import { jsOMS }      from '../../Utils/oLib.js';
import { HttpUri }    from '../../Uri/HttpUri.js';
import { UriFactory } from '../../Uri/UriFactory.js';

/**
 * Tab manager class.
 *
 * @copyright Dennis Eichhorn
 * @license   OMS License 2.2
 * @version   1.0.0
 * @since     1.0.0
 */
export class Tab
{
    /**
     * @constructor
     *
     * @param {Object} app Application
     *
     * @since 1.0.0
     */
    constructor (app)
    {
        this.app = app;
    };

    /**
     * Bind & rebind UI elements.
     *
     * @param {null|string} [id] Element id
     *
     * @return {void}
     *
     * @since 1.0.0
     */
    bind (id = null)
    {
        if (id !== null) {
            const e = document.getElementById(id);

            if (e) {
                this.bindElement(e);
            }

            return;
        }

        const tabs   = document.getElementsByClassName('tabview');
        const length = !tabs ? 0 : tabs.length;

        for (let i = 0; i < length; ++i) {
            this.bindElement(tabs[i]);
        }
    };

    /**
     * Bind & rebind UI element.
     *
     * @param {Element} e Element
     *
     * @return {void}
     *
     * @since 1.0.0
     */
    bindElement (e)
    {
        const nodes  = e.querySelectorAll('.tab-links li');
        const length = nodes.length;

        for (let i = 0; i < length; ++i) {
            nodes[i].addEventListener('click', function (evt)
            {
                this.querySelector('label').click();
                let fragmentString = this.querySelector('label').getAttribute('for');

                /* Change Tab */
                /* Remove selected tab */
                const oldActive = this.parentNode.getElementsByClassName('active');
                if (oldActive.length > 0) {
                    const fragments = fragmentString.split('&');
                    const index     = fragments.indexOf(oldActive[0].getElementsByTagName('label')[0].getAttribute('for'));

                    if (index > -1) {
                        fragments.splice(index, 1);
                    }

                    // find old active and remove it
                    fragmentString = fragments.join('&');

                    jsOMS.removeClass(oldActive[0], 'active');
                }

                const fragments = fragmentString.split('&');

                /**
                const index = fragments.indexOf(this.getElementsByTagName('label')[0].getAttribute('for'));
                if (index > -1) {
                    fragments.splice(index, 1);
                } */

                // find old active and remove it
                fragmentString = fragments.join('&');

                jsOMS.addClass(this, 'active');

                /* Add selected tab */
                if (jsOMS.hasClass(this.closest('.tabview'), 'url-rewrite')) {
                    window.history.replaceState(null, '',
                        UriFactory.build(
                            '{%}#' + (fragmentString === '' ? '' : fragmentString)
                        )
                    );
                }
            });
        }

        this.activateTabUri(e);
    };

    /**
     * Activates the correct tab based on URI fragment.
     *
     * This allows to link a specific open tab to a user or make it a bookmark
     *
     * @param {Element} e Element
     *
     * @return {void}
     *
     * @since 1.0.0
     */
    activateTabUri (e)
    {
        const fragmentString = window.location.href.includes('#') ? HttpUri.parseUrl(window.location.href).fragment : '';

        if (fragmentString === null || typeof fragmentString === 'undefined') {
            return;
        }

        const fragments  = fragmentString.split('&');
        const fragLength = fragments.length;

        // @bug The frontend loads the correct tab based on the provided fragment,
        //      but it is slow. Doing this in the backend can already fix this but the frontend implementation should be fixed,
        //      because this should be the job of the frontend.
        //      https://github.com/Karaka-Management/Karaka/issues/164
        if (fragLength > 0 && fragmentString !== '') {
            for (let i = 0; i < fragLength; ++i) {
                const label = e.querySelector('label[for="' + fragments[i] + '"]');
                if (typeof label !== 'undefined' && label !== null) {
                    label.click();
                }
            }
        }

        if (e.querySelector('.tab-links')?.querySelector('.active') === null) {
            e.querySelector('.tab-links').querySelector('label').click();
        }
    };
};