#requires -Version 7.0
<#
.SYNOPSIS
    Universal DHCP Scope Monitoring Utility

.DESCRIPTION
    Cross-platform DHCP monitoring utility for:
      - Windows
      - macOS
      - Linux (including Debian)

    Execution modes:
      1. LOCAL  : On Windows with the DhcpServer module available.
      2. REMOTE : On Windows/macOS/Linux using PowerShell Remoting over SSH
                  to a Windows DHCP Server.

    Remote DHCP objects are flattened on the Windows server before being
    returned to non-Windows clients, avoiding CIM/MI serialization issues
    such as libmi errors on macOS/Linux.

.EXAMPLE
    pwsh ./dhcp-monitor-universal.ps1

    On macOS/Linux (or Windows without the local DhcpServer module), the
    script asks for the DHCP Server hostname/IP and SSH username.

.EXAMPLE
    pwsh ./dhcp-monitor-universal.ps1 -DhcpServer 192.168.1.10 -UserName "CONTOSO\\administrator"

    Skips the interactive server/username questions.

.EXAMPLE
    pwsh ./dhcp-monitor-universal.ps1 -Mode Local

    Forces Local mode. Requires Windows and the DhcpServer module.

.NOTES
    In Remote mode, the script interactively asks for:
      - DHCP Server hostname or IP address
      - SSH username
#>

param (
    [string]$DhcpServer,
    [string]$UserName,
    [ValidateSet("Auto", "Local", "Remote")]
    [string]$Mode = "Auto"
)

$ErrorActionPreference = "Stop"
$script:DhcpSession = $null
$script:ExecutionMode = $null
$script:DhcpServer = $DhcpServer
$script:UserName = $UserName

# ============================================================
# UI HELPERS
# ============================================================

function Show-Title {
    Clear-Host
    Write-Host "===================================================" -ForegroundColor Cyan
    Write-Host "       Universal DHCP Scope Monitoring Utility" -ForegroundColor Cyan
    Write-Host "===================================================" -ForegroundColor Cyan
    Write-Host
    Write-Host "Client OS   : $([System.Runtime.InteropServices.RuntimeInformation]::OSDescription)"
    Write-Host "Mode        : $script:ExecutionMode"
    if ($script:ExecutionMode -eq "Remote") {
        Write-Host "DHCP Server : $script:DhcpServer"
        Write-Host "SSH User    : $script:UserName"
    }
    Write-Host
}

function Wait-Enter {
    param([string]$Message = "Tekan ENTER untuk melanjutkan")
    [void](Read-Host $Message)
}

function Convert-ToDisplayString {
    param($Value)
    if ($null -eq $Value) { return "" }
    return $Value.ToString()
}

# ============================================================
# CONNECTION / EXECUTION MODE
# ============================================================

function Test-LocalDhcpModule {
    if (-not $IsWindows) {
        return $false
    }

    return [bool](Get-Module -ListAvailable -Name DhcpServer)
}

function Connect-DhcpBackend {
    if ($Mode -eq "Local") {
        if (-not (Test-LocalDhcpModule)) {
            throw "Mode Local dipilih, tetapi module DhcpServer tidak tersedia."
        }

        Import-Module DhcpServer -ErrorAction Stop
        $script:ExecutionMode = "Local"
        return
    }

    if ($Mode -eq "Auto" -and (Test-LocalDhcpModule)) {
        Import-Module DhcpServer -ErrorAction Stop
        $script:ExecutionMode = "Local"
        return
    }

    $script:ExecutionMode = "Remote"

    Write-Host
    Write-Host "Remote DHCP Server Configuration" -ForegroundColor Cyan
    Write-Host "---------------------------------------------------"

    while ([string]::IsNullOrWhiteSpace($script:DhcpServer)) {
        $script:DhcpServer = Read-Host "DHCP Server hostname / IP"
        if ([string]::IsNullOrWhiteSpace($script:DhcpServer)) {
            Write-Host "DHCP Server tidak boleh kosong." -ForegroundColor Red
        }
    }

    while ([string]::IsNullOrWhiteSpace($script:UserName)) {
        $script:UserName = Read-Host "SSH username (contoh: DOMAIN\administrator)"
        if ([string]::IsNullOrWhiteSpace($script:UserName)) {
            Write-Host "Username tidak boleh kosong." -ForegroundColor Red
        }
    }

