/* ----------------------------------------------------------------------
   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
   https://www.lammps.org/, Sandia National Laboratories
   LAMMPS development team: developers@lammps.org

   Copyright (2003) Sandia Corporation.  Under the terms of Contract
   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
   certain rights in this software.  This software is distributed under
   the GNU General Public License.

   See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */

#include "highlighter.h"

Highlighter::Highlighter(QTextDocument *parent) : QSyntaxHighlighter(parent)
{
    HighlightingRule rule;

    keywordFormat.setForeground(Qt::darkBlue);
    keywordFormat.setFontWeight(QFont::Bold);
    const QString keywordPatterns[] = {
        QStringLiteral("\\bchar\\b"),      QStringLiteral("\\bclass\\b"),
        QStringLiteral("\\bconst\\b"),     QStringLiteral("\\bdouble\\b"),
        QStringLiteral("\\benum\\b"),      QStringLiteral("\\bexplicit\\b"),
        QStringLiteral("\\bfriend\\b"),    QStringLiteral("\\binline\\b"),
        QStringLiteral("\\bint\\b"),       QStringLiteral("\\blong\\b"),
        QStringLiteral("\\bnamespace\\b"), QStringLiteral("\\boperator\\b"),
        QStringLiteral("\\bprivate\\b"),   QStringLiteral("\\bprotected\\b"),
        QStringLiteral("\\bpublic\\b"),    QStringLiteral("\\bshort\\b"),
        QStringLiteral("\\bsignals\\b"),   QStringLiteral("\\bsigned\\b"),
        QStringLiteral("\\bslots\\b"),     QStringLiteral("\\bstatic\\b"),
        QStringLiteral("\\bstruct\\b"),    QStringLiteral("\\btemplate\\b"),
        QStringLiteral("\\btypedef\\b"),   QStringLiteral("\\btypename\\b"),
        QStringLiteral("\\bunion\\b"),     QStringLiteral("\\bunsigned\\b"),
        QStringLiteral("\\bvirtual\\b"),   QStringLiteral("\\bvoid\\b"),
        QStringLiteral("\\bvolatile\\b"),  QStringLiteral("\\bbool\\b")};
    for (const QString &pattern : keywordPatterns) {
        rule.pattern = QRegularExpression(pattern);
        rule.format  = keywordFormat;
        highlightingRules.append(rule);
    }
    classFormat.setFontWeight(QFont::Bold);
    classFormat.setForeground(Qt::darkMagenta);
    rule.pattern = QRegularExpression(QStringLiteral("\\bQ[A-Za-z]+\\b"));
    rule.format  = classFormat;
    highlightingRules.append(rule);

    quotationFormat.setForeground(Qt::darkGreen);
    rule.pattern = QRegularExpression(QStringLiteral("\".*\""));
    rule.format  = quotationFormat;
    highlightingRules.append(rule);

    functionFormat.setFontItalic(true);
    functionFormat.setForeground(Qt::blue);
    rule.pattern = QRegularExpression(QStringLiteral("\\b[A-Za-z0-9_]+(?=\\()"));
    rule.format  = functionFormat;
    highlightingRules.append(rule);
    singleLineCommentFormat.setForeground(Qt::red);
    rule.pattern = QRegularExpression(QStringLiteral("//[^\n]*"));
    rule.format  = singleLineCommentFormat;
    highlightingRules.append(rule);

    multiLineCommentFormat.setForeground(Qt::red);

    commentStartExpression = QRegularExpression(QStringLiteral("/\\*"));
    commentEndExpression   = QRegularExpression(QStringLiteral("\\*/"));
}

void Highlighter::highlightBlock(const QString &text)
{
    for (const HighlightingRule &rule : qAsConst(highlightingRules)) {
        QRegularExpressionMatchIterator matchIterator = rule.pattern.globalMatch(text);
        while (matchIterator.hasNext()) {
            QRegularExpressionMatch match = matchIterator.next();
            setFormat(match.capturedStart(), match.capturedLength(), rule.format);
        }
    }
    setCurrentBlockState(0);
    int startIndex = 0;
    if (previousBlockState() != 1) startIndex = text.indexOf(commentStartExpression);
    while (startIndex >= 0) {
        QRegularExpressionMatch match = commentEndExpression.match(text, startIndex);
        int endIndex                  = match.capturedStart();
        int commentLength             = 0;
        if (endIndex == -1) {
            setCurrentBlockState(1);
            commentLength = text.length() - startIndex;
        } else {
            commentLength = endIndex - startIndex + match.capturedLength();
        }
        setFormat(startIndex, commentLength, multiLineCommentFormat);
        startIndex = text.indexOf(commentStartExpression, startIndex + commentLength);
    }
}
// Local Variables:
// c-basic-offset: 4
// End: