// ==UserScript==
// @name         抖音表情包下载（网页版）douyin
// @namespace    https://local.9527/
// @version      0.1.1
// @description  Parse already-loaded Douyin comment stickers safely, preview them, and download individually or as a zip bundle.
// @author       代号_9527
// @match        https://www.douyin.com/*
// @grant        GM_addStyle
// @grant        GM_download
// @grant        GM.download
// @grant        GM_xmlhttpRequest
// @grant        GM.xmlHttpRequest
// @connect      *
// ==/UserScript==

(function () {
  "use strict";

  const PANEL_ID = "dy-sticker-parser-panel";
  const MODAL_ID = "dy-sticker-parser-modal";
  const LAUNCHER_CAT_DATA_URL = "data:image/png;base64,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";
  const STATE = {
    items: [],
    lastScanAt: null,
    pageUrl: "",
    pageTitle: "",
    ui: {
      collapsed: false,
      position: null,
      drag: null,
    },
  };
  const CRC32_TABLE = (() => {
    const table = new Uint32Array(256);
    for (let i = 0; i < 256; i += 1) {
      let c = i;
      for (let j = 0; j < 8; j += 1) {
        c = (c & 1) ? (0xedb88320 ^ (c >>> 1)) : (c >>> 1);
      }
      table[i] = c >>> 0;
    }
    return table;
  })();

  function getGmXmlHttpRequest() {
    if (typeof GM_xmlhttpRequest === "function") return GM_xmlhttpRequest;
    if (typeof GM !== "undefined" && GM && typeof GM.xmlHttpRequest === "function") {
      return GM.xmlHttpRequest.bind(GM);
    }
    return null;
  }

  function getGmDownload() {
    if (typeof GM_download === "function") return GM_download;
    if (typeof GM !== "undefined" && GM && typeof GM.download === "function") {
      return GM.download.bind(GM);
    }
    return null;
  }

  function isStickerResourceUrl(url) {
    if (!url || typeof url !== "string") return false;
    return (
      url.includes("douyinpic.com") &&
      (url.includes("sticker_comment") || url.includes("biz_tag=aweme_comment"))
    );
  }

  function isInlineEmojiImage(img) {
    if (!img || img.tagName !== "IMG") return false;
    const src = img.getAttribute("src") || "";
    const alt = img.getAttribute("alt") || "";
    return !!alt && !isStickerResourceUrl(src);
  }

  function sanitizeFilename(input) {
    const value = String(input || "")
      .replace(/[\\/:*?"<>|]/g, "_")
      .replace(/\s+/g, " ")
      .trim();
    return value || "sticker";
  }

  function extensionFromContentType(contentType) {
    const value = String(contentType || "").toLowerCase();
    if (value.includes("image/gif")) return ".gif";
    if (value.includes("image/webp")) return ".webp";
    if (value.includes("image/png")) return ".png";
    if (value.includes("image/jpeg")) return ".jpg";
    if (value.includes("image/jpg")) return ".jpg";
    if (value.includes("image/bmp")) return ".bmp";
    if (value.includes("image/heic")) return ".heic";
    if (value.includes("image/heif")) return ".heif";
    return ".bin";
  }

  function normalizeUrl(url) {
    return String(url || "").replace(/&amp;/g, "&").trim();
  }

  function inferExtensionFromUrl(url) {
    const clean = normalizeUrl(url);
    try {
      const parsed = new URL(clean, location.href);
      const path = parsed.pathname.toLowerCase();
      const match = path.match(/\.(gif|png|jpe?g|webp|bmp|heic|heif)$/);
      return match ? `.${match[1] === "jpeg" ? "jpg" : match[1]}` : "";
    } catch (e) {
      console.warn("[douyin-sticker-parser] 无法从 URL 推断扩展名：", e);
      return "";
    }
  }

  function buildReadmeText({ pageTitle, pageUrl, generatedAt, items, failures }) {
    const lines = [
      "抖音评论贴纸导出摘要",
      "",
      `导出时间：${generatedAt}`,
      `页面标题：${pageTitle || ""}`,
      `页面链接：${pageUrl || ""}`,
      `资源总数：${items.length}`,
      `失败项：${failures.length}`,
      "",
      "资源明细：",
    ];

    items.forEach((item, index) => {
      lines.push(
        `${index + 1}. 文件名：${item.filename}`,
        `   作者：${item.author || "未知作者"}`,
        `   时间：${item.timeText || "未知时间"}`,
        `   类型：${item.resourceKind || "未知类型"}`,
        `   原始 MIME：${item.originalMime || "未知"}`,
        `   最终 MIME：${item.finalMime || "未知"}`,
        `   来源：${item.resourceUrl}`,
        ""
      );
    });

    if (failures.length > 0) {
      lines.push("失败明细：");
      failures.forEach((failure, index) => {
        lines.push(
          `${index + 1}. 链接：${failure.resourceUrl}`,
          `   原因：${failure.reason}`,
          ""
        );
      });
    }

    return lines.join("\n");
  }

  function parseContentTypeFromHeaders(headersText) {
    const line = String(headersText || "")
      .split(/\r?\n/)
      .find((entry) => /^content-type:/i.test(entry));
    return line ? line.split(":").slice(1).join(":").trim() : "";
  }

  function clampPanelPosition(position, viewport, panelSize, margin = 12) {
    const maxLeft = Math.max(margin, viewport.width - panelSize.width - margin);
    const maxTop = Math.max(margin, viewport.height - panelSize.height - margin);
    return {
      left: Math.min(Math.max(position.left, margin), maxLeft),
      top: Math.min(Math.max(position.top, margin), maxTop),
    };
  }

  function getCollapsedBadgeText(count) {
    if (!Number.isFinite(count) || count <= 0) return "";
    return count > 99 ? "99+" : String(count);
  }

