// ==UserScript==
// @name         微信文章自动加载图片 (防盗链穿透版)
// @namespace    http://tampermonkey.net/
// @version      1.2
// @description  解决微信防盗链和URL参数问题
// @author       You
// @match        *://mp.weixin.qq.com/*
// @grant        none
// @run-at       document-start
// ==/UserScript==

(function () {
    'use strict';

    // 1. 强制设置 Referrer Policy，骗过微信防盗链
    // 这能让图片在被外部工具抓取时也认为是“自己人”
    function setReferrerPolicy() {
        if (!document.head || document.querySelector('meta[name="referrer"]')) {
            return;
        }

        const meta = document.createElement('meta');
        meta.name = 'referrer';
        meta.content = 'no-referrer-when-downgrade'; // 或者 'unsafe-url'
        document.head.appendChild(meta);
    }

    function cleanWeChatImageUrl(src) {
        let cleanSrc = src.split('#')[0];

        try {
            const url = new URL(cleanSrc);
            ['tp', 'wxfrom', 'from'].forEach(param => url.searchParams.delete(param));
            cleanSrc = url.toString();
        } catch (error) {
            // Keep the original fallback behavior for non-standard URLs.
            if (cleanSrc.includes('&tp=')) {
                cleanSrc = cleanSrc.split('&tp=')[0];
            }
            if (cleanSrc.includes('&wxfrom=')) {
                cleanSrc = cleanSrc.split('&wxfrom=')[0];
            }
            if (cleanSrc.includes('&from=')) {
                cleanSrc = cleanSrc.split('&from=')[0];
            }
        }

        return cleanSrc;
    }

    function isWeChatPlaceholderImage(img) {
        return img.src.includes('mmbiz.qpic.cn') && (
            img.classList.contains('js_img_placeholder') ||
            img.classList.contains('wx_img_placeholder') ||
            img.hasAttribute('data-imgfileid') ||
            img.hasAttribute('data-aistatus')
        );
    }

    function makeImageVisible(img) {
        img.style.setProperty('visibility', 'visible', 'important');
        img.style.setProperty('height', 'auto', 'important');

        if (!img.style.width && img.dataset.w) {
            img.style.setProperty('width', `${img.dataset.w}px`, 'important');
        }
    }

    function makeImageEager(img, src) {
        img.loading = 'eager';
        img.decoding = 'sync';
        img.setAttribute('data-src', src);
        img.setAttribute('data-original', src);
        img.setAttribute('data-original-src', src);
        img.removeAttribute('data-index');
        img.removeAttribute('data-original-style');
        img.removeAttribute('_width');
    }

    function wrapImageForClipper(img) {
        if (img.closest('figure[data-wechat-img-loader]')) {
            return;
        }

        const parent = img.parentElement;
        if (!parent) {
            return;
        }

        const figure = document.createElement('figure');
        figure.setAttribute('data-wechat-img-loader', '');
        figure.style.setProperty('margin', '15px 0');
        figure.style.setProperty('visibility', 'visible');

        const link = document.createElement('a');
        link.href = img.src;
        link.target = '_blank';
        link.rel = 'noreferrer';

        parent.insertBefore(figure, img);
        figure.appendChild(link);
        link.appendChild(img);
    }

    function normalizeImageOnlyParagraph(img) {
        if (img.closest('section[nodeleaf]')) {
            return;
        }

        const paragraph = img.closest('p');
        if (!paragraph) {
            return;
        }

        const images = paragraph.querySelectorAll('img');
        if (images.length !== 1 || images[0] !== img || paragraph.textContent.trim()) {
            return;
        }

        const section = document.createElement('section');
        section.setAttribute('nodeleaf', '');
        section.style.setProperty('visibility', 'visible');
        section.appendChild(img);
        paragraph.replaceWith(section);
    }

    function replaceSrc() {
        document.querySelectorAll('img[data-src]').forEach(img => {
            // 2. 提取真实链接
            let trueSrc = img.dataset.src;

            // 3. 【强力清洗】去除所有可能干扰的参数和锚点
            trueSrc = cleanWeChatImageUrl(trueSrc);

            // 4. 只有链接发生变化时才替换
            if (img.src !== trueSrc) {
                img.src = trueSrc;
                // 修改 referrerPolicy 属性，告诉浏览器不要隐藏来源
                img.referrerPolicy = 'no-referrer-when-downgrade';
                // 移除可能导致冲突的 data-src
                img.removeAttribute('data-src');
            }

            makeImageVisible(img);
            makeImageEager(img, trueSrc);
            normalizeImageOnlyParagraph(img);
            wrapImageForClipper(img);
        });

        document.querySelectorAll('img[src]').forEach(img => {
            if (!isWeChatPlaceholderImage(img)) {
                return;
            }

            const trueSrc = cleanWeChatImageUrl(img.src);

            if (img.src !== trueSrc) {
                img.src = trueSrc;
            }

            img.referrerPolicy = 'no-referrer-when-downgrade';
            img.classList.remove('js_img_placeholder', 'wx_img_placeholder');
            makeImageVisible(img);
            makeImageEager(img, trueSrc);
            normalizeImageOnlyParagraph(img);
            wrapImageForClipper(img);
        });
    }

    function run() {
        setReferrerPolicy();

        if (!document.body) {
            return;
        }

        replaceSrc();

        // 监听动态加载
        const observer = new MutationObserver(replaceSrc);
        observer.observe(document.body, { childList: true, subtree: true });
    }

    // 立即运行
    if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', run);
    } else {
        run();
    }
})();