fix: refactor database client initialization and improve error handling

Author: spences10

.gitignore

@@ -22,4 +22,6 @@ Thumbs.db
 # Vite
 vite.config.js.timestamp-*
 vite.config.ts.timestamp-*
-replica.db*
+# Database files
+local-dev-replica.db*
+local-dev-replica.db-*

src/lib/server/client.ts

@@ -1,24 +1,36 @@
+import { dev } from '$app/environment';
 import { env } from '$env/dynamic/private';
 import { createClient, type Client } from '@libsql/client';
 
-const { TURSO_DB_URL, TURSO_DB_AUTH_TOKEN, TURSO_SYNC_URL } = env;
+const { TURSO_DB_URL, TURSO_DB_AUTH_TOKEN } = env;
+
+const LOCAL_DB_PATH = dev
+	? './local-dev-replica.db'
+	: '/app/data/turso-replica.db';
+
+let client_instance: Client | null = null;
 
 export const turso_client = (): Client => {
-	const url = TURSO_DB_URL?.trim();
-	if (url === undefined) {
+	if (client_instance) {
+		return client_instance;
+	}
+
+	const remote_url = TURSO_DB_URL?.trim();
+	if (remote_url === undefined) {
 		throw new Error('TURSO_DB_URL is not defined');
 	}
 
 	const auth_token = TURSO_DB_AUTH_TOKEN?.trim();
 	if (auth_token === undefined) {
-		if (!url.includes('file:')) {
-			throw new Error('TURSO_DB_AUTH_TOKEN is not defined');
-		}
+		throw new Error('TURSO_DB_AUTH_TOKEN is not defined');
 	}
 
-	return createClient({
-		url: TURSO_DB_URL as string,
-		syncUrl: TURSO_SYNC_URL as string,
-		authToken: TURSO_DB_AUTH_TOKEN as string,
+	client_instance = createClient({
+		url: `file:${LOCAL_DB_PATH}`,
+		syncUrl: remote_url,
+		authToken: auth_token,
+		syncInterval: dev ? 60 : 300,
 	});
+
+	return client_instance;
 };