/*      $NetBSD: chartype.c,v 1.37 2023/08/10 20:38:00 mrg Exp $        */

/*-
 * Copyright (c) 2009 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * chartype.c: character classification and meta information
 */
#include "config.h"
#if !defined(lint) && !defined(SCCSID)
__RCSID("$NetBSD: chartype.c,v 1.37 2023/08/10 20:38:00 mrg Exp $");
#endif /* not lint && not SCCSID */

#include <ctype.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>

#include "el.h"

#define CT_BUFSIZ ((size_t)1024)

static int ct_conv_cbuff_resize(ct_buffer_t *, size_t);
static int ct_conv_wbuff_resize(ct_buffer_t *, size_t);

static int
ct_conv_cbuff_resize(ct_buffer_t *conv, size_t csize)
{
        void *p;

        if (csize <= conv->csize)
                return 0;

        conv->csize = csize;

        p = el_realloc(conv->cbuff, conv->csize * sizeof(*conv->cbuff));
        if (p == NULL) {
                conv->csize = 0;
                el_free(conv->cbuff);
                conv->cbuff = NULL;
                return -1;
        }
        conv->cbuff = p;
        return 0;
}

static int
ct_conv_wbuff_resize(ct_buffer_t *conv, size_t wsize)
{
        void *p;

        if (wsize <= conv->wsize)
                return 0;

        conv->wsize = wsize;

        p = el_realloc(conv->wbuff, conv->wsize * sizeof(*conv->wbuff));
        if (p == NULL) {
                conv->wsize = 0;
                el_free(conv->wbuff);
                conv->wbuff = NULL;
                return -1;
        }
        conv->wbuff = p;
        return 0;
}


char *
ct_encode_string(const wchar_t *s, ct_buffer_t *conv)
{
        char *dst;
        ssize_t used;

        if (!s)
                return NULL;

        dst = conv->cbuff;
        for (;;) {
                used = (ssize_t)(dst - conv->cbuff);
                if ((conv->csize - (size_t)used) < 5) {
                        if (ct_conv_cbuff_resize(conv,
                            conv->csize + CT_BUFSIZ) == -1)
                                return NULL;
                        dst = conv->cbuff + used;
                }
                if (!*s)
                        break;
                used = ct_encode_char(dst, (size_t)5, *s);
                if (used == -1) /* failed to encode, need more buffer space */
                        abort();
                ++s;
                dst += used;
        }
        *dst = '\0';
        return conv->cbuff;
}

wchar_t *
ct_decode_string(const char *s, ct_buffer_t *conv)
{
        size_t len;

        if (!s)
                return NULL;

        len = mbstowcs(NULL, s, (size_t)0);
        if (len == (size_t)-1)
                return NULL;

        if (conv->wsize < ++len)
                if (ct_conv_wbuff_resize(conv, len + CT_BUFSIZ) == -1)
                        return NULL;

        mbstowcs(conv->wbuff, s, conv->wsize);
        return conv->wbuff;
}


libedit_private wchar_t **
ct_decode_argv(int argc, const char *argv[], ct_buffer_t *conv)
{
        size_t bufspace;
        int i;
        wchar_t *p;
        wchar_t **wargv;
        ssize_t bytes;

        /* Make sure we have enough space in the conversion buffer to store all
         * the argv strings. */
        for (i = 0, bufspace = 0; i < argc; ++i)
                bufspace += argv[i] ? strlen(argv[i]) + 1 : 0;
        if (conv->wsize < ++bufspace)
                if (ct_conv_wbuff_resize(conv, bufspace + CT_BUFSIZ) == -1)
                        return NULL;

        wargv = el_calloc((size_t)(argc + 1), sizeof(*wargv));
        if (wargv == NULL)
                return NULL;

        for (i = 0, p = conv->wbuff; i < argc; ++i) {
                if (!argv[i]) {   /* don't pass null pointers to mbstowcs */
                        wargv[i] = NULL;
                        continue;
                } else {
                        wargv[i] = p;
                        bytes = (ssize_t)mbstowcs(p, argv[i], bufspace);
                }
                if (bytes == -1) {
                        el_free(wargv);
                        return NULL;
                } else
                        bytes++;  /* include '\0' in the count */
                bufspace -= (size_t)bytes;
                p += bytes;
        }
        wargv[i] = NULL;

        return wargv;
}


libedit_private size_t
ct_enc_width(wchar_t c)
{
        mbstate_t mbs;
        char buf[MB_LEN_MAX];
        size_t size;
        memset(&mbs, 0, sizeof(mbs));

