// ==UserScript==
// @name         8chan Spoiler Disabler
// @namespace    http://tampermonkey.net/
// @version      1.4
// @description  Disables image and video spoilers on 8chan (moe/se/cc) for both thread and catalog pages by replacing custom and default spoiler placeholders with thumbnails, including dynamically loaded posts.
// @author       impregnator
// @match        https://8chan.moe/*
// @match        https://8chan.se/*
// @match        https://8chan.cc/*
// @grant        none
// @license      MIT
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    // Function to process images and replace spoiler placeholders with thumbnails
    function processImages(images, isCatalog = false) {
        images.forEach(img => {
            // Check if the image is a spoiler placeholder (custom or default)
            if (img.src.includes('custom.spoiler') || img.src.includes('spoiler.png')) {
                let fullFileUrl;
                if (isCatalog) {
                    // Catalog: Get the href from the parent <a class="linkThumb">
                    const link = img.closest('a.linkThumb');
                    if (link) {
                        // Construct the thumbnail URL based on the thread URL
                        fullFileUrl = link.href;
                        const threadMatch = fullFileUrl.match(/\/([a-z0-9]+)\/res\/([0-9]+)\.html$/i);
                        if (threadMatch && threadMatch[1] && threadMatch[2]) {
                            const board = threadMatch[1];
                            const threadId = threadMatch[2];
                            // Fetch the thread page to find the actual image URL
                            fetchThreadImage(board, threadId).then(thumbnailUrl => {
                                if (thumbnailUrl) {
                                    img.src = thumbnailUrl;
                                }
                            });
                        }
                    }
                } else {
                    // Thread: Get the parent <a> element containing the full-sized file URL
                    const link = img.closest('a.imgLink');
                    if (link) {
                        // Extract the full-sized file URL
                        fullFileUrl = link.href;
                        // Extract the file hash (everything after /.media/ up to the extension)
                        const fileHash = fullFileUrl.match(/\/\.media\/([a-f0-9]+)\.[a-z0-9]+$/i);
                        if (fileHash && fileHash[1]) {
                            // Construct the thumbnail URL using the current domain
                            const thumbnailUrl = `${window.location.origin}/.media/t_${fileHash[1]}`;
                            // Replace the spoiler image with the thumbnail
                            img.src = thumbnailUrl;
                        }
                    }
                }
            }
        });
    }

    // Function to fetch the thread page and extract the thumbnail URL
    async function fetchThreadImage(board, threadId) {
        try {
            const response = await fetch(`https://${window.location.host}/${board}/res/${threadId}.html`);
            const text = await response.text();
            const parser = new DOMParser();
            const doc = parser.parseFromString(text, 'text/html');
            // Find the first image in the thread's OP post
            const imgLink = doc.querySelector('.uploadCell a.imgLink');
            if (imgLink) {
                const fullFileUrl = imgLink.href;
                const fileHash = fullFileUrl.match(/\/\.media\/([a-f0-9]+)\.[a-z0-9]+$/i);
                if (fileHash && fileHash[1]) {
                    return `${window.location.origin}/.media/t_${fileHash[1]}`;
                }
            }
            return null;
        } catch (error) {
            console.error('Error fetching thread image:', error);
            return null;
        }
    }

    // Process existing images on page load
    const isCatalogPage = window.location.pathname.includes('catalog.html');
    if (isCatalogPage) {
        const initialCatalogImages = document.querySelectorAll('.catalogCell a.linkThumb img');
        processImages(initialCatalogImages, true);
    } else {
        const initialThreadImages = document.querySelectorAll('.uploadCell img');
        processImages(initialThreadImages, false);
    }

    // Set up MutationObserver to handle dynamically added posts
    const observer = new MutationObserver(mutations => {
        mutations.forEach(mutation => {
            if (mutation.addedNodes.length) {
                // Check each added node for new images
                mutation.addedNodes.forEach(node => {
                    if (node.nodeType === Node.ELEMENT_NODE) {
                        if (isCatalogPage) {
                            const newCatalogImages = node.querySelectorAll('.catalogCell a.linkThumb img');
                            processImages(newCatalogImages, true);
                        } else {
                            const newThreadImages = node.querySelectorAll('.uploadCell img');
                            processImages(newThreadImages, false);
                        }
                    }
                });
            }
        });
    });

    // Observe changes to the document body, including child nodes and subtrees
    observer.observe(document.body, {
        childList: true,
        subtree: true
    });
})();