Voting.bas

Attribute VB_Name = "Voting"
Option Explicit


Public votes As Dictionary


Private started As Boolean

Private COMPort As Integer

Private timerID As Variant

Private lastSlideIndex As Integer


Public Sub Start()
    On Error GoTo HandleError

    COMPort = settings("voting.port")

    Dim status As Long
    status = CommOpen(COMPort, "COM" & COMPort, "baud=115200 parity=N data=8 stop=1")

    If status <> 0 Then
        Dim errorString As String
        status = CommGetError(errorString)
        Err.Raise status, Description:=errorString
    End If

    CommSetLine COMPort, LINE_RTS, True
    CommSetLine COMPort, LINE_DTR, True

    timerID = System.SetTimer(0, 0, 100, AddressOf Run) ' Repeat every 100 ms

    started = True

    LogInfoAt "Voting.start", "Communication started on COM port " & COMPort & ", frequency 115200 bauds, 8N1 configuration"

    Exit Sub

HandleError:

    LogLastErrorAt "Voting.Start"

End Sub


Sub Run()
    On Error GoTo HandleError

    Dim key As Variant

    For Each key In Utils.GetBlankSlideKeys()

        If System.GetAsyncKeyState(key) Then
            With diagram
                If .Visible Then
                    .Hide

                    ActivePresentation.SlideShowWindow.View.GotoSlide lastSlideIndex
                Else
                    lastSlideIndex = ActivePresentation.SlideShowWindow.View.slide.slideIndex
                    loadVotes
                    .Show
                End If
            End With
        End If

    Next key


    If diagram.Visible Then

        For Each key In Utils.GetBackwardKeys()
            If System.GetAsyncKeyState(key) Then
                clearVotes
                diagram.Hide
                ActivePresentation.SlideShowWindow.View.GotoSlide lastSlideIndex
            End If
        Next key

        For Each key In Utils.GetForwardKeys()
            If System.GetAsyncKeyState(key) Then LoadVotes
        Next key

    End If


    Exit Sub

HandleError:

    LogLastErrorAt "Voting.Run"

End Sub


Public Sub Finish()
    On Error GoTo HandleError

    If started Then
        System.KillTimer 0, timerID

        CommSetLine COMPort, LINE_RTS, False
        CommSetLine COMPort, LINE_DTR, False
        CommClose COMPort

        LogInfoAt "Voting.Finish", "COM communication shut down"
    End If

    started = False

    Exit Sub

HandleError:

    started = False

    LogLastErrorAt "Voting.Finish"

End Sub


Private Sub SendMessage(msg As String)
    On Error GoTo HandleError

    Dim status As Long
    Dim size As Long
    size = Len(msg)
    status = CommWrite(COMPort, msg)

    If status <> size Then
        Dim description As String
        status = CommGetError(description)
        Err.Raise status, Description:=description
    End If

    Exit Sub

HandleError:

    LogLastErrorAt "Voting.SendMessage"

End Sub


Public Sub ClearVotes()
    On Error GoTo HandleError

    diagram.ClearVotes
    SendMessage "c"
    LogInfoAt "Voting.ClearVotes", "All votes cleared from the server"

    Exit Sub

HandleError:

    LogLastErrorAt "Voting.ClearVotes"

End Sub


Public Sub LoadVotes()
    On Error GoTo HandleError

    SendMessage "g"

    System.Sleep 100

    Dim status As Long
    Dim readData As String
    status = CommRead(COMPort, readData, 1)

    If status < 0 Then
        Dim description As String
        status = CommGetError(description)
        Err.Raise status, Description:=description
    End If

    Set votes = Json.ParseJson(readData)

    If Not votes.Exists("total") Then
        Err.Raise 0, Description:="Invalid JSON respond: no 'total' key"
    End If

    LogVotes votes

    ' Copy voter("total") {Array of Variant} to totalVotes {Array of Integer}
    Dim totalVotes(7) As Integer
    Dim i As Integer
    For i = 1 To 7
        totalVotes(i) = votes("total")(i)
    Next i

    diagram.DrawValues totalVotes

    Exit Sub

HandleError:

    LogLastErrorAt "Voting.LoadVotes"

End Sub


Public Sub CheckConnection()
    On Error GoTo HandleError

    COMPort = settings("voting.port")

    Dim status As Long
    status = CommOpen(COMPort, "COM" & COMPort, "baud=115200 parity=N data=8 stop=1")
    If status <> 0 Then
        MsgBox "Failed to connect (code: 1)", vbCritical, "PPVoting error"
        Exit Sub
    End If

    CommSetLine COMPort, LINE_RTS, True
    CommSetLine COMPort, LINE_DTR, True

    status = CommWrite(COMPort, "k")
    If status <> 1 Then
        MsgBox "Failed to send validation request (code: 2)", vbCritical, "PPVoting error"
        GoTo Terminate
    End If

    System.Sleep 100

    Dim readData As String
    status = CommRead(COMPort, readData, 2)
    If status < 0 Then
        MsgBox "Failed to get validation respond (code: 3)", vbCritical, "PPVoting error"
        GoTo Terminate
    End If

    If readData <> "OK" Then
        MsgBox "Validation failed (code: 4)", vbCritical, "PPVoting error"
        GoTo Terminate
    End If

    MsgBox "Success", vbInformation, "PPVoting info"

Terminate:

    CommSetLine COMPort, LINE_RTS, False
    CommSetLine COMPort, LINE_DTR, False

    CommClose COMPort

    Exit Sub

HandleError:

    LogLastErrorAt "Voting.CheckConnection"

End Sub