refactor!: serve the static frontend trough the backend (#520)

Co-authored-by: Alessandro (Ale) Segala <43508+ItalyPaleAle@users.noreply.github.com>

frontend/src/lib/services/version-service.ts

@@ -0,0 +1,109 @@
+import { version as currentVersion } from '$app/environment';
+import axios from 'axios';
+
+const VERSION_CACHE_KEY = 'version_cache';
+const CACHE_DURATION = 2 * 60 * 60 * 1000; // 2 hours
+
+async function getNewestVersion() {
+	const cachedData = await getVersionFromCache();
+
+	// If we have valid cached data, return it
+	if (cachedData) {
+		return cachedData;
+	}
+
+	// Otherwise fetch from API
+	try {
+		const response = await axios
+			.get('https://api.github.com/repos/pocket-id/pocket-id/releases/latest', {
+				timeout: 2000
+			})
+			.then((res) => res.data);
+		console.log('Fetched newest version:', response);
+		const newestVersion = response.tag_name.replace('v', '');
+
+		// Cache the result
+		cacheVersion(newestVersion);
+
+		return newestVersion;
+	} catch (error) {
+		console.error('Failed to fetch newest version:', error);
+		// If fetch fails but we have an expired cache, return that as fallback
+		const cache = getCacheObject();
+		return cache?.newestVersion || currentVersion;
+	}
+}
+
+function getCurrentVersion() {
+	return currentVersion;
+}
+
+async function isUpToDate() {
+	const newestVersion = await getNewestVersion();
+	const currentVersion = getCurrentVersion();
+
+	// If the current version changed, invalidate the cache
+	const cache = getCacheObject();
+	if (cache?.lastCurrentVersion && currentVersion !== cache.lastCurrentVersion) {
+		invalidateCache();
+	}
+
+	return newestVersion === currentVersion;
+}
+
+// Helper methods for caching
+function getCacheObject() {
+	const cacheJson = localStorage.getItem(VERSION_CACHE_KEY);
+	if (!cacheJson) return null;
+
+	try {
+		return JSON.parse(cacheJson);
+	} catch (e) {
+		console.error('Failed to parse cache:', e);
+		return null;
+	}
+}
+
+async function getVersionFromCache() {
+	const cache = getCacheObject();
+
+	if (!cache || !cache.newestVersion || !cache.timestamp) {
+		return null;
+	}
+
+	const now = Date.now();
+
+	// Check if cache is still valid
+	if (now - cache.timestamp > CACHE_DURATION) {
+		invalidateCache();
+		return null;
+	}
+
+	// Check if current version matches what it was when we cached
+	if (cache.lastCurrentVersion && cache.lastCurrentVersion !== currentVersion) {
+		invalidateCache();
+		return null;
+	}
+
+	return cache.newestVersion;
+}
+
+async function cacheVersion(version :string) {
+	const cacheObject = {
+		newestVersion: version,
+		timestamp: Date.now(),
+		lastCurrentVersion: currentVersion
+	};
+
+	localStorage.setItem(VERSION_CACHE_KEY, JSON.stringify(cacheObject));
+}
+
+async function invalidateCache() {
+	localStorage.removeItem(VERSION_CACHE_KEY);
+}
+
+export default {
+	getNewestVersion,
+	getCurrentVersion,
+	isUpToDate
+};