  function createStyles() {
    const css = `
#${PANEL_ID} {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 2147483640;
  width: 368px;
  max-width: calc(100vw - 20px);
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 14px;
  pointer-events: none;
  color: #553246;
  font: 13px/1.5 "Trebuchet MS", "Microsoft YaHei", sans-serif;
  --dysp-bg-1: #fff9fc;
  --dysp-bg-2: #ffe5f1;
  --dysp-bg-3: #ffd2e7;
  --dysp-ink: #553246;
  --dysp-subtle: #8a6476;
  --dysp-accent: #ff72ac;
  --dysp-accent-strong: #ff4f95;
  --dysp-accent-soft: #ffc0da;
  --dysp-line: rgba(255, 119, 174, 0.2);
  --dysp-shadow: 0 24px 60px rgba(255, 116, 172, 0.22);
}
#${PANEL_ID} * {
  box-sizing: border-box;
}
#${PANEL_ID} .dysp-launcher {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-width: 58px;
  height: 48px;
  padding: 0 12px;
  pointer-events: auto;
  border: 1px solid rgba(255, 122, 180, 0.34);
  border-radius: 18px;
  background:
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.96), transparent 38%),
    linear-gradient(135deg, rgba(255, 227, 239, 0.98), rgba(255, 244, 249, 0.98) 56%, rgba(255, 210, 231, 0.98));
  color: #8b4069;
  box-shadow:
    0 18px 34px rgba(255, 109, 170, 0.22),
    inset 0 1px 0 rgba(255, 255, 255, 0.92);
  transform-origin: right bottom;
  transition:
    transform 340ms cubic-bezier(0.22, 1, 0.36, 1),
    opacity 240ms ease,
    filter 240ms ease,
    box-shadow 240ms ease;
}
#${PANEL_ID} .dysp-launcher::before {
  content: "✿";
  font-size: 18px;
  line-height: 1;
  display: none;
}
#${PANEL_ID} .dysp-launcher-badge:empty {
  display: none;
}
#${PANEL_ID} .dysp-launcher-cat {
  width: 24px;
  height: 24px;
  flex: none;
  object-fit: contain;
  pointer-events: none;
}
#${PANEL_ID} .dysp-launcher-face {
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.03em;
}
#${PANEL_ID} .dysp-launcher-badge {
  min-width: 18px;
  height: 18px;
  padding: 0 5px;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #ff76b1, #ff5a97);
  color: #fff8fc;
  box-shadow: 0 8px 18px rgba(255, 91, 150, 0.28);
  font-size: 11px;
  font-weight: 800;
}
#${PANEL_ID} .dysp-shell {
  display: flex;
  flex-direction: column;
  min-height: 0;
  width: 100%;
  max-height: 78vh;
  pointer-events: auto;
  position: relative;
  overflow: hidden;
  border: 1px solid var(--dysp-line);
  border-radius: 28px;
  background:
    radial-gradient(circle at top right, rgba(255, 255, 255, 0.92), transparent 28%),
    linear-gradient(180deg, rgba(255, 251, 253, 0.98), rgba(255, 234, 243, 0.96) 55%, rgba(255, 223, 236, 0.96));
  box-shadow: var(--dysp-shadow);
  backdrop-filter: blur(16px);
  transform-origin: right bottom;
  transition:
    transform 360ms cubic-bezier(0.22, 1, 0.36, 1),
    opacity 260ms ease,
    visibility 260ms ease,
    max-height 260ms ease,
    filter 260ms ease;
}
#${PANEL_ID} .dysp-shell::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 16% 18%, rgba(255, 255, 255, 0.9), transparent 16%),
    radial-gradient(circle at 84% 12%, rgba(255, 191, 221, 0.35), transparent 18%),
    linear-gradient(135deg, rgba(255, 255, 255, 0.2), transparent 48%);
  pointer-events: none;
}
#${PANEL_ID}.is-collapsed {
  width: auto;
  max-width: none;
}
#${PANEL_ID}.is-collapsed .dysp-launcher {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
  filter: saturate(1);
}
#${PANEL_ID}.is-collapsed .dysp-shell {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  max-height: 0;
  transform: translateY(22px) scale(0.86);
  filter: blur(2px);
}
#${PANEL_ID}.is-expanded .dysp-launcher {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(14px) scale(0.84);
  filter: saturate(0.85);
  animation: none;
}
#${PANEL_ID}.is-expanded .dysp-shell {
  opacity: 1;
  visibility: visible;
  max-height: 78vh;
  transform: translateY(0) scale(1);
  filter: blur(0);
}
#${PANEL_ID} .dysp-header {
  position: relative;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  padding: 18px 18px 14px;
  background:
    radial-gradient(circle at top right, rgba(255, 255, 255, 0.9), transparent 26%),
    linear-gradient(135deg, rgba(255, 228, 240, 0.96), rgba(255, 247, 251, 0.98) 58%, rgba(255, 219, 235, 0.94));
  border-bottom: 1px solid var(--dysp-line);
  cursor: grab;
  user-select: none;
  touch-action: none;
}
#${PANEL_ID}.is-dragging .dysp-header {
  cursor: grabbing;
}
#${PANEL_ID} .dysp-header::after {
  content: "";
  width: 16px;
  height: 16px;
  border-radius: 999px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.88), rgba(255, 196, 221, 0.28) 70%, transparent 72%);
  color: transparent;
  font-size: 0;
}
#${PANEL_ID} .dysp-header-copy {
  min-width: 0;
}
#${PANEL_ID} .dysp-title {
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 0.02em;
}
#${PANEL_ID} .dysp-subtitle {
  margin-top: 7px;
  color: var(--dysp-subtle);
  font-size: 12px;
}
#${PANEL_ID} .dysp-actions {
  display: flex;
  gap: 10px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--dysp-line);
  background: rgba(255, 252, 254, 0.7);
}
#${PANEL_ID} button {
  appearance: none;
  border: 1px solid rgba(255, 128, 181, 0.22);
  border-radius: 16px;
  padding: 10px 12px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(255, 241, 247, 0.94));
  color: var(--dysp-ink);
  cursor: pointer;
  font-weight: 700;
  box-shadow:
    0 8px 18px rgba(255, 134, 187, 0.12),
    inset 0 1px 0 rgba(255, 255, 255, 0.9);
  transition:
    transform 180ms ease,
    box-shadow 180ms ease,
    background 180ms ease,
    border-color 180ms ease;
