Imports System.Data.OleDb

Public Class StudentLogSystem
    Private connectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Path\To\Your\Database.accdb"
    Private connection As OleDbConnection
    Private dataTable As DataTable

    Public Sub New()
        connection = New OleDbConnection(connectionString)
        dataTable = New DataTable()
    End Sub

    Private Sub StudentLogSystem_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        LoadData()
    End Sub

    Public Sub LoadData()
        Dim query As String = "SELECT * FROM Log"
        Dim adapter As OleDbDataAdapter = New OleDbDataAdapter(query, connection)
        dataTable.Clear()
        adapter.Fill(dataTable)
        dgvStudents.DataSource = dataTable
    End Sub

    Public Sub LogInStudent()
        Dim studentId As Integer
        If Integer.TryParse(txtStudentId.Text, studentId) Then
            Dim query As String = "INSERT INTO Log (StudentId, LogDate, LogTime) VALUES (@StudentId, @LogDate, @LogTime)"
            Dim command As OleDbCommand = New OleDbCommand(query, connection)
            command.Parameters.AddWithValue("@StudentId", studentId)
            command.Parameters.AddWithValue("@LogDate", DateTime.Today)
            command.Parameters.AddWithValue("@LogTime", DateTime.Now)
            ExecuteNonQuery(command)
            LoadData()
            MessageBox.Show("Time in recorded successfully.")
        Else
            MessageBox.Show("Invalid student ID")
        End If
    End Sub

    Public Sub LogOutStudent()
        Dim studentId As Integer
        If Integer.TryParse(txtStudentId.Text, studentId) Then
            Dim query As String = "UPDATE Log SET LogoutDate = @LogoutDate, LogoutTime = @LogoutTime WHERE StudentId = @StudentId AND LogoutDate IS NULL"
            Dim command As OleDbCommand = New OleDbCommand(query, connection)
            command.Parameters.AddWithValue("@LogoutDate", DateTime.Today)
            command.Parameters.AddWithValue("@LogoutTime", DateTime.Now)
            command.Parameters.AddWithValue("@StudentId", studentId)
            ExecuteNonQuery(command)
            LoadData()
            MessageBox.Show("Time out recorded successfully.")
        Else
            MessageBox.Show("Invalid student ID")
        End If
    End Sub

    Private Sub ExecuteNonQuery(command As OleDbCommand)
        Try
            connection.Open()
            command.ExecuteNonQuery()
        Catch ex As Exception
            MessageBox.Show("Error: " & ex.Message)
        Finally
            connection.Close()
        End Try
    End Sub

    Private Sub dgvStudents_CellClick(sender As Object, e As DataGridViewCellEventArgs) Handles dgvStudents.CellClick
        If e.RowIndex >= 0 Then
            Dim selectedRow As DataGridViewRow = dgvStudents.Rows(e.RowIndex)
            txtStudentId.Text = selectedRow.Cells("StudentId").Value.ToString()
        End If
    End Sub

    Private Sub btnTimeIn_Click(sender As Object, e As EventArgs) Handles btnTimeIn.Click
        If String.IsNullOrWhiteSpace(txtStudentId.Text) Then
            MessageBox.Show("Please enter a student ID.")
        Else
            LogInStudent()
        End If
    End Sub

    Private Sub btnTimeOut_Click(sender As Object, e As EventArgs) Handles btnTimeOut.Click
        If String.IsNullOrWhiteSpace(txtStudentId.Text) Then
            MessageBox.Show("Please enter a student ID.")
        Else
            LogOutStudent()
        End If
    End Sub
End Class