())
    return;

  mutable_property_alist_ = SCM_EOL;
  immutable_property_alist_ = SCM_EOL;

  set_extent (SCM_EOL, Y_AXIS);
  set_extent (SCM_EOL, X_AXIS);

  for (int a = X_AXIS; a <= Y_AXIS; a++)
    {
      dim_cache_[a].offset_callbacks_ = SCM_EOL;
      dim_cache_[a].offsets_left_ = 0;
    }
}

void
Grob::handle_prebroken_dependencies ()
{
  /* Don't do this in the derived method, since we want to keep access to
     mutable_property_alist_ centralized.  */
  if (original_)
    {
      Item *it = dynamic_cast<Item*> (this);
      substitute_mutable_properties (scm_int2num (it->break_status_dir ()),
				     original_->mutable_property_alist_);
    }
}

Grob *
Grob::find_broken_piece (System *) const
{
  return 0;
}

/* Translate in one direction.  */
void
Grob::translate_axis (Real y, Axis a)
{
  if (isinf (y) || isnan (y))
    programming_error (_ (INFINITY_MSG));
  else
    dim_cache_[a].offset_ += y;
}


/* Find the offset relative to D.  If D equals THIS, then it is 0.
   Otherwise, it recursively defd as

   OFFSET_ + PARENT_L_->relative_coordinate (D) */
Real
Grob::relative_coordinate (Grob const *refp, Axis a) const
{
  if (refp == this)
    return 0.0;

  /* We catch PARENT_L_ == nil case with this, but we crash if we did
     not ask for the absolute coordinate (ie. REFP == nil.)  */
  if (refp == dim_cache_[a].parent_)
    return get_offset (a);

  return get_offset (a) + dim_cache_[a].parent_->relative_coordinate (refp, a);
}

/* Invoke callbacks to get offset relative to parent.  */
Real
Grob::get_offset (Axis a) const
{
  Grob *me = (Grob*) this;
  while (dim_cache_[a].offsets_left_)
    {
      int l = --me->dim_cache_[a].offsets_left_;
      SCM cb = scm_list_ref (dim_cache_[a].offset_callbacks_, scm_int2num (l));
      SCM retval = scm_call_2 (cb, self_scm (), scm_int2num (a));

      Real r =  scm_to_double (retval);
      if (isinf (r) || isnan (r))
	{
	  programming_error (INFINITY_MSG);
	  r = 0.0;
	}
      me->dim_cache_[a].offset_ += r;
    }
  return dim_cache_[a].offset_;
}

bool
Grob::is_empty (Axis a) const
{
  return ! (ly_c_pair_p (dim_cache_[a].dimension_)
	    || ly_c_procedure_p (dim_cache_[a].dimension_));
}

Interval
Grob::extent (Grob *refp, Axis a) const
{
  Real x = relative_coordinate (refp, a);

  Dimension_cache *d = (Dimension_cache *) &dim_cache_[a];
  Interval ext;
  if (ly_c_pair_p (d->dimension_))
    ;
  else if (ly_c_procedure_p (d->dimension_))
    /* FIXME: add doco on types, and should typecheck maybe?  */
    d->dimension_= scm_call_2 (d->dimension_, self_scm (), scm_int2num (a));
  else
    return ext;

  if (!ly_c_pair_p (d->dimension_))
    return ext;

  ext = ly_scm2interval (d->dimension_);

  SCM extra = get_property (a == X_AXIS
			    ? "extra-X-extent"
			    : "extra-Y-extent");

  /* Signs ?  */
  if (ly_c_pair_p (extra))
    {
      ext[BIGGER] += scm_to_double (ly_cdr (extra));
      ext[SMALLER] += scm_to_double (ly_car (extra));
    }

  extra = get_property (a == X_AXIS
			? "minimum-X-extent"
			: "minimum-Y-extent");
  if (ly_c_pair_p (extra))
    ext.unite (Interval (scm_to_double (ly_car (extra)),
			 scm_to_double (ly_cdr (extra))));

  ext.translate (x);

