/*
  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 "config.hh"

#include "dimensions.hh"
#include "all-font-metrics.hh"
#include "libc-extension.hh"
#include "output-def.hh"
#include "pango-font.hh"

#include <cmath>

using std::string;

PangoFontDescription *
properties_to_pango_description (SCM chain, Real text_size)
{
  SCM name = ly_chain_assoc_get (ly_symbol2scm ("font-name"), chain, SCM_BOOL_F);

  PangoFontDescription *description = 0;
  if (scm_is_string (name))
    {
      string name_str = ly_scm2string (name);
      description = pango_font_description_from_string (name_str.c_str ());
    }
  else
    {
      SCM family = ly_chain_assoc_get (ly_symbol2scm ("font-family"), chain,
                                       SCM_BOOL_F);
      SCM variant = ly_chain_assoc_get (ly_symbol2scm ("font-shape"), chain,
                                        SCM_BOOL_F);

      SCM style = ly_chain_assoc_get (ly_symbol2scm ("font-shape"), chain,
                                      SCM_BOOL_F);
      SCM weight = ly_chain_assoc_get (ly_symbol2scm ("font-series"), chain,
                                       SCM_BOOL_F);

      description
        = symbols_to_pango_font_description (family, style, variant, weight,
                                             SCM_BOOL_F);
    }

  Real step = from_scm<double> (ly_chain_assoc_get (ly_symbol2scm ("font-size"), chain, SCM_BOOL_F),
                                0.0);
  Real size = text_size * pow (2.0, step / 6.0);

  pango_font_description_set_size (description,
                                   gint (round_halfway_up (size * PANGO_SCALE)));
  return description;
}

Font_metric *
select_pango_font (Output_def *layout, SCM chain)
{
  PangoFontDescription *pfd
    = properties_to_pango_description (chain,
                                       point_constant
                                       * layout->get_dimension (ly_symbol2scm ("text-font-size")));

  char *str = pango_font_description_to_string (pfd);
  SCM scm_str = scm_from_locale_string (str);
  g_free (str);
  pango_font_description_free (pfd);

  return find_pango_font (layout, scm_str, 1.0);
}

PangoStyle
symbol_to_pango_style (SCM style)
{
  PangoStyle pstyle = PANGO_STYLE_NORMAL;
  if (scm_is_eq (style, ly_symbol2scm ("italic")))
    pstyle = PANGO_STYLE_ITALIC;
  else if (scm_is_eq (style, ly_symbol2scm ("oblique"))
           || scm_is_eq (style, ly_symbol2scm ("slanted")))
    pstyle = PANGO_STYLE_OBLIQUE;

  return pstyle;
}

PangoVariant
symbol_to_pango_variant (SCM variant)
{
  PangoVariant pvariant = PANGO_VARIANT_NORMAL;
  if (scm_is_eq (variant, ly_symbol2scm ("caps")))
    pvariant = PANGO_VARIANT_SMALL_CAPS;
  return pvariant;
}

PangoWeight
symbol_to_pango_weight (SCM weight)
{
  PangoWeight pw = PANGO_WEIGHT_NORMAL;
  if (scm_is_eq (weight, ly_symbol2scm ("bold")))
    pw = PANGO_WEIGHT_BOLD;
  if (scm_is_eq (weight, ly_symbol2scm ("heavy")))
    pw = PANGO_WEIGHT_HEAVY;
  if (scm_is_eq (weight, ly_symbol2scm ("ultrabold")))
    pw = PANGO_WEIGHT_ULTRABOLD;
  if (scm_is_eq (weight, ly_symbol2scm ("light")))
    pw = PANGO_WEIGHT_LIGHT;
  if (scm_is_eq (weight, ly_symbol2scm ("ultralight")))
    pw = PANGO_WEIGHT_ULTRALIGHT;

  return pw;
}

PangoStretch
symbol_to_pango_stretch (SCM) //  stretch)
{
  PangoStretch ps = PANGO_STRETCH_NORMAL;

  /*
  // TODO

  PANGO_STRETCH_ULTRA_CONDENSED,
  PANGO_STRETCH_EXTRA_CONDENSED,
  PANGO_STRETCH_CONDENSED,
  PANGO_STRETCH_SEMI_CONDENSED,

  PANGO_STRETCH_SEMI_EXPANDED,
  PANGO_STRETCH_EXPANDED,
  PANGO_STRETCH_EXTRA_EXPANDED,
  PANGO_STRETCH_ULTRA_EXPANDED
  */
  return ps;
}

PangoFontDescription *
symbols_to_pango_font_description (SCM family,
                                   SCM style,
                                   SCM variant,
                                   SCM weight,
                                   SCM stretch)
{
  PangoFontDescription *description = pango_font_description_new ();

  string family_str = "roman";
  if (scm_is_symbol (family))
    family_str = ly_symbol2string (family);
  else if (scm_is_string (family))
    family_str = ly_scm2string (family);

  pango_font_description_set_family (description,
                                     family_str.c_str ());
  pango_font_description_set_style (description,
                                    symbol_to_pango_style (style));
  pango_font_description_set_variant (description,
                                      symbol_to_pango_variant (variant));
  pango_font_description_set_weight (description,
                                     symbol_to_pango_weight (weight));
  pango_font_description_set_stretch (description,
                                      symbol_to_pango_stretch (stretch));

  return description;
}