    Write-Host
    Write-Host "Menghubungkan ke Windows DHCP Server..." -ForegroundColor Cyan
    Write-Host "Server : $script:DhcpServer"
    Write-Host "User   : $script:UserName"
    Write-Host

    try {
        $script:DhcpSession = New-PSSession `
            -HostName $script:DhcpServer `
            -UserName $script:UserName `
            -ErrorAction Stop

        Write-Host "Koneksi berhasil." -ForegroundColor Green
        Start-Sleep -Milliseconds 700
    }
    catch {
        throw "Gagal membuat PowerShell SSH session ke $script:DhcpServer. $($_.Exception.Message)"
    }
}

function Disconnect-DhcpBackend {
    if ($null -ne $script:DhcpSession) {
        try {
            Remove-PSSession -Session $script:DhcpSession -ErrorAction SilentlyContinue
        }
        catch {}
        $script:DhcpSession = $null
    }
}

function Test-DhcpSession {
    if ($script:ExecutionMode -ne "Remote") {
        return $true
    }

    if ($null -eq $script:DhcpSession) {
        return $false
    }

    return ($script:DhcpSession.State -eq "Opened")
}

# ============================================================
# DATA ACCESS LAYER
# ============================================================

function Get-DhcpScopeData {
    param (
        [Parameter(Mandatory)]
        [string]$ScopeId
    )

    if ($script:ExecutionMode -eq "Local") {
        $s = Get-DhcpServerv4Scope -ScopeId $ScopeId -ErrorAction Stop

        return [PSCustomObject]@{
            ScopeId       = Convert-ToDisplayString $s.ScopeId
            Name          = $s.Name
            State         = Convert-ToDisplayString $s.State
            StartRange    = Convert-ToDisplayString $s.StartRange
            EndRange      = Convert-ToDisplayString $s.EndRange
            SubnetMask    = Convert-ToDisplayString $s.SubnetMask
            LeaseDuration = Convert-ToDisplayString $s.LeaseDuration
        }
    }

    return Invoke-Command -Session $script:DhcpSession -ArgumentList $ScopeId -ScriptBlock {
        param($RemoteScopeId)

        $s = Get-DhcpServerv4Scope -ScopeId $RemoteScopeId -ErrorAction Stop

        [PSCustomObject]@{
            ScopeId       = if ($null -eq $s.ScopeId)       { "" } else { $s.ScopeId.ToString() }
            Name          = $s.Name
            State         = if ($null -eq $s.State)         { "" } else { $s.State.ToString() }
            StartRange    = if ($null -eq $s.StartRange)    { "" } else { $s.StartRange.ToString() }
            EndRange      = if ($null -eq $s.EndRange)      { "" } else { $s.EndRange.ToString() }
            SubnetMask    = if ($null -eq $s.SubnetMask)    { "" } else { $s.SubnetMask.ToString() }
            LeaseDuration = if ($null -eq $s.LeaseDuration) { "" } else { $s.LeaseDuration.ToString() }
        }
    } -ErrorAction Stop
}

function Get-DhcpStatisticsData {
    param (
        [Parameter(Mandatory)]
        [string]$ScopeId
    )

    if ($script:ExecutionMode -eq "Local") {
        $s = Get-DhcpServerv4ScopeStatistics -ScopeId $ScopeId -ErrorAction Stop

        return [PSCustomObject]@{
            Free            = [long]$s.Free
            InUse           = [long]$s.InUse
            PercentageInUse = [double]$s.PercentageInUse
            Reserved        = [long]$s.Reserved
            Pending         = [long]$s.Pending
            SuperscopeName  = Convert-ToDisplayString $s.SuperscopeName
        }
    }

    return Invoke-Command -Session $script:DhcpSession -ArgumentList $ScopeId -ScriptBlock {
        param($RemoteScopeId)

