/* $OpenBSD: comp_expand.c,v 1.8 2023/10/17 09:52:09 nicm Exp $ */

/****************************************************************************
 * Copyright 2020-2021,2023 Thomas E. Dickey                                *
 * Copyright 1998-2016,2017 Free Software Foundation, Inc.                  *
 *                                                                          *
 * Permission is hereby granted, free of charge, to any person obtaining a  *
 * copy of this software and associated documentation files (the            *
 * "Software"), to deal in the Software without restriction, including      *
 * without limitation the rights to use, copy, modify, merge, publish,      *
 * distribute, distribute with modifications, sublicense, and/or sell       *
 * copies of the Software, and to permit persons to whom the Software is    *
 * furnished to do so, subject to the following conditions:                 *
 *                                                                          *
 * The above copyright notice and this permission notice shall be included  *
 * in all copies or substantial portions of the Software.                   *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
 *                                                                          *
 * Except as contained in this notice, the name(s) of the above copyright   *
 * holders shall not be used in advertising or otherwise to promote the     *
 * sale, use or other dealings in this Software without prior written       *
 * authorization.                                                           *
 ****************************************************************************/

/****************************************************************************
 *  Author: Thomas E. Dickey                    1998                        *
 ****************************************************************************/

#include <curses.priv.h>

#include <ctype.h>
#include <tic.h>

MODULE_ID("$Id: comp_expand.c,v 1.8 2023/10/17 09:52:09 nicm Exp $")

#if 0
#define DEBUG_THIS(p) DEBUG(9, p)
#else
#define DEBUG_THIS(p)           /* nothing */
#endif

static int
trailing_spaces(const char *src)
{
    while (*src == ' ')
        src++;
    return *src == 0;
}

/* this deals with differences over whether 0x7f and 0x80..0x9f are controls */
#define REALPRINT(s) (UChar(*(s)) < 127 && isprint(UChar(*(s))))

#define P_LIMIT(p)   (length - (size_t)(p))

NCURSES_EXPORT(char *)
_nc_tic_expand(const char *srcp, bool tic_format, int numbers)
{
    static char *buffer;
    static size_t length;

    int bufp;
    const char *str = VALID_STRING(srcp) ? srcp : "\0\0";
    size_t need = (2 + strlen(str)) * 4;
    int ch;
    int octals = 0;
    struct {
        int ch;
        int offset;
    } fixups[MAX_TC_FIXUPS];

    if (srcp == 0) {
#if NO_LEAKS
        if (buffer != 0) {
            FreeAndNull(buffer);
            length = 0;
        }
#endif
        return 0;
    }
    if (buffer == 0 || need > length) {
        if ((buffer = typeRealloc(char, length = need, buffer)) == 0)
              return 0;
    }

    DEBUG_THIS(("_nc_tic_expand %s:%s:%s",
                tic_format ? "ti" : "tc",
                numbers ? "#" : "",
                _nc_visbuf(srcp)));
    bufp = 0;
    while ((ch = UChar(*str)) != 0) {
        if (ch == '%' && REALPRINT(str + 1)) {
            buffer[bufp++] = *str++;
            /*
             * Though the character literals are more compact, most
             * terminal descriptions use numbers and are not easy
             * to read in character-literal form.
             */
            switch (numbers) {
            case -1:
                if (str[0] == S_QUOTE
                    && str[1] != '\\'
                    && REALPRINT(str + 1)
                    && str[2] == S_QUOTE) {
                    _nc_SPRINTF(buffer + bufp, _nc_SLIMIT(P_LIMIT(bufp))
                                "{%d}", str[1]);
                    bufp += (int) strlen(buffer + bufp);
                    str += 2;
                } else {
                    buffer[bufp++] = *str;
                }
                break;
                /*
                 * If we have a "%{number}", try to translate it into
                 * a "%'char'" form, since that will run a little faster
                 * when we're interpreting it.  Also, having one form
                 * for the constant makes it simpler to compare terminal
                 * descriptions.
                 */
            case 1:
                if (str[0] == L_BRACE
                    && isdigit(UChar(str[1]))) {
                    char *dst = 0;
                    long value = strtol(str + 1, &dst, 0);
                    if (dst != 0
                        && *dst == R_BRACE
                        && value < 127
                        && isprint((int) value)) {
                        ch = (int) value;
                        buffer[bufp++] = S_QUOTE;
                        if (ch == '\\'
                            || ch == S_QUOTE)
                            buffer[bufp++] = '\\';
                        buffer[bufp++] = (char) ch;
                        buffer[bufp++] = S_QUOTE;
                        str = dst;
                    } else {
                        buffer[bufp++] = *str;
                    }
                } else {
                    buffer[bufp++] = *str;
                }
                break;
            default:
                if (*str == ',')        /* minitel1 uses this */
                    buffer[bufp++] = '\\';
                buffer[bufp++] = *str;
                break;
            }
        } else if (ch == 128) {
            buffer[bufp++] = '\\';
            buffer[bufp++] = '0';
        } else if (ch == '\033') {
            buffer[bufp++] = '\\';
            buffer[bufp++] = 'E';
        } else if (ch == '\\' && tic_format && (str == srcp || str[-1] != '^')) {
            buffer[bufp++] = '\\';
            buffer[bufp++] = '\\';
        } else if (ch == ' ' && tic_format && (str == srcp ||
                                               trailing_spaces(str))) {
            buffer[bufp++] = '\\';
            buffer[bufp++] = 's';
        } else if ((ch == ',' || ch == '^') && tic_format) {
            buffer[bufp++] = '\\';
            buffer[bufp++] = (char) ch;
        } else if (REALPRINT(str)
                   && (ch != ','
                       && !(ch == ':' && !tic_format)
                       && !(ch == '!' && !tic_format)
                       && ch != '^'))
            buffer[bufp++] = (char) ch;
        else if (ch == '\r') {
            buffer[bufp++] = '\\';
            buffer[bufp++] = 'r';
        } else if (ch == '\n') {
            buffer[bufp++] = '\\';
            buffer[bufp++] = 'n';
        }
#define UnCtl(c) ((c) + '@')
        else if (UChar(ch) < 32
                 && isdigit(UChar(str[1]))) {
            _nc_SPRINTF(&buffer[bufp], _nc_SLIMIT(P_LIMIT(bufp))
                        "^%c", UnCtl(ch));
            bufp += 2;
        } else {
            _nc_SPRINTF(&buffer[bufp], _nc_SLIMIT(P_LIMIT(bufp))
                        "\\%03o", ch);
            if ((octals < MAX_TC_FIXUPS) &&
                ((tic_format && (ch == 127)) || ch < 32)) {
                fixups[octals].ch = UChar(ch);
                fixups[octals].offset = bufp;
                ++octals;
            }
            bufp += 4;
        }

        str++;
    }

    buffer[bufp] = '\0';

    /*
     * If most of a short string is ASCII control characters, reformat the
     * string to show those in up-arrow format.  For longer strings, it is
     * more likely that the characters are just binary coding.
     *
     * If we're formatting termcap, just use the shorter format (up-arrows).
     */
    if (octals != 0 && (!tic_format || (bufp - (4 * octals)) < MIN_TC_FIXUPS)) {
        while (--octals >= 0) {
            char *p = buffer + fixups[octals].offset;
            *p++ = '^';
            *p++ = (char) ((fixups[octals].ch == 127)
                           ? '?'
                           : (fixups[octals].ch + (int) '@'));
            while ((p[0] = p[2]) != 0) {
                ++p;
            }
        }
    }
    DEBUG_THIS(("... %s", _nc_visbuf(buffer)));
    return (buffer);
}