BETTERZON-90: Adding API endpoint for creating price alarms (#42)

Backend/src/models/pricealarms/pricealarm.interface.ts

@@ -0,0 +1,6 @@
+export interface PriceAlarm {
+    alarm_id: number;
+    user_id: number;
+    product_id: number;
+    defined_price: number;
+}

Backend/src/models/pricealarms/pricealarms.interface.ts

@@ -0,0 +1,5 @@
+import {PriceAlarm} from './pricealarm.interface';
+
+export interface PriceAlarms {
+    [key: number]: PriceAlarm;
+}

Backend/src/models/pricealarms/pricealarms.router.ts

@@ -0,0 +1,62 @@
+/**
+ * Required External Modules and Interfaces
+ */
+
+import express, {Request, Response} from 'express';
+import * as PriceAlarmsService from './pricealarms.service';
+import {PriceAlarm} from './pricealarm.interface';
+import {PriceAlarms} from './pricealarms.interface';
+import * as UserService from '../users/users.service';
+
+
+/**
+ * Router Definition
+ */
+export const pricealarmsRouter = express.Router();
+
+
+/**
+ * Controller Definitions
+ */
+
+// POST priceAlarms/create
+pricealarmsRouter.post('/create', async (req: Request, res: Response) => {
+    try {
+        // Authenticate user
+        const session_id = req.body.session_id;
+        const session_key = req.body.session_key;
+        const user_ip = req.connection.remoteAddress ?? '';
+
+        if (!session_id || !session_key) {
+            // Missing
+            res.status(400).send(JSON.stringify({message: 'Missing parameters'}));
+            return;
+        }
+
+        const user = await UserService.checkSession(session_id, session_key, user_ip);
+
+        // Get info for price alarm creation
+        const product_id = req.body.product_id;
+        const defined_price = req.body.defined_price;
+
+        if (!product_id || !defined_price) {
+            // Missing
+            res.status(400).send(JSON.stringify({message: 'Missing parameters'}));
+            return;
+        }
+
+        // Create price alarm
+        const success = await PriceAlarmsService.createPriceAlarm(user.user_id, product_id, defined_price);
+
+        if(success) {
+            res.status(200).send(JSON.stringify({success: true}));
+            return;
+        } else {
+            res.status(400).send(JSON.stringify({success: false}));
+            return;
+        }
+    } catch (e) {
+        console.log('Error handling a request: ' + e.message);
+        res.status(500).send(JSON.stringify({"message": "Internal Server Error. Try again later."}));
+    }
+});

Backend/src/models/pricealarms/pricealarms.service.ts

@@ -0,0 +1,47 @@
+import * as dotenv from 'dotenv';
+
+dotenv.config();
+
+const mariadb = require('mariadb');
+const pool = mariadb.createPool({
+    host: process.env.DB_HOST,
+    user: process.env.DB_USER,
+    password: process.env.DB_PASSWORD,
+    database: process.env.DB_DATABASE,
+    connectionLimit: 5
+});
+
+/**
+ * Data Model Interfaces
+ */
+
+import {PriceAlarm} from './pricealarm.interface';
+import {PriceAlarms} from './pricealarms.interface';
+
+
+/**
+ * Service Methods
+ */
+
+/**
+ * Creates a price alarm for the given user for the product with the defined price
+ */
+export const createPriceAlarm = async (user_id: number, product_id: number, defined_price: number): Promise<Boolean> => {
+    let conn;
+    try {
+        conn = await pool.getConnection();
+        const affected_rows = await conn.query('INSERT INTO price_alarms (user_id, product_id, defined_price) VALUES (?, ?, ?)', [user_id, product_id, defined_price]);
+
+        console.log(affected_rows);
+
+        return true;
+    } catch (err) {
+        throw err;
+    } finally {
+        if (conn) {
+            conn.end();
+        }
+    }
+
+    return false;
+};