chore(#4): Add a database connection to mongodb

src/app.d.ts

@@ -1,13 +1,13 @@
 // See https://kit.svelte.dev/docs/types#app
 // for information about these interfaces
 declare global {
-	namespace App {
-		// interface Error {}
-		// interface Locals {}
-		// interface PageData {}
-		// interface PageState {}
-		// interface Platform {}
-	}
+  namespace App {
+    // interface Error {}
+    // interface Locals {}
+    // interface PageData {}
+    // interface PageState {}
+    // interface Platform {}
+  }
 }
 
 export {};

src/hooks.server.ts

@@ -0,0 +1,9 @@
+import type { Handle } from '@sveltejs/kit';
+import { dbConnect } from '$lib/utils/db';
+
+await dbConnect();
+
+export const handle: Handle = async ({ event, resolve }) => {
+	const response = await resolve(event);
+	return response;
+};

src/lib/utils/db.ts

@@ -0,0 +1,51 @@
+import mongoose from 'mongoose';
+import { getEnv } from '$lib/utils/env';
+const env = getEnv();
+
+/* 
+  0 - disconnected
+  1 - connected
+  2 - connecting
+  3 - disconnecting
+  4 - uninitialized
+*/
+let mongoConnectionState = 0;
+
+export const dbConnect = async () => {
+	if (mongoConnectionState === 1) {
+		console.log('connection established');
+		return;
+	}
+
+	if (mongoose.connections.length > 0) {
+		mongoConnectionState = mongoose.connections[0].readyState;
+		if (mongoConnectionState === 1) {
+			console.log('using existing connection');
+			return;
+		}
+
+		await mongoose.disconnect();
+	}
+
+	try {
+		await mongoose.connect(env.MONGO_URL, {
+			serverApi: { version: '1', strict: true, deprecationErrors: true }
+		});
+		await mongoose.connection.db.admin().command({ ping: 1 });
+		console.log('Pinged your deployment. You successfully connected to MongoDB!');
+		mongoConnectionState = 1;
+	} finally {
+		// Ensures that the client will close when you finish/error
+		await mongoose.disconnect();
+	}
+	mongoConnectionState = 1;
+};
+
+export const dbDisconnect = async () => {
+	if (process.env.NODE_ENV === 'development') return;
+	if (mongoConnectionState === 0) return;
+
+	await mongoose.disconnect();
+	mongoConnectionState = 0;
+	console.log('disconnected from mongodb');
+};

src/lib/utils/env.ts

@@ -0,0 +1,5 @@
+export function getEnv() {
+	return {
+		MONGO_URL: import.meta.env.VITE_MONGO_URL
+	};
+}