User:Bot doubleredirects/Gadget-DoubleRedirectFixer.js

// Credit: HaMiklolah (Improved version - allows execution for any logged-in user)
(() => {
    const api = new mw.Api();

    /**
     * Gets the content of the redirect page.
     * @param {string} title - The page title.
     * @returns {Promise<string|null>} The page content or null if an error occurred.
     */
    const getRedirectContent = async (title) => {
        try {
            const response = await api.get({
                prop: "revisions",
                titles: title,
                rvprop: "content",
                rvslots: "*",
                formatversion: "2",
            });
            const page = response.query?.pages?.[0];
            return page?.revisions?.[0]?.slots?.main?.content ?? null;
        } catch (error) {
            console.error("Error getting redirect content for " + title + ":", error);
            return null;
        }
    };

    /**
     * Gets the final redirect target.
     * @param {string} title - The title of the redirect page.
     * @returns {Promise<string|null>} The redirect target or null if not found.
     */
    const getRedirectTarget = async (title) => {
        try {
            const { query } = await api.get({
                titles: title,
                redirects: true, // Allows MediaWiki to follow redirects
            });

            if (query?.pages) {
                // Find the page that is not missing (the final target)
                const page = Object.values(query.pages).find((p) => !p.missing);
                return page?.title ?? null;
            }
            return null;
        } catch (error) {
            console.error("Error getting redirect target for " + title + ":", error);
            return null;
        }
    };

    /**
     * Extracts the anchor from redirect content (e.g., [[Target_Page#anchor]]).
     * @param {string} content - The content of the redirect page.
     * @returns {string} The anchor with '#' if it exists, otherwise an empty string.
     */
    const extractAnchorFromContent = (content) => {
        // Regex adjusted to look for '#REDIRECT'
        const match = content.match(/#REDIRECT\s*\[\[[^\]]+?(?:#(.+?))?\]\]/i); // 'i' for case-insensitive
        return match?.[1] ? "#" + match[1] : "";
    };

    /**
     * Gets the namespace prefix of a page (e.g., "MediaWiki:", "File:").
     * @param {string} title - The page title.
     * @returns {Promise<string>} The namespace prefix or an empty string.
     */
    const getNamespacePrefix = async (title) => {
        try {
            const { query } = await api.get({
                titles: title,
                prop: "info",
            });

            if (query?.pages) {
                const page = Object.values(query.pages)[0];
                if (page.ns !== undefined) {
                    // Standard MediaWiki namespaces. Adjust '4' if Chabadpedia uses a different name for NS 4.
                    const namespacePrefixes = {
                        0: "", // Main/Article namespace
                        1: "Talk:",
                        2: "User:",
                        3: "User talk:",
                        4: "Chabadpedia:", // Common for English wikis, could also be "Project:" or "Wikipedia:"
                        5: "Chabadpedia talk:",
                        6: "File:",
                        7: "File talk:",
                        8: "MediaWiki:",
                        9: "MediaWiki talk:",
                        10: "Template:",
                        11: "Template talk:",
                        12: "Help:",
                        13: "Help talk:",
                        14: "Category:",
                        15: "Category talk:",
                        // Add more custom namespaces here if applicable, using their numerical IDs.
                    };
                    return namespacePrefixes[page.ns] ?? "";
                }
            }
            return "";
        } catch (error) {
            console.error("Error getting namespace prefix for " + title + ":", error);
            return "";
        }
    };

    /**
     * Creates/fixes a redirect.
     * @param {string} title - The title of the page to become a redirect.
     * @param {string} target - The redirect target.
     */
    const createRedirect = async (title, target) => {
        try {
            await api.postWithEditToken({
                action: "edit",
                format: "json",
                title: title,
                // Changed from #הפניה to #REDIRECT
                text: "#REDIRECT [[" + target + "]]",
                // Localized summary
                summary: "Bot: Fixing double redirect to [[" + target + "]]",
            });
            // Localized success notification
            mw.notify(title + ": Redirect successfully fixed to " + target, { type: 'success', title: 'Success' });
        } catch (error) {
            console.error("Error creating redirect for " + title + " to " + target + ":", error);
            // Localized error notifications
            if (error.code === 'badtags') {
                mw.notify(title + ": Error: Permission denied to use edit tags. Please contact a system administrator.", { type: 'error', title: 'Permission Error' });
            } else {
                mw.notify(title + ": Failed to fix redirect. See console for details.", { type: 'error', title: 'Error' });
            }
        }
    };

    /**
     * Processes a single double redirect: finds the final target and fixes it.
     * @param {string} title - The page title of the double redirect.
     */
    const processRedirect = async (title) => {
        try {
            const content = await getRedirectContent(title);
            if (content === null) {
                mw.notify(title + ": Could not retrieve redirect page content.", { type: 'warn' });
                return;
            }

            const anchor = extractAnchorFromContent(content);
            const finalTarget = await getRedirectTarget(title);

            if (!finalTarget) {
                mw.notify(title + ": No final redirect target found.", { type: 'warn' });
                return;
            }

            const namespace = await getNamespacePrefix(finalTarget);
            const fullTarget = namespace + finalTarget + anchor;

            // Check to prevent circular redirects or unnecessary fixes
            if (title.replace(/_/g, " ") === finalTarget.replace(/_/g, " ") && !anchor) {
                mw.notify(title + ": Redirect is already valid. No fix needed.", { type: 'info' });
                return;
            }

            if (title.replace(/_/g, " ") === fullTarget.replace(/_/g, " ")) {
                mw.notify(title + ": Circular or valid redirect. No fix needed.", { type: 'info' });
                return;
            }

            console.log("Creating new redirect: " + title + " --> " + fullTarget);
            await createRedirect(title, fullTarget);

        } catch (error) {
            console.error("Error processing double redirect for " + title + ":", error);
            mw.notify(title + ": An error occurred while processing the redirect. See console for details.", { type: 'error', title: 'Error' });
        }
    };

    /**
     * The main function that runs the script.
     */
    const init = async () => {
        const pageName = mw.config.get("wgPageName");

        // Ensure the script runs only on the Special:DoubleRedirects page
        if (pageName !== "Special:DoubleRedirects") {
            console.log("This script only runs on Special:DoubleRedirects.");
            return;
        }

        const numInput = prompt("How many double redirects to display and fix? (Recommended to start with a small number, e.g., 10)", "0");
        const num = parseInt(numInput, 10);

        if (isNaN(num) || num <= 0) {
            mw.notify("Invalid input. Please enter a positive integer.", { type: 'error' });
            return;
        }

        try {
            mw.notify("Starting check for " + num + " double redirects...", { type: 'info' });

            // Get the list of double redirects via API
            const { query } = await api.get({
                list: "querypage",
                qppage: "DoubleRedirects",
                qplimit: num,
            });

            const redirects = query.querypage.results;
            if (redirects.length === 0) {
                mw.notify("No double redirects found to fix.", { type: 'info' });
                return;
            }

            // Loop through each redirect and fix it
            for (const redirect of redirects) {
                const title = redirect.title.replace(/_/g, " ");
                await processRedirect(title);
            }
            mw.notify("Finished processing double redirects.", { type: 'success', title: 'Finished' });

        } catch (error) {
            console.error("Error fetching double redirects:", error);
            mw.notify("An error occurred while fetching the list of double redirects.", { type: 'error', title: 'General Error' });
        }
    };

    // Run the script when the page is loaded
    $(init);
})();