}
#${PANEL_ID} button:hover {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(255, 231, 241, 0.96));
  box-shadow:
    0 12px 22px rgba(255, 118, 177, 0.18),
    inset 0 1px 0 rgba(255, 255, 255, 0.94);
  transform: translateY(-1px);
}
#${PANEL_ID} .dysp-utility-button {
  color: #151318;
  border-color: rgba(84, 58, 72, 0.18);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(255, 243, 248, 0.94));
}
#${PANEL_ID} .dysp-utility-button:hover {
  color: #0f0e12;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(255, 238, 245, 0.96));
}
#${PANEL_ID} button:active {
  transform: translateY(0);
}
#${PANEL_ID} button:disabled {
  cursor: not-allowed;
  opacity: 0.65;
  transform: none;
  box-shadow: none;
}
#${PANEL_ID} .dysp-icon-button {
  flex: none;
  min-width: 44px;
  padding: 10px 0;
  border-radius: 14px;
  font-size: 12px;
}
#${PANEL_ID} .dysp-primary {
  background: linear-gradient(135deg, var(--dysp-accent), var(--dysp-accent-strong));
  color: #fff9fc;
  border-color: transparent;
  box-shadow:
    0 14px 26px rgba(255, 95, 156, 0.3),
    inset 0 1px 0 rgba(255, 255, 255, 0.22);
}
#${PANEL_ID} .dysp-primary:hover {
  background: linear-gradient(135deg, #ff6ca8, #ff4b90);
  color: #fff9fc;
}
#${PANEL_ID} .dysp-status {
  position: relative;
  padding: 12px 16px;
  border-bottom: 1px solid var(--dysp-line);
  color: #70475d;
  background: linear-gradient(180deg, rgba(255, 248, 251, 0.82), rgba(255, 236, 244, 0.74));
}
#${PANEL_ID} .dysp-list {
  overflow: auto;
  padding: 14px;
  display: grid;
  gap: 12px;
}
#${PANEL_ID} .dysp-empty {
  padding: 18px;
  text-align: center;
  color: var(--dysp-subtle);
  border: 1px dashed rgba(255, 128, 181, 0.28);
  border-radius: 18px;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.85), rgba(255, 242, 248, 0.88));
}
#${PANEL_ID} .dysp-card {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 12px;
  padding: 12px;
  border-radius: 20px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(255, 241, 247, 0.9)),
    linear-gradient(135deg, rgba(255, 236, 244, 0.7), rgba(255, 255, 255, 0.1));
  border: 1px solid rgba(255, 140, 188, 0.18);
  box-shadow: 0 12px 26px rgba(255, 144, 190, 0.1);
}
#${PANEL_ID} .dysp-thumb {
  width: 80px;
  height: 80px;
  border-radius: 18px;
  overflow: hidden;
  background: linear-gradient(135deg, #ffe0ef, #fff8fc);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.88);
}
#${PANEL_ID} .dysp-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
#${PANEL_ID} .dysp-thumb-button {
  padding: 0;
  border: none;
  cursor: zoom-in;
}
#${PANEL_ID} .dysp-thumb-button:hover,
#${PANEL_ID} .dysp-thumb-button:active {
  background: linear-gradient(135deg, #ffe0ef, #fff8fc);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.88);
  transform: none;
}
#${PANEL_ID} .dysp-card-title {
  font-weight: 700;
  margin-bottom: 6px;
  word-break: break-all;
}
#${PANEL_ID} .dysp-card-title-button {
  display: block;
  width: 100%;
  padding: 0;
  margin-bottom: 6px;
  border: none;
  background: transparent;
  box-shadow: none;
  border-radius: 0;
  color: #402635;
  font-size: 15px;
  font-weight: 800;
  text-align: left;
  word-break: break-all;
  cursor: pointer;
}
#${PANEL_ID} .dysp-card-title-button:hover,
#${PANEL_ID} .dysp-card-title-button:active {
  background: transparent;
  box-shadow: none;
  color: #23131d;
  transform: none;
}
#${PANEL_ID} .dysp-meta {
  color: #7c6070;
  margin-bottom: 8px;
  word-break: break-word;
}
#${PANEL_ID} .dysp-tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 9px;
  border-radius: 999px;
  background: linear-gradient(135deg, rgba(255, 209, 229, 0.98), rgba(255, 236, 245, 0.98));
  color: #af4f7b;
  font-size: 11px;
  margin-bottom: 8px;
  border: 1px solid rgba(255, 141, 190, 0.24);
}
#${PANEL_ID} .dysp-download-button {
  display: inline-flex;
  width: 100%;
  justify-content: center;
}
#${MODAL_ID} {
  position: fixed;
  inset: 0;
  z-index: 2147483646;
  display: none;
  align-items: center;
  justify-content: center;
  background: rgba(64, 30, 48, 0.48);
  padding: 24px;
}
#${MODAL_ID}.is-open {
  display: flex;
}
#${MODAL_ID} .dysp-modal-card {
  width: min(720px, 100%);
  max-height: 86vh;
  overflow: auto;
  background:
    radial-gradient(circle at top right, rgba(255, 255, 255, 0.92), transparent 24%),
    linear-gradient(180deg, rgba(255, 250, 253, 0.98), rgba(255, 233, 242, 0.96));
  border-radius: 28px;
  padding: 20px;
  border: 1px solid rgba(255, 155, 198, 0.28);
  box-shadow: 0 28px 60px rgba(98, 43, 69, 0.28);
}
#${MODAL_ID} .dysp-modal-preview {
  width: 100%;
  min-height: 260px;
  border-radius: 20px;
  background: linear-gradient(135deg, #ffe7f2, #fffafc);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
#${MODAL_ID} .dysp-modal-preview img {
  max-width: 100%;
  max-height: 60vh;
  object-fit: contain;
}
#${MODAL_ID} .dysp-modal-actions {
  display: flex;
  gap: 10px;
  margin-top: 14px;
}
@media (prefers-reduced-motion: reduce) {
  #${PANEL_ID} .dysp-launcher,
  #${PANEL_ID} .dysp-shell,
  #${PANEL_ID} button {
    animation: none !important;
    transition: none !important;
  }
}
@media (max-width: 680px) {
  #${PANEL_ID} {
    width: calc(100vw - 20px);
    max-width: calc(100vw - 20px);
    bottom: 10px;
    right: 10px;
    left: auto;
  }
  #${PANEL_ID} .dysp-shell {
    max-height: 70vh;
  }
  #${PANEL_ID}.is-expanded .dysp-shell {
    max-height: 70vh;
  }
  #${PANEL_ID} .dysp-actions {
    flex-direction: column;
  }
}`;

