// ==UserScript==
// @name         Bilibili图文动态预览图片下载
// @namespace    BilibiliDynamicPreviewDownload
// @license      MIT
// @version      1.6.0
// @description  在B站个人空间的投稿 - 图文界面，提供右键直接下载动态中的图片，并记录已下载的动态ID，改变背景颜色来区别。（新支持新旧动态页面 + 专栏）
// @author       Kaesinol
// @match        https://space.bilibili.com/*
// @match        https://www.bilibili.com/opus/*
// @match        https://t.bilibili.com/*
// @grant        GM_download
// @grant        GM_getValue
// @grant        GM_setValue
// @grant        GM_registerMenuCommand
// @grant        GM_xmlhttpRequest
// @connect      api.bilibili.com
// @require      https://cdn.jsdelivr.net/npm/fflate@0.8.2/umd/index.js
// @require      https://update.greasyfork.org/scripts/580254/1837601/Bilibili%20WBI%20Signer%20Library.js
// @icon         https://www.bilibili.com/favicon.ico
// ==/UserScript==

(function () {
  "use strict";

  const cacheHelper = {
    set: (key, value, minutes = 60) => {
      const data = { value, expire: Date.now() + minutes * 60 * 1000 };
      localStorage.setItem(key, JSON.stringify(data));
    },
    get: (key) => {
      const raw = localStorage.getItem(key);
      if (!raw) return null;
      const data = JSON.parse(raw);
      if (Date.now() > data.expire) {
        localStorage.removeItem(key);
        return null;
      }
      return data.value;
    },
  };

  const getWbiKeysWithCache = async () => {
    const CACHE_KEY = "bili_wbi_cache";

    const cachedKeys = cacheHelper.get(CACHE_KEY);
    if (cachedKeys) return cachedKeys;

    const keys = await BiliWbi.getWbiKeys();
    cacheHelper.set(CACHE_KEY, keys, 60);
    return keys;
  };

  const loadDownloadedDynamicIds = () => {
    const stored = GM_getValue("downloadedDynamicIds", null);
    if (!stored) return new Set();
    if (Array.isArray(stored)) return new Set(stored);
    if (typeof stored === "object") return new Set(Object.keys(stored));
    return new Set();
  };

  let downloadedDynamicIds = loadDownloadedDynamicIds();

  const saveDownloadedDynamicIds = () => {
    GM_setValue("downloadedDynamicIds", Array.from(downloadedDynamicIds));
  };

  const getFileExtensionFromUrl = (url) =>
    (url.match(/\.([a-zA-Z0-9]+)$/) || [])[1] || "jpg";

  const downloadBlob = (blob, name) => {
    const objectUrl = URL.createObjectURL(blob);

    GM_download({
      url: objectUrl,
      name,
      saveAs: false,
      onload: () => URL.revokeObjectURL(objectUrl),
      onerror: () => URL.revokeObjectURL(objectUrl),
    });
  };

  const createZipAndDownload = async (urls, fileName) => {
    const files = {};

    await Promise.all(
      urls.map(async (url, index) => {
        const res = await fetch(url);
        if (!res.ok) throw new Error("fetch failed");

        const data = new Uint8Array(await res.arrayBuffer());
        const ext = getFileExtensionFromUrl(url);
        files[`${fileName} - ${index + 1}.${ext}`] = data;
      }),
    );

    const zipped = fflate.zipSync(files, { level: 0 });
    const blob = new Blob([zipped], { type: "application/zip" });

    downloadBlob(blob, `${fileName}.zip`);
  };

  const downloadFile = async (url, index, fileName) => {
    const res = await fetch(url);
    if (!res.ok) throw new Error("fetch failed");

    const blob = await res.blob();
    const ext = getFileExtensionFromUrl(url);

    downloadBlob(blob, `${fileName} - ${index + 1}.${ext}`);
  };

  const stripThumbnailSuffix = (url) =>
    url
      .replace(/^http:/, "https:")
      .replace(/@\d+w.*$/, "")
      .replace(/@\d+h.*$/, "")
      .replace(/@\..*$/, "");

  const extractImagesFromArticle = async (articleId) => {
    try {
      const apiUrl = `https://api.bilibili.com/x/article/view?id=${articleId}`;

      const response = await new Promise((resolve, reject) => {
        GM_xmlhttpRequest({
          method: "GET",
          url: apiUrl,
          headers: {
            Referer: `https://www.bilibili.com/read/cv${articleId}`,
          },
          onload: resolve,
          onerror: reject,
        });
      });

      const jsonData = JSON.parse(response.responseText);
      if (jsonData.code !== 0) return [];

      const data = jsonData.data;
      const urls = new Set();
      const addUrl = (src) => {
        if (src && src.includes("/article/") && !src.includes("/face/")) {
          urls.add(stripThumbnailSuffix(src));
        }
      };

      if (data.type === 3) {
        const content = JSON.parse(data.content);
        content.ops?.forEach((op) => {
          const image = op.insert?.nativeImage ?? op.insert?.["native-image"];
          if (image?.url) addUrl(image.url);
        });
      } else {
        const doc = new DOMParser().parseFromString(data.content, "text/html");
        doc.querySelectorAll("img").forEach((img) => addUrl(img.src));
      }

      data.image_urls?.forEach(addUrl);
      data.origin_image_urls?.forEach(addUrl);

