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QuellCode/CentronERP war nur als Gitlink (Submodul-Referenz auf 79c1142)
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Die verschachtelte .gitignore der Codebasis gilt weiter, Build-Artefakte
bleiben ausgeschlossen. Details in Versuche/Versuch_01/_Codebasis-Nachweis.md

QuellCode/CentronERP/docs/Background Service/DataQualityService.md

@@ -0,0 +1,171 @@
+# DataQualityService
+
+## Purpose
+The `DataQualityService` is an ASP.NET Core `BackgroundService` that runs periodically to:
+- Clean up outdated data
+- Fix data inconsistencies
+- Update missing database values
+- Validate and repair relationships between database entities
+- Perform regular maintenance tasks on database records
+
+## Implementation Details
+
+### Core Structure
+- Inherits from `BackgroundService` (Microsoft.Extensions.Hosting)
+- Runs every hour on a continuous schedule while the application is active
+- Each maintenance task is executed sequentially in the `ExecuteAsync` method
+
+### Execution Pattern
+- The service runs in an infinite loop until a cancellation is requested
+- Tasks are executed with 1-hour intervals between full cycle executions
+- Cancellation is checked between each task to allow for graceful shutdown
+
+## Task Implementation Rules
+
+When implementing tasks in the `DataQualityService`:
+
+### 1. Session Management
+- Each task must create its own `BLSession` instance within a `using` statement
+- Sessions should be short-lived and disposed immediately after the task completes
+```csharp
+using (var session = new BLSession())
+{
+    // Task implementation here
+}
+```
+
+### 2. Error Handling
+- Every task must be wrapped in a try-catch block
+- Exceptions should be logged with the specific task name in the error message
+- Tasks should not crash the service; errors should be contained
+```csharp
+try
+{
+    // Task implementation
+}
+catch (Exception e) 
+{
+    Logger.Error(e, "Error while executing data quality service - [TASK NAME]");
+}
+```
+
+### 3. Cancellation Checking
+- After each task, check if cancellation has been requested
+- Break the execution loop if cancellation is detected
+```csharp
+if (stoppingToken.IsCancellationRequested)
+{
+    break;
+}
+```
+
+### 4. Business Logic Access
+- Use the session's `GetBL<T>()` method to access the appropriate business logic class
+- Call only methods that are designed for data quality operations
+```csharp
+session.GetBL<BusinessLogicClassName>().DataQualityMethodName();
+```
+
+## Adding New Data Quality Tasks
+
+When adding a new task to the `DataQualityService`:
+
+### 1. Task Placement
+- Add the new task after existing tasks
+- Follow the established pattern of try-catch-cancellation check
+
+### 2. Business Logic Implementation
+- Create a dedicated method in the appropriate BL class
+- Prefix data quality specific methods with `DataQuality` (e.g., `DataQualityCleanupSecondaryStockArticles`)
+- For specialized operations that need filters, create appropriate filter classes (e.g., `TicketPatternUpdateCustomerMappingsFilter`)
+
+### 3. Performance Considerations
+- Design tasks to be efficient and lightweight
+- Avoid long-running operations that might block other tasks
+- Consider implementing pagination for large datasets
+
+### 4. Documentation
+- Add a descriptive error message that clearly identifies the task
+- Comment the task implementation if it performs complex operations
+
+## Existing Task Reference
+
+The `DataQualityService` currently handles these tasks:
+
+1. **Ticket pattern customer mappings updates**
+   - Updates customer mappings for ticket patterns
+   - Uses `TicketPatternUpdateCustomerMappingsFilter`
+
+2. **Directory checks**
+   - Executes directory validation and checking
+   - Uses `DirectoryCheckBL.ExecuteDirectoryCheck()`
+
+3. **Cleanup of Centron notifications**
+   - Removes old or expired notifications
+   - Uses `CentronNotificationsBL.CleanupCentronNotifications()`
+
+4. **Checklist customer mappings updates**
+   - Updates customer mappings for checklists
+   - Uses `CentronChecklistUpdateCustomerMappingsFilter`
+
+5. **Profiler entries reorganization**
+   - Reorganizes and optimizes profiler entries
+   - Uses `ProfilerBL.ReorganizeProfilerEntries()`
+
+6. **Todo-list missing Account I3D filling**
+   - Fills missing Account I3Ds in Todo items
+   - Uses `ToDoBL.DataQualityFillAccountI3D()`
+
+7. **AccountTypeToAccounts table repair**
+   - Checks and repairs AccountTypeToAccounts relationships
+   - Uses `AccountBL.CheckAndRepairAccountTypeToAccountsTable()`
+
+8. **HelpdeskTimer properties updates**
+   - Updates missing properties in HelpdeskTimer records
+   - Uses `HelpdeskTimerBL.DataQualityUpdateMissingHelpdeskTimerProperties()`
+
+9. **Secondary stock articles cleanup**
+   - Cleans up secondary stock article records
+   - Uses `SecondStockArticleBL.DataQualityCleanupSecondaryStockArticles()`
+
+## Best Practices
+
+### 1. Task Independence
+- Each task should be independent of other tasks
+- Failure in one task should not affect subsequent tasks
+
+### 2. Resource Utilization
+- Consider the server load when implementing new tasks
+- Use database indexes for heavy operations
+- Run operations during off-peak hours if possible
+
+### 3. Logging
+- Log the start and completion of tasks at the Debug or Info level for monitoring
+- Include sufficient context in error messages for troubleshooting
+
+### 4. Testing
+- Test new tasks thoroughly in a development environment
+- Verify that new tasks fix the intended issues without side effects
+
+## Example Implementation
+
+Adding a new data quality task:
+
+```csharp
+if (stoppingToken.IsCancellationRequested)
+{
+    break;
+}
+
+try
+{
+    using (var session = new BLSession())
+    {
+        session.GetBL<YourBusinessLogic>().DataQualityYourNewTask();
+    }
+}
+catch (Exception e)
+{
+    Logger.Error(e, "Error while executing data quality service - Your new task description");
+}
+```