API-23: Refactoring for better architecture (#12)

Endpoints are separated into distinct packages and interfaces are extracted into files

Co-authored-by: Patrick Müller <patrick@mueller-patrick.tech>
Reviewed-on: #12
Co-authored-by: Patrick Müller <patrick@plutodev.de>
Co-committed-by: Patrick Müller <patrick@plutodev.de>

src/models/partyplaner/friendship/Friendship.interface.ts

@@ -0,0 +1,10 @@
+/**
+ * Used in the getFriendshipData method as a return value
+ */
+export interface Friendship {
+    friendshipId: string;
+    friendId: string;
+    friendFirstName: string;
+    friendLastName: string;
+    friendUsername: string;
+}

src/models/partyplaner/friendship/Friendship.router.ts

@@ -0,0 +1,44 @@
+/**
+ * Required External Modules and Interfaces
+ */
+import express, {Request, Response} from 'express';
+import * as FriendshipService from './friendship.service';
+import * as UserService from '../user/user.service';
+import logger from '../../../middleware/logger';
+
+/**
+ * Router Definition
+ */
+export const friendshipRouter = express.Router();
+
+friendshipRouter.get('/:isDevCall', async (req: Request, res: Response) => {
+    try {
+        let userId = (req.query.userId ?? '').toString();
+        let sessionId = (req.query.sessionId ?? '').toString();
+        let sessionKey = (req.query.sessionKey ?? '').toString();
+        let useDev: boolean = (req.params.isDevCall ?? '') === 'dev'; // TBD
+
+        if (userId === '' || sessionId === '' || sessionKey === '') {
+            res.status(400).send({
+                'status': 'WRONG_PARAMS',
+                'message': 'Missing or wrong parameters'
+            });
+            return;
+        }
+
+        if (!await UserService.checkSession(useDev, userId, sessionId, sessionKey)) {
+            res.status(403).send({
+                'status': 'INVALID_SESSION',
+                'message': 'The user or session could not be found or the session is invalid'
+            });
+            return;
+        }
+
+        let data = await FriendshipService.getFriendshipData(useDev, userId);
+
+        res.status(200).send(data);
+    } catch (e) {
+        logger.error('Error handling a request: ' + e.message);
+        res.status(500).send({'message': 'Internal Server Error. Try again later.'});
+    }
+});

src/models/partyplaner/friendship/friendship.service.ts

@@ -0,0 +1,59 @@
+import * as dotenv from 'dotenv';
+import {Friendship} from './Friendship.interface';
+
+dotenv.config();
+
+const mariadb = require('mariadb');
+const prod_pool = mariadb.createPool({
+    host: process.env.DB_HOST,
+    user: process.env.DB_USER,
+    password: process.env.DB_PASSWORD,
+    database: process.env.PARTYPLANER_PROD_DATABASE,
+    connectionLimit: 5
+});
+const dev_pool = mariadb.createPool({
+    host: process.env.DB_HOST,
+    user: process.env.DB_USER,
+    password: process.env.DB_PASSWORD,
+    database: process.env.PARTYPLANER_DEV_DATABASE,
+    connectionLimit: 5
+});
+
+/**
+ * Returns all friends of the given user
+ * @param useDev If the dev or prod database should be used
+ * @param userId The userId of the user to fetch the friends for
+ * @return Friendship[] A list of friends
+ */
+export const getFriendshipData = async (useDev: boolean, userId: string): Promise<Friendship[]> => {
+    let conn;
+    try {
+        if (useDev) {
+            conn = await dev_pool.getConnection();
+        } else {
+            conn = await prod_pool.getConnection();
+        }
+
+        let rows = await conn.query('SELECT f.friendship_id, f.friend_id, u.first_name as friend_first_name, u.last_name as friend_last_name, u.username as friend_username FROM friendships f LEFT OUTER JOIN users u ON f.friend_id = u.user_id WHERE f.user_id = ?', userId);
+
+        let friends: Friendship[] = [];
+
+        for (let row of rows) {
+            friends.push({
+                friendshipId: row.friendship_id,
+                friendId: row.friend_id,
+                friendFirstName: row.friend_first_name,
+                friendLastName: row.friend_last_name,
+                friendUsername: row.friend_username
+            });
+        }
+
+        return friends;
+    } catch (err) {
+        throw err;
+    } finally {
+        if (conn) {
+            conn.end();
+        }
+    }
+};