From 0c8779abc5dcb7a4c898cf00061a832812d68028 Mon Sep 17 00:00:00 2001
From: 0d0 <0d0acre@esiliati.org>
Date: Fri, 7 Feb 2025 02:22:45 +0100
Subject: [PATCH] Add service worker

---
 src/app.html          |  1 +
 src/service-worker.js | 79 +++++++++++++++++++++++++++++++++++++++++++
 static/manifest.json  |  9 +++++
 3 files changed, 89 insertions(+)
 create mode 100644 src/service-worker.js
 create mode 100644 static/manifest.json
diff --git a/src/app.html b/src/app.html
index 5e73032..4bb3fa3 100644
--- a/src/app.html
+++ b/src/app.html
@@ -3,6 +3,7 @@
 	<head>
 		<meta charset="utf-8" />
 		<link rel="icon" href="%sveltekit.assets%/favicon.png" />
+		<link rel="manifest" href="manifest.json">
 		<meta name="viewport" content="width=device-width, initial-scale=1" />
 		%sveltekit.head%
 		<style>
diff --git a/src/service-worker.js b/src/service-worker.js
new file mode 100644
index 0000000..e425db3
--- /dev/null
+++ b/src/service-worker.js
@@ -0,0 +1,79 @@
+import { build, files, version } from '$service-worker';
+
+// Create a unique cache name for this deployment
+const CACHE = `cache-${version}`;
+
+const ASSETS = [
+	...build, // the app itself
+	...files  // everything in `static`
+];
+
+self.addEventListener('install', (event) => {
+	// Create a new cache and add all files to it
+	async function addFilesToCache() {
+		const cache = await caches.open(CACHE);
+		await cache.addAll(ASSETS);
+	}
+
+	event.waitUntil(addFilesToCache());
+});
+
+self.addEventListener('activate', (event) => {
+	// Remove previous cached data from disk
+	async function deleteOldCaches() {
+		for (const key of await caches.keys()) {
+			if (key !== CACHE) await caches.delete(key);
+		}
+	}
+
+	event.waitUntil(deleteOldCaches());
+});
+
+self.addEventListener('fetch', (event) => {
+	// ignore POST requests etc
+	if (event.request.method !== 'GET' || event.request.pathname === 'download') return;
+
+	async function respond() {
+		const url = new URL(event.request.url);
+		const cache = await caches.open(CACHE);
+
+		// `build`/`files` can always be served from the cache
+		if (ASSETS.includes(url.pathname)) {
+			const response = await cache.match(url.pathname);
+
+			if (response) {
+				return response;
+			}
+		}
+
+		// for everything else, try the network first, but
+		// fall back to the cache if we're offline
+		try {
+			const response = await fetch(event.request);
+
+			// if we're offline, fetch can return a value that is not a Response
+			// instead of throwing - and we can't pass this non-Response to respondWith
+			if (!(response instanceof Response)) {
+				throw new Error('invalid response from fetch');
+			}
+
+			if (response.status === 200) {
+				cache.put(event.request, response.clone());
+			}
+
+			return response;
+		} catch (err) {
+			const response = await cache.match(event.request);
+
+			if (response) {
+				return response;
+			}
+
+			// if there's no cache, then just error out
+			// as there is nothing we can do to respond to this request
+			throw err;
+		}
+	}
+
+	event.respondWith(respond());
+});
diff --git a/static/manifest.json b/static/manifest.json
new file mode 100644
index 0000000..46b4f0e
--- /dev/null
+++ b/static/manifest.json
@@ -0,0 +1,9 @@
+{
+    "name": "EmersaDownloader",
+    "start_url": "https://dl.emersa.it",
+    "theme_color": "rgb(34,197,94)",
+    "background": "black",
+    "orientation": "portrait",
+    "display": "fullscreen",
+    "short_name": "e-downloader"
+}
\ No newline at end of file