        $s = Get-DhcpServerv4ScopeStatistics -ScopeId $RemoteScopeId -ErrorAction Stop

        [PSCustomObject]@{
            Free            = [long]$s.Free
            InUse           = [long]$s.InUse
            PercentageInUse = [double]$s.PercentageInUse
            Reserved        = [long]$s.Reserved
            Pending         = [long]$s.Pending
            SuperscopeName  = if ($null -eq $s.SuperscopeName) { "" } else { $s.SuperscopeName.ToString() }
        }
    } -ErrorAction Stop
}

function Get-DhcpLeaseData {
    param (
        [Parameter(Mandatory)]
        [string]$ScopeId
    )

    if ($script:ExecutionMode -eq "Local") {
        $raw = @(Get-DhcpServerv4Lease -ScopeId $ScopeId -ErrorAction Stop)

        return @(
            foreach ($lease in $raw) {
                [PSCustomObject]@{
                    IPAddress       = Convert-ToDisplayString $lease.IPAddress
                    HostName        = Convert-ToDisplayString $lease.HostName
                    ClientId        = Convert-ToDisplayString $lease.ClientId
                    AddressState    = Convert-ToDisplayString $lease.AddressState
                    LeaseExpiryTime = $lease.LeaseExpiryTime
                }
            }
        )
    }

    # IMPORTANT:
    # Materialize the DHCP CIM result first, then flatten every property
    # while still executing on Windows. This prevents libmi/CIM objects
    # from crossing the SSH remoting boundary.
    return @(
        Invoke-Command -Session $script:DhcpSession -ArgumentList $ScopeId -ScriptBlock {
            param($RemoteScopeId)

            $rawLeases = @(Get-DhcpServerv4Lease -ScopeId $RemoteScopeId -ErrorAction Stop)

            foreach ($lease in $rawLeases) {
                $expiry = $null

                if ($null -ne $lease.LeaseExpiryTime) {
                    try {
                        $expiry = $lease.LeaseExpiryTime.ToString("o")
                    }
                    catch {
                        $expiry = $lease.LeaseExpiryTime.ToString()
                    }
                }

                [PSCustomObject]@{
                    IPAddress       = if ($null -eq $lease.IPAddress)    { "" } else { $lease.IPAddress.ToString() }
                    HostName        = if ($null -eq $lease.HostName)     { "" } else { $lease.HostName.ToString() }
                    ClientId        = if ($null -eq $lease.ClientId)     { "" } else { $lease.ClientId.ToString() }
                    AddressState    = if ($null -eq $lease.AddressState) { "" } else { $lease.AddressState.ToString() }
                    LeaseExpiryTime = $expiry
                }
            }
        } -ErrorAction Stop
    )
}

# ============================================================
# NORMALIZATION / SORTING
# ============================================================

function Convert-LeaseExpiry {
    param($Value)

    if ($null -eq $Value -or [string]::IsNullOrWhiteSpace($Value.ToString())) {
        return $null
    }

    if ($Value -is [datetime]) {
        return $Value
    }

    $parsed = [datetime]::MinValue

    if ([datetime]::TryParse(
        $Value.ToString(),
        [System.Globalization.CultureInfo]::InvariantCulture,
        [System.Globalization.DateTimeStyles]::RoundtripKind,
        [ref]$parsed
    )) {
        return $parsed
    }

    if ([datetime]::TryParse($Value.ToString(), [ref]$parsed)) {
        return $parsed
    }

    return $null
}

function Get-IPv4SortKey {
    param([string]$IPAddress)

    try {
        $bytes = [System.Net.IPAddress]::Parse($IPAddress).GetAddressBytes()
        if ($bytes.Count -ne 4) {
            return [uint64]::MaxValue
        }

        return (
            ([uint64]$bytes[0] -shl 24) -bor
            ([uint64]$bytes[1] -shl 16) -bor
            ([uint64]$bytes[2] -shl 8)  -bor
            ([uint64]$bytes[3])
        )
    }
    catch {
        return [uint64]::MaxValue
    }
}

# ============================================================
# SCOPE FUNCTIONS
# ============================================================

function Test-DhcpScope {
    param (
        [Parameter(Mandatory)]
        [string]$ScopeId
    )

    try {
        [void](Get-DhcpScopeData -ScopeId $ScopeId)
        return $true
    }
    catch {
        return $false
    }
}

function Show-ScopeSummary {
    param (
        [Parameter(Mandatory)]
        [string]$ScopeId
    )

    try {
        $scope = Get-DhcpScopeData -ScopeId $ScopeId
        $stats = Get-DhcpStatisticsData -ScopeId $ScopeId

        Write-Host
        Write-Host "Summary Scope" -ForegroundColor Yellow
        Write-Host "---------------------------------------------------"

