WebComics Chapter Downloader

Downloads chapter images from webcomicsapp.com with retries and stability fixes.

Tendrás que instalar una extensión para tu navegador como Tampermonkey, Greasemonkey o Violentmonkey si quieres utilizar este script.

You will need to install an extension such as Tampermonkey to install this script.

Tendrás que instalar una extensión como Tampermonkey o Violentmonkey para instalar este script.

Necesitarás instalar una extensión como Tampermonkey o Userscripts para instalar este script.

Tendrás que instalar una extensión como Tampermonkey antes de poder instalar este script.

Necesitarás instalar una extensión para administrar scripts de usuario si quieres instalar este script.

(Ya tengo un administrador de scripts de usuario, déjame instalarlo)

Tendrás que instalar una extensión como Stylus antes de poder instalar este script.

Tendrás que instalar una extensión como Stylus antes de poder instalar este script.

Tendrás que instalar una extensión como Stylus antes de poder instalar este script.

Para poder instalar esto tendrás que instalar primero una extensión de estilos de usuario.

Para poder instalar esto tendrás que instalar primero una extensión de estilos de usuario.

Para poder instalar esto tendrás que instalar primero una extensión de estilos de usuario.

(Ya tengo un administrador de estilos de usuario, déjame instalarlo)

// ==UserScript==
// @name         WebComics Chapter Downloader
// @namespace    http://tampermonkey.net/
// @version      1.2
// @description  Downloads chapter images from webcomicsapp.com with retries and stability fixes.
// @author       ozler365
// @license      MIT
// @match        https://webcomicsapp.com/*
// @icon         https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/c0/87/41/c08741e4-bfca-c565-e3e6-3ba1d5ccd853/Placeholder.mill/400x400bb-75.webp
// @grant        GM_xmlhttpRequest
// @grant        GM_download
// @run-at       document-start
// ==/UserScript==

(function() {
    'use strict';

    let capturedChapterData = null;
    let downloadBtn = null;
    let isDownloading = false;

    // --- Configuration ---
    const DELAY_BETWEEN_IMAGES = 500; // 0.5 seconds (slower = safer)
    const MAX_RETRIES = 3;            // How many times to retry a failed image
    const RETRY_WAIT = 3000;          // Wait 3 seconds before retrying

    // --- Extract Episode/Chapter ID from URL ---
    function getChapterIdFromUrl() {
        const match = window.location.href.match(/([a-f0-9]{24})(?=-Ch)/i);
        if (!match) {
             const fallback = window.location.pathname.match(/\/([a-f0-9]{24})\b/i);
             return fallback ? fallback[1] : null;
        }
        return match ? match[1] : null;
    }

    // --- Data Interception ---
    function findChapterData(obj, url) {
        if (!obj || typeof obj !== 'object') return null;
        
        if (!obj.data || !obj.data.pages) return null;

        const chapterId = getChapterIdFromUrl();
        if (chapterId && url && !url.includes(chapterId)) return null;

        const pages = obj.data.pages;
        if (!Array.isArray(pages) || pages.length === 0) return null;

        const images = pages.map((page, index) => {
            let imgUrl = null;
            if (typeof page === 'string') {
                imgUrl = page;
            } else if (typeof page === 'object' && page !== null) {
                imgUrl = page.url || page.image || page.src || page.link || page.contentUrl;
            }

            if (imgUrl) {
                return {
                    ord: index + 1,
                    downloadUrl: imgUrl
                };
            }
            return null;
        }).filter(item => item !== null);

        if (images.length > 0) {
            return {
                images: images,
                title: document.title || `Chapter ${chapterId}`,
                chapterId: chapterId
            };
        }
        return null;
    }

    // Hook into XMLHttpRequest
    const originalOpen = XMLHttpRequest.prototype.open;
    XMLHttpRequest.prototype.open = function(method, url) {
        this.addEventListener('load', function() {
            try {
                const res = JSON.parse(this.responseText);
                const found = findChapterData(res, typeof url === 'string' ? url : url.toString());
                if (found && found.images.length > 0) {
                    capturedChapterData = found;
                    updateButtonState();
                }
            } catch (e) {}
        });
        originalOpen.apply(this, arguments);
    };

    // Hook into Fetch API
    const originalFetch = window.fetch;
    window.fetch = async (...args) => {
        const response = await originalFetch(...args);
        try {
            const url = typeof args[0] === 'string' ? args[0] : args[0].url;
            const clone = response.clone();
            clone.json().then(data => {
                const found = findChapterData(data, url);
                if (found && found.images.length > 0) {
                    capturedChapterData = found;
                    updateButtonState();
                }
            }).catch(() => {});
        } catch (e) {}
        return response;
    };

