Emby 封面查看&下载助手：在详情页与操作菜单添加查看/下载封面按钮，自动识别语言，性能优化、防重复注入。
// ==UserScript==
// @name Emby Cover Art Helper
// @namespace https://github.com/kumu-ze/Emby-Cover-Art-Helper
// @version 1.0.1
// @description Emby 封面查看&下载助手：在详情页与操作菜单添加查看/下载封面按钮，自动识别语言，性能优化、防重复注入。
// @description:en View & download Emby cover images on detail pages and action sheet; i18n + perf optimized.
// @author kumuze (orig idea & maintenance); contributors: Gemini, GitHub Copilot
// @license MIT
// @icon https://github.githubassets.com/pinned-octocat.svg
// @match *://*/web/index.html*
// @run-at document-idle
// @grant GM_addStyle
// @grant GM_xmlhttpRequest
// @grant GM_download
// ==/UserScript==
(function () {
'use strict';
/********************** 环境探测与兼容层 ************************/
const HAS_GM_ADDSTYLE = typeof GM_addStyle === 'function';
const HAS_GM_XHR = typeof GM_xmlhttpRequest === 'function';
const HAS_GM_DOWNLOAD = typeof GM_download === 'function';
function injectStyleFallback(css) {
if (document.getElementById('cover-helper-style')) return;
const style = document.createElement('style');
style.id = 'cover-helper-style';
style.textContent = css;
document.head.appendChild(style);
}
/********************** 样式 ************************/
const STYLE_BLOCK = `
.detailButton.custom-cover-btn {
background-color: #525252;
color: #fff;
margin-left: 10px;
transition: background-color .2s;
}
.detailButton.custom-cover-btn:hover { background-color: #626262 !important; }
.custom-cover-inline-icon { vertical-align: middle; }
/* ActionSheet 自定义按钮（跟随原主题即可，主要保证结构一致） */
.actionSheetMenuItem.custom-cover-btn-injected .listItemBodyText { font-weight: 500; }
`;
if (HAS_GM_ADDSTYLE) {
GM_addStyle(STYLE_BLOCK);
} else {
injectStyleFallback(STYLE_BLOCK);
}
/********************** 配置 / 可调参数 ************************/
const CONFIG = {
debounceMs: 120, // MutationObserver 去抖间隔
enableActionSheet: true, // 是否在操作菜单中注入
enableDetailButtons: true, // 是否在详情页注入
preferGMDownload: true, // 如果 GM_download 可用则优先使用
openInNewTab: true // 点击“查看封面”是否新标签打开
};
/********************** 国际化 ************************/
const LANG = (navigator.language || '').toLowerCase();
const isZH = LANG.startsWith('zh');
const I18N = {
view: isZH ? '查看封面' : 'View Cover',
download: isZH ? '下载封面' : 'Download Cover',
downloading: isZH ? '下载中...' : 'Downloading...',
failed: isZH ? '下载图片失败，请检查控制台。' : 'Failed to download cover. Check console.'
};
/********************** 工具函数 ************************/
function log(...args) { console.debug('[CoverHelper]', ...args); }
function safeFileName(name, fallback = 'poster') {
const base = (name || fallback).trim().replace(/[\\/:"*?<>|]/g, '-');
return base || fallback;
}
function guessExtensionFromHeaders(headers) {
if (!headers) return 'jpg';
const match = headers.match(/content-type:\s*([^;\n]+)/i);
if (match && match[1]) {
const subtype = match[1].split('/')[1];
if (subtype) {
if (/jpeg/i.test(subtype)) return 'jpg';
return subtype.split('+')[0];
}
}
return 'jpg';
}
function extractHighRes(url) {
if (!url) return null;
// Emby/Jellyfin 通常参数控制尺寸，去掉查询可获取原图；某些情况可以替换 quality 指示符，这里保持简单
return url.split('?')[0];
}
function currentDetailImage() {
return document.querySelector('.detailImageContainer-main img.cardImage, .detail-main-items-container-inner img.cardImage');
}
function currentTitle() {
const h1 = document.querySelector('h1.itemName-primary');
if (h1 && h1.textContent) return h1.textContent.trim();
return undefined;
}
/********************** 下载逻辑（多环境） ************************/
function downloadImage(url, titleHint) {
if (!url) return;
const baseName = safeFileName(titleHint || currentTitle());
// 1. 优先 GM_download
if (CONFIG.preferGMDownload && HAS_GM_DOWNLOAD) {
try {
GM_download({ url, name: baseName + '.jpg', saveAs: true, ontimeout: () => log('GM_download timeout') });
return;
} catch (e) { log('GM_download error -> fallback', e); }
}
// 2. GM_xmlhttpRequest 分支
if (HAS_GM_XHR) {
GM_xmlhttpRequest({
method: 'GET',
url,
responseType: 'blob',
onload: (res) => genericDownloadHandler(res.response, guessExtensionFromHeaders(res.responseHeaders || ''), baseName),
onerror: (e) => { console.error('Download error', e); alert(I18N.failed); }
});
return;
}
// 3. 纯浏览器 fetch 回退
fetch(url, { credentials: 'include' })
.then(res => {
if (!res.ok) throw new Error(res.status + ' ' + res.statusText);
const ct = res.headers.get('content-type') || '';
const ext = guessExtensionFromHeaders('content-type: ' + ct);
return res.blob().then(blob => genericDownloadHandler(blob, ext, baseName));
})
.catch(err => { console.error('Fetch download failed', err); alert(I18N.failed); });
}
function genericDownloadHandler(blob, extension, baseName) {
try {
const a = document.createElement('a');
a.href = URL.createObjectURL(blob);