        [PSCustomObject]@{
            ScopeId         = $scope.ScopeId
            Name            = $scope.Name
            State           = $scope.State
            StartRange      = $scope.StartRange
            EndRange        = $scope.EndRange
            SubnetMask      = $scope.SubnetMask
            LeaseDuration   = $scope.LeaseDuration
            Free            = $stats.Free
            InUse           = $stats.InUse
            PercentageInUse = ("{0:N2}%" -f [double]$stats.PercentageInUse)
            Reserved        = $stats.Reserved
            Pending         = $stats.Pending
            SuperscopeName  = $stats.SuperscopeName
        } | Format-List | Out-Host

        Write-Host "---------------------------------------------------"

        if ([double]$stats.PercentageInUse -ge 95) {
            Write-Host "WARNING: Scope hampir penuh!" -ForegroundColor Red
        }
        elseif ([double]$stats.PercentageInUse -ge 80) {
            Write-Host "WARNING: Pemakaian scope sudah tinggi." -ForegroundColor Yellow
        }
        else {
            Write-Host "Status kapasitas scope masih aman." -ForegroundColor Green
        }

        Write-Host
    }
    catch {
        Write-Host
        Write-Host "Gagal membaca Scope $ScopeId." -ForegroundColor Red
        Write-Host $_.Exception.Message -ForegroundColor DarkRed
        Write-Host
    }
}

# ============================================================
# DEVICE / LEASE LIST
# ============================================================

function Show-ScopeClients {
    param (
        [Parameter(Mandatory)]
        [string]$ScopeId
    )

    Clear-Host

    Write-Host "===================================================" -ForegroundColor Cyan
    Write-Host "          DHCP Lease / Device List" -ForegroundColor Cyan
    Write-Host "===================================================" -ForegroundColor Cyan
    Write-Host
    Write-Host "ScopeId : $ScopeId" -ForegroundColor Yellow
    Write-Host

    try {
        $leases = @(Get-DhcpLeaseData -ScopeId $ScopeId)

        if ($leases.Count -eq 0) {
            Write-Host "Tidak ada lease yang dikembalikan untuk scope ini." -ForegroundColor Yellow
            Write-Host
            return
        }

        $normalized = @(
            foreach ($lease in $leases) {
                [PSCustomObject]@{
                    IPAddress       = $lease.IPAddress
                    HostName        = $lease.HostName
                    ClientId        = $lease.ClientId
                    AddressState    = $lease.AddressState
                    LeaseExpiryTime = Convert-LeaseExpiry $lease.LeaseExpiryTime
                }
            }
        )

        $normalized |
            Sort-Object @{ Expression = { Get-IPv4SortKey $_.IPAddress } } |
            Select-Object IPAddress, HostName, ClientId, AddressState, LeaseExpiryTime |
            Format-Table -AutoSize |
            Out-Host

        Write-Host
        Write-Host "---------------------------------------------------"
        Write-Host "Total lease : $($normalized.Count)" -ForegroundColor Cyan

        $activeCount = @(
            $normalized | Where-Object { $_.AddressState -match '^Active' }
        ).Count

        Write-Host "Active lease: $activeCount" -ForegroundColor Green
        Write-Host "---------------------------------------------------"
        Write-Host
    }
    catch {
        Write-Host
        Write-Host "Gagal membaca daftar lease." -ForegroundColor Red
        Write-Host $_.Exception.Message -ForegroundColor DarkRed
        Write-Host
    }
}

# ============================================================
# LEASE ANALYSIS
# ============================================================

function Show-LeaseAnalysis {
    param (
        [Parameter(Mandatory)]
        [string]$ScopeId
    )

    Clear-Host

    Write-Host "===================================================" -ForegroundColor Cyan
    Write-Host "             DHCP Lease Analysis" -ForegroundColor Cyan
    Write-Host "===================================================" -ForegroundColor Cyan
    Write-Host
    Write-Host "ScopeId : $ScopeId" -ForegroundColor Yellow
    Write-Host

    try {
        $now   = Get-Date
        $scope = Get-DhcpScopeData -ScopeId $ScopeId
        $stats = Get-DhcpStatisticsData -ScopeId $ScopeId
        $rawLeases = @(Get-DhcpLeaseData -ScopeId $ScopeId)

