/*      $OpenBSD: chartype.c,v 1.16 2019/01/29 09:47:00 yasuoka Exp $   */
/*      $NetBSD: chartype.c,v 1.6 2011/07/28 00:48:21 christos 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"

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

#include "el.h"

#define CT_BUFSIZ 1024

static void ct_conv_buff_resize(ct_buffer_t *, size_t, size_t);

static void
ct_conv_buff_resize(ct_buffer_t *conv, size_t mincsize, size_t minwsize)
{
        void *p;
        if (mincsize > conv->csize) {
                conv->csize = mincsize;
                p = reallocarray(conv->cbuff, conv->csize, sizeof(char));
                if (p == NULL) {
                        conv->csize = 0;
                        free(conv->cbuff);
                        conv->cbuff = NULL;
                } else
                        conv->cbuff = p;
        }

        if (minwsize > conv->wsize) {
                conv->wsize = minwsize;
                p = reallocarray(conv->wbuff, conv->wsize, sizeof(wchar_t));
                if (p == NULL) {
                        conv->wsize = 0;
                        free(conv->wbuff);
                        conv->wbuff = NULL;
                } else
                        conv->wbuff = p;
        }
}


char *
ct_encode_string(const wchar_t *s, ct_buffer_t *conv)
{
        char *dst;
        ssize_t used = 0;

        if (!s)
                return NULL;
        if (!conv->cbuff)
                ct_conv_buff_resize(conv, CT_BUFSIZ, 0);
        if (!conv->cbuff)
                return NULL;

        dst = conv->cbuff;
        while (*s) {
                used = conv->csize - (dst - conv->cbuff);
                if (used < 5) {
                        used = dst - conv->cbuff;
                        ct_conv_buff_resize(conv, conv->csize + CT_BUFSIZ, 0);
                        if (!conv->cbuff)
                                return NULL;
                        dst = conv->cbuff + used;
                }
                used = ct_encode_char(dst, 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 = 0;

        if (!s)
                return NULL;
        if (!conv->wbuff)
                ct_conv_buff_resize(conv, 0, CT_BUFSIZ);
        if (!conv->wbuff)
                return NULL;

        len = mbstowcs(NULL, s, 0);
        if (len == (size_t)-1)
                return NULL;
        if (len > conv->wsize)
                ct_conv_buff_resize(conv, 0, len + 1);
        if (!conv->wbuff)
                return NULL;

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


protected 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;
        size_t wlen;

        /* 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;
        ct_conv_buff_resize(conv, 0, bufspace * sizeof(*p));
        if (!conv->wsize)
                return NULL;

        wargv = reallocarray(NULL, argc + 1, sizeof(*wargv));

        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;
                        wlen = mbstowcs(p, argv[i], bufspace);
                }
                if (wlen == (size_t)-1 || wlen == bufspace) {
                        /* Encoding error or not enough room for NUL. */
                        free(wargv);
                        return NULL;
                } else
                        wlen++; /* include NUL in the count */
                bufspace -= wlen;
                p += wlen;
        }
        wargv[i] = NULL;

        return wargv;
}


protected size_t
ct_enc_width(wchar_t c)
{
        /* UTF-8 encoding specific values */
        if (c < 0x80)
                return 1;
        else if (c < 0x0800)
                return 2;
        else if (c < 0x10000)
                return 3;
        else if (c < 0x110000)
                return 4;
        else
                return 0; /* not a valid codepoint */
}

protected 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;
}

protected const wchar_t *
ct_visual_string(const wchar_t *s)
{
        static wchar_t *buff = NULL;
        static size_t buffsize = 0;
        void *p;
        wchar_t *dst;
        ssize_t used = 0;

        if (!s)
                return NULL;
        if (!buff) {
            buffsize = CT_BUFSIZ;
            buff = reallocarray(NULL, buffsize, sizeof(*buff));
        }
        dst = buff;
        while (*s) {
                used = ct_visual_char(dst, buffsize - (dst - buff), *s);
                if (used == -1) { /* failed to encode, need more buffer space */
                        used = dst - buff;
                        buffsize += CT_BUFSIZ;
                        p = reallocarray(buff, buffsize, sizeof(*buff));
                        if (p == NULL)
                                goto out;
                        buff = p;
                        dst = buff + used;
                        /* don't increment s here - we want to retry it! */
                }
                else
                    ++s;
                dst += used;
        }
        if (dst >= (buff + buffsize)) { /* sigh */
                buffsize += 1;
                p = reallocarray(buff, buffsize, sizeof(*buff));
                if (p == NULL)
                        goto out;
                buff = p;
                dst = buff + buffsize - 1;
        }
        *dst = 0;
        return buff;
out:
        free(buff);
        buffsize = 0;
        return NULL;
}



protected int
ct_visual_width(wchar_t c)
{
        int t = ct_chr_class(c);
        int w;
        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:
                w = wcwidth(c);
                return (w == -1 ? 0 : w);
        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 */
        }
}


protected 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;
        }
}




protected 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;
}