' Program counts down from one hour for purposes of monitoring lab time
' Programmer: George Robinson
' Begin: 28 January 2020
' Final: 5 February 2020

Option Strict On
Option Explicit On


Public Class frmCountdown

    Const X As Integer = 60
    Const Y As Integer = 120
    Const Z As Integer = 180
    Dim dtmCountdown As DateTime = DateTime.Now.AddMinutes(X)

    Private Sub frmCountdown_Load(sender As Object, e As EventArgs) Handles Me.Load
        lblProgrammer.Text = "Programmer: George Robinson"
        tmrCountdown.Interval = 1000
        tmrCountdown.Enabled = True
        lblDate.Text = Now.ToString

    End Sub

    Private Sub tmrCountdown_Tick(sender As Object, e As EventArgs) Handles tmrCountdown.Tick

        lblDate.Text = Now.ToString

        ' Establishes remaining time for start of timer
        Dim remaining As TimeSpan = dtmCountdown.Subtract(Now)
        remaining = New TimeSpan(remaining.Hours, remaining.Minutes, remaining.Seconds)

        ' Colors the Text Label for timer to dark red.
        If remaining.TotalSeconds < 300 Then
            lblCountdown.ForeColor = Color.DarkRed
        End If

        ' If Time reaches Zero, expands window to maximized and sets as TopMost window.
        If remaining.TotalSeconds <= 0 Then
            remaining = TimeSpan.Zero
            Me.WindowState = FormWindowState.Maximized
            Me.TopMost = True
        Else
            ' Updates the time on the label.
            remaining = New TimeSpan(remaining.Hours, remaining.Minutes, remaining.Seconds)
            lblCountdown.Text = remaining.ToString
        End If

    End Sub

    Private Sub btnReset_Click(sender As Object, e As EventArgs) Handles btnReset.Click

        ' End the Top Most, Maximized Window State for the timer to indicate the time is done.
        Me.WindowState = FormWindowState.Normal
        Me.TopMost = False
        lblCountdown.ForeColor = Color.Black

        ' Resets time to 1 hour and restarts the clock
        dtmCountdown = DateTime.Now.AddMinutes(X)
        tmrCountdown.Enabled = True

    End Sub

    Private Sub btn2Hour_Click(sender As Object, e As EventArgs) Handles btn2Hour.Click
        ' End the Top Most, Maximized Window State for the timer to indicate the time is done.
        Me.WindowState = FormWindowState.Normal
        Me.TopMost = False
        lblCountdown.ForeColor = Color.Black

        ' Resets time to 2 hour and restarts the clock

        dtmCountdown = DateTime.Now.AddMinutes(Y)
        tmrCountdown.Enabled = True

    End Sub

    Private Sub btn3Hour_Click(sender As Object, e As EventArgs) Handles btn3Hour.Click
        ' End the Top Most, Maximized Window State for the timer to indicate the time is done.
        Me.WindowState = FormWindowState.Normal
        Me.TopMost = False
        lblCountdown.ForeColor = Color.Black

        ' Resets time to 3 hour and restarts the clock

        dtmCountdown = DateTime.Now.AddMinutes(Z)
        tmrCountdown.Enabled = True

    End Sub

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

        ' End the Top Most, Maximized Window State for the timer to indicate the time is done.
        Me.WindowState = FormWindowState.Normal
        Me.TopMost = False
        lblCountdown.ForeColor = Color.Black

        'Stops the timer and sets to 00:00:00
        tmrCountdown.Enabled = False
        Dim dtmCountdown As DateTime = DateTime.Now
        Dim remaining As TimeSpan = dtmCountdown.Subtract(Now)
        remaining = New TimeSpan(remaining.Hours, remaining.Minutes, remaining.Seconds)
        lblCountdown.Text = remaining.ToString

    End Sub

    Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
        'Closes program
        Me.Close()

    End Sub

End Class