let register = Toolkit => Toolkit.Menu =

// Pop-up menu container
class Menu extends Toolkit.Component {

    ///////////////////////// Initialization Methods //////////////////////////

    constructor(app, options = {}) {
        super(app, Object.assign({
            class     : "tk menu",
            id        : Toolkit.id(),
            role      : "menu",
            visibility: true,
            visible   : false
        }, options, { style: Object.assign({
            display      : "inline-flex",
            flexDirection: "column",
            position     : "absolute",
            zIndex       : "1"
        }, options.style || {}) }));

        // Configure instance fields
        this.parent = null;

        // Configure event handlers
        this.addEventListener("focusout", e=>this.onBlur(e));
    }



    ///////////////////////////// Event Handlers //////////////////////////////

    // Child blur
    onBlur(e) {
        if (this.parent instanceof Toolkit.MenuItem)
            this.parent.onBlur(e);
    }



    ///////////////////////////// Public Methods //////////////////////////////

    // Add a child menu item
    add(item) {
        if (!(item instanceof Toolkit.MenuItem) || !super.add(item))
            return false;
        this.detectIcons();
        return true;
    }

    // Add a sepearator
    addSeparator() {
        let item = new Toolkit.Component(this.app, { role: "separator" });
        super.add(item);
        return item;
    }

    // Remove the menu from its parent menu item or remove a child menu item
    remove() {

        // Remove child
        if (arguments.length != 0) {
            if (!super.remove.apply(this, arguments))
                return false;
            this.detectIcons();
            return true;
        }

        // Remove from parent
        this.parent = null;
        this.element.remove();
        this.element.removeAttribute("aria-labelledby");
        this.setVisible(false);
        return null;
    }



    ///////////////////////////// Package Methods /////////////////////////////

    // Show or hide the icons column
    detectIcons() {
        this.element.classList[
            this.children && this.children.find(i=>
                i.visible && i.type == "checkbox") ?
            "add" : "remove"
        ]("icons");
    }

};

export { register };