Public Class GameBoard

    Dim Board(6, 5) As Integer
    Dim col0 As Integer = 0
    Dim col1 As Integer = 0
    Dim col2 As Integer = 0
    Dim col3 As Integer = 0
    Dim col4 As Integer = 0
    Dim col5 As Integer = 0
    Dim Col6 As Integer = 0
    Dim OffsetFromLeft As Integer
    Dim OffsetFromTop As Integer
    Dim Player1 As New Player(Form1.txtPlayer1Name.Text, 1)
    Dim Player2 As New Player(Form1.txtPlayer2Name.Text, 2)
    Dim currentPlayerColor As Integer = 1
    Dim currentPlayerName As String



    'Sets the current player to player1. Is called at load
    Private Sub setInitialPlayer(ByVal Player As Player)

        currentPlayerName = Player.Name()
        currentPlayerColor = Player.Color
    End Sub

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

        setInitialPlayer(Player1)
        ClearBoardArray(Board)



    End Sub
    'Creates a red token picture box, with coordinates taken in as paramaters
    Private Sub createRedPicbox(ByVal OffsetFromLeft As Integer, ByVal OffsetFromTop As Integer)
        Dim ctlPicbox As New PictureBox
        ctlPicbox.BackgroundImage = My.Resources.red
        ctlPicbox.Location = New System.Drawing.Point(OffsetFromLeft, OffsetFromTop)
        ctlPicbox.Size = CType(New System.Drawing.Point(55, 55), Drawing.Size)
        Me.Controls.Add(ctlPicbox)
    End Sub
    'Creates a black token picture box the same way
    Private Sub createBlackPicbox(ByVal OffsetFromLeft As Integer, ByVal OffsetFromTop As Integer)
        Dim ctlPicbox As New PictureBox
        ctlPicbox.BackgroundImage = My.Resources.black
        ctlPicbox.Location = New System.Drawing.Point(OffsetFromLeft, OffsetFromTop)
        ctlPicbox.Size = CType(New System.Drawing.Point(55, 55), Drawing.Size)
        Me.Controls.Add(ctlPicbox)
    End Sub
    'Sets all values in the Integer array Board(,) to 9, which represents an empty space
    Private Sub ClearBoardArray(ByRef Board(,) As Integer)
        Dim row As Integer = 6
        Dim column As Integer
        Do While row >= 0
            For column = 5 To 0 Step -1
                Board(row, column) = 9
            Next
            row = -1
            column = 5

        Loop



    End Sub
    'coordinates for picture box determined by the column corresponding to the button clicked, and the current row counter for that column
    Sub DropTokenPicture(ByVal Column As Integer, ByVal row As Integer)
        Select Case Column
            Case 0
                OffsetFromLeft = 14
            Case 1
                OffsetFromLeft = 85
            Case 2
                OffsetFromLeft = 150
            Case 3
                OffsetFromLeft = 220
            Case 4
                OffsetFromLeft = 290
            Case 5
                OffsetFromLeft = 360
            Case 6
                OffsetFromLeft = 425

        End Select
        If row = 0 Then
            OffsetFromTop = 442
        ElseIf row = 1 Then
            OffsetFromTop = 377
        ElseIf row = 2 Then
            OffsetFromTop = 309
        ElseIf row = 3 Then
            OffsetFromTop = 240
        ElseIf row = 4 Then
            OffsetFromTop = 170
        ElseIf row = 5 Then
            OffsetFromTop = 100
        End If

        If currentPlayerColor = 1 Then
            createRedPicbox(OffsetFromLeft, OffsetFromTop)
        Else
            createBlackPicbox(OffsetFromLeft, OffsetFromTop)
        End If
    End Sub
    'Swaps the currentPlayerName and currentPlayerColor with the other player's
    Private Sub TakeTurn(ByRef currentPlayerName As String)

