feat(telegram): add daily deletion warning cron job (Phase 5)

- Added Telegram warning cron job at 09:00 (1 hour before cleanup)
- Integrated with GroupCleanupService.findGroupsForDeletion()
- Sends sendDeletionWarning() notification for groups pending deletion
- Added manual trigger method triggerTelegramWarningNow() for development
- Added POST /api/admin/telegram/warning endpoint for manual testing
- Fixed SchedulerService singleton instance in server.js app.set()
- Added Telegram ENV vars to docker-compose.yml environment section

Tested successfully with test data showing warning message in Telegram.

backend/docs/openapi.json

@@ -39,6 +39,9 @@
     {
       "name": "Admin - Cleanup"
     },
+    {
+      "name": "Admin - Telegram"
+    },
     {
       "name": "Admin - Monitoring"
     },
@@ -1726,6 +1729,46 @@
         }
       }
     },
+    "/api/admin/telegram/warning": {
+      "post": {
+        "tags": [
+          "Admin - Telegram"
+        ],
+        "summary": "Manually trigger Telegram deletion warning",
+        "description": "Sends deletion warning to Telegram for testing (normally runs daily at 09:00)",
+        "responses": {
+          "200": {
+            "description": "Warning sent successfully",
+            "schema": {
+              "type": "object",
+              "properties": {
+                "success": {
+                  "type": "boolean",
+                  "example": true
+                },
+                "groupsWarned": {
+                  "type": "number",
+                  "example": 2
+                },
+                "message": {
+                  "type": "string",
+                  "example": "Deletion warning sent for 2 groups"
+                }
+              },
+              "xml": {
+                "name": "main"
+              }
+            }
+          },
+          "403": {
+            "description": "Forbidden"
+          },
+          "500": {
+            "description": "Internal Server Error"
+          }
+        }
+      }
+    },
     "/api/admin/cleanup/preview": {
       "get": {
         "tags": [

backend/src/routes/admin.js

@@ -237,6 +237,46 @@ router.post('/cleanup/trigger', async (req, res) => {
     }
 });
 
+router.post('/telegram/warning', async (req, res) => {
+    /* 
+        #swagger.tags = ['Admin - Telegram']
+        #swagger.summary = 'Manually trigger Telegram deletion warning'
+        #swagger.description = 'Sends deletion warning to Telegram for testing (normally runs daily at 09:00)'
+        #swagger.responses[200] = {
+            description: 'Warning sent successfully',
+            schema: {
+                success: true,
+                groupsWarned: 2,
+                message: 'Deletion warning sent for 2 groups'
+            }
+        }
+    */
+    try {
+        const schedulerService = req.app.get('schedulerService');
+        
+        if (!schedulerService) {
+            return res.status(500).json({
+                success: false,
+                message: 'Scheduler service not available'
+            });
+        }
+
+        const result = await schedulerService.triggerTelegramWarningNow();
+        
+        res.json({
+            success: true,
+            groupsWarned: result.groupCount,
+            message: result.message
+        });
+    } catch (error) {
+        console.error('[Admin API] Error triggering Telegram warning:', error);
+        res.status(500).json({
+            error: 'Internal server error',
+            message: error.message
+        });
+    }
+});
+
 router.get('/cleanup/preview', async (req, res) => {
     /* 
         #swagger.tags = ['Admin - Cleanup']

backend/src/server.js

@@ -82,6 +82,9 @@ class Server {
                 console.log(`✅ Server läuft auf Port ${this._port}`);
                 console.log(`📊 SQLite Datenbank aktiv`);
                 
+                // Speichere SchedulerService in app für Admin-Endpoints
+                this._app.set('schedulerService', SchedulerService);
+                
                 // Starte Scheduler für automatisches Cleanup
                 SchedulerService.start();
 

backend/src/services/SchedulerService.js

@@ -1,9 +1,11 @@
 const cron = require('node-cron');
 const GroupCleanupService = require('./GroupCleanupService');
+const TelegramNotificationService = require('./TelegramNotificationService');
 
 class SchedulerService {
     constructor() {
         this.tasks = [];
+        this.telegramService = new TelegramNotificationService();
     }
 
     start() {
@@ -30,7 +32,35 @@ class SchedulerService {
 
         this.tasks.push(cleanupTask);
 