    if (typeof GM_addStyle === "function") {
      GM_addStyle(css);
      return;
    }

    const style = document.createElement("style");
    style.textContent = css;
    document.head.appendChild(style);
  }

  function findCommentRoot(node) {
    if (!node || typeof node.closest !== "function") return null;
    return (
      node.closest('[data-e2e="comment-item"]') ||
      node.closest(".UuCzPLbi") ||
      node.closest(".EpsntdUI")
    );
  }

  function textOf(element) {
    return element ? String(element.textContent || "").trim() : "";
  }

  function simpleHash(input) {
    const text = String(input || "");
    let hash = 0;
    for (let i = 0; i < text.length; i += 1) {
      hash = ((hash << 5) - hash + text.charCodeAt(i)) | 0;
    }
    return Math.abs(hash).toString(36);
  }

  function formatLabelFromMime(contentType) {
    const value = String(contentType || "").toLowerCase();
    if (value.includes("image/gif")) return "GIF";
    if (value.includes("image/png")) return "PNG";
    if (value.includes("image/jpeg")) return "JPG";
    if (value.includes("image/webp")) return "WEBP";
    if (value.includes("image/heic")) return "HEIC";
    if (value.includes("image/heif")) return "HEIF";
    return "";
  }

  function formatLabelFromUrl(url) {
    const value = String(url || "").toLowerCase();
    if (value.includes(".gif")) return "GIF";
    if (value.includes(".png")) return "PNG";
    if (value.includes(".jpg") || value.includes(".jpeg")) return "JPG";
    if (value.includes(".webp")) return "WEBP";
    if (value.includes("sc=sticker_heif")) return "HEIF";
    return "未知";
  }

  function resourceKindFromUrl(url) {
    const clean = normalizeUrl(url).toLowerCase();
    if (clean.includes(".gif")) return "gif";
    if (clean.includes("sticker_heif")) return "sticker";
    if (clean.includes("sticker_comment")) return "sticker";
    return "image";
  }

  function collectLoadedResources() {
    const seen = new Set();
    const items = [];
    const candidates = Array.from(document.querySelectorAll("img[src]"));

    for (const img of candidates) {
      const rawSrc = img.getAttribute("src") || "";
      const resourceUrl = normalizeUrl(rawSrc);
      if (!isStickerResourceUrl(resourceUrl)) continue;
      if (isInlineEmojiImage(img)) continue;

      const commentRoot = findCommentRoot(img);
      if (!commentRoot) continue;

      const key = `${location.href}::${resourceUrl}`;
      if (seen.has(key)) continue;
      seen.add(key);

      const authorLink =
        commentRoot.querySelector(".comment-item-info-wrap a") ||
        commentRoot.querySelector('a[href*="/user/"]');
      const timeNode = commentRoot.querySelector(".fJhvAqos") || commentRoot.querySelector("time");
      const contentWrap = commentRoot.querySelector(".C7LroK_h") || commentRoot;
      const textFlow = contentWrap.querySelector(".WFJiGxr7");
      const textContent = textOf(textFlow || contentWrap).replace(/\s+/g, " ").trim();

      items.push({
        id: key,
        resourceUrl,
        previewUrl: resourceUrl,
        author: textOf(authorLink) || "未知作者",
        timeText: textOf(timeNode) || "未知时间",
        commentText: textContent || "无可读文本",
        resourceKind: resourceKindFromUrl(resourceUrl),
        formatHint: formatLabelFromUrl(resourceUrl),
        originalMime: "",
        finalMime: "",
      });
    }

    return items;
  }

  // Legacy panel markup removed. Use ensurePanel() instead.

  function ensurePanel() {
    let panel = document.getElementById(PANEL_ID);
    if (panel) return panel;

    panel = document.createElement("aside");
    panel.id = PANEL_ID;
    panel.innerHTML = `
      <button type="button" class="dysp-launcher" data-action="toggle-panel" aria-expanded="true">
        <span class="dysp-launcher-face">贴纸</span>
        <span class="dysp-launcher-badge" data-role="launcher-badge"></span>
      </button>
      <section class="dysp-shell" data-role="shell">
        <div class="dysp-header" data-role="drag-handle">
          <div class="dysp-header-copy">
            <div class="dysp-title">Douyin Sticker Parser</div>
            <div class="dysp-subtitle">只扫描当前已加载评论，不自动滚动，不自动点击。</div>
          </div>
          <button type="button" class="dysp-icon-button" data-action="collapse-panel" aria-label="折叠面板">−</button>
        </div>
        <div class="dysp-actions">
          <button type="button" data-action="scan">Scan Loaded</button>
          <button type="button" class="dysp-primary" data-action="download-all" disabled>Download All</button>
        </div>
        <div class="dysp-status" data-role="status">等待手动扫描。</div>
        <div class="dysp-list" data-role="list">
          <div class="dysp-empty">还没有扫描结果。</div>
        </div>
      </section>
    `;

    const launcher = panel.querySelector(".dysp-launcher");
    const launcherFace = panel.querySelector(".dysp-launcher-face");
    const titleNode = panel.querySelector(".dysp-title");
    const subtitleNode = panel.querySelector(".dysp-subtitle");
    const collapseButton = panel.querySelector('[data-action="collapse-panel"]');
    const scanButton = panel.querySelector('[data-action="scan"]');
    const downloadAllButton = panel.querySelector('[data-action="download-all"]');
    const statusNode = panel.querySelector('[data-role="status"]');
    const emptyNode = panel.querySelector(".dysp-empty");

    if (launcher instanceof HTMLElement && !launcher.querySelector(".dysp-launcher-cat")) {
      const cat = document.createElement("img");
      cat.className = "dysp-launcher-cat";
      cat.src = LAUNCHER_CAT_DATA_URL;
      cat.alt = "";
      cat.setAttribute("aria-hidden", "true");
      launcher.insertBefore(cat, launcher.firstChild);
    }
    if (launcherFace) launcherFace.textContent = "摸摸";
    if (titleNode) titleNode.textContent = "抖音表情包助手";
    if (subtitleNode) subtitleNode.textContent = "只处理当前已加载评论，不自动滚动，不自动点击。";
    if (collapseButton) {
      collapseButton.textContent = "收起";
      collapseButton.setAttribute("aria-label", "折叠面板");
    }
    if (scanButton) {
      scanButton.textContent = "扫描已加载";
      scanButton.classList.add("dysp-utility-button");
    }
    if (downloadAllButton) downloadAllButton.textContent = "全部下载";
    if (statusNode) statusNode.textContent = "等待手动扫描。";
    if (emptyNode) emptyNode.textContent = "还没有扫描结果。";