        If currentPlayerName = Form1.txtPlayer1Name.Text Then
            currentPlayerName = Form1.txtPlayer2Name.Text
            currentPlayerColor = Player2.Color
        Else
            currentPlayerColor = Player1.Color
            currentPlayerName = Form1.txtPlayer1Name.Text
        End If
    End Sub
    'Sets the corresponding slot to 1 for a red token (player 1) 2 for a black token (player 2)
    Private Sub DropToken(ByVal Column As Integer, ByVal row As Integer)

        Board(Column, row) = currentPlayerColor


    End Sub

    'Event handler for the first column's button click event. Calls the DropTokenPicture DropToken checkWinner and takeTurn methods, also increments the column's row counter(col0)
    Private Sub btnCol0_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCol0.Click
        Try
            DropTokenPicture(0, col0)
            DropToken(0, col0)
        checkWinner(Board, 0, col0)
        col0 += 1
        TakeTurn(currentPlayerName)
        Catch ex As Exception
            Dim Str As String = "Column Full"
            MessageBox.Show(Str)
        End Try
    End Sub

    Private Sub btnCol1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCol1.Click
        Try
            DropTokenPicture(1, col1)
            DropToken(1, col1)
            checkWinner(Board, 1, col1)
            col1 += 1
            TakeTurn(currentPlayerName)
        Catch ex As Exception
            Dim Str As String = "Column Full"
            MessageBox.Show(Str)
        End Try

    End Sub

    Private Sub btnCol2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCol2.Click
        Try
            DropTokenPicture(2, col2)
            DropToken(2, col2)
            checkWinner(Board, 2, col2)
            col2 += 1
            TakeTurn(currentPlayerName)
        Catch ex As Exception
            Dim Str As String = "Column Full"
            MessageBox.Show(Str)
        End Try
    End Sub

    Private Sub btnCol3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCol3.Click
        Try
            DropTokenPicture(3, col3)
            DropToken(3, col3)
            checkWinner(Board, 3, col3)
            col3 += 1
            TakeTurn(currentPlayerName)
        Catch ex As Exception
            Dim Str As String = "Column Full"
            MessageBox.Show(Str)
        End Try
    End Sub

    Private Sub btnCol4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCol4.Click
        Try
            DropTokenPicture(4, col4)
            DropToken(4, col4)
            checkWinner(Board, 4, col4)
            col4 += 1
            TakeTurn(currentPlayerName)
        Catch ex As Exception
            Dim Str As String = "Column Full"
            MessageBox.Show(Str)
        End Try
    End Sub

    Private Sub btnCol5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCol5.Click
        Try
            DropTokenPicture(5, col5)
            DropToken(5, col5)
            checkWinner(Board, 5, col5)
            col5 += 1
            TakeTurn(currentPlayerName)
        Catch ex As Exception
            Dim Str As String = "Column Full"
            MessageBox.Show(Str)
        End Try
    End Sub

    Private Sub btnCol6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCol6.Click
        Try
            DropTokenPicture(6, Col6)
            DropToken(6, Col6)

            checkWinner(Board, 6, Col6)
            'INSERT CODE TO DISPLAY UPDATE DB, DISPLAY NEW SCOREBOARD AND CLOSE THE GAMEBOARD FORM
            Col6 += 1
            TakeTurn(currentPlayerName)
        Catch ex As Exception
            Dim Str As String = "Column Full"
            MessageBox.Show(Str)
        End Try
    End Sub
    'Checks horizontally around the token that was just placed for tree adjacent matching tokens. returns true if there are 4 in a row
    Private Function checkHorizontal(ByRef Board As Integer(,), ByVal Column As Integer, ByVal Row As Integer) As Boolean
        Dim numcheckleft As Integer = 0
        Dim numcheckright As Integer = 0
        Dim result As Boolean
        Dim numtokens As Integer = 1
        Dim coltemp1 As Integer = Column
        Dim coltemp2 As Integer = Column
        Select Case Column
            Case 0
                numcheckleft = 0
                numcheckright = 3
            Case 1
                numcheckleft = 1
                numcheckright = 2
            Case 2
                numcheckleft = 2
                numcheckright = 3
            Case 3
                numcheckleft = 3
                numcheckright = 3
            Case 4
                numcheckleft = 3
                numcheckright = 2
            Case 5
                numcheckleft = 3
                numcheckright = 1
            Case 6
                numcheckleft = 3
                numcheckright = 0

