<#
.SYNOPSIS
Pre-stage VirtIO drivers on a VMware Windows Server 2025 VM prior to migration to Proxmox.

.DESCRIPTION
- Downloads (or uses provided) virtio-win.iso
- Mounts ISO and installs storage (vioscsi, viostor), network (NetKVM), balloon drivers
- Verifies driver install
- Unmounts ISO

.PARAMETER IsoPath
Optional. Local path to virtio-win.iso if you already downloaded it.

.PARAMETER Download
Switch. Force download latest virtio-win.iso from Fedora mirrors.

.EXAMPLE
.\Prep-VirtIODrivers.ps1 -Download

.EXAMPLE
.\Prep-VirtIODrivers.ps1 -IsoPath "C:\Temp\virtio-win.iso"
#>

param(
    [string]$IsoPath,
    [switch]$Download
)

# --- Require admin ---
if (-not ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()
    ).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator")) {
    Write-Error "Run this script in an elevated PowerShell (Run as Administrator)."
    exit 1
}

$ErrorActionPreference = 'Stop'

# --- Prepare working paths ---
$WorkDir = Join-Path $env:TEMP "virtio-prep"
New-Item -ItemType Directory -Force -Path $WorkDir | Out-Null

if (-not $IsoPath -and -not $Download) {
    # default to download
    $Download = $true
}

if ($Download) {
    $IsoPath = Join-Path $WorkDir "virtio-win.iso"
    Write-Host "Downloading latest virtio-win.iso..." -ForegroundColor Cyan

    # Primary URL (Fedora people direct-downloads)
    $url = "https://fedorapeople.org/groups/virt/virtio-win/direct-downloads/latest-virtio/virtio-win.iso"
    try {
        Invoke-WebRequest -Uri $url -OutFile $IsoPath -UseBasicParsing
    }
    catch {
        Write-Host "Primary download failed, trying mirror..." -ForegroundColor Yellow
        # Fallback mirror (if needed, simple same path assumption)
        $url2 = "https://dl.fedoraproject.org/pub/alt/virtio-win/latest-virtio/virtio-win.iso"
        Invoke-WebRequest -Uri $url2 -OutFile $IsoPath -UseBasicParsing
    }
    Write-Host "Downloaded to $IsoPath" -ForegroundColor Green
}
elseif (-not (Test-Path $IsoPath)) {
    Write-Error "IsoPath not found: $IsoPath"
    exit 1
}

# --- Mount ISO ---
Write-Host "Mounting ISO..." -ForegroundColor Cyan
$mount = Mount-DiskImage -ImagePath $IsoPath -PassThru
$vol   = ($mount | Get-Volume)
$cd    = $vol.DriveLetter + ":"
Write-Host "Mounted at $cd" -ForegroundColor Green

# Driver roots (Windows Server 2025 uses the 'w11' folder)
$Paths = @(
    Join-Path $cd "vioscsi\w11\amd64",   # VirtIO SCSI storage
    Join-Path $cd "viostor\w11\amd64",   # VirtIO block storage
    Join-Path $cd "NetKVM\w11\amd64",    # VirtIO network
    Join-Path $cd "Balloon\w11\amd64"    # Memory balloon
)

# --- Install drivers with pnputil (online) ---
Write-Host "Installing VirtIO drivers..." -ForegroundColor Cyan
foreach ($p in $Paths) {
    if (Test-Path $p) {
        Write-Host "  -> $p" -ForegroundColor DarkCyan
        # add + install all INF in this dir (no recurse needed; w11\amd64 holds INF)
        pnputil /add-driver "$p\*.inf" /install | Out-Null
    } else {
        Write-Warning "Path not found: $p"
    }
}

# --- Optional extras (uncomment if you want them now) ---
# QXL display driver (not required for server core/headless):
# pnputil /add-driver "$cd\qxldod\w11\amd64\*.inf" /install | Out-Null
# VioSerial / pvpanic (not strictly required for boot):
# pnputil /add-driver "$cd\vioserial\w11\amd64\*.inf" /install | Out-Null
# pnputil /add-driver "$cd\pvpanic\w11\amd64\*.inf" /install | Out-Null

# --- Verify key drivers staged ---
Write-Host "`nVerifying driver presence..." -ForegroundColor Cyan
$need = @('vioscsi','viostor','NetKVM','Balloon')
$drivers = (pnputil /enum-drivers) -join "`n"
foreach ($n in $need) {
    if ($drivers -match $n) {
        Write-Host ("  [+] {0} present" -f $n) -ForegroundColor Green
    } else {
        Write-Warning ("  [!] {0} NOT found in driver store" -f $n)
    }
}

# --- Unmount ISO ---
Write-Host "`nUnmounting ISO..." -ForegroundColor Cyan
Dismount-DiskImage -ImagePath $IsoPath

Write-Host "`nAll done." -ForegroundColor Green
Write-Host "Next steps:" -ForegroundColor Yellow
Write-Host @"
1) Maak nu je Veeam backup (of export) van deze VM.
2) Herstel in Proxmox:
   - Disk op **VirtIO SCSI** (controller: virtio-scsi-pci; boot: scsi0)
   - NIC op **VirtIO (paravirtualized)**
   - Voeg CD-ROM met virtio-win.iso toe voor het geval je nog wilt bij-installeren
3) Start de VM. Na eerste boot kun je (optioneel) 'virtio-win-guest-tools.exe' draaien
   vanaf de ISO voor QEMU agent en aanvullende drivers.
"@