Imports System.IO
Imports System.Reflection
Imports System.Drawing.Printing
Public Class Form1
    Dim _assembly As [Assembly]  'to get at pdf file
    Dim r As BinaryReader  'to read pdf file
    Dim sudoku(80, 2, 2, 2, 2, 2, 2) As Byte  '0 1 2 and 81 steps
    'this is suduku(step,x large,y large,x small,y small,num X,num Y)
    Dim sustep As Byte
    Dim xl As Byte
    Dim yl As Byte  'the large square
    Dim xs As Byte
    Dim ys As Byte   'the small square
    Dim nx As Byte
    Dim ny As Byte  ' numbers 1 to 9 in each small square
    Dim randomgenerator As New Random
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        _assembly = [Assembly].GetExecutingAssembly()
        Dim sunum As Byte = 1  'set initial suddoku
        For n = 1 To 3
            For m = 1 To 3              'set 1 to 9 in each number box
                For l = 1 To 3
                    For k = 1 To 3
                        For j = 1 To 3
                            For i = 1 To 3
                                sudoku(sustep, m - 1, n - 1, k - 1, l - 1, i - 1, j - 1) = sunum
                                sunum = sunum + 1
                            Next i
                        Next j
                        sunum = 1 'set number back to 1 for next box
                    Next k
                Next l
            Next m
        Next n

    End Sub
    Private Sub Form1_MouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseClick
        Dim xmouse As Integer = MousePosition.X - 400
        Dim ymouse As Integer = MousePosition.Y - 120 'is MouseButtons in sudoku
        nx = 0
        xs = 0
        xl = 0  'reset matrix counters to find selected position
        ny = 0
        ys = 0
        yl = 0
        If xmouse > 0 And xmouse < 540 And ymouse > 0 And ymouse < 540 Then
            'find x position for selected number
            Do While xmouse > 0
                xmouse = xmouse - 20
                If xmouse > 0 Then
                    nx = nx + 1
                    If nx = 3 Then
                        nx = 0
                        xs = xs + 1
                        If xs = 3 Then
                            xs = 0
                            xl = xl + 1
                        End If
                    End If
                End If
            Loop
            'find y position for selected number
            Do While ymouse > 0
                ymouse = ymouse - 20
                If ymouse > 0 Then
                    ny = ny + 1
                    If ny = 3 Then
                        ny = 0
                        ys = ys + 1
                        If ys = 3 Then
                            ys = 0
                            yl = yl + 1
                        End If
                    End If
                End If
            Loop
            numberselected()  'incorporate number in sudoku
            checkselection()
            'display new sudoku
            Form1_Paint(Nothing, Nothing)
        End If
    End Sub
    Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
        Dim g As Graphics = CreateGraphics()
        g.FillRectangle(Brushes.White, 400, 100, 540, 540)
        Dim blackpen As New Pen(Color.Black, 3)
        For i = 0 To 3 ' large squaresdraw
            g.DrawLine(blackpen, 400, i * 180 + 100, 940, i * 180 + 100)
            g.DrawLine(blackpen, i * 180 + 400, 100, i * 180 + 400, 640)
        Next
        For i = 0 To 9  'draw small squares
            g.DrawLine(Pens.Black, 400, i * 60 + 100, 940, i * 60 + 100)
            g.DrawLine(Pens.Black, i * 60 + 400, 100, i * 60 + 400, 640)
        Next
        Dim bigfont As New System.Drawing.Font("arial", 42, FontStyle.Regular)
        Dim textfont As New System.Drawing.Font("arial", 16, FontStyle.Regular)
        Dim textbrush As New System.Drawing.SolidBrush(System.Drawing.Color.Black)
        Dim bignum As Byte 'start with 0 for big number display
        Label2.Text = "This is step  " & sustep
        For n = 1 To 3
            For m = 1 To 3
                For l = 1 To 3
                    For k = 1 To 3
                        Dim numselect As Byte = 0 'determine how many zeros in number box
                        For j = 0 To 2
                            For i = 0 To 2
                                If sudoku(sustep, m - 1, n - 1, k - 1, l - 1, i, j) = 0 Then
                                    numselect = numselect + 1
                                Else : bignum = sudoku(sustep, m - 1, n - 1, k - 1, l - 1, i, j)
                                End If
                            Next
                        Next
                        If numselect <> 8 Then 'number not selected show all possibles
                            For j = 1 To 3
                                For i = 1 To 3
                                    Dim nums As String = sudoku(sustep, m - 1, n - 1, k - 1, l - 1, i - 1, j - 1)
                                    If nums = "0" Then nums = " "
                                    g.DrawString(nums, textfont, textbrush, 400 + (i - 1) * 20 + (k - 1) * 60 + (m - 1) * 180, 100 + (j - 1) * 20 + (l - 1) * 60 + (n - 1) * 180)
                                Next i
                            Next j
                        Else : If bignum > 9 Then bignum = bignum - 10
                            'number has been through selection so has 10 added
                            g.DrawString(bignum, bigfont, textbrush, 400 + (k - 1) * 60 + (m - 1) * 180, 100 + (l - 1) * 60 + (n - 1) * 180)
                            'one number only in box so display that number as big
                        End If
                    Next k
                Next l
            Next m
        Next n
        g.Dispose()
    End Sub
    Private Sub numberselected()
        If sudoku(sustep, xl, yl, xs, ys, nx, ny) <> 0 And sudoku(sustep, xl, yl, xs, ys, nx, ny) < 10 Then
            ' if zero cant select if >9 already selected
            If sustep < 80 Then sustep = sustep + 1 'number selected go to next step but < 80
            For n = 1 To 3
                For m = 1 To 3   'copy all to the next step
                    For l = 1 To 3
                        For k = 1 To 3
                            For j = 1 To 3
                                For i = 1 To 3
