Option Strict On
Option Explicit On

Public Class Form1

    Const queenPts As Integer = 13
    Const numHearts As Integer = 13
    Const moonPts As Integer = 26

    Private Sub ClearHand()
        txtHearts1.Clear()
        txtHearts2.Clear()
        txtHearts3.Clear()
        txtHearts4.Clear()
        radQueen1.Checked = True
        radQueen2.Checked = False
        radQueen3.Checked = False
        radQueen4.Checked = False
        txtPoints1.Clear()
        txtPoints2.Clear()
        txtPoints3.Clear()
        txtPoints4.Clear()
    End Sub

    Private Sub UpdateTotal(ByVal newPts As Integer, ByRef total As String)

        Dim pts As Integer
        Dim isconverted As Boolean
        ' convert
        isconverted = Integer.TryParse(total, pts)
        ' add
        pts = pts + newPts
        ' display
        total = pts.ToString()
    End Sub

    Private Function calcScore(ByVal hearts As Integer, ByVal queen As Boolean) As Integer
        Dim score As Integer
        score = hearts
        ' add points if they have the quuen of spades
        If queen Then
            score = score + queenPts
        End If
        ' check for "shooting the moon"
        If score = moonPts Then
            score = -1 * moonPts
        End If
        Return score

    End Function

    Private Function validateHearts(ByVal heartStr As String, ByRef hearts As Integer, ByVal min As Integer, ByVal max As Integer, ByVal what As String) As Boolean
        Dim isConverted As Boolean
        isConverted = Integer.TryParse(heartStr, hearts)
        If isConverted Then
            If hearts >= min AndAlso hearts <= max Then
                Return True
            Else
                MsgBox(what & " needs to be between " & min & " and " & max)
                Return False
            End If
        Else
            MsgBox(what & " needs to be a whole number")
            Return False
        End If
    End Function


    Private Function checkHeartTotal(ByVal hearts1 As Integer, ByVal hearts2 As Integer, ByVal hearts3 As Integer, ByVal hearts4 As Integer) As Boolean
        Dim total As Integer
        total = hearts1 + hearts2 + hearts3 + hearts4
        If total = numHearts Then
            ' valid inputs 
            Return True
        Else
            MsgBox("The total number of hearts won by all players MUST add up to 13")
            Return False
        End If
    End Function

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click
        ClearHand()

    End Sub

    Private Sub BtnReset_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnReset.Click
        ClearHand()
        txtTotal1.Text = "0"
        txtTotal2.Text = "0"
        txtTotal3.Text = "0"
        txtTotal4.Text = "0"

    End Sub

    Private Sub btnPlay_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPlay.Click

        Dim points1 As Integer
        Dim points2 As Integer
        Dim points3 As Integer
        Dim points4 As Integer
        Dim hearts1 As Integer
        Dim hearts2 As Integer
        Dim hearts3 As Integer
        Dim hearts4 As Integer
        Dim isValid1 As Boolean
        Dim isValid2 As Boolean
        Dim isValid3 As Boolean
        Dim isValid4 As Boolean
        Dim isCompatible As Boolean
        isValid1 = validateHearts(txtHearts1.Text, hearts1, 0, queenPts, "Player 1 Hearts")
        isValid2 = validateHearts(txtHearts2.Text, hearts2, 0, queenPts, "Player 2 Hearts")
        isValid3 = validateHearts(txtHearts3.Text, hearts3, 0, queenPts, "Player 3 Hearts")
        isValid4 = validateHearts(txtHearts4.Text, hearts4, 0, queenPts, "Player 4 Hearts")

        If isValid1 AndAlso isValid2 AndAlso isValid3 AndAlso isValid4 Then
            isCompatible = checkHeartTotal(hearts1, hearts2, hearts3, hearts4)
            If isCompatible Then
                ' inputs are valid and compatible
                ' calculate points
                points1 = calcScore(hearts1, radQueen1.Checked)
                txtPoints1.Text = points1.ToString()
                ' update total
                UpdateTotal(points1, txtTotal1.Text)
                ' calculate points for player 2
                points2 = calcScore(hearts2, radQueen2.Checked)
                txtPoints2.Text = points2.ToString()
                ' update total
                UpdateTotal(points2, txtTotal2.Text) 
                ' calculate points for player 3
                points3 = calcScore(hearts3, radQueen3.Checked)
                txtPoints3.Text = points3.ToString()
                ' update total
                UpdateTotal(points3, txtTotal3.Text)
                ' calculate points for player 4
                points4 = calcScore(hearts4, radQueen4.Checked)
                txtPoints4.Text = points4.ToString()
                ' update total
                UpdateTotal(points4, txtTotal4.Text)
            End If
        End If

    End Sub
End Class