add features

backend/src/services/notification.service.ts

@@ -0,0 +1,131 @@
+// =============================================================================
+// Notification Service
+// =============================================================================
+
+import pool from '../config/database';
+import logger from '../utils/logger';
+import { Notification, CreateNotificationData } from '../models/notification.model';
+
+function rowToNotification(row: any): Notification {
+  return {
+    id:          row.id,
+    user_id:     row.user_id,
+    typ:         row.typ,
+    titel:       row.titel,
+    nachricht:   row.nachricht,
+    schwere:     row.schwere,
+    gelesen:     row.gelesen,
+    gelesen_am:  row.gelesen_am ? new Date(row.gelesen_am) : null,
+    link:        row.link ?? null,
+    quell_id:    row.quell_id ?? null,
+    quell_typ:   row.quell_typ ?? null,
+    erstellt_am: new Date(row.erstellt_am),
+  };
+}
+
+class NotificationService {
+  /** Returns all notifications for a user (newest first, max 100). */
+  async getByUser(userId: string): Promise<Notification[]> {
+    try {
+      const result = await pool.query(
+        `SELECT * FROM notifications WHERE user_id = $1 ORDER BY erstellt_am DESC LIMIT 100`,
+        [userId]
+      );
+      return result.rows.map(rowToNotification);
+    } catch (error) {
+      logger.error('NotificationService.getByUser failed', { error, userId });
+      throw new Error('Notifications konnten nicht geladen werden');
+    }
+  }
+
+  /** Returns the count of unread notifications for a user. */
+  async getUnreadCount(userId: string): Promise<number> {
+    try {
+      const result = await pool.query(
+        `SELECT COUNT(*) AS cnt FROM notifications WHERE user_id = $1 AND gelesen = FALSE`,
+        [userId]
+      );
+      return parseInt(result.rows[0].cnt, 10);
+    } catch (error) {
+      logger.error('NotificationService.getUnreadCount failed', { error, userId });
+      throw new Error('Ungelesene Notifications konnten nicht gezählt werden');
+    }
+  }
+
+  /** Marks a single notification as read. Returns false if not found or not owned by user. */
+  async markAsRead(id: string, userId: string): Promise<boolean> {
+    try {
+      const result = await pool.query(
+        `UPDATE notifications
+         SET gelesen = TRUE, gelesen_am = NOW()
+         WHERE id = $1 AND user_id = $2 AND gelesen = FALSE
+         RETURNING id`,
+        [id, userId]
+      );
+      return (result.rowCount ?? 0) > 0;
+    } catch (error) {
+      logger.error('NotificationService.markAsRead failed', { error, id, userId });
+      throw new Error('Notification konnte nicht als gelesen markiert werden');
+    }
+  }
+
+  /** Marks all notifications as read for a user. */
+  async markAllRead(userId: string): Promise<void> {
+    try {
+      await pool.query(
+        `UPDATE notifications SET gelesen = TRUE, gelesen_am = NOW()
+         WHERE user_id = $1 AND gelesen = FALSE`,
+        [userId]
+      );
+    } catch (error) {
+      logger.error('NotificationService.markAllRead failed', { error, userId });
+      throw new Error('Notifications konnten nicht als gelesen markiert werden');
+    }
+  }
+
+  /**
+   * Creates a notification.  If quell_typ + quell_id are provided the insert is
+   * silently ignored when an identical unread notification already exists
+   * (dedup via unique index).
+   */
+  async createNotification(data: CreateNotificationData): Promise<void> {
+    try {
+      await pool.query(
+        `INSERT INTO notifications
+           (user_id, typ, titel, nachricht, schwere, link, quell_id, quell_typ)
+         VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+         ON CONFLICT (user_id, quell_typ, quell_id) WHERE NOT gelesen AND quell_typ IS NOT NULL AND quell_id IS NOT NULL
+         DO NOTHING`,
+        [
+          data.user_id,
+          data.typ,
+          data.titel,
+          data.nachricht,
+          data.schwere ?? 'info',
+          data.link    ?? null,
+          data.quell_id  ?? null,
+          data.quell_typ ?? null,
+        ]
+      );
+    } catch (error) {
+      logger.error('NotificationService.createNotification failed', { error });
+      // Non-fatal — don't propagate to callers
+    }
+  }
+
+  /** Deletes read notifications older than 90 days for all users. */
+  async deleteOldRead(): Promise<void> {
+    try {
+      const result = await pool.query(
+        `DELETE FROM notifications WHERE gelesen = TRUE AND gelesen_am < NOW() - INTERVAL '90 days'`
+      );
+      if ((result.rowCount ?? 0) > 0) {
+        logger.info(`NotificationService.deleteOldRead: removed ${result.rowCount} old notifications`);
+      }
+    } catch (error) {
+      logger.error('NotificationService.deleteOldRead failed', { error });
+    }
+  }
+}
+
+export default new NotificationService();