      return [...urls];
    } catch (e) {
      console.error(e);
      return [];
    }
  };

  const extractImagesFromDom = () => {
    const contentArea = document.querySelector(".opus-module-content");
    if (!contentArea) return [];
    const images = contentArea.querySelectorAll("img");
    const urls = new Set();
    images.forEach((img) => {
      const src = img.src || img.dataset?.src || "";
      if (src.includes("/article/") && !src.includes("/face/")) {
        urls.add(stripThumbnailSuffix(src));
      }
    });
    return [...urls];
  };
  const fetchJsonData = async (dynamicId) => {
    try {
      const { img_key, sub_key } = await getWbiKeysWithCache();

      const queryString = BiliWbi.getWbiQuery(
        { id: dynamicId },
        img_key,
        sub_key,
      );

      const apiUrl =
        "https://api.bilibili.com/x/polymer/web-dynamic/v1/detail?" +
        queryString;

      const response = await new Promise((resolve, reject) => {
        GM_xmlhttpRequest({
          method: "GET",
          url: apiUrl,
          onload: resolve,
          onerror: reject,
        });
      });

      const jsonData = JSON.parse(response.responseText);

      if (jsonData.code !== 0) return;

      const info = jsonData.data.item.modules.module_author;
      const fileName = `${info.name} - ${info.mid} - ${dynamicId}`;
      const major = jsonData.data.item.modules.module_dynamic.major;

      let pictures = [];

      if (major?.draw?.items) {
        pictures = major.draw.items.map((p) =>
          p.src.replace(/^http:/, "https:")
        );
      } else if (major?.opus?.pics) {
        pictures = major.opus.pics.map((p) =>
          p.url.replace(/^http:/, "https:")
        );
      } else if (major?.type === "MAJOR_TYPE_ARTICLE") {
        const articleId =
          major?.article?.id ?? major?.id ?? major?.biz_id;
        pictures = articleId
          ? await extractImagesFromArticle(articleId)
          : [];
        if (pictures.length === 0) pictures = extractImagesFromDom();
      }

      if (pictures.length > 1) {
        await createZipAndDownload(pictures, fileName);
      } else if (pictures.length === 1) {
        await downloadFile(pictures[0], 0, fileName);
      }

      if (pictures.length > 0) {
        downloadedDynamicIds.add(String(dynamicId));
        saveDownloadedDynamicIds();
        updateLinkColor(dynamicId);
      }
    } catch (e) {
      console.error(e);
    }
  };

  const handleEvent = (event, targetElement) => {
    event.preventDefault();
    event.stopPropagation();

    const link = targetElement.querySelector("a");
    const match = link?.href.match(/\/(\d+)\??/);
    if (match) fetchJsonData(match[1]);
  };

  const updateLinkColor = (dynamicId) => {
    const link = document.querySelector(`a[href*="${dynamicId}"]`);
    if (link) link.parentElement.style.backgroundColor = "green";
  };

  const observer = new MutationObserver(() => {
    document
      .querySelectorAll("div.opus-body div.item")
      .forEach((el) => {
        if (!el.hasAttribute("data-listener")) {
          el.addEventListener("contextmenu", (e) => handleEvent(e, el), true);
          el.setAttribute("data-listener", "true");
        }

        const link = el.querySelector("a");
        const m = link?.href.match(/\/(\d+)\??/);
        if (m && downloadedDynamicIds.has(m[1])) {
          link.parentElement.style.backgroundColor = "green";
        }
      });
  });

  const startObserver = () => {
    const target = document.querySelector("div.space-upload");

    if (target) {
      observer.observe(target, { childList: true, subtree: true });
      return;
    }

    const wait = new MutationObserver(() => {
      const t = document.querySelector("div.space-upload");
      if (!t) return;

      wait.disconnect();
      observer.observe(t, { childList: true, subtree: true });
    });

    wait.observe(document.body, { childList: true, subtree: true });
  };

  startObserver();

  const getID = () => {
    const opus = location.pathname.match(/^\/opus\/(\d+)/);
    if (opus) return opus[1];
    const t = location.href.match(/^https?:\/\/t\.bilibili\.com\/(\d+)/);
    return t?.[1] || null;
  };

  const exportDownloadedDynamicIds = () => {
    const blob = new Blob(
      [JSON.stringify([...downloadedDynamicIds])],
      { type: "application/json" },
    );

    downloadBlob(blob, "downloadedDynamicIds.json");
  };

  const importDownloadedDynamicIds = () => {
    const input = document.createElement("input");
    input.type = "file";
    input.accept = "application/json";

    input.onchange = () => {
      const reader = new FileReader();
      reader.onload = () => {
        JSON.parse(reader.result).forEach((id) =>
          downloadedDynamicIds.add(String(id))
        );
        saveDownloadedDynamicIds();
        alert("导入成功");
      };
      reader.readAsText(input.files[0]);
    };

    input.click();
  };

  GM_registerMenuCommand("导出已下载ID", exportDownloadedDynamicIds);
  GM_registerMenuCommand("导入已下载ID", importDownloadedDynamicIds);

  const dynamicId = getID();
  if (dynamicId) {
    GM_registerMenuCommand("下载本条动态图片", () => fetchJsonData(dynamicId));
  }
})();