Add admin identity module: better-auth, per-app permissions, invitations (#12)

Reviewed-on: #12
Co-authored-by: Patrick Müller <mail@pmueller.me>
Co-committed-by: Patrick Müller <mail@pmueller.me>

src/app.factory.ts

@@ -0,0 +1,166 @@
+import express from 'express';
+import * as dotenv from 'dotenv';
+import swaggerUi from 'swagger-ui-express';
+import swaggerJSDoc from 'swagger-jsdoc';
+import cors from 'cors';
+import {toNodeHandler} from 'better-auth/node';
+import logger from './middleware/logger.js';
+
+// Router imports
+import {calendarRouter} from './models/calendar/Calendar.router.js';
+import {feedbackRouter} from './models/feedback/Feedback.router.js';
+import {ticketsRouter} from './models/tickets/Tickets.router.js';
+import {adminRouter} from './models/admin/Admin.router.js';
+import {auth} from './models/admin/admin.auth.js';
+import {ADMIN_ALLOWED_ORIGINS, isProd} from './models/admin/admin.config.js';
+
+
+dotenv.config();
+
+
+/**
+ * Builds the Express app with every router and middleware in place.
+ *
+ * Separate from app.ts so the integration tests can drive the *real* wiring
+ * with supertest instead of a hand-rolled copy of it. The order below is not
+ * cosmetic - CORS has to precede the better-auth handler so preflights get
+ * their headers, and the better-auth handler has to precede express.json()
+ * because it reads the raw body stream itself.
+ */
+export const createApp = (): express.Application => {
+	const app: express.Application = express();
+
+	// Behind Plesk's nginx, req.ip is the proxy unless we trust the forwarded header.
+	// Verify the resolved client IP is correct in staging before relying on it
+	// (used by the feedback rate limiter).
+	app.set('trust proxy', 1);
+
+	// Configure CORS. This has to run before the better-auth handler below, so
+	// that preflights for /admin/auth/* get their headers, which is why it now
+	// sits above express.json() instead of after it.
+	let allowedHosts = [
+		'https://www.nachklang.art',
+		'https://calendar.nachklang.art',
+		'https://feedback.nachklang.art',
+		'https://tickets.nachklang.art',
+		'https://admin.nachklang.art',
+		// The admin app's origin comes from ADMIN_APP_URL, so a rename or a
+		// staging host does not need a code change here.
+		...ADMIN_ALLOWED_ORIGINS
+	];
+	// `isProd` from admin.config, NOT `NODE_ENV !== 'production'`. The two are not
+	// the same when NODE_ENV is unset, which is exactly what a fresh Plesk vhost
+	// gives you: the old test called that "dev" and opened the loopback and
+	// private-LAN exceptions below. With `credentials: true` on this CORS config
+	// and a session cookie scoped to .nachklang.art, that let any page served
+	// from localhost read a signed-in admin's data cross-origin. admin.config
+	// treats anything but an explicit 'development'/'test' as production, so an
+	// unset value now fails closed.
+	const isDev = !isProd;
+	const localhostRegex = /^http:\/\/localhost:\d+$/;
+	// Matches http://<private-LAN-IPv4>:<port> - needed so the feedback form can
+	// be reached from a real phone over WiFi during dev (the phone's Origin is
+	// the dev machine's LAN IP, never "localhost"). Dev-only, same as above.
+	const lanIpRegex = /^http:\/\/(192\.168\.\d{1,3}\.\d{1,3}|10\.\d{1,3}\.\d{1,3}\.\d{1,3}|172\.(1[6-9]|2\d|3[01])\.\d{1,3}\.\d{1,3}):\d+$/;
+	app.use(cors({
+		// X-Session-* stay allowed until the calendar module is migrated off the
+		// legacy header sessions (see docs/calendar-auth-migration.md).
+		allowedHeaders: ['Content-Type', 'X-Session-Id', 'X-Session-Key'],
+		// The admin session lives in a cookie, so browsers must be allowed to send
+		// it cross-origin - this is what makes credentials: 'include' work.
+		credentials: true,
+		origin: function (origin: any, callback: any) {
+			// Allow requests with no origin
+			if (!origin) return callback(null, true);
+
+			// Any localhost port, or a private-LAN IP, is fine outside production -
+			// dev servers pick whatever port is free (Next.js falls back from 3000
+			// if it's taken), and real-device testing hits the dev machine by IP.
+			if (isDev && (localhostRegex.test(origin) || lanIpRegex.test(origin))) {
+				return callback(null, true);
+			}
+
+			// Block requests with wrong origin
+			if (allowedHosts.indexOf(origin) === -1) {
+				return callback(new Error('The CORS policy doesn\'t allow access for your origin.'), false);
+			}
+
+			// Allow all other requests
+			return callback(null, true);
+		}
+	}));
+
+	// better-auth's own handler, mounted before express.json(): it reads the raw
+	// request body stream itself and a parsed body would leave it hanging.
+	//
+	// Wrapped, because Express 4 does not await an async handler: a rejected
+	// promise escapes as an unhandled rejection instead of becoming a response.
+	// Nearly every better-auth route touches the admin database, so a database
+	// blip would leave the request hanging with no answer at all while the
+	// process logged an uncaughtException - observed by pointing ADMIN_DB at a
+	// database the user cannot open. Answer 503 instead: the caller learns, and
+	// the other domains keep serving.
+	const authHandler = toNodeHandler(auth);
+	app.all('/admin/auth/*', (req, res) => {
+		Promise.resolve(authHandler(req, res)).catch((e: any) => {
+			logger.error('Admin auth handler failed', {path: req.path, detail: e?.message});
+			if (!res.headersSent) {
+				res.status(503).send({
+					status: 'SERVICE_UNAVAILABLE',
+					message: 'Die Anmeldung ist derzeit nicht verfügbar. Bitte versuche es später erneut.'
+				});
+			}
+		});
+	});
+
+	// here we are adding middleware to parse all incoming requests as JSON
+	app.use(express.json());
+
+	// Swagger documentation
+	const swaggerDefinition = {
+		openapi: '3.0.0',
+		info: {
+			title: 'Nachklang e.V. REST API',
+			version: '1.0.0',
+			license: {
+				name: 'Licensed Under MIT',
+				url: 'https://spdx.org/licenses/MIT.html'
+			},
+			contact: {
+				name: 'Nachklang e.V.',
+				url: 'https://www.nachklang.art'
+			}
+		}
+	};
+
+	const options = {
+		swaggerDefinition,
+		// Paths to files containing OpenAPI definitions
+		apis: [
+			'./src/models/**/*.interface.ts',
+			'./src/models/**/*.router.ts'
+		]
+	};
+
+	const swaggerSpec = swaggerJSDoc(options);
+
+	app.use(
+		'/docs',
+		swaggerUi.serve,
+		swaggerUi.setup(swaggerSpec)
+	);
+
+	// Add routers
+	app.use('/calendar', calendarRouter);
+	app.use('/feedback', feedbackRouter);
+	app.use('/tickets', ticketsRouter);
+	// JSON routes only; the auth handler above is mounted separately.
+	app.use('/admin', adminRouter);
+
+	// this is a simple route to make sure everything is working properly
+	app.get('/', (req: express.Request, res: express.Response) => {
+		res.status(200).send('Welcome to the Nachklang e.V. REST API!');
+	});
+
+	return app;
+};