  return ext;
}

/* Find the group-element which has both #this# and #s#  */
Grob *
Grob::common_refpoint (Grob const *s, Axis a) const
{
  /* I don't like the quadratic aspect of this code, but I see no
     other way.  The largest chain of parents might be 10 high or so,
     so it shouldn't be a real issue.  */
  for (Grob const *c = this; c; c = c->dim_cache_[a].parent_)
    for (Grob const *d = s; d; d = d->dim_cache_[a].parent_)
      if (d == c)
	return (Grob*) d;

  return 0;
}

Grob *
common_refpoint_of_list (SCM elist, Grob *common, Axis a)
{
  for (; ly_c_pair_p (elist); elist = ly_cdr (elist))
    if (Grob *s = unsmob_grob (ly_car (elist)))
      {
	if (common)
	  common = common->common_refpoint (s, a);
	else
	  common = s;
      }

  return common;
}

Grob *
common_refpoint_of_array (Link_array<Grob> const &arr, Grob *common, Axis a)
{
  for (int i = arr.size (); i--; )
    if (Grob *s = arr[i])
      {
	if (common)
	  common = common->common_refpoint (s, a);
	else
	  common = s;
      }

  return common;
}

String
Grob::name () const
{
  SCM meta = get_property ("meta");
  SCM nm = scm_assoc (ly_symbol2scm ("name"), meta);
  nm = (ly_c_pair_p (nm)) ? ly_cdr (nm) : SCM_EOL;
  return scm_is_symbol (nm) ? ly_symbol2string (nm) : classname (this);
}

void
Grob::add_offset_callback (SCM cb, Axis a)
{
  if (!has_offset_callback (cb, a))
  {
    dim_cache_[a].offset_callbacks_
      = scm_cons (cb, dim_cache_[a].offset_callbacks_);
    dim_cache_[a].offsets_left_ ++;
  }
}

bool
Grob::has_extent_callback (SCM cb, Axis a)const
{
  return scm_equal_p (cb, dim_cache_[a].dimension_) == SCM_BOOL_T;
}

bool
Grob::has_offset_callback (SCM cb, Axis a)const
{
  return scm_c_memq (cb, dim_cache_[a].offset_callbacks_) != SCM_BOOL_F;
}

void
Grob::set_extent (SCM dc, Axis a)
{
  dim_cache_[a].dimension_ = dc;
}

void
Grob::set_parent (Grob *g, Axis a)
{
  dim_cache_[a].parent_ = g;
}

MAKE_SCHEME_CALLBACK (Grob,fixup_refpoint,1);
SCM
Grob::fixup_refpoint (SCM smob)
{
  Grob *me = unsmob_grob (smob);
  for (int a = X_AXIS; a < NO_AXES; a ++)
    {
      Axis ax = (Axis)a;
      Grob *parent = me->get_parent (ax);

      if (!parent)
	continue;

      if (parent->get_system () != me->get_system () && me->get_system ())
	{
	  Grob *newparent = parent->find_broken_piece (me->get_system ());
	  me->set_parent (newparent, ax);
	}

      if (Item *i = dynamic_cast<Item*> (me))
	{
	  Item *parenti = dynamic_cast<Item*> (parent);

	  if (parenti && i)
	    {
	      Direction  my_dir = i->break_status_dir () ;
	      if (my_dir!= parenti->break_status_dir ())
		{
		  Item *newparent = parenti->find_prebroken_piece (my_dir);
		  me->set_parent (newparent, ax);
		}
	    }
	}
    }
  return smob;
}

void
Grob::warning (String s)const
{
  SCM cause = self_scm ();
  while (Grob *g = unsmob_grob (cause))
    cause = g->get_property ("cause");

  if (Music *m = unsmob_music (cause))
    m->origin ()->warning (s);
  else
    ::warning (s);
}

void
Grob::programming_error (String s) const
{
  s = "Programming error: " + s;
  warning (s);
}


/****************************************************
  SMOB funcs
 ****************************************************/

IMPLEMENT_SMOBS (Grob);
IMPLEMENT_DEFAULT_EQUAL_P (Grob);

