Imports DigitalData.Modules.Database
Imports DigitalData.Modules.Language
Imports DigitalData.Modules.Logging

Namespace Methods.Database.GetDatatableFromCache
    Public Class GetDatatableFromCacheMethod
        Inherits BaseMethod

        Public Sub New(pLogConfig As LogConfig, pDatabaseIDB As MSSQLServer, pDatabaseECM As MSSQLServer, pGlobalState As GlobalState)
            MyBase.New(pLogConfig, pDatabaseIDB, pDatabaseECM, pGlobalState)
        End Sub

        Public Function Run(pData As GetDatatableFromCacheRequest) As GetDatatableFromCacheResponse
            Try
                Logger.Debug($"ReturnDatatableFromCache: Datatable: {pData.DataTable}")

                ' ✅ NEU: Sicherheitsprüfung (sollte nie auftreten, aber defensiv)
                If GlobalState.JobListener Is Nothing Then
                    Logger.Warn("JobListener not initialized - this should not happen! Using direct TableStore access.")

                    ' Fallback: Direkter Zugriff auf TableStore
                    If Not GlobalState.TableStore.Tables.Contains(pData.DataTable) Then
                        Return New GetDatatableFromCacheResponse(
                    New KeyNotFoundException($"Datatable {pData.DataTable} does not exist"))
                    End If

                    Dim oDirectTable = GlobalState.TableStore.Tables(pData.DataTable).Copy()
                    ' ... Filter/Sort anwenden wie gehabt
                    Return New GetDatatableFromCacheResponse(ApplyFilterAndSort(oDirectTable, pData))
                End If

                ' ✅ Normal: Thread-sicheren Zugriff verwenden
                Dim oDataTable As DataTable = GlobalState.JobListener.GetTableSafely(pData.DataTable)

                If oDataTable Is Nothing Then
                    Logger.Warn($"Datatable {pData.DataTable} does not exist")
                    Return New GetDatatableFromCacheResponse(
                New KeyNotFoundException($"Datatable {pData.DataTable} does not exist"))
                End If

                Return New GetDatatableFromCacheResponse(ApplyFilterAndSort(oDataTable, pData))


            Catch ex As Exception
                Logger.Error(ex)
                Return New GetDatatableFromCacheResponse(ex)

            End Try
        End Function
        ' ✅ Hilfsmethode zum Filter/Sort anwenden
        Private Function ApplyFilterAndSort(table As DataTable, request As GetDatatableFromCacheRequest) As DataTable
            Dim oFilterExpression = IIf(IsDBNull(request.FilterExpression), String.Empty, request.FilterExpression)
            Dim oSortByColumn = IIf(IsDBNull(request.SortByColumn), String.Empty, request.SortByColumn)

            Logger.Debug("Filter: [{0}], Sort: [{1}]", oFilterExpression, oSortByColumn)

            Dim oFilteredRows = table.Select(oFilterExpression, oSortByColumn)
            Dim oResult As DataTable

            If oFilteredRows.Count > 0 Then
                oResult = oFilteredRows.CopyToDataTable()
            Else
                oResult = table.Clone()
            End If

            oResult.TableName = request.DataTable
            Logger.Debug("Rows: {0} → {1}", table.Rows.Count, oResult.Rows.Count)

            Return oResult
        End Function
    End Class

End Namespace