    panel.addEventListener("click", handlePanelClick);
    document.body.appendChild(panel);
    bindPanelDrag(panel);
    applyPanelUiState();
    return panel;
  }

  function setPanelCollapsed(nextCollapsed) {
    STATE.ui.collapsed = !!nextCollapsed;
    applyPanelUiState();
  }

  function bindPanelDrag(panel) {
    if (panel.dataset.dragBound === "true") return;
    panel.dataset.dragBound = "true";

    const handle = panel.querySelector('[data-role="drag-handle"]');
    if (!(handle instanceof HTMLElement)) return;
    let lastPointerDownAt = 0;

    const updateDragPosition = (clientX, clientY) => {
      if (!STATE.ui.drag) return;
      STATE.ui.position = clampPanelPosition(
        {
          left: clientX - STATE.ui.drag.offsetX,
          top: clientY - STATE.ui.drag.offsetY,
        },
        { width: window.innerWidth, height: window.innerHeight },
        { width: STATE.ui.drag.width, height: STATE.ui.drag.height }
      );
      applyPanelUiState();
    };

    const clearDrag = () => {
      if (!STATE.ui.drag) return;
      if (STATE.ui.drag.mode === "pointer" && typeof STATE.ui.drag.pointerId === "number") {
        try {
          handle.releasePointerCapture?.(STATE.ui.drag.pointerId);
        } catch (_error) {
          // Ignore release failures when capture was never acquired.
        }
      }
      STATE.ui.drag = null;
      applyPanelUiState();
    };

    const beginDrag = (event, mode, pointerId = null) => {
      if (STATE.ui.collapsed) return false;
      if (typeof event.button === "number" && event.button !== 0) return false;
      if (event.target instanceof HTMLElement && event.target.closest("button")) return false;

      const rect = panel.getBoundingClientRect();
      STATE.ui.drag = {
        mode,
        pointerId,
        offsetX: event.clientX - rect.left,
        offsetY: event.clientY - rect.top,
        width: rect.width,
        height: rect.height,
      };

      if (mode === "pointer" && typeof pointerId === "number") {
        handle.setPointerCapture?.(pointerId);
      }

      applyPanelUiState();
      event.preventDefault();
      return true;
    };

    handle.addEventListener("pointerdown", (event) => {
      lastPointerDownAt = Date.now();
      beginDrag(event, "pointer", event.pointerId);
    });

    handle.addEventListener("mousedown", (event) => {
      if (Date.now() - lastPointerDownAt < 80) return;
      beginDrag(event, "mouse");
    });

    document.addEventListener("pointermove", (event) => {
      if (!STATE.ui.drag || STATE.ui.drag.mode !== "pointer") return;
      if (typeof STATE.ui.drag.pointerId === "number" && event.pointerId !== STATE.ui.drag.pointerId) return;
      updateDragPosition(event.clientX, event.clientY);
    });

    document.addEventListener("mousemove", (event) => {
      if (!STATE.ui.drag || STATE.ui.drag.mode !== "mouse") return;
      if (typeof event.buttons === "number" && (event.buttons & 1) !== 1) {
        clearDrag();
        return;
      }
      updateDragPosition(event.clientX, event.clientY);
    });

    document.addEventListener("pointerup", (event) => {
      if (!STATE.ui.drag || STATE.ui.drag.mode !== "pointer") return;
      if (typeof STATE.ui.drag.pointerId === "number" && event.pointerId !== STATE.ui.drag.pointerId) return;
      clearDrag();
    });
    document.addEventListener("pointercancel", clearDrag);
    document.addEventListener("mouseup", (event) => {
      if (!STATE.ui.drag || STATE.ui.drag.mode !== "mouse") return;
      if (typeof event.button === "number" && event.button !== 0) return;
      clearDrag();
    });
  }

  function applyPanelUiState() {
    const panel = ensurePanel();
    const launcher = panel.querySelector('[data-action="toggle-panel"]');
    const shell = panel.querySelector('[data-role="shell"]');
    const badge = panel.querySelector('[data-role="launcher-badge"]');
    const expanded = !STATE.ui.collapsed;

    panel.classList.toggle("is-collapsed", STATE.ui.collapsed);
    panel.classList.toggle("is-expanded", expanded);
    panel.classList.toggle("is-dragging", Boolean(STATE.ui.drag));
    panel.style.left = STATE.ui.position ? `${STATE.ui.position.left}px` : "";
    panel.style.top = STATE.ui.position ? `${STATE.ui.position.top}px` : "";
    panel.style.right = STATE.ui.position ? "auto" : "20px";
    panel.style.bottom = STATE.ui.position ? "auto" : "20px";

    if (launcher instanceof HTMLElement) {
      launcher.setAttribute("aria-expanded", String(expanded));
      launcher.setAttribute("aria-hidden", String(expanded));
    }
    if (shell instanceof HTMLElement) {
      shell.setAttribute("aria-hidden", String(STATE.ui.collapsed));
    }
    if (badge) badge.textContent = getCollapsedBadgeText(STATE.items.length);
  }

  function ensureModal() {
    let modal = document.getElementById(MODAL_ID);
    if (modal) return modal;

    modal = document.createElement("div");
    modal.id = MODAL_ID;
    modal.innerHTML = `
      <div class="dysp-modal-card">
        <div class="dysp-modal-preview" data-role="preview"></div>
        <div class="dysp-status" data-role="meta"></div>
        <div class="dysp-modal-actions">
          <button type="button" data-action="close-preview">取消</button>
          <button type="button" class="dysp-primary" data-action="confirm-download">确认下载</button>
        </div>
      </div>
    `;

    const closeButton = modal.querySelector('[data-action="close-preview"]');
    const confirmButton = modal.querySelector('[data-action="confirm-download"]');
    if (closeButton) closeButton.textContent = "关闭";
    if (confirmButton) confirmButton.remove();

    modal.addEventListener("click", (event) => {
      const target = event.target;
      if (!(target instanceof HTMLElement)) return;
      if (target.id === MODAL_ID) {
        closePreviewModal();
        return;
      }
      if (target.dataset.action === "close-preview") {
        closePreviewModal();
      }
    });

