# Script Name:  lm1200-prtg-usage.v1.ps1
# Beschreibung: Überwacht einen Netgear LM1200 auf Traffic und Netzwerkstatus
# Aufruf:       powershell -NoProfile  -ExecutionPolicy Bypass -File .\lm1200-prtg-usage.v1.ps1 -LmIp IP_ADRESSE -LmPass "MEIN_PASSWORD"
# Autor:        Patrick Asmus
# Web:          https://www.cleveradmin.de
# Git-Reposit.: https://git.techniverse.net/scriptos/lm1200-prtg-datausage-sensor.git
# Version:      1.0
# Datum:        23.09.2025
# Modifikation: Release Version 1
#####################################################


param(
  [Parameter(Mandatory = $true)][string]$LmIp,
  [ValidateSet("http","https")][string]$LmProto = "http",
  [Parameter(Mandatory = $true)][string]$LmPass,
  [int]$TimeoutSec = 10,
  [switch]$InsecureTls,
  [double]$MinRemainingGiB = [double]::NaN,
  [double]$MaxPercentUsed  = [double]::NaN,
  [switch]$TripSensorOnThreshold
)

$ErrorActionPreference = 'Stop'
$ProgressPreference    = 'SilentlyContinue'
[Console]::OutputEncoding = [System.Text.Encoding]::UTF8
[System.Threading.Thread]::CurrentThread.CurrentCulture   = [System.Globalization.CultureInfo]::InvariantCulture
[System.Threading.Thread]::CurrentThread.CurrentUICulture = [System.Globalization.CultureInfo]::InvariantCulture

$Base = "${LmProto}://${LmIp}"
$Sess = New-Object Microsoft.PowerShell.Commands.WebRequestSession
$Headers = @{ "Accept"="application/json"; "X-Requested-With"="XMLHttpRequest" }
$HasBasic = $PSVersionTable.PSVersion.Major -lt 6

if ($LmProto -eq "https" -and $InsecureTls) {
  Add-Type @"
using System.Net;
using System.Security.Cryptography.X509Certificates;
public class TrustAllCertsPolicy : ICertificatePolicy {
  public bool CheckValidationResult(ServicePoint srvPoint, X509Certificate certificate, WebRequest request, int certificateProblem) { return true; }
}
"@ | Out-Null
  [System.Net.ServicePointManager]::CertificatePolicy = New-Object TrustAllCertsPolicy
}

function Invoke-Json([string]$Uri) {
  if ($HasBasic) { Invoke-RestMethod -UseBasicParsing -Uri $Uri -Headers $Headers -WebSession $Sess -TimeoutSec $TimeoutSec -MaximumRedirection 5 }
  else           { Invoke-RestMethod                -Uri $Uri -Headers $Headers -WebSession $Sess -TimeoutSec $TimeoutSec -MaximumRedirection 5 }
}
function Invoke-Post([string]$Uri, [hashtable]$Form) {
  if ($HasBasic) { Invoke-WebRequest -UseBasicParsing -Uri $Uri -Method Post -Body $Form -ContentType "application/x-www-form-urlencoded" -Headers @{'X-Requested-With'='XMLHttpRequest'} -WebSession $Sess -TimeoutSec $TimeoutSec | Out-Null }
  else           { Invoke-WebRequest                -Uri $Uri -Method Post -Body $Form -ContentType "application/x-www-form-urlencoded" -Headers @{'X-Requested-With'='XMLHttpRequest'} -WebSession $Sess -TimeoutSec $TimeoutSec | Out-Null }
}

function XmlEsc([string]$s){
  if($null -eq $s){ return "" }
  ($s -replace '&','&amp;') -replace '<','&lt;' -replace '>','&gt;'
}

function Num([object]$x){ if($null -eq $x){[double]0}else{ try{[double]$x}catch{[double]0}} }

function ChannelXml([string]$name,[double]$value,[string]$unit,[string]$customUnit,[bool]$isFloat){
  $valStr = $value.ToString([System.Globalization.CultureInfo]::InvariantCulture)
  $n  = XmlEsc $name
  $cu = if($customUnit){ XmlEsc $customUnit } else { "" }
  $sb = New-Object System.Text.StringBuilder
  [void]$sb.Append("<result><channel>$n</channel><value>$valStr</value>")
  if($unit){       [void]$sb.Append("<unit>$unit</unit>") }
  if($customUnit){ [void]$sb.Append("<customunit>$cu</customunit>") }
  if($isFloat){    [void]$sb.Append("<float>1</float><decimalmode>2</decimalmode>") }
  [void]$sb.Append("</result>")
  $sb.ToString()
}

function Write-PrtgError([string]$msg){ "<prtg><error>1</error><text>$(XmlEsc $msg)</text></prtg>" }
function Write-PrtgOk([System.Collections.Generic.List[string]]$results,[string]$text="OK",[bool]$trip=$false,[string]$tripText=""){
  $sb=New-Object System.Text.StringBuilder
  [void]$sb.Append("<prtg>")
  foreach($r in $results){ [void]$sb.Append($r) }
  $t = if($trip -and $tripText){ $tripText } else { $text }
  [void]$sb.Append("<text>$(XmlEsc $t)</text>")
  if($trip){ [void]$sb.Append("<error>1</error>") }
  [void]$sb.Append("</prtg>")
  $sb.ToString()
}

function Get-DaysToBilling([int]$billingDay){
  if($billingDay -lt 1 -or $billingDay -gt 31){ return [double]::NaN }
  $now = [DateTime]::Now.Date
  $daysInThis = [DateTime]::DaysInMonth($now.Year, $now.Month)
  $targetThis = [DateTime]::new($now.Year, $now.Month, [Math]::Min($billingDay,$daysInThis))
  if($now -lt $targetThis){ return [double]([int]($targetThis - $now).TotalDays) }
  $next = $now.AddMonths(1)
  $daysInNext = [DateTime]::DaysInMonth($next.Year, $next.Month)
  $targetNext = [DateTime]::new($next.Year, $next.Month, [Math]::Min($billingDay,$daysInNext))
  return [double]([int]($targetNext - $now).TotalDays)
}

try{
  $model1 = Invoke-Json "$Base/api/model.json"
  $token = $model1.session.secToken
  if(-not $token){ throw "secToken nicht gefunden (Login-Flow geaendert?)" }

