Public Class CalEvent
    Dim varTitle As String
    Public Location As String
    Public Organizer As User
    Dim varStartDate, varStopDate As DateTime
    Dim UID As String
    Dim Busy As Boolean = True
    Public Categories As New List(Of String)
    Dim StartDateSet, StopDateSet, StartTimeSet, StopTimeSet As Boolean



    Public Sub New(creator As User)
        UID = Format(DateTime.Now, "yyyyMMdd-HHmmssffff") & "@" & creator.EMail.Split(CChar("@"))(1)
        setStartDate(Now.Year, Now.Month, Now.Day)
    End Sub


    Public Function getVEvent() As String
        If StartTimeSet = False Then StopTimeSet = False

        If StopDateSet = False Then
            setStopDate(varStartDate.Year, varStartDate.Month, varStartDate.Day)
        End If
        If StartTimeSet And StopTimeSet = False Then
            setStopTime(DateAdd(DateInterval.Hour, 3, varStartDate))
        End If



        getVEvent = "BEGIN:VEVENT" & vbCrLf
        getVEvent &= "UID:" & UID & vbCrLf
        getVEvent &= "DTSTAMP:" & Format(DateTime.UtcNow, "yyyyMMdd""T""HHmmss") & vbCrLf
        If Organizer IsNot Nothing Then getVEvent &= "ORGANIZER:" & Organizer.QualifiedName & vbCrLf
        If StartTimeSet = False Then
            getVEvent &= "DTSTART;VALUE=DATE:" & Format(varStartDate, "yyyyMMdd") & vbCrLf
            getVEvent &= "DTEND;VALUE=DATE:" & Format(varStopDate, "yyyyMMdd") & vbCrLf
        Else
            getVEvent &= "DTSTART:" & Format(varStartDate, "yyyyMMdd""T""HHmmss") & vbCrLf
            getVEvent &= "DTEND:" & Format(varStopDate, "yyyyMMdd""T""HHmmss") & vbCrLf
        End If
        getVEvent &= "SUMMARY:" & varTitle & vbCrLf


        Dim catstring As String = Nothing
        For Each itm As String In Categories
            catstring &= itm & ","
        Next
        catstring = catstring.Remove(catstring.LastIndexOf(","))
        getVEvent &= "CATEGORIES:" & catstring & vbCrLf
        getVEvent &= "END:VEVENT"

    End Function

    Public Property Title As String
        Get
            Return varTitle
        End Get
        Set(value As String)
            varTitle = value.Replace("\", "\\").Replace(";", "\;").Replace(",", "\,")
        End Set
    End Property

    Public Sub setStartDate(year As Integer, month As Integer, day As Integer)
        varStartDate = New Date(year, month, day, varStartDate.Hour, varStartDate.Minute, varStartDate.Second)
        StartDateSet = True
    End Sub

    Public Sub setStopDate(year As Integer, month As Integer, day As Integer)
        varStopDate = New Date(year, month, day, varStopDate.Hour, varStopDate.Minute, varStopDate.Second)
        StopDateSet = True
    End Sub

    Public Sub setStartTime(hour As Integer, minute As Integer, second As Integer)
        varStartDate = New Date(varStartDate.Year, varStartDate.Month, varStartDate.Day, hour, minute, second)
        StartTimeSet = True
    End Sub

    Public Sub setStopTime(hour As Integer, minute As Integer, second As Integer)
        varStopDate = New Date(varStopDate.Year, varStopDate.Month, varStopDate.Day, hour, minute, second)
        StopTimeSet = True
    End Sub

    Public Sub setStopTime(time As Date)
        varStopDate = time
        StopTimeSet = True
    End Sub


End Class



Public Class User
    Public Name, EMail As String

    Public Sub New(varName As String, varMail As String)
        Name = varName
        EMail = varMail
    End Sub

    Public Function QualifiedName() As String
        QualifiedName = "CN=" & Name & ":MAILTO:" & EMail
    End Function
End Class