                                    sudoku(sustep, m - 1, n - 1, k - 1, l - 1, i - 1, j - 1) = sudoku(sustep - 1, m - 1, n - 1, k - 1, l - 1, i - 1, j - 1)
                                Next i
                            Next j
                        Next k
                    Next l
                Next m
            Next n  'add 10 to selected number to show its selected
            sudoku(sustep, xl, yl, xs, ys, nx, ny) = sudoku(sustep, xl, yl, xs, ys, nx, ny) + 10
            'set all to zero except selected number in the number box
            For j = 0 To 2
                For i = 0 To 2
                    If Not (i = nx And j = ny) Then
                        sudoku(sustep, xl, yl, xs, ys, i, j) = 0
                    End If
                Next i
            Next j
            'horizontal row cannot have this number
            For j = 0 To 2
                For i = 0 To 2 'horizontal row cannot have this number
                    If Not (i = xs And j = xl) Then
                        sudoku(sustep, j, yl, i, ys, nx, ny) = 0
                    End If
                Next i
            Next j
            'vertical row cannot have this number
            For j = 0 To 2
                For i = 0 To 2 'vertical row cannot have this number
                    If Not (i = ys And j = yl) Then
                        sudoku(sustep, xl, j, xs, i, nx, ny) = 0
                    End If
                Next i
            Next j
            ' box of 9 numbers(large) cannot have this number
            For j = 0 To 2
                For i = 0 To 2 'box of 9 cannot have this number
                    If Not (i = ys And j = xs) Then
                        sudoku(sustep, xl, yl, j, i, nx, ny) = 0
                    End If
                Next i
            Next j
        End If
    End Sub
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim TempFile As String = Path.GetTempFileName()
        TempFile = TempFile & "sudoku.pdf"
        r = New BinaryReader(_assembly.GetManifestResourceStream("Windowsform2.sudoku.pdf"))
        'gets file data into r to write to tempory file
        My.Computer.FileSystem.WriteAllBytes(TempFile, r.ReadBytes(100000000), True)
        'for some reason cant use direct into process start to run adobe
        Dim ProcessStart As New ProcessStartInfo(TempFile)
        Process.Start(ProcessStart)

    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        If sustep <> 0 Then
            sustep = sustep - 1
            Form1_Paint(Nothing, Nothing)
        End If
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        ' Create the document and attach an event handler.
        Dim MyDoc As New PrintDocument()
        AddHandler MyDoc.PrintPage, AddressOf MyDoc_PrintPage
        MyDoc.Print() 'just print direct without user input
    End Sub
    Private Sub MyDoc_PrintPage(ByVal sender As Object, _
   ByVal e As PrintPageEventArgs)
        ' Draw the sudoku image on screen
        Dim suprint As New Bitmap(543, 543)
        Dim subound As New Rectangle(403, 122, 543, 543) 'bit different because of frame
        Dim graph As Graphics = Graphics.FromImage(suprint)
        'to print image must have in image format drawing to screen does not count
        graph.CopyFromScreen(subound.Location, New Point(0, 0), subound.Size)
        e.Graphics.DrawImage(suprint, 100, 100)
    End Sub
    Private Sub checkselection()
        Dim bignum As Byte
        Dim nonselect As Byte
        While nonselect = 0
            For k = 0 To 2
                For l = 0 To 2
                    For m = 0 To 2
                        For n = 0 To 2
                            Dim numselect As Byte = 0 'determine how many zeros in number box
                            For j = 0 To 2
                                For i = 0 To 2
                                    If sudoku(sustep, k, l, m, n, j, i) = 0 Then
                                        numselect = numselect + 1
                                    Else : bignum = sudoku(sustep, k, l, m, n, j, i)
                                        xl = k
                                        yl = l
                                        xs = m
                                        ys = n
                                        nx = j
                                        ny = i  'the position of the number
                                    End If
                                Next
                            Next
                            If numselect = 8 And bignum < 10 Then
                                numberselected()
                                nonselect = 0 ' found one so try again
                            Else : nonselect = 1
                            End If
                        Next
                    Next
                Next
            Next
        End While  'should now have done all non user selected numbers
    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        While sustep <> 80  'try until have full sudoku
            generatesudoku()
        End While
        sustep = sustep - 1
        Form1_Paint(Nothing, Nothing)
    End Sub
    Private Sub generatesudoku()
        sustep = 0
        Dim blank As Byte = 0
        While blank = 0 And sustep < 80
            xl = randomgenerator.Next(0, 3)
            yl = randomgenerator.Next(0, 3)
            xs = randomgenerator.Next(0, 3)
            ys = randomgenerator.Next(0, 3)
            nx = randomgenerator.Next(0, 3)
            ny = randomgenerator.Next(0, 3) 'totally random number
            numberselected()
            checkselection()
            For k = 0 To 2
                For l = 0 To 2
                    For m = 0 To 2
                        For n = 0 To 2
                            Dim numselect As Byte = 0 'determine how many zeros in number box
                            For j = 0 To 2
                                For i = 0 To 2
                                    If sudoku(sustep, k, l, m, n, j, i) = 0 Then
                                        numselect = numselect + 1
                                    End If
                                Next
                            Next
                            If numselect = 9 Then blank = 1
                        Next    ' sudoku cannot be solved
                    Next
                Next
            Next
        End While
    End Sub
End Class