Imports System.Collections.Generic
Imports System.Diagnostics
Imports System.Globalization
Imports System.IO
Imports System.Linq
Imports System.Net
Imports System.Security.Cryptography
Imports System.Text
Imports System.Threading
Imports System.Threading.Tasks

Namespace RiotHelper.ProxyChecker
    Public Class ProxyChecker

#Region "Properties / Fields"

        Public Property ProxyTimeout() As Integer

        Public Property ThreadCount() As Integer
            Get
                Return m_ThreadCount
            End Get
            Set(value As Integer)
                m_ThreadCount = value
            End Set
        End Property
        Private m_ThreadCount As Integer
        Public Property Finished() As Boolean
            Get
                Return m_Finished
            End Get
            Set(value As Boolean)
                m_Finished = value
            End Set
        End Property
        Private m_Finished As Boolean
        Public Property Processed() As Double
            Get
                Return m_Processed
            End Get
            Set(value As Double)
                m_Processed = value
            End Set
        End Property
        Private m_Processed As Double
        Public ReadOnly Property Left() As Integer
            Get
                Return _queue.Count
            End Get
        End Property

        Private ReadOnly _queue As New Queue(Of String)()
        Private _tasks As Task()

        Private _stop As Boolean
        Private _running As Boolean

        Private _threadsRunning As Integer = 0

#End Region

#Region "Events"


        Public Delegate Sub WorkingProxyEventHandler(sender As Object, proxy As String)

        Public Event WorkingProxy As WorkingProxyEventHandler

        Public Sub OnWorkingProxy(proxy As String)
            RaiseEvent WorkingProxy(Me, proxy)
        End Sub

#End Region

#Region "Constructor"

        Public Sub New(threadCount__1 As Integer)
            ThreadCount = threadCount__1
            Finished = False
            Processed = 0
        End Sub

#End Region

#Region "Public Functions"

        Public Sub AddProxy(proxy As String)
            SyncLock _queue
                _queue.Enqueue(proxy)
            End SyncLock
        End Sub

        Public Async Sub Start()

            If _running Then
                Throw New Exception("Checker already running")
            End If

            _running = True
            _stop = False

            _tasks = New Task(ThreadCount - 1) {}

            For i As Integer = 0 To _tasks.Length - 1
                _tasks(i) = New Task(AddressOf CheckerLoop, TaskCreationOptions.LongRunning)
                _tasks(i).Start()
                Await Task.Delay(150)
                Interlocked.Increment(_threadsRunning)
            Next

        End Sub

        Public Sub [Stop]()
            _stop = True
        End Sub

#End Region

        Private Sub CheckerLoop()
            While Not _stop
                Try
                    Dim proxy As String
                    SyncLock _queue
                        proxy = If(_queue.Count > 0, _queue.Dequeue(), Nothing)
                    End SyncLock

                    If proxy Is Nothing Then
                        _stop = True
                    End If

                    Dim success As Boolean = CheckProxy(proxy, False, ProxyTimeout) '10 seconds now. It's in ms ow ok
                    If success Then
                        OnWorkingProxy(proxy)
                    End If

                    Processed += 1
                Catch generatedExceptionName As Exception
                End Try
            End While

            Interlocked.Decrement(_threadsRunning)
            If _threadsRunning <= 0 Then
                Finished = True
            End If
        End Sub

        Private Function CheckProxy(proxy As String, https As Boolean, timeout As Integer) As Boolean
            Try
                Dim request As HttpWebRequest
                If (https) Then
                    request = DirectCast(WebRequest.Create("https://www.google.com/"), HttpWebRequest)
                Else
                    request = DirectCast(WebRequest.Create("http://www.google.com/"), HttpWebRequest)
                End If

                request.Proxy = New WebProxy(proxy)
                request.Method = "GET"
                request.Timeout = timeout
                request.ReadWriteTimeout = timeout



                Dim startTime = DateTime.Now
                Dim responseTask = request.GetResponseAsync()
                While responseTask.Status = TaskStatus.WaitingForActivation OrElse responseTask.Status = TaskStatus.WaitingToRun
                    If startTime.AddSeconds(30) < DateTime.Now Then
                        Exit While
                    Else
                        Thread.Sleep(500)
                    End If
                End While
                startTime = DateTime.Now

                While responseTask.Status = TaskStatus.Running
                    If startTime.AddSeconds(10) > DateTime.Now Then
                        Exit While
                    End If
                    Thread.Sleep(500)
                End While
                If responseTask.Status = TaskStatus.RanToCompletion Then
                    Return True
                End If

                Return False
            Catch ex As Exception
            End Try
            Return False
        End Function
    End Class
End Namespace