#include "transcode_data.h"

<%
  map = {
    "1b2842" => :func_so,       # designate US-ASCII to G0.             "ESC ( B"
    "1b284a" => :func_so,       # designate JIS X 0201 latin to G0.     "ESC ( J"
    "1b2440" => :func_so,       # designate JIS X 0208 1978 to G0.      "ESC $ @"
    "1b2442" => :func_so,       # designate JIS X 0208 1983 to G0.      "ESC $ B"
    "{00-0d,10-1a,1c-7f}" => :func_si,
  }
  transcode_generate_node(ActionMap.parse(map), "iso2022jp_decoder")

  map_jisx0208_rest = {
    "{21-7e}" => :func_so
  }
  transcode_generate_node(ActionMap.parse(map_jisx0208_rest), "iso2022jp_decoder_jisx0208_rest")

  map = {
    "{00-0d,10-1a,1c-7f}" => :func_so,
    "90{a1-fe}{a1-fe}" => :func_so,
    "92{a1-fe}{a1-fe}" => :func_so,
  }
  transcode_generate_node(ActionMap.parse(map), "iso2022jp_encoder")

  map = {
    "{00-0d,10-1a,1c-7f}" => :nomap,
    "90{a1-fe}{a1-fe}" => :func_so,
    "92{a1-fe}{a1-fe}" => :func_so,
  }
  transcode_generate_node(ActionMap.parse(map), "stateless_iso2022jp_to_eucjp")

  map = {
    "{0e,0f,1b}" => :undef,
    "{00-0d,10-1a,1c-7f}" => :nomap,
    "{a1-fe}{a1-fe}" => :func_so,
    "8e{a1-fe}" => :undef,
    "8f{a1-fe}{a1-fe}" => :undef,
  }
  transcode_generate_node(ActionMap.parse(map), "eucjp_to_stateless_iso2022jp")

%>

<%= transcode_generated_code %>

#define G0_ASCII 0
/* ignore JIS X 0201 latin */
#define G0_JISX0208_1978 1
#define G0_JISX0208_1983 2

#define EMACS_MULE_LEADING_CODE_JISX0208_1978   0220
#define EMACS_MULE_LEADING_CODE_JISX0208_1983   0222

static int
iso2022jp_init(void *statep)
{
    unsigned char *sp = statep;
    *sp = G0_ASCII;
    return 0;
}

static VALUE
fun_si_iso2022jp_decoder(void *statep, const unsigned char *s, size_t l)
{
    unsigned char *sp = statep;
    if (*sp == G0_ASCII)
        return (VALUE)NOMAP;
    else if (0x21 <= s[0] && s[0] <= 0x7e)
        return (VALUE)iso2022jp_decoder_jisx0208_rest;
    else
        return (VALUE)INVALID;
}

static int
fun_so_iso2022jp_decoder(void *statep, const unsigned char *s, size_t l, unsigned char* o)
{
    unsigned char *sp = statep;
    if (s[0] == 0x1b) {
        if (s[1] == '(') {
            switch (s[l-1]) {
              case 'B':
              case 'J':
                *sp = G0_ASCII;
                break;
            }
        }
        else {
            switch (s[l-1]) {
              case '@':
                *sp = G0_JISX0208_1978;
                break;

              case 'B':
                *sp = G0_JISX0208_1983;
                break;
            }
        }
        return 0;
    }
    else {
        if (*sp == G0_JISX0208_1978)
            o[0] = EMACS_MULE_LEADING_CODE_JISX0208_1978;
        else
            o[0] = EMACS_MULE_LEADING_CODE_JISX0208_1983;
        o[1] = s[0] | 0x80;
        o[2] = s[1] | 0x80;
        return 3;
    }
}

static const rb_transcoder
rb_iso2022jp_decoder = {
    "ISO-2022-JP", "stateless-ISO-2022-JP", iso2022jp_decoder,
    TRANSCODE_TABLE_INFO,
    1, /* input_unit_length */
    3, /* max_input */
    3, /* max_output */
    asciicompat_decoder, /* asciicompat_type */
    1, iso2022jp_init, iso2022jp_init, /* state_size, state_init, state_fini */
    NULL, fun_si_iso2022jp_decoder, NULL, fun_so_iso2022jp_decoder
};

