Imports System.IO
Imports Microsoft.Office.Interop
Imports Microsoft.Office.Interop.Outlook

Public Class ClassDragDrop
    Public Shared files_dropped As String()
    Public Shared Event FilesDroppedReady(ByVal files As String())
    Public Shared Function Drop_File(e As DragEventArgs)
        Try
            LOGGER.Debug("In Drop_File....")
            files_dropped = New String() {}

            ' WICHTIG: DB-Löschung NICHT im UI-Thread erzwingen.
            ' => Verschiebe in aufrufenden Code per BeginInvoke/Task.Run (siehe Kommentar unten).
            ' MYDB_ECM?.ExecuteNonQuery(Sql)

            Dim hasOutlookUnicode As Boolean = e.Data.GetDataPresent("FileGroupDescriptorW")
            Dim hasOutlookAnsi As Boolean = e.Data.GetDataPresent("FileGroupDescriptor")
            Dim hasOutlookContents As Boolean = e.Data.GetDataPresent("FileContents")
            Dim hasChromiumMime As Boolean = e.Data.GetDataPresent("Chromium Web Custom MIME Data Format")
            Dim hasFileNameW As Boolean = e.Data.GetDataPresent("FileNameW") OrElse e.Data.GetDataPresent("FileName")
            Dim hasFileDrop As Boolean = e.Data.GetDataPresent(DataFormats.FileDrop)

            '1) Klassische Outlook-Attachments: Descriptor + Contents
            If (hasOutlookUnicode OrElse hasOutlookAnsi) AndAlso hasOutlookContents Then
                ' ... dein bestehender Descriptor/Contents-Code ...
                ' Return True wenn erfolgreich
            End If

            '2) ATTACHMENT oder komplette Mail aus Outlook/WebView2: KEIN Descriptor+Contents, ABER FileDrop vorhanden
            ' => zuerst FileDrop verarbeiten. Wenn leer (delayed rendering), dann Fallback über Outlook COM Selection/Inspector
            If hasFileDrop AndAlso (hasChromiumMime OrElse hasFileNameW) AndAlso Not hasOutlookContents Then
                LOGGER?.Debug("WebView2/Outlook Attachment or Mail: try FileDrop, skip Outlook COM initially")
                Dim ok As Boolean = HandleFileDrop(e)
                If ok Then Return True

                ' FileDrop leer -> Fallback: versuche ausgewählte Mail via Outlook COM zu speichern
                LOGGER?.Warn("FileDrop vorhanden, aber leer. Fallback auf Outlook COM für komplette Mail.")
                ScheduleOutlookComFallback()
                Return True ' Wichtig: UI-Thread nicht blockieren; wir verarbeiten asynchron.
            End If

            '3) Outlook Mail (.msg): Descriptor ohne Contents ODER Chromium/WebView2 Indikatoren – nur wenn KEIN FileDrop vorhanden
            If Not hasFileDrop AndAlso ((hasOutlookAnsi OrElse hasOutlookUnicode) OrElse hasChromiumMime OrElse hasFileNameW) Then
                Try
                    Dim oApp As Outlook.Application = Nothing
                    Try
                        oApp = New Outlook.Application()
                    Catch ex As System.Exception
                        MsgBox("Fehler beim Initialisieren der Outlook-API:" & vbNewLine & ex.Message, MsgBoxStyle.Critical)
                        GoTo CheckFileDrop
                    End Try

                    Dim explorer = oApp.ActiveExplorer
                    If explorer IsNot Nothing AndAlso explorer.Selection IsNot Nothing AndAlso explorer.Selection.Count > 0 Then
                        LOGGER?.Debug("Drop of msg (Outlook Explorer Selection)")
                        For i As Integer = 1 To explorer.Selection.Count
                            Dim myobj As Object = explorer.Selection.Item(i)
                            If myobj Is Nothing Then Continue For
                            SaveMailItemToTemp(myobj)
                        Next
                        Return True
                    Else
                        Dim inspector = oApp.ActiveInspector
                        If inspector IsNot Nothing AndAlso inspector.CurrentItem IsNot Nothing Then
                            LOGGER?.Debug("Drop of msg (ActiveInspector.CurrentItem) Fallback")
                            SaveMailItemToTemp(inspector.CurrentItem)
                            Return True
                        Else
                            LOGGER?.Warn("Outlook: Keine Auswahl im Explorer und kein ActiveInspector.CurrentItem verfügbar.")
                            ' Namen loggen – aber zurück zum FileDrop-Fallback
                            If hasFileNameW Then
                                Dim namesObj As Object = e.Data.GetData(If(e.Data.GetDataPresent("FileNameW"), "FileNameW", "FileName"), True)
                                Dim names As String() = TryCast(namesObj, String())
                                If names Is Nothing Then
                                    Dim nameSingle As String = TryCast(namesObj, String)
                                    If Not String.IsNullOrWhiteSpace(nameSingle) Then
                                        LOGGER?.Warn("Vorgeschlagener Name (ohne Inhalt): " & nameSingle)
                                    End If
                                Else
                                    LOGGER?.Warn("Vorgeschlagene Namen (ohne Inhalt): " & String.Join("; ", names))
                                End If
                            End If
                            GoTo CheckFileDrop
                        End If
                    End If
                Catch ex As System.Exception
                    LOGGER?.Warn("Outlook MSG-Drop Fehler: " & ex.Message)
                End Try
            End If

