BETTERZON-75: User registration API endpoint (#34)

* BETTERZON-75: Adding backend functions to enable user registration

* BETTERZON-75: Adding regex to check email and username

Backend/src/models/users/users.router.ts

@@ -0,0 +1,54 @@
+/**
+ * Required External Modules and Interfaces
+ */
+
+import express, {Request, Response} from 'express';
+import * as UserService from './users.service';
+import {User} from './user.interface';
+import {Users} from './users.interface';
+import {Session} from './session.interface';
+
+
+/**
+ * Router Definition
+ */
+
+export const usersRouter = express.Router();
+
+
+/**
+ * Controller Definitions
+ */
+
+// POST users/register
+usersRouter.post('/register', async (req: Request, res: Response) => {
+    try {
+        const username: string = req.body.username;
+        const password: string = req.body.password;
+        const email: string = req.body.email;
+        const ip: string = req.connection.remoteAddress?? '';
+
+        if (!username || !password || !email) {
+            // Missing
+            res.status(400).send(JSON.stringify({message: 'Missing parameters'}));
+            return;
+        }
+
+        // Check if username and / or email are already used
+        const status = await UserService.checkUsernameAndEmail(username, email);
+
+        if (status.hasProblems) {
+            // Username and/or email are duplicates, return error
+            res.status(400).send(JSON.stringify({messages: status.messages, codes: status.codes}));
+            return;
+        }
+
+        // Create the user and a session
+        const session: Session = await UserService.createUser(username, password, email, ip);
+
+        // Send the session details back to the user
+        res.status(201).send(session);
+    } catch (e) {
+        res.status(404).send(e.message);
+    }
+});