        if ((size = wcrtomb(buf, c, &mbs)) == (size_t)-1)
                return 0;
        return size;
}

libedit_private ssize_t
ct_encode_char(char *dst, size_t len, wchar_t c)
{
        ssize_t l = 0;
        if (len < ct_enc_width(c))
                return -1;
        l = wctomb(dst, c);

        if (l < 0) {
                wctomb(NULL, L'\0');
                l = 0;
        }
        return l;
}

libedit_private const wchar_t *
ct_visual_string(const wchar_t *s, ct_buffer_t *conv)
{
        wchar_t *dst;
        ssize_t used;

        if (!s)
                return NULL;

        if (ct_conv_wbuff_resize(conv, CT_BUFSIZ) == -1)
                return NULL;

        used = 0;
        dst = conv->wbuff;
        while (*s) {
                used = ct_visual_char(dst,
                    conv->wsize - (size_t)(dst - conv->wbuff), *s);
                if (used != -1) {
                        ++s;
                        dst += used;
                        continue;
                }

                /* failed to encode, need more buffer space */
                uintptr_t sused = (uintptr_t)dst - (uintptr_t)conv->wbuff;
                if (ct_conv_wbuff_resize(conv, conv->wsize + CT_BUFSIZ) == -1)
                        return NULL;
                dst = conv->wbuff + sused;
        }

        if (dst >= (conv->wbuff + conv->wsize)) { /* sigh */
                uintptr_t sused = (uintptr_t)dst - (uintptr_t)conv->wbuff;
                if (ct_conv_wbuff_resize(conv, conv->wsize + CT_BUFSIZ) == -1)
                        return NULL;
                dst = conv->wbuff + sused;
        }

        *dst = L'\0';
        return conv->wbuff;
}



libedit_private int
ct_visual_width(wchar_t c)
{
        int t = ct_chr_class(c);
        switch (t) {
        case CHTYPE_ASCIICTL:
                return 2; /* ^@ ^? etc. */
        case CHTYPE_TAB:
                return 1; /* Hmm, this really need to be handled outside! */
        case CHTYPE_NL:
                return 0; /* Should this be 1 instead? */
        case CHTYPE_PRINT:
                return wcwidth(c);
        case CHTYPE_NONPRINT:
                if (c > 0xffff) /* prefer standard 4-byte display over 5-byte */
                        return 8; /* \U+12345 */
                else
                        return 7; /* \U+1234 */
        default:
                return 0; /* should not happen */
        }
}


libedit_private ssize_t
ct_visual_char(wchar_t *dst, size_t len, wchar_t c)
{
        int t = ct_chr_class(c);
        switch (t) {
        case CHTYPE_TAB:
        case CHTYPE_NL:
        case CHTYPE_ASCIICTL:
                if (len < 2)
                        return -1;   /* insufficient space */
                *dst++ = '^';
                if (c == '\177')
                        *dst = '?'; /* DEL -> ^? */
                else
                        *dst = c | 0100;    /* uncontrolify it */
                return 2;
        case CHTYPE_PRINT:
                if (len < 1)
                        return -1;  /* insufficient space */
                *dst = c;
                return 1;
        case CHTYPE_NONPRINT:
                /* we only use single-width glyphs for display,
                 * so this is right */
                if ((ssize_t)len < ct_visual_width(c))
                        return -1;   /* insufficient space */
                *dst++ = '\\';
                *dst++ = 'U';
                *dst++ = '+';
#define tohexdigit(v) "0123456789ABCDEF"[v]
                if (c > 0xffff) /* prefer standard 4-byte display over 5-byte */
                        *dst++ = tohexdigit(((unsigned int) c >> 16) & 0xf);
                *dst++ = tohexdigit(((unsigned int) c >> 12) & 0xf);
                *dst++ = tohexdigit(((unsigned int) c >>  8) & 0xf);
                *dst++ = tohexdigit(((unsigned int) c >>  4) & 0xf);
                *dst   = tohexdigit(((unsigned int) c      ) & 0xf);
                return c > 0xffff ? 8 : 7;
                /*FALLTHROUGH*/
        /* these two should be handled outside this function */
        default:            /* we should never hit the default */
                return 0;
        }
}




libedit_private int
ct_chr_class(wchar_t c)
{
        if (c == '\t')
                return CHTYPE_TAB;
        else if (c == '\n')
                return CHTYPE_NL;
        else if (c < 0x100 && iswcntrl(c))
                return CHTYPE_ASCIICTL;
        else if (iswprint(c))
                return CHTYPE_PRINT;
        else
                return CHTYPE_NONPRINT;
}