<#
.SYNOPSIS
  This script helps you monitor packet loss on your network by continuously pinging a specified target (website or IP address) 
  and providing real-time updates on successful responses and timeouts.
.PARAMETER target
  Specifies the target website or IP address to ping. Defaults to "vc.voipoperator.de" if not specified.
.PARAMETER count
  Specifies the number of times to ping the target. Defaults to 900 if not specified.
.PARAMETER OnFailure
 (scriptblock, optional): A script block to execute when a ping attempt fails (i.e., when a timeout occurs). This script block will be executed in the context of the script. If not provided, no action will be taken on failure.
.PARAMETER LogFile
 Specifies the log file path. Example: -LogFile "C:\logs\packetloss.txt"
.INPUTS
  None
.OUTPUTS
  Just output on screen, unless redirected to a file
.NOTES
  Version:        1.1
  Author:         Heko Büroservice GmbH & Co. KG.
  Creation Date:  2025-03-10
.EXAMPLE
  .\packetloss_tester.ps1 -target "example.com" -count 1000 -OnFailure $failureAction -LogFile "C:\logs\packetloss.txt"
#>
param (
    [string]$target = "vc.voipoperator.de",
    [int]$count = 900,
    [scriptblock]$OnFailure,
    [string]$LogFile  # Optionaler Parameter für Logging
)

$successCount = 0
$timeoutCount = 0
$processed = 0
$allTimeouts = @()
$start = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
$timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"

Function Write-Log {
    param (
        [string]$message
    )
    if ($LogFile) {
        # In Log-Datei schreiben
        Add-Content -Path $LogFile -Value $message
    }
    # In Konsole ausgeben
    Write-Host $message
}

Function Invoke-Intro {
    Write-Log " _   _      _          ______ _   _                               _          "
    Write-Log "| | | |    | |         | ___ (_) (_)                             (_)         "
    Write-Log "| |_| | ___| | _____   | |_/ /_   _ _ __ ___  ___  ___ _ ____   ___  ___ ___ "
    Write-Log "|  _  |/ _ \ |/ / _ \  | ___ \ | | | '__/ _ \/ __|/ _ \ '__\ \ / / |/ __/ _ \"
    Write-Log "| | | |  __/   < (_) | | |_/ / |_| | | | (_) \__ \  __/ |   \ V /| | (_|  __/"
    Write-Log "\_| |_/\___|_|\_\___/  \____/ \__,_|_|  \___/|___/\___|_|    \_/ |_|\___\___|"
    Write-Log ""
    Write-Log "Packetloss Tester"
    Write-Log "by Max Krieger"
    Write-Log "heko-bs.de"
    Write-Log ""                                                                                                                                                  
}

Write-Log "$timestamp - Pinging $target ..."

try {
    trap [System.Management.Automation.PipelineStoppedException] {
        Write-Log "`nSkript wurde abgebrochen. Zusammenfassung wird nicht ausgeführt."
        exit
    }

    for ($processed = 0; $processed -lt $count; $processed++) {
        $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
        $pingResult = Test-Connection -ComputerName $target -Count 1 -Quiet

        if ($pingResult) {
            $successCount++
            $pingReply = Test-Connection -ComputerName $target -Count 1
            if ($pingReply -ne $null) {
                Write-Log "[$($processed+1)/$count] $timestamp - Reply from $($pingReply.Address): bytes=$($pingReply.BufferSize) time=$($pingReply.ResponseTime)ms TTL=$($pingReply.TimeToLive)"
            }
        } else {
            $timeoutCount++
            Write-Log "[$($processed+1)/$count] $timestamp - Request timed out"
            $allTimeouts += "[$($processed+1)/$count] $timestamp"

            if ($OnFailure) {
                Invoke-Command -ScriptBlock $OnFailure
            }
        }

        Start-Sleep -Seconds 1  # Pause für 1 Sekunde
    }
} catch {
    Write-Log "`nEin Fehler ist aufgetreten: $_"   
} finally {
    if ($? -eq $false) {
        Write-Log "`nSkript wurde abgebrochen oder ein Fehler ist aufgetreten. Keine Zusammenfassung."
        exit
    }

    $packetLoss = [Math]::Round(($timeoutCount / $processed) * 100, 2)
    $totalTimeouts = $timeoutCount
    Invoke-Intro

    Write-Log "===== Zusammenfassung ====="
    Write-Log "From: $start || To: $timestamp"
    Write-Log "Total Packets sent: $processed"
    Write-Log "Packet loss: $packetLoss%"
    Write-Log "Total timeouts: $totalTimeouts"
    Write-Log "== Alle Timeouts: =="
    foreach ($timeout in $allTimeouts) {
        Write-Log $timeout
    }
    Write-Log "==================="

    # Warte auf Tastendruck, nur wenn keine Datei geschrieben wird
    if (-not $LogFile) {
        Write-Host "Beliebige Taste zum Beenden drücken..."
        $null = $Host.UI.RawUI.ReadKey('NoEcho,IncludeKeyDown')
    }
}