Option Explicit On
Option Strict On
Option Infer Off

Public Class MainForm

    Private Sub btnCalc_Click(ByVal sender As Object, _
                                  ByVal e As System.EventArgs) _
                                  Handles btnCalc.Click



        ' Declare variables

        Dim strCurrentMonth As String

        Dim decCurrentSales As Decimal = 0D
        Dim decCurrentExpenses As Decimal = 0D
        Dim decCurrentProfit As Decimal = 0D

        Dim decAvgSales As Decimal = 0D
        Dim decAvgExpenses As Decimal = 0D
        Dim decAvgProfit As Decimal = 0D

        Dim decTotalSales As Decimal = 0D
        Dim decTotalExpenses As Decimal = 0D
        Dim decTotalProfit As Decimal = 0D

        Dim decMargin As Decimal

        Dim cntMonths As Integer = 0

        ' Clear current month label contents
        lblCurrentMonth.Text = String.Empty
        lblCurrentSales.Text = String.Empty
        lblCurrentExpenses.Text = String.Empty
        lblCurrentProfit.Text = String.Empty


        ' Loop!
        Do
            ' Assign
            strCurrentMonth = InputBox("Enter the month: ", "First Month")

            ' If the user entered a month (or anything). This way is filthy.
            If strCurrentMonth > "" Then

                ' Count months added
                cntMonths = cntMonths + 1

                ' Parse strings to decimals
                Decimal.TryParse(InputBox("Enter the sales amount for " & strCurrentMonth, "Sales"), decCurrentSales)
                Decimal.TryParse(InputBox("Enter the expense amount for " & strCurrentMonth, "Expenses"), decCurrentExpenses)

                ' math stuff
                decCurrentProfit = decCurrentSales - decCurrentExpenses

                decTotalSales = decTotalSales + decCurrentSales
                decTotalExpenses = decTotalExpenses + decCurrentExpenses
                decTotalProfit = decTotalSales - decTotalExpenses

                decAvgSales = decTotalSales / cntMonths
                decAvgExpenses = decTotalExpenses / cntMonths
                decAvgProfit = decTotalProfit / cntMonths
            Else
                ' No input, so exit loop
                Exit Do
            End If

            ' Profit margin math:
            decMargin = decTotalProfit / decTotalSales


            If decMargin >= 0.1 Then
                lblMsg.Text = "The profit margin of " & Format(Convert.ToString(decMargin), "Percent") & " is great performance."
            ElseIf decMargin >= 0.05 Then
                lblMsg.Text = "The profit margin of " & Format(Convert.ToString(decMargin), "Percent") & " is average performance."
            Else
                lblMsg.Text = "The profit margin of " & Format(Convert.ToString(decMargin), "Percent") & " is subpar performance."
            End If

            ' Show labels
            lblCurrentSales.Text = Format(Convert.ToString(decCurrentSales), "Currency")
            lblCurrentExpenses.Text = Format(Convert.ToString(decCurrentExpenses), "Currency")
            lblCurrentProfit.Text = Format(Convert.ToString(decCurrentProfit), "Currency")

            lblAvgSales.Text = Format(Convert.ToString(decAvgSales), "Currency")
            lblAvgExpenses.Text = Format(Convert.ToString(decAvgExpenses), "Currency")
            lblAvgProfit.Text = Format(Convert.ToString(decAvgProfit), "Currency")

            lblTotalMonths.Text = Convert.ToString(cntMonths)
            lblTotalSales.Text = Format(Convert.ToString(decTotalSales), "Currency")
            lblTotalExpenses.Text = Format(Convert.ToString(decTotalExpenses), "Currency")
            lblTotalProfit.Text = Format(Convert.ToString(decTotalProfit), "Currency")

            lblCurrentMonth.Text = strCurrentMonth



            'Loop while there's 'month' input
        Loop While strCurrentMonth > ""



    End Sub

    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click

        ' Declare button result var
        Dim dlgButton As DialogResult

        Dim strPROMPT As String = "Do you wish to exit?"

        ' Ask the user to confirm exit
        dlgButton = MessageBox.Show(strPROMPT, "Exit?", _
                                    MessageBoxButtons.YesNo, _
                                    MessageBoxIcon.Question)

        ' If Yes button is hit, close application
        If dlgButton = Windows.Forms.DialogResult.Yes Then
            Me.Close()
        End If

        ' Ideally, we'd want to use an Else or ElseIf statement to deal with the "No" button option, but in this case,
        ' VB does what we need it to do, for us

    End Sub

    Private Sub btnReset_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnReset.Click

        lblTotalMonths.Text = String.Empty
        lblTotalExpenses.Text = String.Empty
        lblTotalSales.Text = String.Empty
        lblTotalProfit.Text = String.Empty

        lblAvgProfit.Text = String.Empty
        lblAvgExpenses.Text = String.Empty
        lblAvgSales.Text = String.Empty

        lblCurrentExpenses.Text = String.Empty
        lblCurrentMonth.Text = String.Empty
        lblCurrentProfit.Text = String.Empty
        lblCurrentSales.Text = String.Empty

        lblMsg.Text = String.Empty


    End Sub
End Class