#ifndef DIRTYSTATEMANAGER_H
#define DIRTYSTATEMANAGER_H

#include <QObject>
#include <QSet>
#include <QMap>

class QWidget;

/**
 * @brief Tracks dirty (unsaved changes) state for editor tabs.
 *
 * The DirtyStateManager is a singleton that tracks which editor widgets
 * have unsaved changes. It emits signals when dirty state changes, allowing
 * the UI to update tab titles (add/remove asterisk) and prompt on close.
 */
class DirtyStateManager : public QObject {
    Q_OBJECT

public:
    static DirtyStateManager& instance();

    /**
     * @brief Mark a tab as having unsaved changes.
     * @param tab The widget to mark as dirty
     */
    void markDirty(QWidget* tab);

    /**
     * @brief Mark a tab as having no unsaved changes.
     * @param tab The widget to mark as clean
     */
    void markClean(QWidget* tab);

    /**
     * @brief Check if a tab has unsaved changes.
     * @param tab The widget to check
     * @return true if the tab has unsaved changes
     */
    bool isDirty(QWidget* tab) const;

    /**
     * @brief Get list of all tabs with unsaved changes.
     * @return List of dirty widgets
     */
    QList<QWidget*> dirtyTabs() const;

    /**
     * @brief Check if any tabs have unsaved changes.
     * @return true if at least one tab is dirty
     */
    bool hasDirtyTabs() const;

    /**
     * @brief Store the original file path for a tab (for Save functionality).
     * @param tab The widget
     * @param path The file path
     */
    void setFilePath(QWidget* tab, const QString& path);

    /**
     * @brief Get the original file path for a tab.
     * @param tab The widget
     * @return The file path, or empty string if not set
     */
    QString filePath(QWidget* tab) const;

    /**
     * @brief Remove tracking for a tab (call when tab is closed).
     * @param tab The widget being closed
     */
    void removeTab(QWidget* tab);

signals:
    /**
     * @brief Emitted when a tab's dirty state changes.
     * @param tab The affected widget
     * @param isDirty The new dirty state
     */
    void dirtyStateChanged(QWidget* tab, bool isDirty);

private:
    DirtyStateManager() = default;
    ~DirtyStateManager() = default;
    DirtyStateManager(const DirtyStateManager&) = delete;
    DirtyStateManager& operator=(const DirtyStateManager&) = delete;

    QSet<QWidget*> m_dirtyTabs;
    QMap<QWidget*, QString> m_filePaths;
};

#endif // DIRTYSTATEMANAGER_H