        End Select

        Do Until numcheckleft = 0

            If pieceMatches(Board, coltemp1 - 1, Row) = True Then
                numtokens = numtokens + 1
            Else
                Exit Do
            End If
            numcheckleft = numcheckleft - 1
            coltemp1 = coltemp1 - 1
        Loop

        Do Until numcheckright = 0

            If pieceMatches(Board, coltemp2 + 1, Row) = True Then
                numtokens = numtokens + 1
            Else
                Exit Do
            End If

            numcheckright = numcheckright - 1
            coltemp2 = coltemp2 + 1
        Loop

        If numtokens >= 4 Then
            result = True
        Else
            result = False

        End If

        numcheckleft = 0
        numtokens = 0
        Return result
    End Function
    'Checks vertically around the token that was just placed for tree adjacent matching tokens. returns true if there are 4 in a row
    Private Function checkVertical(ByRef Board As Integer(,), ByVal Column As Integer, ByVal Row As Integer) As Boolean
        Dim numcheckup As Integer = 0
        Dim numcheckdown As Integer = 0
        Dim result As Boolean
        Dim numtokens As Integer = 1
        Dim rowtemp1 As Integer = Row
        Dim rowtemp2 As Integer = Row

        Select Case Row
            Case 0
                numcheckdown = 0
                numcheckup = 3
            Case 1
                numcheckdown = 1
                numcheckup = 2
            Case 2
                numcheckdown = 2
                numcheckup = 3
            Case 3
                numcheckdown = 3
                numcheckup = 2
            Case 4
                numcheckdown = 3
                numcheckup = 1
            Case 5
                numcheckdown = 3
                numcheckup = 0

        End Select

        Do Until numcheckdown = 0

            If pieceMatches(Board, Column, rowtemp1 - 1) = True Then
                numtokens = numtokens + 1
            Else
                Exit Do
            End If
            numcheckdown = numcheckdown - 1
            rowtemp1 = rowtemp1 - 1
        Loop

        Do Until numcheckup = 0
            If pieceMatches(Board, Column, Row + 1) = True Then
                numtokens = numtokens + 1
            Else
                Exit Do
            End If
            numcheckup = numcheckup - 1
            rowtemp2 = rowtemp2 + 1
        Loop

        If numtokens = 4 Then
            result = True
        Else
            result = False

        End If
        numcheckup = 0
        numcheckdown = 0
        numtokens = 0
        Return result
    End Function
    'Checks diagonally around the token that was just placed for tree adjacent matching tokens. returns true if there are 4 in a row
    Private Function checkDiagonal(ByRef Board As Integer(,), ByVal Column As Integer, ByVal Row As Integer) As Boolean
        Dim numcheckupright As Integer = 0
        Dim numcheckdownleft As Integer = 0
        Dim result As Boolean
        Dim numtokens As Integer = 1
        Dim rowtemp1 As Integer = Row
        Dim rowtemp2 As Integer = Row
        Dim coltemp1 As Integer = Column
        Dim coltemp2 As Integer = Column