    document.body.appendChild(modal);
    return modal;
  }

  function setStatus(message) {
    const panel = ensurePanel();
    const node = panel.querySelector('[data-role="status"]');
    if (node) node.textContent = message;
  }

  function renderList() {
    const panel = ensurePanel();
    const list = panel.querySelector('[data-role="list"]');
    const downloadAllButton = panel.querySelector('[data-action="download-all"]');
    if (!list || !downloadAllButton) return;

    downloadAllButton.disabled = STATE.items.length === 0;
    if (STATE.items.length === 0) {
      const emptyState = document.createElement("div");
      emptyState.className = "dysp-empty";
      emptyState.textContent = "当前已加载评论里还没有找到贴纸资源。";
      list.innerHTML = "";
      list.appendChild(emptyState);
      return;
    }

    list.innerHTML = STATE.items
      .map((item, index) => {
        const title = sanitizeFilename(`${index + 1}-${item.author}`);
        const summary = sanitizeFilename(item.commentText).slice(0, 60);
        const formatTag = item.finalMime
          ? formatLabelFromMime(item.finalMime)
          : (item.originalMime ? formatLabelFromMime(item.originalMime) : item.formatHint);
        return `
          <div class="dysp-card">
            <button type="button" class="dysp-thumb dysp-thumb-button" data-action="open-preview" data-item-id="${escapeHtml(item.id)}">
              <img src="${escapeHtml(item.previewUrl)}" alt="${escapeHtml(title)}">
            </button>
            <div>
              <button type="button" class="dysp-card-title-button" data-action="open-preview" data-item-id="${escapeHtml(item.id)}">${escapeHtml(summary || title)}</button>
              <div class="dysp-tag">${escapeHtml(item.resourceKind.toUpperCase())} / ${escapeHtml(formatTag || "未知")}</div>
              <div class="dysp-meta">作者：${escapeHtml(item.author)}<br>时间：${escapeHtml(item.timeText)}</div>
              <button type="button" class="dysp-download-button" data-action="download-item" data-item-id="${escapeHtml(item.id)}">直接下载</button>
            </div>
          </div>
        `;
      })
      .join("");

    applyPanelUiState();
  }

  function escapeHtml(value) {
    return String(value || "")
      .replace(/&/g, "&amp;")
      .replace(/</g, "&lt;")
      .replace(/>/g, "&gt;")
      .replace(/"/g, "&quot;");
  }

  function scanLoaded() {
    STATE.pageUrl = location.href;
    STATE.pageTitle = document.title;
    STATE.items = collectLoadedResources();
    STATE.lastScanAt = new Date();

    renderList();
    setStatus(
      STATE.items.length > 0
        ? `扫描完成：识别到 ${STATE.items.length} 个已加载资源。`
        : "扫描完成：当前已加载评论中未发现贴纸资源。"
    );
  }

  function handlePanelClick(event) {
    const target = event.target;
    if (!(target instanceof HTMLElement)) return;
    const actionTarget = target.closest("[data-action]");
    if (!(actionTarget instanceof HTMLElement)) return;
    const action = actionTarget.dataset.action;

    if (action === "toggle-panel") {
      setPanelCollapsed(!STATE.ui.collapsed);
      return;
    }

    if (action === "collapse-panel") {
      setPanelCollapsed(true);
      return;
    }

    if (action === "scan") {
      scanLoaded();
      return;
    }

    if (action === "download-all") {
      void downloadAllItems();
      return;
    }

    if (action === "download-item") {
      const item = STATE.items.find((entry) => entry.id === actionTarget.dataset.itemId);
      if (item) void downloadSingleItem(item);
      return;
    }

    if (action === "open-preview" || action === "preview-item") {
      const item = STATE.items.find((entry) => entry.id === actionTarget.dataset.itemId);
      if (item) void openPreviewModal(item);
    }
  }

  async function openPreviewModal(item) {
    const modal = ensureModal();
    modal.setAttribute("data-item-id", item.id);
    const preview = modal.querySelector('[data-role="preview"]');
    const meta = modal.querySelector('[data-role="meta"]');
    if (preview) {
      preview.innerHTML = `<img src="${escapeHtml(item.previewUrl)}" alt="${escapeHtml(item.commentText || item.author)}">`;
    }
    if (meta) {
      meta.innerHTML = [
        `作者：${escapeHtml(item.author)}`,
        `时间：${escapeHtml(item.timeText)}`,
        `类型：${escapeHtml(item.resourceKind)}`,
        `估计格式：${escapeHtml(item.formatHint || "未知")}`,
        `说明：单项下载时，非 GIF 优先保存为 JPG。`,
      ].join("<br>");
    }
    modal.classList.add("is-open");

    if (meta && !item.originalMime) {
      const probe = await probeResourceMetadata(item.resourceUrl).catch(() => ({ contentType: "" }));
      if (probe.contentType) {
        item.originalMime = probe.contentType;
        renderList();
        meta.innerHTML = [
          `作者：${escapeHtml(item.author)}`,
          `时间：${escapeHtml(item.timeText)}`,
          `类型：${escapeHtml(item.resourceKind)}`,
          `真实格式：${escapeHtml(formatLabelFromMime(item.originalMime) || item.originalMime)}`,
          `最终保存：${escapeHtml(item.originalMime.includes("image/gif") ? "GIF 原样" : "JPG")}`,
        ].join("<br>");
      }
    }
  }

  function closePreviewModal() {
    const modal = ensureModal();
    modal.classList.remove("is-open");
    modal.removeAttribute("data-item-id");
  }

  function fileBaseName(item, index) {
    const author = sanitizeFilename(item.author).slice(0, 24);
    const hash = simpleHash(item.resourceUrl).slice(0, 6);
    return `${String(index + 1).padStart(3, "0")}-${author}-${hash}`;
  }

  function crc32(data) {
    let crc = 0xffffffff;
    for (let i = 0; i < data.length; i += 1) {
      crc = CRC32_TABLE[(crc ^ data[i]) & 0xff] ^ (crc >>> 8);
    }
    return (crc ^ 0xffffffff) >>> 0;
  }