-        console.log('✓ Scheduler started - Daily cleanup at 10:00 AM (Europe/Berlin)');
+        // Telegram Warning-Job: Jeden Tag um 09:00 Uhr (1 Stunde vor Cleanup)
+        const telegramWarningTask = cron.schedule('0 9 * * *', async () => {
+            console.log('[Scheduler] Running daily Telegram deletion warning at 09:00 AM...');
+            try {
+                if (this.telegramService.isAvailable()) {
+                    const groupsForDeletion = await GroupCleanupService.findGroupsForDeletion();
+                    
+                    if (groupsForDeletion && groupsForDeletion.length > 0) {
+                        await this.telegramService.sendDeletionWarning(groupsForDeletion);
+                        console.log(`[Scheduler] Sent deletion warning for ${groupsForDeletion.length} groups`);
+                    } else {
+                        console.log('[Scheduler] No groups pending deletion');
+                    }
+                } else {
+                    console.log('[Scheduler] Telegram service not available, skipping warning');
+                }
+            } catch (error) {
+                console.error('[Scheduler] Telegram warning task failed:', error);
+            }
+        }, {
+            scheduled: true,
+            timezone: "Europe/Berlin"
+        });
+
+        this.tasks.push(telegramWarningTask);
+
+        console.log('✓ Scheduler started:');
+        console.log('  - Daily cleanup at 10:00 AM (Europe/Berlin)');
+        console.log('  - Daily Telegram warning at 09:00 AM (Europe/Berlin)');
         
         // Für Development: Manueller Trigger
         if (process.env.NODE_ENV === 'development') {
@@ -50,6 +80,42 @@ class SchedulerService {
         console.log('[Scheduler] Manual cleanup triggered...');
         return await GroupCleanupService.performScheduledCleanup();
     }
+
+    // Für Development: Manueller Telegram-Warning-Trigger
+    async triggerTelegramWarningNow() {
+        console.log('[Scheduler] Manual Telegram warning triggered...');
+        try {
+            if (!this.telegramService.isAvailable()) {
+                console.log('[Scheduler] Telegram service not available');
+                return { success: false, message: 'Telegram service not available' };
+            }
+
+            const groupsForDeletion = await GroupCleanupService.findGroupsForDeletion();
+            
+            if (!groupsForDeletion || groupsForDeletion.length === 0) {
+                console.log('[Scheduler] No groups pending deletion');
+                return { success: true, message: 'No groups pending deletion', groupCount: 0 };
+            }
+
+            await this.telegramService.sendDeletionWarning(groupsForDeletion);
+            console.log(`[Scheduler] Sent deletion warning for ${groupsForDeletion.length} groups`);
+            
+            return { 
+                success: true, 
+                message: `Warning sent for ${groupsForDeletion.length} groups`,
+                groupCount: groupsForDeletion.length,
+                groups: groupsForDeletion.map(g => ({
+                    groupId: g.groupId,
+                    name: g.name,
+                    year: g.year,
+                    uploadDate: g.uploadDate
+                }))
+            };
+        } catch (error) {
+            console.error('[Scheduler] Manual Telegram warning failed:', error);
+            return { success: false, message: error.message };
+        }
+    }
 }
 
 module.exports = new SchedulerService();

docker/dev/docker-compose.yml

@@ -46,6 +46,9 @@ services:
       - ENABLE_HOST_RESTRICTION=true
       - TRUST_PROXY_HOPS=0
       - PUBLIC_UPLOAD_RATE_LIMIT=20
+      - TELEGRAM_ENABLED=true
+      - TELEGRAM_BOT_TOKEN=8496813818:AAHShJP_cqOuWIW66ROUCxa-1C83CCCZmqU
+      - TELEGRAM_CHAT_ID=-1003064825033
     networks:
       - dev-internal
     command: [ "npm", "run", "server" ]