import { Component } from /**/"./Component.js";
let Toolkit;



///////////////////////////////////////////////////////////////////////////////
//                                 DropDown                                  //
///////////////////////////////////////////////////////////////////////////////

// Text entry field
class DropDown extends Component {
    static Component = Component;

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

    constructor(gui, options) {
        super(gui, options, {
            className: "tk tk-dropdown",
            tagName  : "select"
        });

        // Configure instance fields
        this.isEnabled = null;
        this.options   = [];

        // Configure component
        options = options || {};
        this.setEnabled(!("enabled" in options) || options.enabled);
        if ("options" in options)
            this.setOptions(options.options);
        this.setSelectedIndex(
            ("selectedIndex" in options ? options : this).selectedIndex);

        // Configure event handlers
        this.addEventListener("keydown"    , e=>e.stopPropagation());
        this.addEventListener("pointerdown", e=>e.stopPropagation());
    }



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

    // Programmatically change the selection
    change() {
        this.element.dispatchEvent(this.event("input"));
    }

    // Retrieve the current selection index
    getSelectedIndex() {
        return this.element.selectedIndex;
    }

    // Specify whether the button can be activated
    setEnabled(enabled) {
        this.isEnabled = enabled = !!enabled;
        this.setAttribute("disabled", enabled ? null : "true");
    }

    // Specify the list contents
    setOptions(options) {

        // Error checking
        if (!Array.isArray(options))
            return;

        // Erase the list of options
        this.options.splice(0);
        this.element.replaceChildren();

        // Add options from the input
        for (let option of options) {
            if (typeof option != "string")
                continue;
            this.options.push(option);
            this.element.add(document.createElement("option"));
        }

        // Update the display text
        this.translate();
    }

    // Specify the current selection
    setSelectedIndex(index) {

        // Error checking
        if (typeof index != "number" || isNaN(index))
            return this.element.selectedIndex;
        index = Math.round(index);
        if (index < -1 || index >= this.options.length)
            return this.element.selectedIndex;

        // Configure element and instance fields
        return this.element.selectedIndex = index;
    }



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

    // Update the global Toolkit object
    static setToolkit(toolkit) {
        Toolkit = toolkit;
    }

    // Regenerate localized display text
    translate() {
        super.translate();

        // Error checking
        if (!this.options)
            return;

        // Update the list items
        for (let x = 0; x < this.options.length; x++) {
            this.element.item(x).innerText =
                this.gui.translate(this.options[x], this);
        }

    }

}



export { DropDown };