feat: implement save receipt functionality with transaction handling and DTOs

backend/src/receipt-import/receipt-import.controller.ts

@@ -14,6 +14,8 @@ import { FileInterceptor } from '@nestjs/platform-express';
 import { memoryStorage } from 'multer';
 import { ReceiptImportService } from './receipt-import.service';
 import { ParsedReceiptItem } from './dto/parsed-receipt-item.dto';
+import { SaveReceiptDto } from './dto/save-receipt.dto';
+import { SaveReceiptResponse } from './dto/save-receipt.response';
 import { CreateUnitMappingDto } from './dto/create-unit-mapping.dto';
 import { AuthGuard } from '@nestjs/passport';
 
@@ -87,4 +89,31 @@ export class ReceiptImportController {
       dto.preferredUnit,
     );
   }
+
+  @HttpCode(200)
+  @Post('save')
+  @UseGuards(AuthGuard('jwt'))
+  @Throttle({ default: { ttl: 60_000, limit: 10 } })
+  async saveReceipt(
+    @Body() dto: SaveReceiptDto,
+    @Request() req?: any,
+  ): Promise<SaveReceiptResponse> {
+    const userId =
+      typeof req?.user?.id === 'number'
+        ? req.user.id
+        : typeof req?.user?.userId === 'number'
+          ? req.user.userId
+          : undefined;
+    if (!userId) {
+      throw new BadRequestException('Kunde inte identifiera användaren.');
+    }
+
+    const isAdmin = req?.user?.role === 'admin';
+    if (dto.isAdminLearning && !isAdmin) {
+      throw new BadRequestException('Endast administratörer kan spara globala aliaser.');
+    }
+
+    return this.receiptImportService.saveReceipt(userId, dto);
+  }
 }
+