// ==UserScript==
// @name         小红书无水印解析
// @version      1.0
// @description  提取小红书官网中的图片并下载
// @author       princewen
// @icon         https://s4.zstatic.net/images/2024/02/27-dee8a1b54cbf770ab8a3d0d8ed96931a.ico
// @match        https://www.xiaohongshu.com/*
// @grant        GM_xmlhttpRequest
// @license      MIT
// @namespace https://greasyfork.org/users/1258677
// @downloadURL none
// ==/UserScript==

(function() {
    'use strict';

    function extractHash(content) {
        var startIndex = content.lastIndexOf("/") + 1;
        var endIndex = content.indexOf("!");
        return content.substring(startIndex, endIndex);
    }

    function downloadImage(hash) {
        var imageUrl = "https://ci.xiaohongshu.com/" + hash + "?imageView2/2/w/format/png";
        GM_xmlhttpRequest({
            method: "GET",
            url: imageUrl,
            responseType: "blob",
            onload: function(response) {
                var blob = response.response;
                var a = document.createElement("a");
                var url = window.URL.createObjectURL(blob);
                a.href = url;
                a.download = "image.png";
                a.click();
                window.URL.revokeObjectURL(url);
            }
        });
    }

    function extractAndDownloadImages() {
        var metaTags = document.querySelectorAll('meta[name="og:image"]');
        if (metaTags.length > 0) {
            var downloadedHashes = [];
            metaTags.forEach(function(metaTag) {
                var content = metaTag.content;
                var hash = extractHash(content);
                if (!downloadedHashes.includes(hash)) {
                    downloadImage(hash);
                    downloadedHashes.push(hash);
                }
            });
        }
    }

    window.addEventListener("load", function() {
        extractAndDownloadImages();
    });
})();