#include "javascripthighlighter.h"

namespace QtGui {

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

    m_keywordFormat.setForeground(Qt::darkBlue);
    m_keywordFormat.setFontWeight(QFont::Bold);
    QStringList keywordPatterns;
    keywordPatterns << "\\bvar\\b" << "\\bArray\\b" << "\\bfunction\\b"
                    << "\\breturn\\b" << "\\barguments\\b" << "\\bif\\b"
                    << "\\belse\\b" << "\\bfor\\b" << "\\bswitch\\b"
                    << "\\bcase\\b" << "\\bbreak\\b" << "\\bwhile\\b"
                    << "\\bundefined\\b" << "\\continue\\b";
    foreach (const QString &pattern, keywordPatterns) {
        rule.pattern = QRegExp(pattern);
        rule.format = m_keywordFormat;
        m_highlightingRules.append(rule);
    }

    m_singleLineCommentFormat.setForeground(Qt::red);
    rule.pattern = QRegExp("//[^\n]*");
    rule.format = m_singleLineCommentFormat;
    m_highlightingRules.append(rule);

    m_multiLineCommentFormat.setForeground(Qt::red);

    m_quotationFormat.setForeground(Qt::darkGreen);
    rule.pattern = QRegExp("\".*\"");
    rule.format = m_quotationFormat;
    m_highlightingRules.append(rule);

    m_functionFormat.setFontItalic(true);
    m_functionFormat.setForeground(Qt::blue);
    rule.pattern = QRegExp("(?!if)\\b[A-Za-z0-9_]+(?=\\()");
    rule.format = m_functionFormat;
    m_highlightingRules.append(rule);

    m_commentStartExpression = QRegExp("/\\*");
    m_commentEndExpression = QRegExp("\\*/");
}

void JavaScriptHighlighter::highlightBlock(const QString &text)
{
    foreach (const HighlightingRule &rule, m_highlightingRules) {
        QRegExp expression(rule.pattern);
        int index = expression.indexIn(text);
        while (index >= 0) {
            int length = expression.matchedLength();
            setFormat(index, length, rule.format);
            index = expression.indexIn(text, index + length);
        }
    }
    setCurrentBlockState(0);

    int startIndex = 0;
    if (previousBlockState() != 1)
        startIndex = m_commentStartExpression.indexIn(text);

    while (startIndex >= 0) {
        int endIndex = m_commentEndExpression.indexIn(text, startIndex);
        int commentLength;
        if (endIndex == -1) {
            setCurrentBlockState(1);
            commentLength = text.length() - startIndex;
        } else {
            commentLength = endIndex - startIndex
                            + m_commentEndExpression.matchedLength();
        }
        setFormat(startIndex, commentLength, m_multiLineCommentFormat);
        startIndex = m_commentStartExpression.indexIn(text, startIndex + commentLength);
    }
}

}