' FORM1 with
' Chart1
' ComboBox1 with 12 hours, 7 days, Month, Year
' TextBox1 for StepSize
' Button1 to GO
' DataGridView1 for display of raw
' data if needed

' Needs the data file in a Folder named
' Data in same place as executable

Option Strict On
Option Explicit On
Imports System.IO
Imports System.Windows.Forms.DataVisualization.Charting
Public Class Form1
  Dim path As String = IO.Path.Combine(Application.StartupPath, "Data", "Agriculture_Humidity_Log.csv")
  Dim dt As New DataTable("Freddy")
  Dim LogData() As String
  Dim WithEvents FSW As FileSystemWatcher
  Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    If Not Directory.Exists(Directory.GetParent(path).FullName) Then
      MessageBox.Show("Need to have the datafile in a folder named 'Data' alongside the executable file", "ERROR")
      Directory.CreateDirectory(Directory.GetParent(path).FullName)
    End If
    If File.Exists(path) Then
      FSW = New FileSystemWatcher()
      With FSW
        .Path = Directory.GetParent(path).FullName
        .EnableRaisingEvents = False
        .NotifyFilter = NotifyFilters.LastWrite
        .Filter = "*.csv"
      End With
    End If

    With dt
      .Columns.Add("ID", GetType(Integer))
      .Columns.Add("DateTime", GetType(DateTime))
      .Columns.Add("Humidity", GetType(Double))
    End With
    With ComboBox1
      .Items.AddRange({"12 hours", "7 days", "Month", "Year"})
      .SelectedIndex = 0
    End With

    Chart1.Series(0).ChartType = SeriesChartType.Spline

    ' comment/uncomment the with ... end
    ' with block below to hide/see data
    ' in the datagridview (slows down
    ' performance)

    'With DataGridView1
    '  .DataSource = dt
    '  .SelectionMode = DataGridViewSelectionMode.FullRowSelect
    '  .Columns("ID").AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells
    '  .Columns("DateTime").DefaultCellStyle.Format = "ddd, dd MMM yyyy  HH:mm:ss"
    '  .Columns("DateTime").AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
    '  .Columns("Humidity").DefaultCellStyle.Format = "0.0"
    'End With

    ReadLogData()
  End Sub
  Sub ReadLogData()
    LogData = ReadData()
    If LogData Is Nothing Then
      MessageBox.Show("Data file not found can not continue .......", "ERROR")
      End
    End If
    dt.Clear()
    With dt
      Dim id As Integer = 1
      For Each s As String In LogData
        Dim a() As String = s.Split(","c)
        If a(0) = "Date" Then Continue For
        Dim comb As DateTime = CDate(String.Join(","c, a(0), a(1)))
        .Rows.Add(id, comb, a(2))
        id += 1
      Next
    End With
    FSW.EnableRaisingEvents = True
  End Sub
  Function ReadData() As String()
    Dim s() As String = Nothing
    If File.Exists(path) Then
      s = File.ReadAllLines(path)
    End If
    Return s
  End Function
  Dim max As Double = 0.0
  Dim min As Double = 9999.9
  Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    max = 0 : min = 9999
    Select Case ComboBox1.SelectedItem.ToString
      Case "12 hours"
        MakeGraph(12)
      Case "7 days"
        MakeGraph(7 * 24)
      Case "Month"
        ' 28 day month
        MakeGraph(28 * 24)
      Case "Year"
        MakeGraph(365 * 24)
    End Select
    With Chart1
      With .ChartAreas(0).AxisY
        .Maximum = CInt(max + 1)
        .Minimum = CInt(min - 1)
        .Interval = 2
      End With
      .ResetAutoValues()
    End With
  End Sub
  Sub MakeGraph(added As Integer)
    If dt.Rows.Count < 1 Then Exit Sub
    Dim stepsize As Integer
    Integer.TryParse(TextBox1.Text, stepsize)
    If stepsize < 1 Then Exit Sub
    Dim start As DateTime = CDate(dt(0)(1))
    Chart1.Series(0).Points.Clear()
    For i As Integer = 0 To dt.Rows.Count - 1 Step stepsize
      If CDate(dt(i)(1)) > start.AddHours(added) Then
        Exit Sub
      End If
      If CDate(dt(i)(1)) < start Then Continue For
      With Chart1.Series(0).Points
        Dim v As Double = CDbl(dt(i)(2))
        .AddXY((dt(i)(1)).ToString, v)
        If v > max Then max = v
        If v < min Then min = v
      End With
    Next
  End Sub
  Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
    ReadLogData()
    Button1.PerformClick()
  End Sub
  Private Sub FSW_Changed(sender As Object, e As FileSystemEventArgs) Handles FSW.Changed
    FSW.EnableRaisingEvents = False
    Threading.Thread.Sleep(200)
    ReadLogData()
    Invoke(Sub() Button1.PerformClick())
  End Sub
  Dim fillDGV As Boolean = False
  Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
    fillDGV = Not fillDGV
    If Not fillDGV Then
      With DataGridView1
        .Rows.Clear()
        .Columns.Clear()
      End With
    End If

  End Sub
End Class