    // --- UI Construction ---
    function createButton() {
        if (document.getElementById('wc-dl-btn')) return;

        downloadBtn = document.createElement('button');
        downloadBtn.id = 'wc-dl-btn';
        downloadBtn.innerText = 'Wait for Data...';
        Object.assign(downloadBtn.style, {
            position: 'fixed', bottom: '20px', right: '20px', zIndex: '10000',
            padding: '12px 24px', backgroundColor: '#444', color: '#fff',
            border: 'none', borderRadius: '8px', cursor: 'not-allowed',
            fontWeight: 'bold', fontFamily: 'sans-serif',
            boxShadow: '0 4px 10px rgba(0,0,0,0.3)'
        });
        downloadBtn.disabled = true;
        downloadBtn.onclick = startDownload;
        document.body.appendChild(downloadBtn);
    }

    function updateButtonState() {
        if (!downloadBtn) createButton();
        if (capturedChapterData && !isDownloading) {
            downloadBtn.style.backgroundColor = '#ff5722';
            downloadBtn.style.cursor = 'pointer';
            downloadBtn.innerText = `Download ${capturedChapterData.images.length} Images`;
            downloadBtn.disabled = false;
        }
    }

    // --- Download Logic ---
    function startDownload() {
        if (!capturedChapterData || isDownloading) return;

        isDownloading = true;
        const images = capturedChapterData.images;
        const folderName = sanitizeFilename(document.title).trim() || 'WebComic_Chapter';

        downloadBtn.innerText = `Starting...`;
        downloadBtn.disabled = true;
        downloadBtn.style.backgroundColor = '#f57c00';

        let completed = 0;
        let failed = 0;
        let currentIndex = 0;
        let currentRetries = 0; // Track retries for current image

        function downloadNext() {
            // Check if finished
            if (currentIndex >= images.length) {
                isDownloading = false;
                downloadBtn.style.backgroundColor = '#4caf50';
                downloadBtn.innerText = `✓ Done (${completed}/${images.length})`;
                downloadBtn.disabled = false;
                setTimeout(() => updateButtonState(), 4000);
                return;
            }

            const imgData = images[currentIndex];
            const url = imgData.downloadUrl;
            
            // Guess extension
            let ext = 'jpg';
            if (url.includes('.png')) ext = 'png';
            if (url.includes('.webp')) ext = 'webp';
            if (url.includes('.gif')) ext = 'gif';

            const filename = `${String(imgData.ord).padStart(3, '0')}.${ext}`;
            const fullPath = `${folderName}/${filename}`;

            // Helper to handle failure/retry
            const handleFailure = (reason) => {
                console.warn(`Failed: ${filename} (${reason})`);
                if (currentRetries < MAX_RETRIES) {
                    currentRetries++;
                    downloadBtn.innerText = `Retry ${currentRetries}/${MAX_RETRIES} for img ${currentIndex + 1}...`;
                    setTimeout(downloadNext, RETRY_WAIT); // Wait longer before retry
                } else {
                    // Give up on this one
                    failed++;
                    currentIndex++;
                    currentRetries = 0;
                    downloadBtn.innerText = `Skip ${currentIndex}/${images.length}...`;
                    setTimeout(downloadNext, DELAY_BETWEEN_IMAGES);
                }
            };

            GM_download({
                url: url,
                name: fullPath,
                timeout: 15000, // 15 seconds timeout per image
                onload: function() {
                    completed++;
                    currentIndex++;
                    currentRetries = 0; // Reset retry counter
                    downloadBtn.innerText = `Downloading ${currentIndex}/${images.length}...`;
                    setTimeout(downloadNext, DELAY_BETWEEN_IMAGES);
                },
                onerror: function(err) { handleFailure('Error'); },
                ontimeout: function() { handleFailure('Timeout'); }
            });
        }

        downloadNext();
    }

    function sanitizeFilename(name) {
        return name.replace(/[<>:"/\\|?*]/g, "").replace(/\s+/g, " ").trim().substring(0, 100);
    }

    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', createButton);
    } else {
        createButton();
    }
    window.addEventListener('load', createButton);

    // Watch for URL changes
    let lastUrl = location.href;
    new MutationObserver(() => {
        const url = location.href;
        if (url !== lastUrl) {
            lastUrl = url;
            capturedChapterData = null;
            isDownloading = false;
            if (downloadBtn) {
                downloadBtn.style.backgroundColor = '#444';
                downloadBtn.style.cursor = 'not-allowed';
                downloadBtn.innerText = 'Wait for Data...';
                downloadBtn.disabled = true;
            }
        }
    }).observe(document, {subtree: true, childList: true});

})();