fix: 图片预览错误返回可读 503 + feat: PWA 支持(manifest/sw/图标)

app/plugins/pwa.client.ts

@@ -0,0 +1,5 @@
+export default defineNuxtPlugin(() => {
+  if (typeof navigator !== 'undefined' && 'serviceWorker' in navigator) {
+    navigator.serviceWorker.register('/sw.js').catch(() => {})
+  }
+})

nuxt.config.ts

@@ -8,7 +8,15 @@ export default defineNuxtConfig({
       title: 'BT 种子预览台',
       meta: [
         { name: 'viewport', content: 'width=device-width, initial-scale=1' },
-        { name: 'description', content: '搜索 / 解析 / 预览 BT 种子内容，并投递到本机下载工具' }
+        { name: 'description', content: '搜索 / 解析 / 预览 BT 种子内容，并投递到本机下载工具' },
+        { name: 'theme-color', content: '#0f0f11' },
+        { name: 'apple-mobile-web-app-capable', content: 'yes' },
+        { name: 'apple-mobile-web-app-status-bar-style', content: 'black-translucent' },
+        { name: 'apple-mobile-web-app-title', content: 'BT 预览台' }
+      ],
+      link: [
+        { rel: 'manifest', href: '/manifest.json' },
+        { rel: 'apple-touch-icon', href: '/icon.svg', sizes: 'any' }
       ]
     }
   },

public/icon.svg

@@ -0,0 +1,4 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512">
+  <rect width="512" height="512" rx="96" fill="#0f0f11"/>
+  <text x="256" y="330" font-family="system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif" font-size="220" font-weight="700" text-anchor="middle" fill="#00d9a3">BT</text>
+</svg>

public/manifest.json

@@ -0,0 +1,19 @@
+{
+  "name": "BT 种子预览台",
+  "short_name": "BT 预览台",
+  "description": "搜索 / 解析 / 预览 BT 种子内容，并投递到本机下载工具",
+  "start_url": "/",
+  "scope": "/",
+  "display": "standalone",
+  "orientation": "portrait-primary",
+  "background_color": "#0f0f11",
+  "theme_color": "#0f0f11",
+  "icons": [
+    {
+      "src": "/icon.svg",
+      "sizes": "any",
+      "type": "image/svg+xml",
+      "purpose": "any maskable"
+    }
+  ]
+}

public/sw.js

@@ -0,0 +1,33 @@
+const CACHE_NAME = 'bt-preview-v1'
+const SHELL = ['/', '/gate', '/settings', '/manifest.json', '/icon.svg']
+
+self.addEventListener('install', (event) => {
+  event.waitUntil(
+    caches.open(CACHE_NAME).then((cache) => cache.addAll(SHELL)).then(() => self.skipWaiting())
+  )
+})
+
+self.addEventListener('activate', (event) => {
+  event.waitUntil(self.clients.claim())
+})
+
+self.addEventListener('fetch', (event) => {
+  const { request } = event
+  const url = new URL(request.url)
+
+  // API、图片预览、下载等动态请求走网络，不做缓存
+  if (url.pathname.startsWith('/api/')) return
+
+  event.respondWith(
+    caches.match(request).then((cached) => {
+      if (cached) return cached
+      return fetch(request).then((res) => {
+        if (request.method === 'GET' && res.status === 200 && res.type === 'basic') {
+          const clone = res.clone()
+          caches.open(CACHE_NAME).then((cache) => cache.put(request, clone)).catch(() => {})
+        }
+        return res
+      })
+    })
+  )
+})

server/api/torrent/[infohash]/preview.get.ts

@@ -47,37 +47,45 @@ export default defineEventHandler(async (event) => {
   }
 
   const settings = await loadSettings()
-  const bytes = await withSwarm(infoHash, magnet, settings.metadataTimeout, async (torrent) => {
-    const target = (torrent.files || []).find(
-      (f: any) => normPath(String(f.path || f.name || '')) === normPath(filePath)
-    )
-    if (!target) {
-      throw createError({ statusCode: 404, statusMessage: '这个种子里没有该文件，文件清单可能已过期' })
-    }
-    if (target.length > MAX_PREVIEW_BYTES) {
-      throw createError({
-        statusCode: 413,
-        statusMessage: `这张图 ${Math.round(target.length / 1024 / 1024)} MB，超过在线预览上限 ${MAX_PREVIEW_BYTES / 1024 / 1024} MB`
-      })
-    }
-    return Promise.race<ArrayBuffer>([
-      target.arrayBuffer(),
-      new Promise<never>((_, reject) => {
-        setTimeout(
-          () => reject(new Error('下载图片超时：暂时没有可用的做种节点，稍后再试')),
-          DOWNLOAD_TIMEOUT_MS
-        )
-      })
-    ])
-  })
+  try {
+    const bytes = await withSwarm(infoHash, magnet, settings.metadataTimeout, async (torrent) => {
+      const target = (torrent.files || []).find(
+        (f: any) => normPath(String(f.path || f.name || '')) === normPath(filePath)
+      )
+      if (!target) {
+        throw createError({ statusCode: 404, statusMessage: '这个种子里没有该文件，文件清单可能已过期' })
+      }
+      if (target.length > MAX_PREVIEW_BYTES) {
+        throw createError({
+          statusCode: 413,
+          statusMessage: `这张图 ${Math.round(target.length / 1024 / 1024)} MB，超过在线预览上限 ${MAX_PREVIEW_BYTES / 1024 / 1024} MB`
+        })
+      }
+      return Promise.race<ArrayBuffer>([
+        target.arrayBuffer(),
+        new Promise<never>((_, reject) => {
+          setTimeout(
+            () => reject(new Error('下载图片超时：暂时没有可用的做种节点，稍后再试')),
+            DOWNLOAD_TIMEOUT_MS
+          )
+        })
+      ])
+    })
 
-  setHeader(event, 'content-type', mime)
-  setHeader(event, 'content-length', String(bytes.byteLength))
-  setHeader(
-    event,
-    'content-disposition',
-    `inline; filename="${encodeURIComponent(filePath.slice(filePath.lastIndexOf('/') + 1))}"`
-  )
-  setHeader(event, 'cache-control', 'private, max-age=3600')
-  return Buffer.from(bytes)
+    setHeader(event, 'content-type', mime)
+    setHeader(event, 'content-length', String(bytes.byteLength))
+    setHeader(
+      event,
+      'content-disposition',
+      `inline; filename="${encodeURIComponent(filePath.slice(filePath.lastIndexOf('/') + 1))}"`
+    )
+    setHeader(event, 'cache-control', 'private, max-age=3600')
+    return Buffer.from(bytes)
+  } catch (err) {
+    // 把 withSwarm 抛出的原始错误（如 webtorrent 无法加载）转成可读的 HTTP 错误，
+    // 避免前端看到 Nitro 的通用 Server Error 页面。
+    if (err && typeof err === 'object' && 'statusCode' in err) throw err
+    const message = err instanceof Error ? err.message : '从做种节点获取图片失败'
+    throw createError({ statusCode: 503, statusMessage: message })
+  }
 })