SCM
Grob::mark_smob (SCM ses)
{
  Grob *s = (Grob*) SCM_CELL_WORD_1 (ses);
  scm_gc_mark (s->immutable_property_alist_);

  for (int a = 0 ; a < 2; a++)
    {
      scm_gc_mark (s->dim_cache_[a].offset_callbacks_);
      scm_gc_mark (s->dim_cache_[a].dimension_);

      /* Do not mark the parents.  The pointers in the mutable
	 property list form two tree like structures (one for X
	 relations, one for Y relations).  Marking these can be done
	 in limited stack space.  If we add the parents, we will jump
	 between X and Y in an erratic manner, leading to much more
	 recursion depth (and core dumps if we link to pthreads).  */
    }

  if (s->original_)
    scm_gc_mark (s->original_->self_scm ());

  s->do_derived_mark ();
  return s->mutable_property_alist_;
}

int
Grob::print_smob (SCM s, SCM port, scm_print_state *)
{
  Grob *sc = (Grob *) ly_cdr (s);

  scm_puts ("#<Grob ", port);
  scm_puts ((char *) sc->name ().to_str0 (), port);

  /* Do not print properties, that is too much hassle.  */
  scm_puts (" >", port);
  return 1;
}

SCM
Grob::do_derived_mark () const
{
  return SCM_EOL;
}

void
Grob::discretionary_processing ()
{
}

bool
Grob::internal_has_interface (SCM k)
{
  SCM ifs = get_property ("interfaces");

  return scm_c_memq (k, ifs) != SCM_BOOL_F;
}

/** Return Array of Grobs in SCM list LST */
Link_array<Grob>
ly_scm2grobs (SCM lst)
{
  Link_array<Grob> arr;

  for (SCM s = lst; ly_c_pair_p (s); s = ly_cdr (s))
    {
      SCM e = ly_car (s);
      arr.push (unsmob_grob (e));
    }

  arr.reverse ();
  return arr;
}

/** Return SCM list of Grob array A */
SCM
ly_grobs2scm (Link_array<Grob> a)
{
  SCM s = SCM_EOL;
  for (int i = a.size (); i; i--)
    s = scm_cons (a[i-1]->self_scm (), s);

  return s;
}


IMPLEMENT_TYPE_P (Grob, "ly:grob?");

ADD_INTERFACE (Grob, "grob-interface",
	       "A grob represents a piece of music notation\n"
	       "\n"
"All grobs have an X and Y-position on the page.  These X and Y positions\n"
"are stored in a relative format, so they can easily be combined by\n"
"stacking them, hanging one grob to the side of another, and coupling\n"
"them into a grouping objects.\n"
"\n"
"Each grob has a reference point (a.k.a.  parent): the position of a grob\n"
"is stored relative to that reference point. For example the X-reference\n"
"point of a staccato dot usually is the note head that it applies\n"
"to. When the note head is moved, the staccato dot moves along\n"
"automatically.\n"
"\n"
"A grob is often associated with a symbol, but some grobs do not print\n"
"any symbols. They take care of grouping objects. For example, there is a\n"
"separate grob that stacks staves vertically. The @ref{NoteCollision}\n"
"is also an abstract grob: it only moves around chords, but doesn't print\n"
"anything.\n"
"\n"
	       "Grobs have a properties: Scheme variables, that can be read and set. "
	       "They have two types. Immutable variables "
	       "define the default style and behavior.  They are shared between  many objects. "
	       "They can be changed using @code{\\override} and @code{\\revert}. "
	       "\n\n"
	       "Mutable properties are variables that are specific to one grob. Typically, "
	       "lists of other objects, or results from computations are stored in"
	       "mutable properties: every call to set-grob-property (or its C++ equivalent) "
	       "sets a mutable property. "

,
	       "X-offset-callbacks Y-offset-callbacks X-extent-callback stencil cause "
	       "Y-extent-callback print-function extra-offset spacing-procedure "
	       "staff-symbol interfaces dependencies X-extent Y-extent extra-X-extent "
	       "meta layer before-line-breaking-callback "
	       "after-line-breaking-callback extra-Y-extent minimum-X-extent "
	       // FIXME: page-penalty?
	       "minimum-Y-extent page-penalty transparent "
	       );


