/*----------------------------------------------------------------------*
 * File:	encoding.C
 *----------------------------------------------------------------------*
 *
 * All portions of code are copyright by their respective author/s.
 * Copyright (c) 2003-2006 Marc Lehmann <pcg@goof.com>
 *
 * This program 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 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *----------------------------------------------------------------------*/

#include "../config.h"

#include "encoding.h"

#include <cstdlib>
#include <cstring>

const struct n2cs {
  const char *name;
  codeset cs;
} n2cs[] = {
  /* first one found is the normalized one */
  { "ISO88591",		CS_ISO8859_1        },
  { "ISO8859PRIMARY",	CS_ISO8859_1        }, // some stupid fonts use this (hi tigert)
  { "ISO88592",		CS_ISO8859_2        },
  { "ISO88593",		CS_ISO8859_3        },
  { "ISO88594",		CS_ISO8859_4        },
  { "ISO88595",		CS_ISO8859_5        },
  { "ISO88596",		CS_ISO8859_6        },
  { "ISO88597",		CS_ISO8859_7        },
  { "ISO88598",		CS_ISO8859_8        },
  { "ISO88599",		CS_ISO8859_9        },
  { "ISO885910",	CS_ISO8859_10       },
  { "ISO885911",	CS_ISO8859_11       },
  { "ISO885913",	CS_ISO8859_13       },
  { "ISO885914",	CS_ISO8859_14       },
  { "ISO885915",	CS_ISO8859_15       },
  { "FCD885915",	CS_ISO8859_15       },
  { "ISO885916",	CS_ISO8859_16       },

  { "TIS620*",		CS_ISO8859_11	    }, // close enough

  { "ISO10646*",	CS_UNICODE          },
  { "UNICODE",		CS_UNICODE          },
  { "UTF8",		CS_UNICODE          },

  { "ASCII",		CS_US_ASCII         },
  { "USASCII",		CS_US_ASCII         },
  { "ANSIX341968",	CS_US_ASCII         },
  { "ISO6461991IRV",	CS_US_ASCII         }, // older versions used the currency sign

  { "KOI8R*",		CS_KOI8_R           },
  { "GOST1976874*",     CS_KOI8_R           },
  { "KOI8RU",		CS_KOI8_U           },
  { "KOI8U",		CS_KOI8_U           },

  { "VISCII*",		CS_VISCII	    },

  { "JISX0201*",	CS_JIS0201_1976_0   },
  { "JISC6226*",	CS_JIS0208_1990_0   }, // also wrongly matches -1987-0? (check Encode::JP)
  { "JISX0208*",	CS_JIS0208_1990_0   }, // also wrongly matches -1987-0? (check Encode::JP)
  { "JISX0212*",	CS_JIS0212_1990_0   },
  { "JISX021320001",	CS_JIS0213_1        },
  { "JISX021320002",	CS_JIS0213_2        },
  { "JISX0221*",	CS_UNICODE          }, // _very_ close

  { "KSC5601*",		CS_KSC5601_1987_0   },
  { "KSX1001*",		CS_KSC5601_1987_0   },
  { "KSC5700*",		CS_UNICODE          }, // unicode plus extensions

  { "BIG5P*",		CS_BIG5_PLUS        },
  { "BIG5ETEN*",	CS_BIG5_EXT         },
  { "BIG5*",		CS_BIG5             },
  { "GB2312*",		CS_GB2312_1980_0    },
  { "GBK*",		CS_GBK_0            },
  { "GB6345*",		CS_GB2312_1980_0    }, // slightly different to gb2312??
  { "GB8565*",		CS_GB2312_1980_0    }, // a superset of gb2312??
  { "GB13000*",		CS_UNICODE          },
  { "CNS1164319921",	CS_CNS11643_1992_1  },
  { "CNS1164319922",	CS_CNS11643_1992_2  },
  { "CNS1164319923",	CS_CNS11643_1992_3  },
  { "CNS1164319924",	CS_CNS11643_1992_4  },
  { "CNS1164319925",	CS_CNS11643_1992_5  },
  { "CNS1164319926",	CS_CNS11643_1992_6  },
  { "CNS1164319927",	CS_CNS11643_1992_7  },
  { "CNS116431992F",	CS_CNS11643_1992_F  },

  { 0,       		CS_UNKNOWN      }
};

static const char *
normalize_name (const char *name)
{
  static char res[16];
  char *r;

  for (r = res; *name && r < res + 15; name++)
    if ((*name >= '0' && *name <= '9')
        || (*name >= 'A' && *name <= 'Z'))
      *r++ = *name;
    else if (*name >= 'a' && *name <= 'z')
      *r++ = *name - ('a' - 'A');

  *r = 0;

  return res;
}

codeset
codeset_from_name (const char *name)
{
  if (!name)
    return CS_UNKNOWN;

  name = normalize_name (name);

  const struct n2cs *i = n2cs;

  do {
    int len = strlen (i->name);

    if ((i->name[len - 1] == '*'
         && !strncmp (name, i->name, len - 1))
        || !strcmp (name, i->name))
        return i->cs;

