#ifndef NAVIGATIONITEMMODEL_H
#define NAVIGATIONITEMMODEL_H

#include <QObject>

/**
 * @brief Model for navigation item.
 *
 * Each item represents a directory that is specified by path.
 * It contains a reference to its parent item as well as to its children.
 * Each directory contains an image named image.jpg that is displayed on
 * on the list delegate.
 * A delegate is circular if it has children and rectangular if it is
 * a leaf, i.e., if it represents a music folder.
 */
class NavigationItemModel : public QObject
{
    Q_OBJECT

    Q_PROPERTY(QString pImageSource READ getImageSource NOTIFY imageSourceChanged)
    Q_PROPERTY(bool pIsCircleDelegate READ isCircleDelegate NOTIFY isCircleDelegateChanged)

signals:
    void isCircleDelegateChanged();
    void imageSourceChanged();
    void clicked();

public:
    explicit NavigationItemModel(QObject *parent = nullptr);

    /**
     * @brief Get source of image displayed on delegate.
     * @return Source of image
     *
     * The image must be named image.jpg and must be postioned in the directory
     * represented by this item. If no such image is found, a default image is displayed
     * on the delegate.
     */
    QString getImageSource() const;

    /**
     * @brief Get path to folder represented by this navigation item.
     * @return Path to folder
     */
    QString getPath() const;
    /**
     * @brief Set folder path and set image source displayed on delegate.
     * @param path Path to directory that is represented by this navigation item.
     * @return returns false if directory specified by path does not exist
     */
    bool setPath(const QString & path);

    /**
     * @brief Indicates whether this item is displayed as a circular or default delegate in navigation list.
     * @return true if the current item is displayed as a circular delegate.
     *
     * An item is displayed as a circular delegate if it has children.
     */
    bool isCircleDelegate() const;

    /**
     * @brief Indicates whether the current item is the root item of the navigation.
     * @return true if the current item is the root item.
     */
    bool isRoot() const;
    /**
     * @brief Get pointer to parent item.
     * @return Pointer to parent item.
     */
    NavigationItemModel* getParentItem();

    /**
     * @brief Indicates whether the current item has children.
     * @return false if children list is empty, true otherwise.
     */
    bool hasChildren() const;
    /**
     * @brief Get all child items
     * @return List of child items
     */
    QList<NavigationItemModel *> getChildren();

    /**
     * @brief Get all siblings, i.e., all children of parent item.
     * @return List of all siblings
     */
    QList<NavigationItemModel *> getSiblings();

    /**
     * @brief Append a child
     * @param item Child item.
     */
    void appendChild(NavigationItemModel* item);
    /**
     * @brief Remove all child items.
     *
     * Will delete children via deleteLater
     */
    void clearChildren();

public slots:
    /**
     * @brief Defines behavior on clicking the current navigation item. Emits the clicked-signal.
     */
    void onClicked();

private:
    QString mPath = QString("");
    QString mImageSource;

    QList<NavigationItemModel*> mChildren;
    NavigationItemModel* mParentItem;
};

#endif // NAVIGATIONITEMMODEL_H