a.download = baseName + '.' + (extension || 'jpg').replace(/[^a-z0-9]/gi, '');
document.body.appendChild(a);
a.click();
document.body.removeChild(a);
setTimeout(() => URL.revokeObjectURL(a.href), 8000);
} catch (err) {
console.error(err);
alert(I18N.failed);
}
}
/********************** 按钮生成 ************************/
function createDetailButton(id, iconName, text) {
const btn = document.createElement('button');
btn.id = id;
btn.setAttribute('is', 'emby-button');
btn.type = 'button';
btn.className = 'detailButton emby-button button-hoverable raised custom-cover-btn';
btn.innerHTML = `<i class="md-icon button-icon button-icon-left custom-cover-inline-icon">${iconName}</i><span>${text}</span>`;
return btn;
}
function createActionSheetButton(id, iconName, text) {
const btn = document.createElement('button');
btn.id = id;
btn.className = 'listItem listItem-autoactive itemAction listItemCursor listItem-hoverable actionSheetMenuItem actionSheetMenuItem-iconright custom-cover-btn-injected';
btn.type = 'button';
btn.innerHTML = `
<div class="listItem-content listItem-content-bg listItemContent-touchzoom listItem-border actionsheet-noborderconditional">
<div class="actionSheetItemImageContainer actionSheetItemImageContainer-customsize actionSheetItemImageContainer-transparent listItemImageContainer listItemImageContainer-margin listItemImageContainer-square defaultCardBackground" style="aspect-ratio:1">
<i class="actionsheetMenuItemIcon listItemIcon listItemIcon-transparent md-icon listItemIcon autortl">${iconName}</i>
</div>
<div class="actionsheetListItemBody actionsheetListItemBody-iconright listItemBody listItemBody-1-lines">
<div class="listItemBodyText actionSheetItemText listItemBodyText-nowrap listItemBodyText-lf">${text}</div>
</div>
</div>`;
return btn;
}
/********************** 注入逻辑：详情页 ************************/
function injectDetailButtons() {
if (! CONFIG.enableDetailButtons) return;
const container = document.querySelector('.detailButtons.mainDetailButtons');
if (!container) return; // 未到详情页
// 避免重复
if (container.dataset.coverHelperInjected === '1') return;
const img = currentDetailImage();
if (!img || !img.src) return;
const highRes = extractHighRes(img.src);
if (!highRes) return;
const viewBtn = createDetailButton('cover-helper-view-btn', 'photo_library', I18N.view);
viewBtn.addEventListener('click', () => {
if (CONFIG.openInNewTab) window.open(highRes, '_blank');
else window.location.href = highRes;
});
const downloadBtn = createDetailButton('cover-helper-download-btn', 'file_download', I18N.download);
downloadBtn.addEventListener('click', () => downloadImage(highRes));
container.appendChild(viewBtn);
container.appendChild(downloadBtn);
container.dataset.coverHelperInjected = '1';
log('Detail buttons injected');
}
/********************** 注入逻辑：Action Sheet ************************/
function injectActionSheetButtons() {
if (! CONFIG.enableActionSheet) return;
const sheet = document.querySelector('div.actionSheet.opened');
if (!sheet) return;
if (sheet.dataset.coverHelperInjected === '1') return;
const list = sheet.querySelector('.actionsheetScrollSlider');
const bgDiv = sheet.querySelector('.actionsheetItemPreviewImage-bg');
if (!list || !bgDiv || !bgDiv.style.backgroundImage) return;
const raw = bgDiv.style.backgroundImage;
const url = extractHighRes(raw.slice(5, -2)); // strip url("...")
if (!url) return;
let titleHint = 'poster';
const titleNode = sheet.querySelector('.actionsheetItemPreviewText-main .actionsheetPreviewTextItem');
if (titleNode && titleNode.textContent) titleHint = titleNode.textContent.trim();
const viewBtn = createActionSheetButton('cover-helper-actionsheet-view-btn', 'photo_library', I18N.view);
viewBtn.addEventListener('click', (e) => { e.stopPropagation(); window.open(url, '_blank'); });
const downloadBtn = createActionSheetButton('cover-helper-actionsheet-download-btn', 'file_download', I18N.download);
downloadBtn.addEventListener('click', (e) => { e.stopPropagation(); downloadImage(url, titleHint); });
list.prepend(downloadBtn);
list.prepend(viewBtn);
sheet.dataset.coverHelperInjected = '1';
log('ActionSheet buttons injected');
}
/********************** MutationObserver + 去抖 ************************/
let debounceTimer = null;
const observer = new MutationObserver(() => {
if (debounceTimer) clearTimeout(debounceTimer);
debounceTimer = setTimeout(() => {
try {
injectDetailButtons();
injectActionSheetButtons();
} catch (err) { console.error('[CoverHelper] inject error', err); }
}, CONFIG.debounceMs);
});
observer.observe(document.documentElement || document.body, { childList: true, subtree: true });
// 初始尝试
injectDetailButtons();
injectActionSheetButtons();
log('Emby Cover Art Helper loaded.');
})();