1/*
2 * Copyright (C) 1999-2001 Free Software Foundation, Inc.
3 * This file is part of the GNU LIBICONV Library.
4 *
5 * The GNU LIBICONV Library is free software; you can redistribute it
6 * and/or modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
9 *
10 * The GNU LIBICONV Library is distributed in the hope that it will be
11 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public
16 * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
17 * If not, write to the Free Software Foundation, Inc., 59 Temple Place -
18 * Suite 330, Boston, MA 02111-1307, USA.
19 */
20
21/*
22 * HZ
23 */
24
25/* Specification: RFC 1842, RFC 1843 */
26
27/*
28 * The state is 1 in GB mode, 0 in ASCII mode.
29 */
30
31static int
32hz_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
33{
34  state_t state = conv->istate;
35  unsigned int count = 0;
36  unsigned char c;
37  for (;;) {
38    c = *s;
39    if (c == '~') {
40      if (n < count+2)
41        goto none;
42      c = s[1];
43      if (state == 0) {
44        if (c == '~') {
45          *pwc = (ucs4_t) '~';
46          conv->istate = state;
47          return count+2;
48        }
49        if (c == '{') {
50          state = 1;
51          s += 2; count += 2;
52          if (n < count+1)
53            goto none;
54          continue;
55        }
56        if (c == '\n') {
57          s += 2; count += 2;
58          if (n < count+1)
59            goto none;
60          continue;
61        }
62      } else {
63        if (c == '}') {
64          state = 0;
65          s += 2; count += 2;
66          if (n < count+1)
67            goto none;
68          continue;
69        }
70      }
71      return RET_ILSEQ;
72    }
73    break;
74  }
75  if (state == 0) {
76    *pwc = (ucs4_t) c;
77    conv->istate = state;
78    return count+1;
79  } else {
80    int ret;
81    if (n < count+2)
82      goto none;
83    ret = gb2312_mbtowc(conv,pwc,s,2);
84    if (ret == RET_ILSEQ)
85      return RET_ILSEQ;
86    if (ret != 2) abort();
87    conv->istate = state;
88    return count+2;
89  }
90
91none:
92  conv->istate = state;
93  return RET_TOOFEW(count);
94}
95
96static int
97hz_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
98{
99  state_t state = conv->ostate;
100  unsigned char buf[2];
101  int ret;
102
103  /* Code set 0 (ASCII or GB 1988-89) */
104  ret = ascii_wctomb(conv,buf,wc,1);
105  if (ret != RET_ILUNI) {
106    if (ret != 1) abort();
107    if (buf[0] < 0x80) {
108      int count = (state ? 3 : 1);
109      if (n < count)
110        return RET_TOOSMALL;
111      if (state) {
112        r[0] = '~';
113        r[1] = '}';
114        r += 2;
115        state = 0;
116      }
117      r[0] = buf[0];
118      conv->ostate = state;
119      return count;
120    }
121  }
122
123  /* Code set 1 (GB 2312-1980) */
124  ret = gb2312_wctomb(conv,buf,wc,2);
125  if (ret != RET_ILUNI) {
126    if (ret != 2) abort();
127    if (buf[0] < 0x80 && buf[1] < 0x80) {
128      int count = (state ? 2 : 4);
129      if (n < count)
130        return RET_TOOSMALL;
131      if (!state) {
132        r[0] = '~';
133        r[1] = '{';
134        r += 2;
135        state = 1;
136      }
137      r[0] = buf[0];
138      r[1] = buf[1];
139      conv->ostate = state;
140      return count;
141    }
142  }
143
144  return RET_ILUNI;
145}
146
147static int
148hz_reset (conv_t conv, unsigned char *r, int n)
149{
150  state_t state = conv->ostate;
151  if (state) {
152    if (n < 2)
153      return RET_TOOSMALL;
154    r[0] = '~';
155    r[1] = '}';
156    /* conv->ostate = 0; will be done by the caller */
157    return 2;
158  } else
159    return 0;
160}
161