'Author: Mike Camenzuli, 100374827
'Title: Lab 2 - Semester Average
'Date: Feb.20/2018
'Description: Calculate student averages based on user input.
Option Strict On
Public Class frmSemGrades
    Dim GradeDouble As Double          'user inputs
    Dim GradeArray(5) As Double        'array for grades to go into
    Dim GradeSum As Double             'variable for grades to be summed up
    Dim PercentGrade As Double

    Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub

    Private Sub btnReset_Click(sender As Object, e As EventArgs) Handles btnReset.Click
        tbGradeCourse1.Text = ""
        tbGradeCourse2.Text = ""
        tbGradeCourse3.Text = ""
        tbGradeCourse4.Text = ""
        tbGradeCourse5.Text = ""
        tbGradeCourse6.Text = ""
        tbGradeSem.Text = ""
        tbLetterGradeSem.Text = ""
        tbLetterGrade1.Text = ""
        tbLetterGrade2.Text = ""
        tbLetterGrade3.Text = ""
        tbLetterGrade4.Text = ""
        tbLetterGrade5.Text = ""
        tbLetterGrade6.Text = ""
        tbErrorOutput.Text = ""
        tbGradeCourse1.Focus()
        btnCalculate.Enabled = True
        tbGradeCourse1.ReadOnly = False
        tbGradeCourse2.ReadOnly = False
        tbGradeCourse3.ReadOnly = False
        tbGradeCourse4.ReadOnly = False
        tbGradeCourse5.ReadOnly = False
        tbGradeCourse6.ReadOnly = False
    End Sub
    Private Function validNumber(currentGrade As String) As Double
        Dim returnNumber As Double = 0.0

        tbErrorOutput.ResetText()

        If (IsNumeric(currentGrade) = False) Then
            returnNumber = 1
            tbErrorOutput.Text += $"Grade input must be numeric.{vbCrLf}"
        ElseIf (CDbl(currentGrade) < 0.0) Or (CDbl(currentGrade) > 100.0) Then
            returnNumber = 2
            tbErrorOutput.Text += $"Please enter a number within 0-100.{vbCrLf}"
        End If

        Return returnNumber

    End Function


    Private Sub btnCalculate_Click(sender As Object, e As EventArgs) Handles btnCalculate.Click

        For Index = 0 To 5
            If tbGradeCourse1.Text = "" Then
                tbErrorOutput.Text = "Entry must be Numeric."
            ElseIf tbGradeCourse2.Text = "" Then
                tbErrorOutput.Text = "Entry must be Numeric."
            ElseIf tbGradeCourse3.Text = "" Then
                tbErrorOutput.Text = "Entry must be Numeric."
            ElseIf tbGradeCourse4.Text = "" Then
                tbErrorOutput.Text = "Entry must be Numeric."
            ElseIf tbGradeCourse5.Text = "" Then
                tbErrorOutput.Text = "Entry must be Numeric."
            ElseIf tbGradeCourse6.Text = "" Then
                tbErrorOutput.Text = "Entry must be Numeric."

            Else

                GradeSum += GradeArray(Index)

            End If
        Next

        tbGradeSem.Text = $"{Math.Round(GradeSum / 6, 2)}"
        tbLetterGradeSem.Text = LetterGrade(CDbl(tbGradeSem.Text))

        tbGradeCourse1.ReadOnly = True
        tbGradeCourse2.ReadOnly = True
        tbGradeCourse3.ReadOnly = True
        tbGradeCourse4.ReadOnly = True
        tbGradeCourse5.ReadOnly = True
        tbGradeCourse6.ReadOnly = True
        btnCalculate.Enabled = False
    End Sub

    Private Function LetterGrade(Letter As Double) As String
        Dim returnLetterGrade As String