CheckFileDrop:
            '4) Filesystem FileDrop (klassisch ODER WebView2 delayed rendering)
            If hasFileDrop Then
                If HandleFileDrop(e) Then Return True
                ScheduleOutlookComFallback()
                Return True
            End If

            '5) SCAN-StringFormat
            If e.Data.GetDataPresent(DataFormats.StringFormat) Then
                Dim Wert As String = TryCast(e.Data.GetData(DataFormats.StringFormat), String)
                If Not String.IsNullOrEmpty(Wert) Then
                    Dim idx As Integer = files_dropped.Length
                    ReDim Preserve files_dropped(idx)
                    files_dropped(idx) = "@SCAN@" & Wert
                    Return True
                End If
            End If

        Catch ex As System.Exception
            MsgBox("Unexpected Error in Drop_File: " & ex.Message, MsgBoxStyle.Critical)
        End Try

        LOGGER?.Warn("Drop_File: Kein extrahierbarer Inhalt. Bitte Attachment aus der Nachrichtenliste ziehen oder zunächst speichern.")
        Return False


    End Function
    ' FileDrop defensiv behandeln – erst ohne, dann mit autoConvert
    Private Shared Function HandleFileDrop(e As DragEventArgs) As Boolean
        Try
            ' Versuch1: ohne AutoConvert
            Dim rawObj As Object = e.Data.GetData(DataFormats.FileDrop)
            Dim rawFiles As String() = TryCast(rawObj, String())
            If Not (rawFiles Is Nothing OrElse rawFiles.Length = 0) Then
                For Each f In rawFiles
                    LOGGER?.Info("FileDrop (raw) - File: " & f)
                    AppendDroppedFile("@DROPFROMFSYSTEM@", f)
                Next
                Return True
            End If

            ' Versuch2: mit AutoConvert (delayed rendering)
            Dim convObj As Object = e.Data.GetData(DataFormats.FileDrop, True)
            Dim convFiles As String() = TryCast(convObj, String())
            If Not (convFiles Is Nothing OrElse convFiles.Length = 0) Then
                For Each f In convFiles
                    LOGGER?.Info("FileDrop (autoConvert) - File: " & f)
                    AppendDroppedFile("@DROPFROMFSYSTEM@", f)
                Next
                Return True
            End If

            LOGGER?.Warn("FileDrop vorhanden, aber keine Dateien (raw/autoConvert leer).")
            Return False
        Catch ex As System.Exception
            LOGGER?.Warn("HandleFileDrop Fehler: " & ex.Message)
            Return False
        End Try
    End Function
    Private Shared Sub AppendDroppedFile(prefix As String, filePath As String)
        Dim idx As Integer = files_dropped.Length
        ReDim Preserve files_dropped(idx)
        files_dropped(idx) = prefix & filePath
    End Sub

    Private Shared Sub SaveMailItemToTemp(ByVal mailObj As Object)
        Dim subj As String = ""
        Try
            subj = mailObj.Subject
        Catch
            subj = "NO_SUBJECT"
        End Try
        If String.IsNullOrWhiteSpace(subj) Then subj = "NO_SUBJECT"

        Dim safeName = subj.Replace("\", "-").Replace("/", "-").Replace(":", "") _
                          .Replace("?", "").Replace("!", "").Replace("%", "").Replace("$", "")
        Dim strFile As String = IO.Path.Combine(Path.GetTempPath(), safeName & ".msg")
        LOGGER?.Info("Drop of msg - File:" & strFile)
        Try
            mailObj.SaveAs(strFile)
            AppendDroppedFile("@OUTLOOK_MESSAGE@", strFile)
        Catch ex As System.Exception
            MsgBox("Error in Save Email2Tempfile" & vbNewLine & ex.Message, MsgBoxStyle.Critical)
        End Try
    End Sub

    Private Shared Sub ScheduleOutlookComFallback()
        Try
            Dim t As New Threading.Thread(
                Sub()
                    Try
                        Threading.Thread.Sleep(200)
                        Dim maxRetries As Integer = 10
                        Dim saved As Boolean = False
                        For attempt As Integer = 1 To maxRetries
                            If TrySaveSelectedMailViaOutlook() Then
                                LOGGER?.Info("Outlook COM Fallback: Mail gespeichert. Versuch " & attempt)
                                saved = True
                                Exit For
                            End If
                            LOGGER?.Debug("Outlook COM Fallback: Keine Auswahl, Retry " & attempt)
                            Threading.Thread.Sleep(200)
                        Next

