every.channel: sanitized baseline

apps/tauri/ui/sw.js

@@ -0,0 +1,103 @@
+/* every.channel PWA service worker
+ *
+ * Goal: cache the app shell so it can be installed and load offline.
+ * Do not interfere with media fetching/streaming: always network-pass-through
+ * for non-GET requests and for large binary media responses.
+ */
+
+const CACHE_NAME = "every.channel-shell-v1";
+const SHELL = [
+  "./",
+  "./index.html",
+  "./style.css",
+  "./manifest.webmanifest",
+  "./icons/icon-192.png",
+  "./icons/icon-512.png",
+  "./icons/apple-touch-icon.png",
+];
+
+self.addEventListener("install", (event) => {
+  event.waitUntil(
+    caches
+      .open(CACHE_NAME)
+      .then((cache) => cache.addAll(SHELL))
+      .then(() => self.skipWaiting())
+  );
+});
+
+self.addEventListener("activate", (event) => {
+  event.waitUntil(
+    caches
+      .keys()
+      .then((keys) =>
+        Promise.all(
+          keys.map((key) => {
+            if (key !== CACHE_NAME) return caches.delete(key);
+            return Promise.resolve();
+          })
+        )
+      )
+      .then(() => self.clients.claim())
+  );
+});
+
+function isNavigationRequest(request) {
+  return request.mode === "navigate";
+}
+
+function isMediaRequest(request) {
+  const url = new URL(request.url);
+  const path = url.pathname.toLowerCase();
+  return (
+    path.endsWith(".m3u8") ||
+    path.endsWith(".m4s") ||
+    path.endsWith(".mp4") ||
+    path.endsWith(".ts")
+  );
+}
+
+self.addEventListener("fetch", (event) => {
+  const { request } = event;
+  if (request.method !== "GET") return;
+
+  // Don't cache/modify streaming media requests.
+  if (isMediaRequest(request)) {
+    event.respondWith(fetch(request));
+    return;
+  }
+
+  // For navigations, prefer network but fall back to cached shell.
+  if (isNavigationRequest(request)) {
+    event.respondWith(
+      fetch(request).catch(() => caches.match("./index.html").then((r) => r || Response.error()))
+    );
+    return;
+  }
+
+  // Cache-first for same-origin static assets; network fallback.
+  const url = new URL(request.url);
+  if (url.origin === self.location.origin) {
+    event.respondWith(
+      caches.match(request).then((cached) => {
+        if (cached) return cached;
+        return fetch(request)
+          .then((resp) => {
+            // Avoid caching huge binary responses.
+            const len = resp.headers.get("content-length");
+            const tooBig = len && Number(len) > 5_000_000;
+            if (resp.ok && !tooBig) {
+              const clone = resp.clone();
+              caches.open(CACHE_NAME).then((cache) => cache.put(request, clone)).catch(() => {});
+            }
+            return resp;
+          })
+          .catch(() => cached || Response.error());
+      })
+    );
+    return;
+  }
+
+  // Default: network.
+  event.respondWith(fetch(request));
+});
+