        Select Case Letter
            Case 90 To 100
                returnLetterGrade = "A+"
            Case 85 To 89.99
                returnLetterGrade = "A"
            Case 80 To 84.99
                returnLetterGrade = "A-"
            Case 77 To 79.99
                returnLetterGrade = "B+"
            Case 73 To 76.99
                returnLetterGrade = "B"
            Case 70 To 72.99
                returnLetterGrade = "B-"
            Case 67 To 69.99
                returnLetterGrade = "C+"
            Case 63 To 66.99
                returnLetterGrade = "C"
            Case 60 To 62.99
                returnLetterGrade = "C-"
            Case 57 To 59.99
                returnLetterGrade = "D+"
            Case 53 To 56.99
                returnLetterGrade = "D"
            Case 50 To 52.99
                returnLetterGrade = "D-"
            Case 0 To 49.99
                returnLetterGrade = "F"
        End Select

        Return returnLetterGrade

    End Function
    Private Sub tbGradeCourse1_LostFocus(sender As Object, e As EventArgs) Handles tbGradeCourse1.LostFocus
        If (validNumber(tbGradeCourse1.Text) = 0) Then
            Double.TryParse(tbGradeCourse1.Text, PercentGrade)
            tbLetterGrade1.Text = LetterGrade(PercentGrade)
            GradeArray(0) = PercentGrade
        Else
            tbGradeCourse1.Clear()
            tbGradeCourse1.Focus()
        End If
    End Sub

    Private Sub tbGradeCourse2_LostFocus(sender As Object, e As EventArgs) Handles tbGradeCourse2.LostFocus
        If (validNumber(tbGradeCourse2.Text) = 0) Then
            Double.TryParse(tbGradeCourse2.Text, PercentGrade)
            tbLetterGrade2.Text = LetterGrade(PercentGrade)
            GradeArray(1) = PercentGrade
        Else
            tbGradeCourse2.Clear()
            tbGradeCourse2.Focus()
        End If
    End Sub

    Private Sub tbGradeCourse3_LostFocus(sender As Object, e As EventArgs) Handles tbGradeCourse3.LostFocus
        If (validNumber(tbGradeCourse3.Text) = 0) Then
            Double.TryParse(tbGradeCourse3.Text, PercentGrade)
            tbLetterGrade3.Text = LetterGrade(PercentGrade)
            GradeArray(2) = PercentGrade
        Else
            tbGradeCourse3.Clear()
            tbGradeCourse3.Focus()
        End If
    End Sub

    Private Sub tbGradeCourse4_LostFocus(sender As Object, e As EventArgs) Handles tbGradeCourse4.LostFocus
        If (validNumber(tbGradeCourse4.Text) = 0) Then
            Double.TryParse(tbGradeCourse4.Text, PercentGrade)
            tbLetterGrade4.Text = LetterGrade(PercentGrade)
            GradeArray(3) = PercentGrade
        Else
            tbGradeCourse4.Clear()
            tbGradeCourse4.Focus()
        End If
    End Sub

    Private Sub tbGradeCourse5_LostFocus(sender As Object, e As EventArgs) Handles tbGradeCourse5.LostFocus
        If (validNumber(tbGradeCourse5.Text) = 0) Then
            Double.TryParse(tbGradeCourse5.Text, PercentGrade)
            tbLetterGrade5.Text = LetterGrade(PercentGrade)
            GradeArray(4) = PercentGrade
        Else
            tbGradeCourse5.Clear()
            tbGradeCourse5.Focus()
        End If
    End Sub

    Private Sub tbGradeCourse6_LostFocus(sender As Object, e As EventArgs) Handles tbGradeCourse6.LostFocus
        If (validNumber(tbGradeCourse6.Text) = 0) Then
            Double.TryParse(tbGradeCourse6.Text, PercentGrade)
            tbLetterGrade6.Text = LetterGrade(PercentGrade)
            GradeArray(5) = PercentGrade
        Else
            tbGradeCourse6.Clear()
            tbGradeCourse6.Focus()
        End If
    End Sub
End Class