#include "highlighter.h"

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

    //keywordFormat.setForeground();
    keywordFormat.setFontWeight(QFont::Bold);
    const QString keywordPatterns[] = {
        QStringLiteral("\\bjump\\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);

    singleLineCommentFormat.setFontItalic(true);
    singleLineCommentFormat.setForeground(QColor("#e6db74"));
    rule.pattern = QRegularExpression(QStringLiteral(";[^\n]*"));
    rule.format = singleLineCommentFormat;
    highlightingRules.append(rule);

    multiLineCommentFormat.setForeground(Qt::red);

    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);

    // Labels
    labelFormat.setFontItalic(true);
    labelFormat.setForeground(QColor("#f9263e"));
    rule.pattern = QRegularExpression(QStringLiteral(R"([.][A-Za-z0-9_]+)"));
    rule.format = labelFormat;
    highlightingRules.append(rule);


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

void Highlighter::highlightLine(int number)
{
    m_currentLine = number;
    fmt.setForeground(QColor(Qt::black));
    fmt.setBackground(QColor("#FFFF00"));
    rehighlight();
}

void Highlighter::highlightBlock(const QString &text)
{
    if (currentBlock().blockNumber() == m_currentLine)
    {
        setFormat(0, text.size(), fmt);
        return;
    }
    /*
    else
    {
        setFormat(0, 0, QTextCharFormat());
    }*/


    for (const HighlightingRule &rule : std::as_const(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);
    }
}