        Select Case Column
            Case 0
                If Row = 2 Then
                    numcheckupright = 3
                    numcheckdownleft = 0
                End If
            Case 1
                If Row = 3 Then
                    numcheckupright = 2
                    numcheckdownleft = 1
                ElseIf Row = 2 Then
                    numcheckupright = 3
                    numcheckdownleft = 1
                ElseIf Row = 1 Then
                    numcheckupright = 3
                    numcheckdownleft = 1
                End If
            Case 2
                If Row = 4 Then
                    numcheckupright = 1
                    numcheckdownleft = 2
                ElseIf Row = 3 Then
                    numcheckupright = 2
                    numcheckdownleft = 2
                ElseIf Row = 2 Then
                    numcheckupright = 3
                    numcheckdownleft = 2
                ElseIf Row = 1 Then
                    numcheckupright = 3
                    numcheckdownleft = 1
                End If
            Case 3
                If Row = 5 Then
                    numcheckupright = 0
                    numcheckdownleft = 3
                ElseIf Row = 4 Then
                    numcheckupright = 1
                    numcheckdownleft = 3
                ElseIf Row = 3 Then
                    numcheckupright = 2
                    numcheckdownleft = 3
                ElseIf Row = 2 Then
                    numcheckupright = 3
                    numcheckdownleft = 2
                ElseIf Row = 1 Then
                    numcheckupright = 3
                    numcheckdownleft = 1
                End If
            Case 4
                If Row = 5 Then
                    numcheckupright = 0
                    numcheckdownleft = 3
                ElseIf Row = 4 Then
                    numcheckupright = 1
                    numcheckdownleft = 3
                ElseIf Row = 3 Then
                    numcheckupright = 2
                    numcheckdownleft = 3
                ElseIf Row = 2 Then
                    numcheckupright = 2
                    numcheckdownleft = 2
                ElseIf Row = 1 Then
                    numcheckupright = 2
                    numcheckdownleft = 1
                End If

            Case 5
                If Row = 5 Then
                    numcheckupright = 0
                    numcheckdownleft = 3
                ElseIf Row = 4 Then
                    numcheckupright = 1
                    numcheckdownleft = 3
                ElseIf Row = 3 Then
                    numcheckupright = 1
                    numcheckdownleft = 3
                ElseIf Row = 2 Then
                    numcheckupright = 1
                    numcheckdownleft = 2
                End If
            Case 6
                If Row = 5 Then
                    numcheckupright = 0
                    numcheckdownleft = 3
                ElseIf Row = 4 Then
                    numcheckupright = 0
                    numcheckdownleft = 3
                ElseIf Row = 3 Then
                    numcheckupright = 0
                    numcheckdownleft = 3
                End If
        End Select

        Do Until numcheckupright = 0

            If pieceMatches(Board, coltemp1 + 1, rowtemp1 + 1) = True Then
                numtokens = numtokens + 1
            Else
                Exit Do
            End If
            coltemp1 = coltemp1 + 1
            rowtemp1 = rowtemp1 + 1
        Loop

        Do Until numcheckdownleft = 0
            If pieceMatches(Board, coltemp2 - 1, rowtemp2 - 1) = True Then
                numtokens = numtokens + 1
            Else
                Exit Do
            End If
            numcheckdownleft = numcheckdownleft - 1
            coltemp2 = coltemp2 - 1
            rowtemp2 = rowtemp2 - 1
        Loop

        If numtokens = 4 Then
            result = True
        Else
            result = False

        End If
        numcheckupright = 0
        numcheckdownleft = 0
        numtokens = 0
        Return result
    End Function
    'Calls all three checking functions. returns true if one of them returned true
    Private Function checkWinner(ByRef Board As Integer(,), ByVal Column As Integer, ByVal Row As Integer) As Boolean
        Dim result As Boolean = False
        If checkHorizontal(Board, Column, Row) Or checkVertical(Board, Column, Row) Or checkDiagonal(Board, Column, Row) Then
            MessageBox.Show(currentPlayerName & " has won!")
            result = True
        End If
        Return result
    End Function
    'Checks to see that a token in the specified location matches the current player's token color
    Private Function pieceMatches(ByRef Board As Integer(,), ByVal x As Integer, ByVal y As Integer) As Boolean
        If Board(x, y) = currentPlayerColor Then
            Return True
        Else
            Return False
        End If
    End Function
End Class