param(
  [string]$BackupRoot = "H:\Windows-Neuaufsetzen-Backup",
  [string]$UserProfilePath = $env:USERPROFILE
)

Set-StrictMode -Version Latest
$ErrorActionPreference = "Stop"

function New-BackupFolder {
  param([string]$Name)

  $Path = Join-Path $BackupRoot $Name
  New-Item -ItemType Directory -Force -Path $Path | Out-Null
  return $Path
}

function Export-CsvSafe {
  param(
    [Parameter(ValueFromPipeline = $true)]$InputObject,
    [string]$Path
  )

  begin {
    $Items = @()
  }

  process {
    $Items += $InputObject
  }

  end {
    $Items | Export-Csv -Path $Path -NoTypeInformation -Encoding UTF8
  }
}

if (-not (Test-Path $UserProfilePath)) {
  throw "UserProfilePath does not exist: $UserProfilePath"
}

New-Item -ItemType Directory -Force -Path $BackupRoot | Out-Null

$Folders = @(
  "01_Desktop",
  "02_Dokumente",
  "03_Bilder",
  "04_Videos",
  "05_Downloads_wichtig",
  "06_Projekte",
  "07_Banking_Finanzen",
  "08_Browser_Lesezeichen_Profile",
  "09_Programme_Settings_Lizenzen",
  "10_Games_Savegames",
  "11_Homelab_NAS_Doku",
  "12_Exportierte_Listen",
  "13_Treiber_Windows",
  "14_Screenshots",
  "15_Musik",
  "99_Unsortiert_von_D_F_G"
)

$Folders | ForEach-Object { New-BackupFolder $_ | Out-Null }
$ExportDir = Join-Path $BackupRoot "12_Exportierte_Listen"

Get-ItemProperty `
  HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*, `
  HKLM:\Software\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\* |
  Where-Object {
    $_.PSObject.Properties.Name -contains "DisplayName" -and
    -not [string]::IsNullOrWhiteSpace($_.DisplayName)
  } |
  Select-Object DisplayName, DisplayVersion, Publisher, InstallDate, InstallLocation |
  Sort-Object DisplayName |
  Export-CsvSafe -Path (Join-Path $ExportDir "installierte_programme.csv")

if (Get-Command winget -ErrorAction SilentlyContinue) {
  winget list | Out-File -FilePath (Join-Path $ExportDir "winget-list.txt") -Encoding UTF8
}

Get-Volume |
  Sort-Object DriveLetter |
  Select-Object DriveLetter, FileSystemLabel, FileSystem, Size, SizeRemaining, HealthStatus |
  Export-CsvSafe -Path (Join-Path $ExportDir "laufwerke.csv")

Get-Disk |
  Select-Object Number, FriendlyName, SerialNumber, HealthStatus, OperationalStatus, Size, PartitionStyle |
  Export-CsvSafe -Path (Join-Path $ExportDir "datentraeger.csv")

Get-Partition |
  Select-Object DiskNumber, PartitionNumber, DriveLetter, Type, Size, GptType |
  Sort-Object DiskNumber, PartitionNumber |
  Export-CsvSafe -Path (Join-Path $ExportDir "partitionen.csv")

try {
  wmic path softwarelicensingservice get OA3xOriginalProductKey |
    Out-File -FilePath (Join-Path $ExportDir "windows_oem_key.txt") -Encoding UTF8
} catch {
  "Could not read OEM key: $($_.Exception.Message)" |
    Out-File -FilePath (Join-Path $ExportDir "windows_oem_key.txt") -Encoding UTF8
}

if (Get-Command manage-bde -ErrorAction SilentlyContinue) {
  manage-bde -status | Out-File -FilePath (Join-Path $ExportDir "bitlocker_status.txt") -Encoding UTF8
}

if (Get-Command wsl -ErrorAction SilentlyContinue) {
  wsl --list --verbose | Out-File -FilePath (Join-Path $ExportDir "wsl-distros.txt") -Encoding UTF8
}

$KnownUserPaths = @(
  "Desktop",
  "Documents",
  "Pictures",
  "Videos",
  "Downloads",
  "Music",
  ".ssh",
  ".gitconfig"
)

$KnownUserPaths |
  ForEach-Object {
    $Path = Join-Path $UserProfilePath $_
    [pscustomobject]@{
      Name = $_
      Path = $Path
      Exists = Test-Path $Path
      LastWriteTime = if (Test-Path $Path) { (Get-Item $Path -Force).LastWriteTime } else { $null }
    }
  } |
  Export-CsvSafe -Path (Join-Path $ExportDir "benutzerpfade.csv")

Write-Host ""
Write-Host "Backup preparation inventory created:"
Write-Host "  $BackupRoot"
Write-Host ""
Write-Host "Next manual steps:"
Write-Host "  1. Save screenshots into: $BackupRoot\14_Screenshots"
Write-Host "  2. Review CSV files in: $ExportDir"
Write-Host "  3. Start data backup only after confirming H: is the correct external drive."