#ifndef MASKMANAGER_H
#define MASKMANAGER_H

#include <QWidget>
#include <QSet>

template <typename T>
class UniqueList
{
private:
    QList<T> m_list;
    QSet<T> m_set;

public:
    const QList<T>& getList() const { return m_list; }

    bool isEmpty() { return m_list.isEmpty(); }

    int size() const { return m_list.size(); }

    void appendUnique(const T& value)
    {
        if(m_set.contains(value))
            return;

        m_set.insert(value);
        m_list.append(value);
    }
    void remove(const T& value)
    {
        if(m_set.remove(value))
        {
            m_list.removeOne(value);
        }
    }

    T& first()
    {
        if(m_list.isEmpty())
            throw std::out_of_range("UniqueList is empty");

        return m_list.first();
    }
    T& last()
    {
        if(m_list.isEmpty())
            throw std::out_of_range("UniqueList is empty");

        return m_list.last();
    }
    T& at(int index)
    {
        if (index < 0 || index >= m_list.size())
            throw std::out_of_range("Index out of range");

        return m_list[index];
    }

    T& operator[](int index) { return at(index); }
};

class MaskLayer;
class MaskManager : public QObject
{
    Q_OBJECT

public:
    //初始化时强制关联窗口
    static void initialize(QWidget* mainWindow);
    static MaskManager* instance();

    void showMask(QWidget* requester);
    void hideMask(QWidget* requester);

protected:
    bool eventFilter(QObject* obj, QEvent* event) override;

private:
    explicit MaskManager(QWidget* mainWindow);
    static MaskManager* m_instance;
    QWidget* m_mainWindow;
    QWidget* m_maskLayer;
    UniqueList<QWidget*> m_activeRequests;
};

#endif //MASKMANAGER_H