#include "transcode_data.h"

<%
  require 'utf8_mac-tbl'

  transcode_tblgen("UTF-8", "UTF8-MAC",
    MAC_DECOMPOSE_TBL + [
    ["{00-7F}", :nomap],
    ["{c2-df}{80-bf}", :nomap0],
    ["e0{a0-bf}{80-bf}", :nomap0],
    ["{e1-ec}{80-bf}{80-bf}", :nomap0],
    ["ed{80-9f}{80-bf}", :nomap0],
    ["{ee-ef}{80-bf}{80-bf}", :nomap0],
    ["f0{90-bf}{80-bf}{80-bf}", :nomap0],
    ["{f1-f3}{80-bf}{80-bf}{80-bf}", :nomap0],
  ])

  map = {}
  map["{00-7f}"] = :func_so
  map["{c2-df}{80-bf}"] = :func_so
  map["e0{a0-bf}{80-bf}"] = :func_so
  map["{e1-ec}{80-bf}{80-bf}"] = :func_so
  map["ed{80-9f}{80-bf}"] = :func_so
  map["{ee-ef}{80-bf}{80-bf}"] = :func_so
  map["f0{90-bf}{80-bf}{80-bf}"] = :func_so
  map["{f1-f3}{80-bf}{80-bf}{80-bf}"] = :func_so
  map["f4{80-8f}{80-bf}{80-bf}"] = :func_so
  transcode_generate_node(ActionMap.parse(map), "from_UTF8_MAC")

  ary = MAC_DECOMPOSE_TBL.select{|k,v|v.scan(/[0-7C-F].(?:[89AB].)*/i).length == 3}
  transcode_generate_node(ActionMap.parse(ary.map{|k,v|[v,k]}), "from_utf8_mac_nfc3")

  ary = MAC_DECOMPOSE_TBL.select{|k,v|v.scan(/[0-7C-F].(?:[89AB].)*/i).length == 2}
  transcode_generate_node(ActionMap.parse(ary.map{|k,v|[v,k]}), "from_utf8_mac_nfc2")
%>

<%= transcode_generated_code %>

#define BYTE_ADDR(index) (<%= OUTPUT_PREFIX %>byte_array + (index))
#define WORD_ADDR(index) (<%= OUTPUT_PREFIX %>word_array + INFO2WORDINDEX(index))
#define BL_BASE BYTE_ADDR(BYTE_LOOKUP_BASE(WORD_ADDR(next_info)))
#define BL_INFO WORD_ADDR(BYTE_LOOKUP_INFO(WORD_ADDR(next_info)))
#define BL_MIN_BYTE     (BL_BASE[0])
#define BL_MAX_BYTE     (BL_BASE[1])
#define BL_OFFSET(byte) (BL_BASE[2+(byte)-BL_MIN_BYTE])
#define BL_ACTION(byte) (BL_INFO[BL_OFFSET((byte))])

#define STATUS_BUF_SIZE 16
struct from_utf8_mac_status {
    unsigned char buf[STATUS_BUF_SIZE];
    int beg;
    int end;
    int len;
};
#define buf_length(sp) (sp->len)

int
buf_bytesize(struct from_utf8_mac_status *sp)
{
    int size = sp->end - sp->beg + STATUS_BUF_SIZE;
    size %= STATUS_BUF_SIZE;
    return size;
}

void
buf_push(struct from_utf8_mac_status *sp, const unsigned char *p, ssize_t l)
{
    const unsigned char *pend = p + l;
    while (p < pend) {
        sp->buf[sp->end++] = *p++;
        sp->end %= STATUS_BUF_SIZE;
    }
    sp->len++;
}

unsigned char
buf_shift(struct from_utf8_mac_status *sp)
{
    unsigned char c = sp->buf[sp->beg++];
    sp->beg %= STATUS_BUF_SIZE;
    if ((c & 0xC0) != 0x80) sp->len--;
    return c;
}

void
buf_shift_char(struct from_utf8_mac_status *sp)
{
    if (sp->beg == sp->end) return;
    do {
        buf_shift(sp);
    } while (sp->beg != sp->end && (sp->buf[sp->beg] & 0xC0) == 0x80);
}

