// ==UserScript==
// @name Vector Layout for Wikipedia (Fast)
// @namespace -
// @version 1.1.7
// @description returns old wikipedia layout. (layout before 2023 redesign of website)
// @author NotYou
// @match *://wikipedia.org/*
// @match *://*.wikipedia.org/*
// @run-at document-start
// @license GPL-3.0-or-later
// @grant none
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    const MAKE_CLEAN_URL = false; // removes "useskin=vector" after loading

    const IS_DEBUG_MODE = false; // instead of redirecting, logs information in console

    const DEBUG_TITLE = 'DEBUG - Vector Layout for Wikipedia\n';

    let href = location.href;

    redirect(href, true);

    window.addEventListener('click', onClick);

    if(MAKE_CLEAN_URL) {
        let url = new URL(href);
        let searchParams = new URLSearchParams(url.search);

        if(searchParams.get('useskin') === 'vector') {
            searchParams.delete('useskin');

            let _searchParams = searchParams.toString();

            let newPath = url.pathname + (_searchParams ? '?' + _searchParams : _searchParams);

            history.replaceState({}, '', newPath);
        }
    }

    function redirect(inputUrl, replaceHistory, inNewTab) {
        let url;

        try {
            url = new URL(inputUrl)
        } catch(e) {
            throw new Error('"' + inputUrl + '" is not valid URL!')
        }

        let searchParams = new URLSearchParams(url.search);
        let pathname = url.pathname;
        let cleanURL = url.origin + pathname;

        if(searchParams.get('useskin') !== 'vector' && url.pathname !== '/') {
            searchParams.set('useskin', 'vector');

            let params = '?' + searchParams.toString();

            let resultURL = cleanURL + params;
            let newPath = pathname + params;

            if(IS_DEBUG_MODE) {
                console.log(DEBUG_TITLE, resultURL, newPath);
            } else {
                history[replaceHistory ? 'replaceState' : 'pushState']({}, '', newPath);
                replaceURL(resultURL);
            }
        }
    }

    function onClick(e) {
        let node = e.target;
        let link = getLink(node);

        if(link) {
            let url = new URL(link.href);
            let isOrigin = url.hostname.indexOf('wikipedia.org') > -1;
            let isNotAnchor = !link.getAttribute('href').startsWith('#');
            let isOnlyLink = !link.getAttribute('role');

            let isValid = isOrigin && isNotAnchor && isOnlyLink;

            if(isValid) {
                e.preventDefault();

                if(e.ctrlKey || e.metaKey) {
                    open(url)
                } else {
                    redirect(url, false);
                }
            }
        }
    }

    function replaceURL(url) {
        if(location.replace) {
            location.replace(url);
        } else {
            location.href = url;
        }
    }

    function getLink(node) {
        if(node.tagName === 'A') {
            return node;
        } else if(node.tagName === 'HTML' || !node.tagName) {
            return null;
        }

        return getLink(node.parentNode);
    }
})();