Public Class Envelope
    Public Property Id As Integer = 0
    Public Property Subject As String
    Public Property Message As String
    Public Property UserId As Integer
    Public Property Uuid As String = Guid.NewGuid.ToString()
    Public Property Status As Constants.EnvelopeStatus

    Public Property Documents As New List(Of EnvelopeDocument)
    Public Property Receivers As New List(Of EnvelopeReceiver)

    Public Function Validate() As List(Of String)
        Dim oErrors As New List(Of String)

        If String.IsNullOrWhiteSpace(Subject) Then
            oErrors.Add(My.Resources.Envelope.Missing_Subject)
        End If

        If String.IsNullOrWhiteSpace(Message) Then
            oErrors.Add(My.Resources.Envelope.Missing_Message)
        End If

        If Documents.Count = 0 Then
            oErrors.Add(My.Resources.Envelope.Missing_Documents)
        End If

        If Receivers.Count = 0 Then
            oErrors.Add(My.Resources.Envelope.Missing_Receivers)
        End If

        Return oErrors
    End Function
End Class