/*
  This file is part of LilyPond, the GNU music typesetter.

  Copyright (C) 2004--2020 Han-Wen Nienhuys <hanwen@xs4all.nl>

  LilyPond is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  LilyPond is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "axis-group-interface.hh"
#include "text-interface.hh"
#include "spanner.hh"
#include "font-interface.hh"
#include "dimensions.hh"
#include "output-def.hh"
#include "warn.hh"
#include "paper-column.hh"
#include "staff-symbol-referencer.hh"
#include "note-column.hh"
#include "directional-element-interface.hh"
#include "bracket.hh"
#include "rhythmic-head.hh"
#include "pointer-group-interface.hh"

struct Ottava_bracket
{
  DECLARE_SCHEME_CALLBACK (print, (SCM));
};

/*
  TODO: the string for ottava shoudl depend on the available space, ie.

  Long: 15ma        Short: 15ma    Empty: 15
  8va                8va            8
  8va bassa          8ba            8
*/
MAKE_SCHEME_CALLBACK (Ottava_bracket, print, 1);
SCM
Ottava_bracket::print (SCM smob)
{
  Spanner *me = unsmob<Spanner> (smob);
  Interval span_points;

  Grob *common = me->get_bound (LEFT)->common_refpoint (me->get_bound (RIGHT), X_AXIS);
  Output_def *layout = me->layout ();

  Drul_array<bool> broken;
  for (LEFT_and_RIGHT (d))
    {
      Item *b = me->get_bound (d);
      broken[d] = (b->break_status_dir () != CENTER);

      if (has_interface<Note_column> (b))
        {
          extract_grob_set (b, "note-heads", heads);
          common = common_refpoint_of_array (heads, common, X_AXIS);
          for (vsize i = 0; i < heads.size (); i++)
            {
              Grob *h = heads[i];
              Grob *dots = Rhythmic_head::get_dots (h);
              if (dots)
                common = dots->common_refpoint (common, X_AXIS);
            }
        }
    }

  SCM properties = Font_interface::text_font_alist_chain (me);
  SCM markup = get_property (me, "text");
  Stencil text;
  if (Text_interface::is_markup (markup))
    text = *unsmob<Stencil> (Text_interface::interpret_markup (layout->self_scm (),
                                                               properties, markup));

  Drul_array<Real> shorten = from_scm (get_property (me, "shorten-pair"),
                                       Drul_array<Real> (0.0, 0.0));

  /*
    TODO: we should check if there are ledgers, and modify length of
    the spanner to that.
  */
  for (LEFT_and_RIGHT (d))
    {
      Item *b = me->get_bound (d);

      Interval ext;
      if (has_interface<Note_column> (b))
        {
          extract_grob_set (b, "note-heads", heads);
          for (vsize i = 0; i < heads.size (); i++)
            {
              Grob *h = heads[i];
              ext.unite (h->extent (common, X_AXIS));
              Grob *dots = Rhythmic_head::get_dots (h);

              if (dots && d == RIGHT)
                ext.unite (dots->extent (common, X_AXIS));
            }
        }

      if (ext.is_empty ())
        ext = robust_relative_extent (b, common, X_AXIS);

      if (broken[d])
        {
          span_points[d] = Axis_group_interface::generic_bound_extent (b, common, X_AXIS)[RIGHT];
          shorten[d] = 0.;
        }

      else
        span_points[d] = ext[d];

      span_points[d] -= d * shorten[d];
    }

  /*
    0.3 is ~ italic correction.
  */
  Real text_size = text.extent (X_AXIS).is_empty ()
                   ? 0.0 : text.extent (X_AXIS)[RIGHT] + 0.3;

  span_points[LEFT]
    = std::min (span_points[LEFT],
                (span_points[RIGHT] - text_size
                 - from_scm<double> (get_property (me, "minimum-length"), -1.0)));

  Interval bracket_span_points = span_points;
  bracket_span_points[LEFT] += text_size;

  Drul_array<Real> edge_height = from_scm (get_property (me, "edge-height"),
                                           Drul_array<Real> (1.0, 1.0));

  Drul_array<Real> flare = from_scm (get_property (me, "bracket-flare"),
                                     Drul_array<Real> (0.0, 0.0));

  for (LEFT_and_RIGHT (d))
    {
      edge_height[d] *= -get_grob_direction (me);
      if (broken[d])
        edge_height[d] = 0.0;
    }

  Stencil b;
  Interval empty;

  if (!bracket_span_points.is_empty () && bracket_span_points.length () > 0.001)
    b = Bracket::make_bracket (me, Y_AXIS, Offset (bracket_span_points.length (), 0),
                               edge_height, empty, flare, Drul_array<Real> (0, 0));

  /*
   * The vertical lines should not take space, for the following scenario:
   *
   * 8 -----+
   *     o  |
   *    |
   *    |
   *
   * Just a small amount, yes.  In tight situations, it is even
   * possible to center the `8' directly below the note, dropping the
   * ottava line completely...
  */

  b = Stencil (Box (b.extent (X_AXIS),
                    Interval (0.1, 0.1)),
               b.expr ());

  b.translate_axis (bracket_span_points[LEFT], X_AXIS);
  text.translate_axis (span_points[LEFT], X_AXIS);
  text.align_to (Y_AXIS, CENTER);
  b.add_stencil (text);

  b.translate_axis (- me->relative_coordinate (common, X_AXIS), X_AXIS);

  return b.smobbed_copy ();
}

ADD_INTERFACE (Ottava_bracket,
               "An ottava bracket.",

               /* properties */
               "bracket-flare "
               "dashed-edge "
               "edge-height "
               "minimum-length "
               "shorten-pair "
              );

