feat(wip): serviceworker

* 用于缓存等

client/index.ts

@@ -25,3 +25,14 @@ const onResize = () => {
 // deno-lint-ignore no-window no-window-prefix
 window.addEventListener('resize', onResize)
 onResize()
+
+// @ts-ignore 工作正常, 这里是获取为 URL 以便于构建
+import sw from './sw.ts?worker&url'
+
+if ("serviceWorker" in navigator)
+    try {
+        navigator.serviceWorker
+            .register(sw as URL)
+    } catch (e) {
+        console.error(e)
+    }

client/sw.ts

@@ -0,0 +1,30 @@
+interface FetchEvent extends Event {
+    waitUntil: (p: Promise<unknown | void>) => void
+    request: Request
+    respondWith: (r: Response | Promise<Response>) => void
+}
+
+// 上传文件的代理与缓存
+self.addEventListener("fetch", (e) => {
+    const event = e as FetchEvent
+    if (event.request.method != "GET" || event.request.url.indexOf("/uploaded_files/") == -1) return
+
+    event.respondWith(
+        (async () => {
+            const cache = await caches.open("LingChair-UploadedFile-Cache")
+            const cachedResponse = await cache.match(event.request)
+            if (cachedResponse) {
+                event.waitUntil(cache.add(event.request))
+                return cachedResponse
+            }
+            return fetch({
+                ...event.request,
+                headers: {
+                    ...event.request.headers,
+                    // 目前还不能获取 token
+                    // localsotrage 在这里不可用
+                }
+            })
+        })()
+    )
+})