/*
 * Postscript language mode for QEmacs.
 *
 * Copyright (c) 2000-2020 Charlie Gordon.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "qe.h"

/*---------------- PostScript colors ----------------*/

enum {
    IN_PS_STRING  = 0x0F            /* ( ... ) level */,
    IN_PS_COMMENT = 0x10,
};

enum {
    PS_STYLE_TEXT =       QE_STYLE_DEFAULT,
    PS_STYLE_COMMENT =    QE_STYLE_COMMENT,
    PS_STYLE_STRING =     QE_STYLE_STRING,
    PS_STYLE_NUMBER =     QE_STYLE_DEFAULT,
    PS_STYLE_IDENTIFIER = QE_STYLE_FUNCTION,
};

#define wrap 0

static void ps_colorize_line(QEColorizeContext *cp,
                             unsigned int *str, int n, ModeDef *syn)
{
    int i = 0, start = i, c;
    int colstate = cp->colorize_state;

    if (colstate & IN_PS_COMMENT)
        goto in_comment;

    if (colstate & IN_PS_STRING)
        goto in_string;

    colstate = 0;

    while (i < n) {
        start = i;
        c = str[i++];
        switch (c) {
            /* Should deal with '<...>' '<<...>>' '<~...~>' tokens. */
        case '%':
        in_comment:
            if (wrap)
                colstate |= IN_PS_COMMENT;
            else
                colstate &= ~IN_PS_COMMENT;
            i = n;
            SET_COLOR(str, start, i, PS_STYLE_COMMENT);
            continue;
        case '(':
            colstate++;
        in_string:
            /* parse string skipping embedded \\ */
            while (i < n) {
                switch (str[i++]) {
                case '(':
                    colstate++;
                    continue;
                case ')':
                    colstate--;
                    if (!(colstate & IN_PS_STRING))
                        break;
                    continue;
                case '\\':
                    if (i == n)
                        break;
                    i++;
                    continue;
                default:
                    continue;
                }
                break;
            }
            SET_COLOR(str, start, i, PS_STYLE_STRING);
            continue;
        default:
            break;
        }
        /* parse numbers */
        if (qe_isdigit(c)) {
            for (; i < n; i++) {
                if (!qe_isalnum(str[i]) && str[i] != '.')
                    break;
            }
            SET_COLOR(str, start, i, PS_STYLE_NUMBER);
            continue;
        }
        /* parse identifiers and keywords */
        if (qe_isalpha_(c)) {
            for (; i < n; i++) {
                if (qe_findchar(" \t\r\n,()<>[]{}/", str[i]))
                    break;
            }
            SET_COLOR(str, start, i, PS_STYLE_IDENTIFIER);
            continue;
        }
    }
    cp->colorize_state = colstate;
#undef wrap
}

static int ps_mode_probe(ModeDef *mode, ModeProbeData *p)
{
    if (match_extension(p->filename, mode->extensions))
        return 80;

    if (*p->buf == '%' && qe_stristr((const char *)p->buf, "script"))
        return 40;

    return 1;
}

static ModeDef ps_mode = {
    .name = "Postscript",
    .extensions = "ps|ms|eps",
    .mode_probe = ps_mode_probe,
    .colorize_func = ps_colorize_line,
};

static int ps_init(void)
{
    qe_register_mode(&ps_mode, MODEF_SYNTAX);

    return 0;
}

qe_module_init(ps_init);