API-26: Creating endpoint for RaPla changes

app.ts

@@ -5,7 +5,8 @@ import * as dotenv from 'dotenv';
 import {partyPlanerRouter} from './src/models/partyplaner/PartyPlaner.router';
 import {highlightMarkerRouter} from './src/models/twitch-highlight-marker/HighlightMarker.router';
 import {dhbwServiceRouter} from './src/models/dhbw-service/DHBWService.router';
-import logger from "./src/middleware/logger";
+import logger from './src/middleware/logger';
+import {dhbwRaPlaChangesRouter} from './src/models/dhbw-rapla-changes/DHBWRaPlaChanges.router';
 
 dotenv.config();
 
@@ -26,6 +27,7 @@ app.use(express.json());
 app.use('/dhbw-service', dhbwServiceRouter);
 app.use('/twitch-highlight-marker', highlightMarkerRouter);
 app.use('/partyplaner', partyPlanerRouter);
+app.use('/raplachanges', dhbwRaPlaChangesRouter);
 
 // this is a simple route to make sure everything is working properly
 app.get('/', (req: express.Request, res: express.Response) => {

src/models/dhbw-rapla-changes/DHBWRaPlaChanges.router.ts

@@ -0,0 +1,30 @@
+/**
+ * Required External Modules and Interfaces
+ */
+import express, {Request, Response} from 'express';
+import logger from '../../middleware/logger';
+import {Guid} from 'guid-typescript';
+import * as ChangeService from './changes/changes.service';
+
+/**
+ * Router Definition
+ */
+export const dhbwRaPlaChangesRouter = express.Router();
+
+dhbwRaPlaChangesRouter.get('/', async (req: Request, res: Response) => {
+    try {
+        let week = (req.query.week ?? '').toString();
+
+        let changes = await ChangeService.getChanges('TINF19B4', week);
+
+        res.status(200).send(changes);
+    } catch (e) {
+        let errorGuid = Guid.create().toString();
+        logger.error('Error handling a request: ' + e.message, {reference: errorGuid});
+        res.status(500).send({
+            'status': 'PROCESSING_ERROR',
+            'message': 'Internal Server Error. Try again later.',
+            'reference': errorGuid
+        });
+    }
+});

src/models/dhbw-rapla-changes/changes/Change.interface.ts

@@ -0,0 +1,16 @@
+export interface Change {
+    change_id: string;
+    event_id: string;
+    change_timestamp: Date;
+    is_deleted: boolean;
+    new_summary: string;
+    new_description: string;
+    new_start: Date;
+    new_end: Date;
+    new_last_modified: Date;
+    new_created: Date;
+    new_location: string;
+    new_organizer: string;
+    new_categories: string;
+    new_recurring: string;
+}

src/models/dhbw-rapla-changes/changes/Event.interface.ts

@@ -0,0 +1,9 @@
+import {Change} from './Change.interface';
+
+export interface Event {
+    event_id: string;
+    event_uid: string;
+    latest_event_summary: string;
+    latest_start_date: Date;
+    changes: Change[];
+}

src/models/dhbw-rapla-changes/changes/changes.service.ts

@@ -0,0 +1,79 @@
+import * as dotenv from 'dotenv';
+import {Event} from './Event.interface';
+import {Change} from './Change.interface';
+
+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.RAPLACHANGES_DATABASE,
+    connectionLimit: 5
+});
+
+export const getChanges = async (course: string, week: string): Promise<Event[]> => {
+    let conn;
+    try {
+        conn = await pool.getConnection();
+
+        let relevantEventsRows = await conn.query('SELECT DISTINCT(entry_id) FROM rapla_changes WHERE new_start > ? AND new_start < DATE_ADD(?, INTERVAL 7 DAY)', [week, week]);
+
+        let relevantEventIds: string[] = [];
+        relevantEventsRows.forEach((row: { entry_id: string; }) => {
+            relevantEventIds.push(row.entry_id);
+        });
+
+        let rows = await conn.query('SELECT c.change_id, c.entry_id, c.change_timestamp, c.isDeleted, c.new_summary, c.new_description, c.new_start, c.new_last_modified, c.new_end, c.new_created, c.new_location, c.new_organizer, c.new_categories, e.uid FROM rapla_changes c LEFT OUTER JOIN rapla_entries e ON c.entry_id = e.entry_id WHERE c.entry_id IN (?) ORDER BY c.change_id', [relevantEventIds]);
+
+        let eventsMap = new Map();
+
+        for (let row of rows) {
+            let change: Change = {
+                change_id: row.change_id,
+                event_id: row.event_id,
+                change_timestamp: row.change_timestamp,
+                is_deleted: row.isDeleted,
+                new_summary: row.new_summary,
+                new_description: row.new_description,
+                new_start: row.new_start,
+                new_end: row.new_end,
+                new_last_modified: row.new_last_modified,
+                new_created: row.new_created,
+                new_location: row.new_location,
+                new_organizer: row.new_organizer,
+                new_categories: row.new_categories,
+                new_recurring: row.new_recurring
+            };
+
+            if (eventsMap.has(row.entry_id)) {
+                let event = eventsMap.get(row.entry_id);
+
+                event.latest_event_summary = row.new_summary;
+                event.latest_start_date = row.new_start;
+                event.changes.push(change);
+
+                eventsMap.set(row.entry_id, event);
+            } else {
+                let event: Event = {
+                    event_id: row.event_id,
+                    event_uid: row.uid,
+                    latest_event_summary: row.event_summary,
+                    latest_start_date: row.new_start,
+                    changes: [change]
+                };
+
+                eventsMap.set(row.entry_id, event);
+            }
+        }
+
+        return Array.from(eventsMap.values()) as Event[];
+    } catch (err) {
+        throw err;
+    } finally {
+        if (conn) {
+            conn.end();
+        }
+    }
+};