Public Class Form1
    'Program: Lab6jtgrkb
    'Author: Tre Griffin, 16054704,lab K, Oct 14, 2010
    'Description: program to determine mid-term grades,read from files,using byref sub procedures and fucntions


    Dim studentname As String
    Private Sub btncalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btncalculate.Click
        '1.  Determine file to read.
        lstdisplay.Items.Clear()
        Dim filename As String = FindFilename(cbofile.Text)
        Dim sr As IO.StreamReader
        sr = IO.File.OpenText(filename)
        '2. Display the table header in the list box


        Dim fmtzone As String = " {0,-20}{1,15}{2,15}{3,15}{4,15}{5,15}{6,15}{7,15}"
        lstdisplay.Items.Add(String.Format(fmtzone, "Reading From" & " " & filename, " " & "Today's Date:" & mtxt.Text, "", "", "", "", "", ""))
        lstdisplay.Items.Add(String.Format(fmtzone, "Student Name", "Mid-Term", "Hw/Exerc", "Written", "Total", "Grade", "Points", " Make it?"))



        '3. Start Loop: repeat 10 times, once for each line of the file.
        Dim counter As Integer = 0
        Do While counter < 10


            '   4. Read a line from the file.
            Dim Line As String
            Line = sr.ReadLine

            '   5. Split line into useful vaules
            '       This is a good place for ByRef subroutine.

            Dim midtermscore, homeworkscore, writtenscore As Integer

            Call splitline(Line, studentname, midtermscore, homeworkscore, writtenscore)
            '   6. Process the line:

            '       a. swap the first and last name, add a comma.(Function)(swap Names)

            Dim positionspace As Integer
            Dim last, first As String
            positionspace = studentname.IndexOf(" ")
            first = studentname.Substring(0, positionspace)
            last = studentname.Substring(positionspace + 1).Trim
            studentname = last & "," & first
            '       b. calculate total score (sum of all the scores).
            Dim totalscore As Double
            totalscore = midtermscore + homeworkscore + writtenscore
            '       c. Determine the current letter grade.(total out of 300)
            Dim grade As String
            Select Case totalscore
                Case Is >= 270
                    grade = "A"
                Case Is >= 240
                    grade = "B"
                Case Is >= 210
                    grade = "C"
                Case Is >= 180
                    grade = "D"
                Case Else
                    grade = "F"
            End Select





            '       d. calculate the points needed on the final to get an A.
            Dim totalneeded As Double

            totalneeded = 450 - totalscore
            ' determine makeitvaule
            Dim makeit As String

            makeit = letsdoit(totalneeded)
            '   7. Display output for this student in the list box.


            lstdisplay.Items.Add(String.Format(fmtzone, studentname, midtermscore, homeworkscore, writtenscore, totalscore, grade, totalneeded, makeit))

            '   8. Increment loop counter.
            counter += 1
            '   9. End the loop.

        Loop

        '   10. close the file

        sr.Close()

    End Sub
    'Sub: to part the line and get the student name and scored.
    'Input: line from the scores file.
    'Output: the student name and scores.
    Sub splitline(ByVal line As String, ByRef studentname As String, ByRef midterm As Integer, _
                  ByRef homework As Integer, ByRef written As Integer)

        Dim pos1, pos2, pos3 As Integer
        pos1 = line.IndexOf(",")
        pos2 = line.IndexOf(",", pos1 + 1)
        pos3 = line.IndexOf(",", pos2 + 1)


        studentname = line.Substring(0, pos1)
        midterm = line.Substring(pos1 + 1, pos2 - (pos1 + 1)).Trim
        homework = line.Substring(pos2 + 1, pos3 - (pos2 + 1)).Trim
        written = line.Substring(pos3 + 1).Trim


    End Sub
    'Function: decide whether or no student can make the right grade
    'Input: points needed
    'Return: No way, Possible, Good Chance

    Function letsdoit(ByVal pointsneeded As Double) As String
        Select Case pointsneeded
            Case Is > 200
                Return "No Way"
            Case Is > 180
                Return " Possible"
            Case Is > 160
                Return " Good Chance"
            Case Else
                Return "Good Chance"
        End Select
    End Function
    'Function: to pick a file based off of a combo box
    'Input: user's selection
    'Return: filename

    Function FindFilename(ByVal selection As String) As String
        Dim filename As String
        Select Case selection
            Case "Anthropology"
                filename = "Anthropology.txt"
            Case "Environmental Science"
                filename = "EnvironmentalScience.txt"
            Case "Geography"
                filename = "Geography.txt"
            Case "Mathematics"
                filename = "Mathematics.txt"
            Case Else
                cbofile.Text = "Anthropology"
                filename = "Anthropology.txt"
                MsgBox("You forgot to select a file - will use Anthropology file")

        End Select
        Return filename
    End Function


    Private Sub btnexit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnexit.Click
        End
    End Sub



End Class