  function dosDateTime(date) {
    const year = Math.max(1980, date.getFullYear());
    const month = date.getMonth() + 1;
    const day = date.getDate();
    const hours = date.getHours();
    const minutes = date.getMinutes();
    const seconds = Math.floor(date.getSeconds() / 2);
    const dosTime = (hours << 11) | (minutes << 5) | seconds;
    const dosDate = ((year - 1980) << 9) | (month << 5) | day;
    return { dosDate, dosTime };
  }

  function encodeUtf8(text) {
    return new TextEncoder().encode(text);
  }

  function writeUint16(view, offset, value) {
    view.setUint16(offset, value & 0xffff, true);
  }

  function writeUint32(view, offset, value) {
    view.setUint32(offset, value >>> 0, true);
  }

  function createStoredZip(files) {
    const now = new Date();
    const { dosDate, dosTime } = dosDateTime(now);
    const utf8Flag = 1 << 11;
    const localParts = [];
    const centralParts = [];
    let offset = 0;

    files.forEach((file) => {
      const nameBytes = encodeUtf8(file.name);
      const data = file.data instanceof Uint8Array ? file.data : new Uint8Array(file.data);
      const fileCrc32 = crc32(data);

      const localHeader = new Uint8Array(30 + nameBytes.length);
      const localView = new DataView(localHeader.buffer);
      writeUint32(localView, 0, 0x04034b50);
      writeUint16(localView, 4, 20);
      writeUint16(localView, 6, utf8Flag);
      writeUint16(localView, 8, 0);
      writeUint16(localView, 10, dosTime);
      writeUint16(localView, 12, dosDate);
      writeUint32(localView, 14, fileCrc32);
      writeUint32(localView, 18, data.length);
      writeUint32(localView, 22, data.length);
      writeUint16(localView, 26, nameBytes.length);
      writeUint16(localView, 28, 0);
      localHeader.set(nameBytes, 30);
      localParts.push(localHeader, data);

      const centralHeader = new Uint8Array(46 + nameBytes.length);
      const centralView = new DataView(centralHeader.buffer);
      writeUint32(centralView, 0, 0x02014b50);
      writeUint16(centralView, 4, 20);
      writeUint16(centralView, 6, 20);
      writeUint16(centralView, 8, utf8Flag);
      writeUint16(centralView, 10, 0);
      writeUint16(centralView, 12, dosTime);
      writeUint16(centralView, 14, dosDate);
      writeUint32(centralView, 16, fileCrc32);
      writeUint32(centralView, 20, data.length);
      writeUint32(centralView, 24, data.length);
      writeUint16(centralView, 28, nameBytes.length);
      writeUint16(centralView, 30, 0);
      writeUint16(centralView, 32, 0);
      writeUint16(centralView, 34, 0);
      writeUint16(centralView, 36, 0);
      writeUint32(centralView, 38, 0);
      writeUint32(centralView, 42, offset);
      centralHeader.set(nameBytes, 46);
      centralParts.push(centralHeader);

      offset += localHeader.length + data.length;
    });

    const centralSize = centralParts.reduce((sum, part) => sum + part.length, 0);
    const endRecord = new Uint8Array(22);
    const endView = new DataView(endRecord.buffer);
    writeUint32(endView, 0, 0x06054b50);
    writeUint16(endView, 4, 0);
    writeUint16(endView, 6, 0);
    writeUint16(endView, 8, files.length);
    writeUint16(endView, 10, files.length);
    writeUint32(endView, 12, centralSize);
    writeUint32(endView, 16, offset);
    writeUint16(endView, 20, 0);

    return new Blob([...localParts, ...centralParts, endRecord], {
      type: "application/zip",
    });
  }

  async function blobToUint8Array(blob) {
    return new Uint8Array(await blob.arrayBuffer());
  }

  function ensureBlobValue(value, contentType) {
    if (value instanceof Blob) {
      return value;
    }
    if (value instanceof ArrayBuffer) {
      return new Blob([value], { type: contentType || "application/octet-stream" });
    }
    if (ArrayBuffer.isView(value)) {
      return new Blob([value], { type: contentType || "application/octet-stream" });
    }
    if (typeof value === "string") {
      return new Blob([value], { type: contentType || "text/plain;charset=utf-8" });
    }
    if (value == null) {
      throw new Error("资源内容为空");
    }
    return new Blob([value], { type: contentType || "application/octet-stream" });
  }

  async function maybeConvertPayload(payload, options = {}) {
    const type = String(payload.contentType || "").toLowerCase();
    if (!type.startsWith("image/") || type.includes("image/gif")) {
      return payload;
    }

    const targetStaticMime =
      options.targetStaticMime ||
      (type.includes("image/webp") ? "image/png" : "");

    if (!targetStaticMime || targetStaticMime === type) {
      return payload;
    }

    try {
      const bitmap = await createImageBitmap(payload.blob);
      const canvas = document.createElement("canvas");
      canvas.width = bitmap.width;
      canvas.height = bitmap.height;
      const ctx = canvas.getContext("2d");
      if (!ctx) {
        bitmap.close();
        return payload;
      }
      ctx.drawImage(bitmap, 0, 0);
      bitmap.close();

      const pngBlob = await new Promise((resolve, reject) => {
        canvas.toBlob((blob) => {
          if (blob) {
            resolve(blob);
            return;
          }
          reject(new Error(`图片转码失败：${targetStaticMime}`));
        }, targetStaticMime, targetStaticMime === "image/jpeg" ? 0.92 : undefined);
      });

      return {
        ...payload,
        blob: pngBlob,
        contentType: targetStaticMime,
        convertedFrom: type,
      };
    } catch (_error) {
      return payload;
    }
  }

  async function fetchBinary(url) {
    const normalized = normalizeUrl(url);
    const gmXhr = getGmXmlHttpRequest();
    if (gmXhr) {
      return await new Promise((resolve, reject) => {
        gmXhr({
          method: "GET",
          url: normalized,
          responseType: "blob",
          timeout: 20000,
          onload: (response) => {
            if (response.status >= 200 && response.status < 300) {
              const contentType = parseContentTypeFromHeaders(response.responseHeaders);
              let blob;
              try {
                blob = ensureBlobValue(response.response, contentType);
              } catch (error) {
                reject(error instanceof Error ? error : new Error(String(error)));
                return;
              }