                        If saved Then
                            ' UI-Thread benachrichtigen
                            Dim uiForm = If(System.Windows.Forms.Application.OpenForms.Count > 0, System.Windows.Forms.Application.OpenForms(0), Nothing)
                            If uiForm IsNot Nothing Then
                                uiForm.BeginInvoke(
                                    Sub()
                                        Try
                                            RaiseEvent FilesDroppedReady(files_dropped)
                                        Catch ex2 As System.Exception
                                            LOGGER?.Warn("FilesDroppedReady Invoke Fehler: " & ex2.Message)
                                        End Try
                                    End Sub)
                            Else
                                ' Falls kein Form verfügbar, zumindest Event auslösen (Listener müssen ggf. selbst marshalen)
                                RaiseEvent FilesDroppedReady(files_dropped)
                            End If
                        Else
                            LOGGER?.Warn("Outlook COM Fallback: Nach Retries keine Mail gespeichert.")
                        End If
                    Catch ex As System.Exception
                        LOGGER?.Warn("Outlook COM Fallback Thread Fehler: " & ex.Message)
                    End Try
                End Sub
            )
            t.IsBackground = True
            t.SetApartmentState(Threading.ApartmentState.STA)
            t.Start()
        Catch ex As System.Exception
            LOGGER?.Warn("ScheduleOutlookComFallback Fehler: " & ex.Message)
        End Try
    End Sub

    Private Shared Function TrySaveSelectedMailViaOutlook() As Boolean
        Try
            Dim oApp As Outlook.Application = Nothing
            Try
                oApp = New Outlook.Application()
            Catch ex As System.Exception
                LOGGER?.Warn("Outlook COM Init fehlgeschlagen: " & ex.Message)
                Return False
            End Try

            Dim savedAny As Boolean = False

            Dim inspector = oApp.ActiveInspector
            If inspector IsNot Nothing AndAlso inspector.CurrentItem IsNot Nothing Then
                LOGGER?.Debug("Fallback: ActiveInspector.CurrentItem speichern")
                SaveMailItemToTemp(inspector.CurrentItem)
                savedAny = True
            End If

            If Not savedAny Then
                Dim explorer = oApp.ActiveExplorer
                If explorer IsNot Nothing AndAlso explorer.Selection IsNot Nothing AndAlso explorer.Selection.Count > 0 Then
                    LOGGER?.Debug("Fallback: Explorer.Selection speichern")
                    For i As Integer = 1 To explorer.Selection.Count
                        Dim myobj As Object = explorer.Selection.Item(i)
                        If myobj Is Nothing Then Continue For
                        SaveMailItemToTemp(myobj)
                        savedAny = True
                    Next
                End If
            End If

            Return savedAny
        Catch ex As System.Exception
            LOGGER?.Warn("TrySaveSelectedMailViaOutlook Fehler: " & ex.Message)
            Return False
        End Try
    End Function

    Public Shared Sub Drag_enter(e As DragEventArgs)
        Try
            My.Settings.WD_INDEXDOKART_SAVE = ""

            Dim hasOutlookUnicode As Boolean = e.Data.GetDataPresent("FileGroupDescriptorW")
            Dim hasOutlookAnsi As Boolean = e.Data.GetDataPresent("FileGroupDescriptor")
            Dim hasOutlookDescriptor As Boolean = hasOutlookUnicode OrElse hasOutlookAnsi

            Dim hasChromiumMime As Boolean = e.Data.GetDataPresent("Chromium Web Custom MIME Data Format")
            Dim hasFileNameW As Boolean = e.Data.GetDataPresent("FileNameW") OrElse e.Data.GetDataPresent("FileName")
            Dim hasOutlookLike As Boolean = hasOutlookDescriptor OrElse hasChromiumMime OrElse hasFileNameW

            Dim hasFileDrop As Boolean = e.Data.GetDataPresent(DataFormats.FileDrop)

            If hasOutlookLike Then
                e.Effect = DragDropEffects.Copy
                LOGGER?.Debug("DragEnter ... Outlook/WebView2 erkannt (Descriptor/Chromium/FileNameW)")
            ElseIf hasFileDrop Then
                e.Effect = DragDropEffects.Copy
                LOGGER?.Debug("DragEnter ... SimpleFileDrop")
            Else
                e.Effect = DragDropEffects.None
                LOGGER?.Debug("DragEnter ... Other FileFormat")
            End If

            LOGGER?.Debug("DragEnter Formats: " & String.Join(", ", e.Data.GetFormats()))
        Catch ex As System.Exception

        End Try
    End Sub

End Class