void
buf_clear(struct from_utf8_mac_status *sp)
{
    sp->beg = sp->end = sp->len = 0;
}

unsigned char
buf_at(struct from_utf8_mac_status *sp, int pos)
{
    pos += sp->beg;
    pos %= STATUS_BUF_SIZE;
    return sp->buf[pos];
}

int
buf_output_char(struct from_utf8_mac_status *sp, unsigned char *o)
{
    int n = 0;
    while (sp->beg != sp->end) {
        o[n++] = buf_shift(sp);
        if ((sp->buf[sp->beg] & 0xC0) != 0x80) break;
    }
    return n;
}

int
buf_output_all(struct from_utf8_mac_status *sp, unsigned char *o)
{
    int n = 0;
    while (sp->beg != sp->end) {
        o[n++] = buf_shift(sp);
    }
    return n;
}

VALUE
get_info(VALUE next_info, struct from_utf8_mac_status *sp) {
    int pos = 0;
    while (pos < buf_bytesize(sp)) {
        unsigned char next_byte = buf_at(sp, pos++);
        if (next_byte < BL_MIN_BYTE || BL_MAX_BYTE < next_byte)
            next_info = INVALID;
        else {
            next_info = (VALUE)BL_ACTION(next_byte);
        }
        if ((next_info & 3) == 0) continue;
        break;
    }
    return next_info;
}

int
buf_apply(int mode, struct from_utf8_mac_status *sp, unsigned char *o)
{
    int n = 0;
    VALUE next_info = mode == 3 ? from_utf8_mac_nfc3 : from_utf8_mac_nfc2;
    next_info = get_info(next_info, sp);
    switch (next_info & 0x1F) {
      case THREEbt:
      case TWObt:
        o[n++] = getBT1(next_info);
        o[n++] = getBT2(next_info);
        if (THREEbt == (next_info & 0x1F)) o[n++] = getBT3(next_info);
        if (mode == 3) {
            buf_clear(sp);
        }
        else {
            buf_shift_char(sp);
            buf_shift_char(sp);
        }
        break;
      default:
        return 0;
    }
    return n;
}

static int
from_utf8_mac_init(void *statep)
{
    struct from_utf8_mac_status *sp = statep;
    buf_clear(sp);
    return 0;
}

static ssize_t
from_utf8_mac_finish(void *statep,
        unsigned char *o, size_t osize)
{
    struct from_utf8_mac_status *sp = statep;
    int n;
    if (buf_length(sp) == 0) return 0;
    n = buf_apply(2, sp, o) + buf_output_all(sp, o);
    return n;
}

static ssize_t
fun_so_from_utf8_mac(void *statep,
        const unsigned char *s, size_t l,
        unsigned char *o, size_t osize)
{
    struct from_utf8_mac_status *sp = statep;
    ssize_t n = 0;

    switch (l) {
      case 1:
        n = from_utf8_mac_finish(sp, o, osize);
        break;
      case 4:
        n = from_utf8_mac_finish(sp, o, osize);
        o[n++] = *s++;
        o[n++] = *s++;
        o[n++] = *s++;
        o[n++] = *s++;
        return n;
    }

    buf_push(sp, s, l);
    if (buf_length(sp) < 3) return n;

    n = buf_apply(3, sp, o);
    if (n > 0) return n;

    n = buf_apply(2, sp, o);
    if (n > 0) return n;

    return buf_output_char(sp, o);
}

static const rb_transcoder
rb_from_UTF8_MAC = {
    "UTF8-MAC", "UTF-8", from_UTF8_MAC,
    TRANSCODE_TABLE_INFO,
    1, /* input_unit_length */
    4, /* max_input */
    10, /* max_output */
    asciicompat_encoder, /* asciicompat_type */
    sizeof(struct from_utf8_mac_status), from_utf8_mac_init, from_utf8_mac_init,
    NULL, NULL, NULL, fun_so_from_utf8_mac,
    from_utf8_mac_finish
};

void
Init_utf8_mac(void)
{
<%= transcode_register_code %>
    rb_register_transcoder(&rb_from_UTF8_MAC);
}