              resolve({
                blob,
                contentType,
              });
              return;
            }
            reject(new Error(`HTTP ${response.status}`));
          },
          onerror: () => reject(new Error("网络请求失败")),
          ontimeout: () => reject(new Error("请求超时")),
        });
      });
    }

    const controller = typeof AbortController !== "undefined" ? new AbortController() : null;
    const timer = controller ? setTimeout(() => controller.abort(), 20000) : null;
    try {
      const response = await fetch(normalized, {
        credentials: "omit",
        signal: controller ? controller.signal : undefined,
      });
      if (!response.ok) {
        throw new Error(`HTTP ${response.status}`);
      }
      const contentType = response.headers.get("content-type") || "";
      const blob = await response.blob();
      return { blob, contentType };
    } finally {
      if (timer) clearTimeout(timer);
    }
  }

  async function probeResourceMetadata(url) {
    const normalized = normalizeUrl(url);
    const gmXhr = getGmXmlHttpRequest();
    if (gmXhr) {
      try {
        return await new Promise((resolve, reject) => {
          gmXhr({
            method: "HEAD",
            url: normalized,
            timeout: 15000,
            onload: (response) => {
              if (response.status >= 200 && response.status < 400) {
                resolve({
                  contentType: parseContentTypeFromHeaders(response.responseHeaders),
                });
                return;
              }
              reject(new Error(`HTTP ${response.status}`));
            },
            onerror: () => reject(new Error("HEAD 请求失败")),
            ontimeout: () => reject(new Error("HEAD 请求超时")),
          });
        });
      } catch (_error) {
        // 继续走 fetch fallback
      }
    }

    const response = await fetch(normalized, {
      method: "HEAD",
      credentials: "omit",
    });
    if (!response.ok) {
      throw new Error(`HTTP ${response.status}`);
    }
    return {
      contentType: response.headers.get("content-type") || "",
    };
  }

  function triggerDownload(blob, filename) {
    const url = URL.createObjectURL(blob);
    const anchor = document.createElement("a");
    anchor.href = url;
    anchor.download = filename;
    anchor.rel = "noopener";
    document.body.appendChild(anchor);
    anchor.click();
    anchor.remove();
    setTimeout(() => URL.revokeObjectURL(url), 1500);
  }

  async function resolveDownloadPayload(item, index, options = {}) {
    const rawPayload = await fetchBinary(item.resourceUrl);
    const convertedPayload = await maybeConvertPayload(rawPayload, options);
    const { blob, contentType } = convertedPayload;
    const guessedExtension = convertedPayload.convertedFrom
      ? extensionFromContentType(contentType)
      : (inferExtensionFromUrl(item.resourceUrl) || extensionFromContentType(contentType));
    const filename = `${fileBaseName(item, index)}${guessedExtension}`;
    return {
      filename,
      blob,
      contentType,
      originalMime: rawPayload.contentType || "",
      finalMime: contentType || "",
      convertedFrom: convertedPayload.convertedFrom || "",
    };
  }

  async function downloadSingleItem(item) {
    setStatus(`准备下载：${item.author} / ${item.timeText}`);
    try {
      const index = STATE.items.findIndex((entry) => entry.id === item.id);
      const payload = await resolveDownloadPayload(item, Math.max(index, 0), {
        targetStaticMime: "image/jpeg",
      });
      const filename = payload.filename;
      item.originalMime = payload.originalMime;
      item.finalMime = payload.finalMime;

      triggerDownload(payload.blob, payload.filename);

      closePreviewModal();
      renderList();
      setStatus(`单项下载完成：${filename}`);
    } catch (error) {
      setStatus(`单项下载失败：${error instanceof Error ? error.message : String(error)}`);
    }
  }

  async function downloadAllItems() {
    if (!STATE.items.length) {
      setStatus("没有可打包的资源，请先扫描。");
      return;
    }

    setStatus(`开始打包 ${STATE.items.length} 个已加载资源...`);
    const failures = [];
    const manifestItems = [];
    const zipEntries = [];

    for (let index = 0; index < STATE.items.length; index += 1) {
      const item = STATE.items[index];
      try {
        const payload = await resolveDownloadPayload(item, index);
        const bytes = await blobToUint8Array(payload.blob);
        zipEntries.push({
          name: payload.filename,
          data: bytes,
        });
        manifestItems.push({
          ...item,
          filename: payload.filename,
          originalMime: payload.originalMime,
          finalMime: payload.finalMime,
        });
        setStatus(`打包中 ${index + 1}/${STATE.items.length}：${payload.filename}`);
      } catch (error) {
        failures.push({
          resourceUrl: item.resourceUrl,
          reason: error instanceof Error ? error.message : String(error),
        });
      }
    }

    const readmeText = buildReadmeText({
      pageTitle: STATE.pageTitle,
      pageUrl: STATE.pageUrl,
      generatedAt: new Date().toISOString(),
      items: manifestItems,
      failures,
    });

    zipEntries.push({
      name: "README.txt",
      data: encodeUtf8(readmeText),
    });

    const archiveBlob = createStoredZip(zipEntries);
    const archiveName = `${sanitizeFilename(document.title).slice(0, 48) || "douyin-stickers"}-${new Date()
      .toISOString()
      .replace(/[:.]/g, "-")}.zip`;
    triggerDownload(archiveBlob, archiveName);

    if (failures.length > 0) {
      setStatus(`整包下载完成，但有 ${failures.length} 个资源失败，详情见 README.txt。`);
      return;
    }

    setStatus(`整包下载完成：${archiveName}`);
  }

  function init() {
    if (!document.body) return;
    createStyles();
    ensurePanel();
    ensureModal();
  }

  const exported = {
    isStickerResourceUrl,
    isInlineEmojiImage,
    sanitizeFilename,
    simpleHash,
    formatLabelFromMime,
    formatLabelFromUrl,
    extensionFromContentType,
    parseContentTypeFromHeaders,
    clampPanelPosition,
    getCollapsedBadgeText,
    ensureBlobValue,
    createStoredZip,
    buildReadmeText,
  };

  if (typeof module !== "undefined" && module.exports) {
    module.exports = exported;
  }

  if (typeof window !== "undefined" && typeof document !== "undefined") {
    if (document.readyState === "loading") {
      document.addEventListener("DOMContentLoaded", init, { once: true });
    } else {
      init();
    }
    window.__DOUYIN_STICKER_PARSER__ = exported;
  }
})();