static int
fun_so_iso2022jp_encoder(void *statep, const unsigned char *s, size_t l, unsigned char *o)
{
    unsigned char *sp = statep;
    unsigned char *output0 = o;
    int newstate;

    if (l == 1)
        newstate = G0_ASCII;
    else if (s[0] == EMACS_MULE_LEADING_CODE_JISX0208_1978)
        newstate = G0_JISX0208_1978;
    else
        newstate = G0_JISX0208_1983;

    if (*sp != newstate) {
        if (newstate == G0_ASCII) {
            *o++ = 0x1b;
            *o++ = '(';
            *o++ = 'B';
        }
        else if (newstate == G0_JISX0208_1978) {
            *o++ = 0x1b;
            *o++ = '$';
            *o++ = '@';
        }
        else {
            *o++ = 0x1b;
            *o++ = '$';
            *o++ = 'B';
        }
        *sp = newstate;
    }

    if (l == 1) {
        *o++ = s[0] & 0x7f;
    }
    else {
        *o++ = s[1] & 0x7f;
        *o++ = s[2] & 0x7f;
    }

    return o - output0;
}

static int
iso2022jp_encoder_reset_sequence_size(void *statep)
{
    unsigned char *sp = statep;
    if (*sp != G0_ASCII)
        return 3;
    return 0;
}

static int
finish_iso2022jp_encoder(void *statep, unsigned char *o)
{
    unsigned char *sp = statep;
    unsigned char *output0 = o;

    if (*sp == G0_ASCII)
        return 0;

    *o++ = 0x1b;
    *o++ = '(';
    *o++ = 'B';
    *sp = G0_ASCII;

    return o - output0;
}

static const rb_transcoder
rb_iso2022jp_encoder = {
    "stateless-ISO-2022-JP", "ISO-2022-JP", iso2022jp_encoder,
    TRANSCODE_TABLE_INFO,
    1, /* input_unit_length */
    3, /* max_input */
    5, /* max_output */
    asciicompat_encoder, /* asciicompat_type */
    1, iso2022jp_init, iso2022jp_init, /* state_size, state_init, state_fini */
    NULL, NULL, NULL, fun_so_iso2022jp_encoder,
    finish_iso2022jp_encoder,
    iso2022jp_encoder_reset_sequence_size, finish_iso2022jp_encoder
};

static int
fun_so_stateless_iso2022jp_to_eucjp(void *statep, const unsigned char *s, size_t l, unsigned char *o)
{
    o[0] = s[1];
    o[1] = s[2];
    return 2;
}

static const rb_transcoder
rb_stateless_iso2022jp_to_eucjp = {
    "stateless-ISO-2022-JP", "EUC-JP", stateless_iso2022jp_to_eucjp,
    TRANSCODE_TABLE_INFO,
    1, /* input_unit_length */
    3, /* max_input */
    2, /* max_output */
    asciicompat_converter, /* asciicompat_type */
    0, NULL, NULL, /* state_size, state_init, state_fini */
    NULL, NULL, NULL, fun_so_stateless_iso2022jp_to_eucjp,
};

static int
fun_so_eucjp_to_stateless_iso2022jp(void *statep, const unsigned char *s, size_t l, unsigned char *o)
{
    o[0] = EMACS_MULE_LEADING_CODE_JISX0208_1983;
    o[1] = s[0];
    o[2] = s[1];
    return 3;
}

static const rb_transcoder
rb_eucjp_to_stateless_iso2022jp = {
    "EUC-JP", "stateless-ISO-2022-JP", eucjp_to_stateless_iso2022jp,
    TRANSCODE_TABLE_INFO,
    1, /* input_unit_length */
    3, /* max_input */
    3, /* max_output */
    asciicompat_converter, /* asciicompat_type */
    0, NULL, NULL, /* state_size, state_init, state_fini */
    NULL, NULL, NULL, fun_so_eucjp_to_stateless_iso2022jp,
};

void
Init_iso2022(void)
{
    rb_register_transcoder(&rb_iso2022jp_decoder);
    rb_register_transcoder(&rb_iso2022jp_encoder);
    rb_register_transcoder(&rb_stateless_iso2022jp_to_eucjp);
    rb_register_transcoder(&rb_eucjp_to_stateless_iso2022jp);
}