/* Categories of Unicode characters.
   Copyright (C) 2002, 2006-2007, 2011-2021 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2002.

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

   This program 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
   Lesser General Public License for more details.

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

#include <config.h>

/* Specification.  */
#include "unictype.h"

static const char u_category_name[30][3] =
{
  "Lu", "Ll", "Lt", "Lm", "Lo", "Mn", "Mc", "Me", "Nd", "Nl",
  "No", "Pc", "Pd", "Ps", "Pe", "Pi", "Pf", "Po", "Sm", "Sc",
  "Sk", "So", "Zs", "Zl", "Zp", "Cc", "Cf", "Cs", "Co", "Cn"
};

const char *
uc_general_category_name (uc_general_category_t category)
{
  uint32_t bitmask = category.bitmask;
  /* bitmask should consist of a single bit.  */
  if (bitmask != 0)
    {
      if ((bitmask & (bitmask - 1)) == 0)
        {
          int bit;
          /* Take log2 using a variant of Robert Harley's method.
             Found by Bruno Haible 1996.  */
          uint32_t n = bitmask;
          static const char ord2_tab[64] =
            {
              -1,  0,  1, 12,  2,  6, -1, 13,  3, -1,  7, -1, -1, -1, -1, 14,
              10,  4, -1, -1,  8, -1, -1, 25, -1, -1, -1, -1, -1, 21, 27, 15,
              31, 11,  5, -1, -1, -1, -1, -1,  9, -1, -1, 24, -1, -1, 20, 26,
              30, -1, -1, -1, -1, 23, -1, 19, 29, -1, 22, 18, 28, 17, 16, -1
            };
          n += n << 4;
          n += n << 6;
          n = (n << 16) - n;
          bit = ord2_tab[n >> 26];

          if (bit < sizeof (u_category_name) / sizeof (u_category_name[0]))
            return u_category_name[bit];
        }
      else
        {
          if (bitmask == UC_CATEGORY_MASK_L)
            return "L";
          if (bitmask == UC_CATEGORY_MASK_LC)
            return "LC";
          if (bitmask == UC_CATEGORY_MASK_M)
            return "M";
          if (bitmask == UC_CATEGORY_MASK_N)
            return "N";
          if (bitmask == UC_CATEGORY_MASK_P)
            return "P";
          if (bitmask == UC_CATEGORY_MASK_S)
            return "S";
          if (bitmask == UC_CATEGORY_MASK_Z)
            return "Z";
          if (bitmask == UC_CATEGORY_MASK_C)
            return "C";
        }
    }
  return NULL;
}