  } while ((++i)->name);

  return CS_UNKNOWN;
}

static unicode_t cs_unknown_to_unicode (uint32_t enc)          { return NOCHAR; }
static uint32_t cs_unknown_from_unicode (unicode_t unicode)    { return NOCHAR; }

static unicode_t cs_unicode_to_unicode (uint32_t enc)          { return enc; }
static uint32_t cs_unicode_from_unicode (unicode_t unicode)    { return unicode; }

#define cs_us_ascii_to_unicode cs_unicode_to_unicode
static uint32_t cs_us_ascii_from_unicode (unicode_t unicode)   { return unicode <= 127 ? unicode : NOCHAR; }

#define cs_us_ascii_to_unicode_16 cs_unicode_to_unicode
static uint32_t cs_unicode_16_from_unicode (unicode_t unicode) { return unicode <= 65535 ? unicode : NOCHAR; }

#define ENCODING_DEFAULT

#include "table/iso8859_1.h"
#include "table/iso8859_15.h"

//#define ENCODING_EU

#include "table/iso8859_2.h"
#include "table/iso8859_3.h"
#include "table/iso8859_4.h"
#include "table/iso8859_5.h"
#include "table/iso8859_6.h"
#include "table/iso8859_7.h"
#include "table/iso8859_8.h"
#include "table/iso8859_9.h"
#include "table/iso8859_10.h"
#include "table/iso8859_11.h"
#include "table/iso8859_13.h"
#include "table/iso8859_14.h"
#include "table/iso8859_16.h"

#include "table/koi8_r.h"
#include "table/koi8_u.h"

//#define ENCODING_KR

#include "table/ksc5601_1987_0.h"

//#define ENCODING_ZH

#include "table/big5.h"
#include "table/gbk_0.h"
#include "table/gb2312_1980_0.h"

//#define ENCODING_ZH_EXT

#include "table/cns11643_1992_1.h"
#include "table/cns11643_1992_2.h"
#include "table/cns11643_1992_3.h"
#include "table/cns11643_1992_4.h"
#include "table/cns11643_1992_5.h"
#include "table/cns11643_1992_6.h"
#include "table/cns11643_1992_7.h"
#include "table/cns11643_1992_f.h"
#include "table/big5_ext.h"
#include "table/big5_plus.h"

//#define ENCODING_VN

#include "table/viscii.h"

//#define ENCODING_JP

#include "table/jis0201_1976_0.h"
#include "table/jis0208_1990_0.h"
#include "table/jis0212_1990_0.h"

//#define ENCODING_JP_EXT

#include "table/jis0213_1.h"
#include "table/jis0213_2.h"

#if ENCODING_TO_UNICODE
# define ENC(base) { cs_ ## base ## _from_unicode, cs_ ## base ## _to_unicode }
#else
# define ENC(base) { cs_ ## base ## _from_unicode }
#endif


// order must match table in encoding.h(!)
const rxvt_codeset_conv rxvt_codeset[NUM_CODESETS] = {
  ENC (unknown),

  ENC (us_ascii),

  ENC (iso8859_1),
  ENC (iso8859_2),
  ENC (iso8859_3),
  ENC (iso8859_4),
  ENC (iso8859_5),
  ENC (iso8859_6),
  ENC (iso8859_7),
  ENC (iso8859_8),
  ENC (iso8859_9),
  ENC (iso8859_10),
  ENC (iso8859_11),
  ENC (iso8859_13),
  ENC (iso8859_14),
  ENC (iso8859_15),
  ENC (iso8859_16),

  ENC (koi8_r),
  ENC (koi8_u),

  ENC (jis0201_1976_0),
  ENC (jis0208_1990_0),
  ENC (jis0212_1990_0),

  ENC (jis0213_1),
  ENC (jis0213_2),

  ENC (ksc5601_1987_0),

  ENC (gb2312_1980_0),
  ENC (gbk_0),

  ENC (cns11643_1992_1),
  ENC (cns11643_1992_2),
  ENC (cns11643_1992_3),
  ENC (cns11643_1992_4),
  ENC (cns11643_1992_5),
  ENC (cns11643_1992_6),
  ENC (cns11643_1992_7),
  ENC (cns11643_1992_f),
  ENC (big5),
  ENC (big5_ext),
  ENC (big5_plus),

  ENC (viscii),

  ENC (unicode_16),
  ENC (unicode),
};

#if ENABLE_COMBINING
# define ENCODING_COMPOSE
#endif

#include "table/compose.h"

unicode_t
rxvt_compose (unicode_t c1, unicode_t c2)
{
  int l = 0;
  int r = sizeof (rxvt_compose_table) / sizeof (rxvt_compose_entry) - 1;
  int m;

  while (r >= l)
    {
      m = (l + r) / 2;
      rxvt_compose_entry &c = rxvt_compose_table[m];

      if (c.c1 < c1 || (c.c1 == c1 && c.c2 < c2))
        l = m + 1;
      else if (c.c1 > c1 || (c.c1 == c1 && c.c2 > c2))
        r = m - 1;
      else
        return c.r;
    }

  return NOCHAR;
}

#include "table/category.h"

bool unicode::is_space (unicode_t c)
{
  return IS_SPACE (c)
         || c == 0x09; // exclude tabs, too, as we store them in the buffer
}