Imports DigitalData.Modules.Database
Imports DigitalData.Modules.EDMI.API
Imports DigitalData.Modules.EDMI.API.Constants
Imports DigitalData.Modules.EDMI.API.EDMIServiceReference
Imports DigitalData.Modules.Logging
Imports DigitalData.Modules.Language.Utils

Public Class DatabaseWithFallback
    Private ReadOnly _Logger As Logger
    Private ReadOnly _Client As Client
    Private ReadOnly _DatabaseEDM As MSSQLServer
    Private ReadOnly _DatabaseIDB As MSSQLServer

    Public Enum TableType
        TBIDB_ATTRIBUTE
    End Enum

    Public Class Table
        Public TableName As String
        Public SQLCommand As String
        Public DatabaseType As Constants.DatabaseType
    End Class

    Public Property Tables As New List(Of Table) From {
        New Table With {.DatabaseType = DatabaseType.IDB, .TableName = "TBIDB_ATTRIBUTE", .SQLCommand = "SELECT * FROM TBIDB_ATTRIBUTE"}
    }


    Public Sub New(LogConfig As LogConfig, Client As Client, DatabaseECM As MSSQLServer, DatabaseIDB As MSSQLServer)
        _Logger = LogConfig.GetLogger()
        _Client = Client
        _DatabaseEDM = DatabaseECM
        _DatabaseIDB = DatabaseIDB
    End Sub

    ''' <summary>
    ''' Attempt at making loading big tables less annoying
    ''' </summary>
    ''' <returns></returns>
    Public Function GetDatatable(pTable As TableType, Optional FilterExpression As String = "", Optional SortByColumn As String = "", Optional ForceFallback As Boolean = False)
        Dim oTable = Tables.Where(Function(t) t.DatabaseType = pTable).SingleOrDefault()

        If oTable Is Nothing Then
            Return Nothing
        Else
            Return GetDatatable(oTable.TableName, oTable.SQLCommand, oTable.DatabaseType, FilterExpression, SortByColumn, ForceFallback)
        End If
    End Function

    Public Function GetDatatable(DataTable As String, FallbackSQL As String, FallbackType As Constants.DatabaseType, Optional FilterExpression As String = "", Optional SortByColumn As String = "", Optional ForceFallback As Boolean = False) As DataTable
        Try
            Dim oResult As DataTable = Nothing

            If ForceFallback = False Then
                Dim oTableResult As TableResult

                Try
                    oTableResult = _Client.GetDatatableByName(DataTable, FilterExpression, SortByColumn)
                Catch ex As Exception
                    _Logger.Error(ex)
                    oTableResult = Nothing
                End Try

                If oTableResult Is Nothing OrElse oTableResult.OK = False Then
                    _Logger.Warn("Datatable [{0}] could not be fetched from AppServer Cache. Falling back to direct Database Access.")
                    Return GetDatatableFromDatabase(FallbackSQL, FallbackType)
                End If

                Return oTableResult.Table
            Else
                Return GetDatatableFromDatabase(FallbackSQL, FallbackType)
            End If
        Catch ex As Exception
            _Logger.Error(ex)
            Return Nothing
        End Try
    End Function

    Private Function GetDatatableFromDatabase(SQLCommand As String, DatabaseType As DatabaseType)
        Try
            Select Case DatabaseType
                Case DatabaseType.ECM
                    Return _DatabaseEDM.GetDatatable(SQLCommand)

                Case DatabaseType.IDB
                    Return _DatabaseIDB.GetDatatable(SQLCommand)

                Case Else
                    Return Nothing

            End Select
        Catch ex As Exception
            _Logger.Error(ex)
            Return Nothing

        End Try
    End Function

    Public Function GetUserData(UserName As String, ModuleCode As String, Client As Integer) As UserData
        'Dim oSQL = $"SELECT * FROM FNDD_CHECK_USER_MODULE('{UserName}','{ModuleCode}',{Client})"
        'Dim oTable As DataTable = GetDatatable("TBDD_USER_MODULE", $"USERNAME = '{UserName.ToLower}' AND MODULE_SHORT = '{ModuleCode}'", "", oSQL, DatabaseType.ECM)

        'If oTable Is Nothing Then
        '    Return Nothing
        'End If

        'If oTable.Rows.Count = 0 Then
        '    Return Nothing
        'End If

        'Dim oRow As DataRow = oTable.Rows.Item(0)
        'Dim oUserData As New UserData With {
        '    .Id = NotNull(oRow, "USER_ID", -1),
        '    .Surname = NotNull(oRow, "USER_SURNAME", String.Empty),
        '    .Prename = NotNull(oRow, "USER_PRENAME", String.Empty),
        '    .Shortname = NotNull(oRow, "USER_SHORTNAME", String.Empty),
        '    .Email = NotNull(oRow, "USER_EMAIL", String.Empty),
        '    .Language = NotNull(oRow, "USER_LANGUAGE", "de-DE"),
        '    .DateFormat = NotNull(oRow, "USER_DATE_FORMAT", "dd.MM.yyyy")
        '}

        Throw New NotImplementedException()
    End Function

End Class