        $leases = @(
            foreach ($lease in $rawLeases) {
                [PSCustomObject]@{
                    IPAddress       = $lease.IPAddress
                    HostName        = $lease.HostName
                    ClientId        = $lease.ClientId
                    AddressState    = $lease.AddressState
                    LeaseExpiryTime = Convert-LeaseExpiry $lease.LeaseExpiryTime
                }
            }
        )

        $leasesWithExpiry = @(
            $leases | Where-Object { $null -ne $_.LeaseExpiryTime }
        )

        $expired = @(
            $leasesWithExpiry |
                Where-Object { $_.LeaseExpiryTime -lt $now }
        ).Count

        $expireWithin4Hour = @(
            $leasesWithExpiry |
                Where-Object {
                    $_.LeaseExpiryTime -ge $now -and
                    $_.LeaseExpiryTime -le $now.AddHours(4)
                }
        ).Count

        $beyond4Hour = @(
            $leasesWithExpiry |
                Where-Object { $_.LeaseExpiryTime -gt $now.AddHours(4) }
        ).Count

        Write-Host "Waktu Pemeriksaan : $now"
        Write-Host "Lease Duration     : $($scope.LeaseDuration)"
        Write-Host

        Write-Host "Pool Statistics" -ForegroundColor Yellow
        Write-Host "---------------------------------------------------"

        [PSCustomObject]@{
            Free            = $stats.Free
            InUse           = $stats.InUse
            PercentageInUse = ("{0:N2}%" -f [double]$stats.PercentageInUse)
            Reserved        = $stats.Reserved
            Pending         = $stats.Pending
        } | Format-List | Out-Host

        Write-Host
        Write-Host "Lease Expiration Analysis" -ForegroundColor Yellow
        Write-Host "---------------------------------------------------"

        [PSCustomObject]@{
            TotalLease        = $leases.Count
            WithExpiry        = $leasesWithExpiry.Count
            Expired           = $expired
            ExpireWithin4Hour = $expireWithin4Hour
            Beyond4Hour       = $beyond4Hour
        } | Format-Table -AutoSize | Out-Host

        Write-Host
        Write-Host "Interpretasi" -ForegroundColor Yellow
        Write-Host "---------------------------------------------------"

        if ([double]$stats.PercentageInUse -ge 95) {
            Write-Host "Kapasitas scope : KRITIS (>=95%)." -ForegroundColor Red
        }
        elseif ([double]$stats.PercentageInUse -ge 80) {
            Write-Host "Kapasitas scope : TINGGI (>=80%)." -ForegroundColor Yellow
        }
        else {
            Write-Host "Kapasitas scope : AMAN (<80%)." -ForegroundColor Green
        }

        if ($leasesWithExpiry.Count -gt 0) {
            if ($beyond4Hour -gt ($leasesWithExpiry.Count / 2)) {
                Write-Host "Mayoritas lease masih memiliki expiry lebih dari 4 jam." -ForegroundColor Yellow
                Write-Host "Kemungkinan masih banyak lease lama dari konfigurasi sebelumnya."
            }
            else {
                Write-Host "Mayoritas lease sudah berada dalam window 4 jam." -ForegroundColor Green
            }
        }
        else {
            Write-Host "Tidak ada data expiry lease yang dapat dianalisis." -ForegroundColor Yellow
        }

        Write-Host
    }
    catch {
        Write-Host
        Write-Host "Gagal melakukan Lease Analysis." -ForegroundColor Red
        Write-Host $_.Exception.Message -ForegroundColor DarkRed
        Write-Host
    }
}

# ============================================================
# MAIN PROGRAM
# ============================================================

try {
    Connect-DhcpBackend

    while ($true) {
        Show-Title

        if (-not (Test-DhcpSession)) {
            throw "PowerShell remote session tidak lagi dalam state Opened."
        }

        Write-Host "Masukkan ScopeId yang ingin diperiksa." -ForegroundColor Green
        Write-Host "Contoh: 10.110.114.0"
        Write-Host
        Write-Host "Ketik 0 untuk keluar."
        Write-Host

