/*
    This file is part of the KDE libraries

    SPDX-FileCopyrightText: 2008 Oswald Buddenhagen <ossi@kde.org>

    SPDX-License-Identifier: LGPL-2.0-or-later
*/

#include "kmacroexpander_p.h"
#include "kshell_p.h"

#include "kshell.h"

#include <QString>
#include <QStringList>

bool KMacroExpanderBase::expandMacrosShellQuote(QString &str, int &pos)
{
    int len;
    int pos2;
    ushort uc;
    ushort ec = d->escapechar.unicode();
    bool shellQuote = false; // shell is in quoted state
    bool crtQuote = false; // c runtime is in quoted state
    bool escaped = false; // previous char was a circumflex
    int bslashes = 0; // previous chars were backslashes
    int parens = 0; // parentheses nesting level
    QStringList rst;
    QString rsts;

    while (pos < str.length()) {
        ushort cc = str.unicode()[pos].unicode();
        if (escaped) { // prevent anomalies due to expansion
            goto notcf;
        }
        if (ec != 0) {
            if (cc != ec) {
                goto nohit;
            }
            if (!(len = expandEscapedMacro(str, pos, rst))) {
                goto nohit;
            }
        } else {
            if (!(len = expandPlainMacro(str, pos, rst))) {
                goto nohit;
            }
        }
        if (len < 0) {
            pos -= len;
            continue;
        }
        if (shellQuote != crtQuote) { // Silly, isn't it? Ahoy to Redmond.
            return false;
        }
        if (shellQuote) {
            rsts = KShell::quoteArgInternal(rst.join(QLatin1Char(' ')), true);
        } else {
            if (rst.isEmpty()) {
                str.remove(pos, len);
                continue;
            }
            rsts = KShell::joinArgs(rst);
        }
        pos2 = 0;
        while (pos2 < rsts.length() &&
                ((uc = rsts.unicode()[pos2].unicode()) == '\\' || uc == '^')) {
            pos2++;
        }
        if (pos2 < rsts.length() && rsts.unicode()[pos2].unicode() == '"') {
            QString bsl;
            bsl.reserve(bslashes);
            for (; bslashes; bslashes--) {
                bsl.append(QLatin1String("\\"));
            }
            rsts.prepend(bsl);
        }
        bslashes = 0;
        rst.clear();
        str.replace(pos, len, rsts);
        pos += rsts.length();
        continue;
    nohit:
        if (!escaped && !shellQuote && cc == '^') {
            escaped = true;
        } else {
        notcf:
            if (cc == '\\') {
                bslashes++;
            } else {
                if (cc == '"') {
                    if (!escaped) {
                        shellQuote = !shellQuote;
                    }
                    if (!(bslashes & 1)) {
                        crtQuote = !crtQuote;
                    }
                } else if (!shellQuote) {
                    if (cc == '(') {
                        parens++;
                    } else if (cc == ')')
                        if (--parens < 0) {
                            break;
                        }
                }
                bslashes = 0;
            }
            escaped = false;
        }
        pos++;
    }
    return true;
}
