ImageFap Gallery Link Indexer

// ==UserScript==
// @name         ImageFap Gallery Link Indexer + Continuous Pagination
// @namespace    http://tampermonkey.net
// @version      3.0
// @description  Calculates the page offset to maintain strict #0, #1, #2 sequential numbering across different gallery pages
// @author       Gemini
// @match        https://www.imagefap.com/pictures/*
// @match        https://www.imagefap.com/gallery/*
// @run-at       document-end
// @grant        none
// @license      free, as is
// ==/UserScript==

(function() {
    'use strict';

    let isUpdating = false;

    // Helper function to extract URL parameters
    function getUrlParameter(name, url = window.location.href) {
        name = name.replace(/[\[\]]/g, '\\$&');
        const regex = new RegExp('[?&]' + name + '(=([^&#]*)|&|#|$)');
        const results = regex.exec(url);
        if (!results) return null;
        if (!results[2]) return '';
        return decodeURIComponent(results[2].replace(/\+/g, ' '));
    }

    // Determine the base starting index based on the view mode and current page number
    function calculateStartingIndex() {
        const viewMode = getUrlParameter('view') || '2'; // Default to One Page (view=2) if not specified
        const pageParam = getUrlParameter('page') || '0'; // Default to first page (page=0)

        const pageNumber = parseInt(pageParam, 10) || 0;
        let itemsPerPage = 100; // Grid size for One Page mode (4x25 = 100)

        if (viewMode === '0') {
            itemsPerPage = 24; // Grid size for Detailed View mode (4x6 = 24)
        }

        // Formula: page_number * items_per_page
        return pageNumber * itemsPerPage;
    }

    function processGalleryLinks() {
        if (isUpdating) return;

        const gallery = document.getElementById('gallery');
        if (!gallery) {
            console.log("[Tampermonkey] #gallery container not found on this page.");
            return;
        }

        isUpdating = true;

        // Calculate where the count should start for this specific page
        const startingOffset = calculateStartingIndex();

        const links = gallery.querySelectorAll('a');
        let localIndex = 0;

        links.forEach((link) => {
            const rawHref = link.getAttribute('href');

            if (rawHref && rawHref.includes('/photo/')) {
                // Total global index = starting page offset + relative link order on current page
                const globalIndex = startingOffset + localIndex;
                const targetHash = '#' + globalIndex;

                if (!rawHref.endsWith(targetHash)) {
                    const baseUrl = rawHref.split('#'); // Clear any existing trailing hash
                    link.setAttribute('href', baseUrl + targetHash);
                }

                localIndex++;
            }
        });

        console.log(`[Tampermonkey] Page Offset: ${startingOffset}. Successfully indexed links on this page: ${localIndex}`);
        isUpdating = false;
    }

    // Initialize layout processing immediately
    processGalleryLinks();

    // Watch for infinite scroll additions or live DOM manipulations
    const observer = new MutationObserver((mutations) => {
        for (let mutation of mutations) {
            if (mutation.addedNodes.length > 0) {
                processGalleryLinks();
                break;
            }
        }
    });

    const targetNode = document.getElementById('gallery');
    if (targetNode) {
        observer.observe(targetNode, { childList: true, subtree: true });
    }

    // Fallback trigger in case layout structure renders after minor delays
    window.addEventListener('load', () => {
        setTimeout(processGalleryLinks, 300);
    });

})();