  Invoke-Post "$Base/Forms/config" @{
    token = $token; err_redirect='/index.html?loginfailed'; ok_redirect='/index.html'; 'session.password'=$LmPass.Trim()
  }

  $m = Invoke-Json "$Base/api/model.json"

  $GiB=[double][Math]::Pow(2,30); $MiB=[double][Math]::Pow(2,20)
  $usedBytes   = Num $m.wwan.dataUsage.generic.dataTransferred
  $limitBytes  = Num $m.wwan.dataUsage.generic.billingCycleLimit
  $billDayRaw  = [int](Num $m.wwan.dataUsage.generic.billingDay)
  $limitKnown  = $limitBytes -gt 0
  $remainBytes = if($limitKnown){$limitBytes-$usedBytes}else{[double]::NaN}
  $usedGiB     = [Math]::Round(($usedBytes/$GiB), 2)
  $limitGiB    = if($limitKnown){[Math]::Round(($limitBytes/$GiB), 2)}else{[double]::NaN}
  $remainGiB   = if($limitKnown){[Math]::Round(($remainBytes/$GiB), 2)}else{[double]::NaN}
  $percentUsed = if($limitKnown){[Math]::Round((($usedBytes*100.0)/$limitBytes), 2)}else{[double]::NaN}
  $rxMiB=[Math]::Round((Num $m.wwan.dataTransferred.rxb)/$MiB,2)
  $txMiB=[Math]::Round((Num $m.wwan.dataTransferred.txb)/$MiB,2)
  $totMiB=[Math]::Round((Num $m.wwan.dataTransferred.totalb)/$MiB,2)
  $daysToBill = if($limitKnown -and $billDayRaw -gt 0){ Get-DaysToBilling $billDayRaw } else { [double]::NaN }

  $provider = $null
  try{ $defId = $m.wwan.profile.default; $provider = ($m.wwan.profileList | Where-Object { $_.id -eq $defId } | Select-Object -First 1).name }catch{}
  if([string]::IsNullOrWhiteSpace($provider)){ $provider = $m.wwan.registerNetworkDisplay }
  if([string]::IsNullOrWhiteSpace($provider)){ $mcc=$m.wwanadv.MCC; $mnc=$m.wwanadv.MNC; if($mcc -and $mnc){ $provider="$mcc-$mnc" } }
  $radio = $m.wwan.connectionText
  $band  = $m.wwanadv.curBand
  $ip    = $m.wwan.IP

  $res=New-Object 'System.Collections.Generic.List[string]'
  function N($i){ $i.ToString().PadLeft(2,'0') }
  $res.Add( (ChannelXml "$(N 1) Datenvolumen Limit (GiB)"                       $limitGiB    "Custom" "GiB" $true) )
  $res.Add( (ChannelXml "$(N 2) Datenvolumen Verfuegbar (GiB)"                   $remainGiB   "Custom" "GiB" $true) )
  $res.Add( (ChannelXml "$(N 3) Datenvolumen Verbrauch aktueller Monat (GiB)"   $usedGiB     "Custom" "GiB" $true) )
  $res.Add( (ChannelXml "$(N 4) Datenvolumen Verbrauch aktueller Monat (%)"     $percentUsed "Percent" ""   $true) )
  $res.Add( (ChannelXml "$(N 5) Tage bis zum neuen Abrechnungszyklus"                     $daysToBill  "Custom" "Tage" $false) )
  $res.Add( (ChannelXml "$(N 6) Empfangene Daten (Sitzung, MiB)"                $rxMiB       "Custom" "MiB" $true) )
  $res.Add( (ChannelXml "$(N 7) Gesendete Daten (Sitzung, MiB)"                 $txMiB       "Custom" "MiB" $true) )
  $res.Add( (ChannelXml "$(N 8) Daten gesamt (Sitzung, MiB)"                    $totMiB      "Custom" "MiB" $true) )
  $res.Add( (ChannelXml "$(N 9) RSRP (Signalpegel)"                             (Num $m.wwan.signalStrength.rsrp) "Custom" "dBm" $false) )
  $res.Add( (ChannelXml "$(N 10) RSRQ (Qualitaet)"                              (Num $m.wwan.signalStrength.rsrq) "Custom" "dB"  $false) )
  $res.Add( (ChannelXml "$(N 11) SINR (Stoerabstand)"                           (Num $m.wwan.signalStrength.sinr) "Custom" "dB"  $false) )

  $title = "IP $ip | Funk $radio | $band | Anbieter $provider"
  [Console]::Out.Write( (Write-PrtgOk -results $res -text $title -trip ($TripSensorOnThreshold -and $limitKnown -and ((-not [double]::IsNaN($MinRemainingGiB) -and $remainGiB -le $MinRemainingGiB) -or (-not [double]::IsNaN($MaxPercentUsed) -and $percentUsed -ge $MaxPercentUsed)))) )
}
catch{
  [Console]::Out.Write( (Write-PrtgError $_.Exception.Message) )
  exit 1
}