        $ScopeId = Read-Host "ScopeId"

        if ($ScopeId -eq "0") {
            break
        }

        if ([string]::IsNullOrWhiteSpace($ScopeId)) {
            Write-Host
            Write-Host "ScopeId tidak boleh kosong." -ForegroundColor Red
            Write-Host
            Wait-Enter
            continue
        }

        if (-not (Test-DhcpScope -ScopeId $ScopeId)) {
            Write-Host
            Write-Host "ScopeId '$ScopeId' tidak ditemukan atau tidak dapat dibaca." -ForegroundColor Red
            Write-Host
            Wait-Enter "Tekan ENTER untuk mencoba lagi"
            continue
        }

        $changeScope = $false

        while (-not $changeScope) {
            Show-Title
            Show-ScopeSummary -ScopeId $ScopeId

            Write-Host "Apa yang ingin dilakukan?" -ForegroundColor Green
            Write-Host
            Write-Host "[1] Tampilkan daftar lease / perangkat"
            Write-Host "[2] Lease Analysis"
            Write-Host "[3] Cek ScopeId lain"
            Write-Host "[4] Refresh summary scope ini"
            Write-Host "[0] Keluar"
            Write-Host

            $choice = Read-Host "Pilihan"

            switch ($choice) {
                "1" {
                    Show-ScopeClients -ScopeId $ScopeId

                    $clientMenu = $true
                    while ($clientMenu) {
                        Write-Host "Apa yang ingin dilakukan selanjutnya?" -ForegroundColor Green
                        Write-Host
                        Write-Host "[1] Kembali ke summary scope ini"
                        Write-Host "[2] Lease Analysis"
                        Write-Host "[3] Cek ScopeId lain"
                        Write-Host "[4] Refresh daftar lease"
                        Write-Host "[0] Keluar"
                        Write-Host

                        $subChoice = Read-Host "Pilihan"

                        switch ($subChoice) {
                            "1" {
                                $clientMenu = $false
                            }
                            "2" {
                                Show-LeaseAnalysis -ScopeId $ScopeId
                                Write-Host
                                Wait-Enter "Tekan ENTER untuk kembali"
                                $clientMenu = $false
                            }
                            "3" {
                                $clientMenu = $false
                                $changeScope = $true
                            }
                            "4" {
                                Show-ScopeClients -ScopeId $ScopeId
                            }
                            "0" {
                                return
                            }
                            default {
                                Write-Host
                                Write-Host "Pilihan tidak valid." -ForegroundColor Red
                                Write-Host
                            }
                        }
                    }
                }

                "2" {
                    Show-LeaseAnalysis -ScopeId $ScopeId

                    $analysisMenu = $true
                    while ($analysisMenu) {
                        Write-Host "Apa yang ingin dilakukan selanjutnya?" -ForegroundColor Green
                        Write-Host
                        Write-Host "[1] Kembali ke summary scope ini"
                        Write-Host "[2] Tampilkan daftar lease / perangkat"
                        Write-Host "[3] Cek ScopeId lain"
                        Write-Host "[4] Refresh Lease Analysis"
                        Write-Host "[0] Keluar"
                        Write-Host

                        $subChoice = Read-Host "Pilihan"

                        switch ($subChoice) {
                            "1" {
                                $analysisMenu = $false
                            }
                            "2" {
                                Show-ScopeClients -ScopeId $ScopeId
                                Write-Host
                                Wait-Enter "Tekan ENTER untuk kembali"
                                $analysisMenu = $false
                            }
                            "3" {
                                $analysisMenu = $false
                                $changeScope = $true
                            }
                            "4" {
                                Show-LeaseAnalysis -ScopeId $ScopeId
                            }
                            "0" {
                                return
                            }
                            default {
                                Write-Host
                                Write-Host "Pilihan tidak valid." -ForegroundColor Red
                                Write-Host
                            }
                        }
                    }
                }

                "3" {
                    $changeScope = $true
                }

                "4" {
                    # Loop refreshes summary.
                }

                "0" {
                    return
                }

                default {
                    Write-Host
                    Write-Host "Pilihan tidak valid." -ForegroundColor Red
                    Start-Sleep -Seconds 1
                }
            }
        }
    }
}
catch {
    Write-Host
    Write-Host "FATAL ERROR" -ForegroundColor Red
    Write-Host "---------------------------------------------------"
    Write-Host $_.Exception.Message -ForegroundColor Red
    Write-Host
    exit 1
}
finally {
    Disconnect-DhcpBackend
    Write-Host
    Write-Host "Keluar dari Universal DHCP Scope Monitoring Utility." -ForegroundColor Cyan
    Write-Host
}