// Copyright (C) Filippo Cucchetto <filippocucchetto@gmail.com>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

#pragma once

#include <QChar>
#include <QString>

namespace Nim {

class SourceCodeStream
{
public:
    SourceCodeStream(const QChar *text, int length)
        : m_text(text)
        , m_textLength(length)
        , m_position(0)
        , m_markedPosition(0)
    {}

    inline void setAnchor()
    {
        m_markedPosition = m_position;
    }

    inline void move(int amount = 1)
    {
        m_position += amount;
    }

    inline void moveToEnd()
    {
        m_position = m_textLength;
    }

    inline int pos()
    {
        return m_position;
    }

    inline int length() const
    {
        return m_position - m_markedPosition;
    }

    inline int anchor() const
    {
        return m_markedPosition;
    }

    inline bool isEnd() const
    {
        return m_position >= m_textLength;
    }

    inline QChar peek(int offset = 0) const
    {
        int pos = m_position + offset;
        if (pos >= m_textLength)
            return QLatin1Char('\0');
        return m_text[pos];
    }

    inline QString value() const
    {
        const QChar *start = m_text + m_markedPosition;
        return QString(start, length());
    }

    inline QString value(int begin, int length) const
    {
        return QString(m_text + begin, length);
    }

private:
    const QChar *m_text;
    const int m_textLength;
    int m_position;
    int m_markedPosition;
};

}