<#
.SYNOPSIS
  Export Active Directory OU structure with GPO links

.DESCRIPTION
  Documents the complete OU hierarchy including GPO links, inheritance settings,
  and description. Useful for documentation, disaster recovery, or comparing
  environments.

.PARAMETER OutputFolder
  Destination folder for reports. Default: .\OU-Structure-<date>

.PARAMETER IncludeGPODetails
  Include detailed GPO information (default: $true)

.PARAMETER SearchBase
  Optional starting point for OU export (default: domain root)

.NOTES
  ⚠️  AI-GENERATED SCRIPT - UNTESTED
  This script was generated by Claude AI and has not been tested in production.
  Review and test thoroughly in a non-production environment before use.

  - Requires Active Directory PowerShell module
  - Run with appropriate AD permissions
  - Exports to both CSV (detailed) and TXT (tree view)

.EXAMPLE
  .\Export-OUStructure.ps1

.EXAMPLE
  .\Export-OUStructure.ps1 -SearchBase "OU=Departments,DC=domain,DC=com"
#>

[CmdletBinding()]
param(
    [string]$OutputFolder = (Join-Path -Path (Get-Location) -ChildPath ("OU-Structure-" + (Get-Date -Format "yyyyMMdd-HHmm"))),
    [bool]$IncludeGPODetails = $true,
    [string]$SearchBase = ""
)

function NowTag { (Get-Date).ToString("yyyy-MM-dd HH:mm:ss") }

Write-Host "[$(NowTag)] ⚠️  AI-GENERATED SCRIPT - UNTESTED" -ForegroundColor Yellow
Write-Host "[$(NowTag)] Exporting OU structure..." -ForegroundColor Green

# Import AD module
try {
    Import-Module ActiveDirectory -ErrorAction Stop
} catch {
    Write-Host "[$(NowTag)] ERROR: Active Directory module not available" -ForegroundColor Red
    exit 1
}

# Create output folder
New-Item -ItemType Directory -Path $OutputFolder -Force | Out-Null

# Get domain info
$domain = Get-ADDomain
if (-not $SearchBase) {
    $SearchBase = $domain.DistinguishedName
}

Write-Host "[$(NowTag)] Domain: $($domain.DNSRoot)"
Write-Host "[$(NowTag)] Search Base: $SearchBase"

# Get all OUs
Write-Host "[$(NowTag)] Retrieving organizational units..."
$ouParams = @{
    Filter     = '*'
    SearchBase = $SearchBase
    Properties = @('Description', 'gPLink', 'gPOptions', 'ProtectedFromAccidentalDeletion', 'WhenCreated', 'WhenChanged')
}

$ous = Get-ADOrganizationalUnit @ouParams | Sort-Object DistinguishedName

$ouCount = ($ous | Measure-Object).Count
Write-Host "[$(NowTag)] Found $ouCount organizational unit(s)"

# Build GPO name lookup if requested
$gpoLookup = @{}
if ($IncludeGPODetails) {
    Write-Host "[$(NowTag)] Building GPO lookup table..."
    try {
        Import-Module GroupPolicy -ErrorAction Stop
        $gpos = Get-GPO -All -ErrorAction SilentlyContinue
        foreach ($gpo in $gpos) {
            $gpoLookup[$gpo.Id.ToString()] = $gpo.DisplayName
        }
        Write-Host "[$(NowTag)] Found $($gpos.Count) GPO(s)"
    } catch {
        Write-Host "[$(NowTag)] WARNING: Could not load GroupPolicy module - GPO names will show as GUIDs" -ForegroundColor Yellow
    }
}

# Process OUs
$ouDetails = @()
$treeLines = @()

foreach ($ou in $ous) {
    # Calculate depth for tree view
    $depth = ($ou.DistinguishedName -split ',OU=').Count - 1
    $indent = "  " * $depth

    # Parse GPO links
    $gpoLinks = @()
    $gpoNames = @()

    if ($ou.gPLink) {
        # gPLink format: [LDAP://cn={GUID},cn=policies,cn=system,DC=domain,DC=com;0]
        $links = $ou.gPLink -split '\]\[' -replace '^\[' -replace '\]$'

        foreach ($link in $links) {
            if ($link -match '\{([^\}]+)\}') {
                $gpoGuid = $matches[1]
                $gpoName = if ($gpoLookup.ContainsKey($gpoGuid)) {
                    $gpoLookup[$gpoGuid]
                } else {
                    $gpoGuid
                }

                # Parse link order and enforcement
                $linkOrder = if ($link -match ';(\d+)') { $matches[1] } else { "0" }
                $enforced = $linkOrder -band 1  # Bit 0 indicates enforcement
                $disabled = $linkOrder -band 2  # Bit 1 indicates disabled

                $gpoNames += $gpoName
                $gpoLinks += [PSCustomObject]@{
                    OU          = $ou.Name
                    GPOName     = $gpoName
                    GPOGUID     = $gpoGuid
                    LinkOrder   = $linkOrder
                    Enforced    = ($enforced -eq 1)
                    Disabled    = ($disabled -eq 2)
                }
            }
        }
    }

    # GPO inheritance blocked?
    $inheritanceBlocked = ($ou.gPOptions -eq 1)

    # Tree view line
    $protectedMark = if ($ou.ProtectedFromAccidentalDeletion) { "[P]" } else { "" }
    $inheritMark = if ($inheritanceBlocked) { "[BLOCKED]" } else { "" }
    $gpoMark = if ($gpoNames.Count -gt 0) { " (GPOs: $($gpoNames -join ', '))" } else { "" }

    $treeLines += "$indent$($ou.Name) $protectedMark$inheritMark$gpoMark"

    # Detailed record
    $ouDetails += [PSCustomObject]@{
        Name                             = $ou.Name
        DistinguishedName                = $ou.DistinguishedName
        Description                      = $ou.Description
        ProtectedFromAccidentalDeletion  = $ou.ProtectedFromAccidentalDeletion
        GPOInheritanceBlocked            = $inheritanceBlocked
        LinkedGPOs                       = ($gpoNames -join "; ")
        LinkedGPOCount                   = $gpoNames.Count
        WhenCreated                      = $ou.WhenCreated
        WhenChanged                      = $ou.WhenChanged
    }
}

# Export detailed CSV
$csvFile = Join-Path $OutputFolder "OU-Structure.csv"
$ouDetails | Export-Csv -NoTypeInformation -Encoding UTF8 -Path $csvFile
Write-Host "[$(NowTag)] OU details exported: $csvFile" -ForegroundColor Green

# Export GPO links if available
if ($IncludeGPODetails -and $gpoLinks.Count -gt 0) {
    $gpoLinksFile = Join-Path $OutputFolder "OU-GPO-Links.csv"
    $gpoLinks | Export-Csv -NoTypeInformation -Encoding UTF8 -Path $gpoLinksFile
    Write-Host "[$(NowTag)] GPO links exported: $gpoLinksFile" -ForegroundColor Green
}

# Export tree view
$treeFile = Join-Path $OutputFolder "OU-Tree.txt"
$treeHeader = @"
Active Directory OU Structure
Domain: $($domain.DNSRoot)
Search Base: $SearchBase
Generated: $(Get-Date)

Legend:
  [P] = Protected from Accidental Deletion
  [BLOCKED] = GPO Inheritance Blocked

"@

$treeHeader | Out-File -FilePath $treeFile -Encoding UTF8
$treeLines | Out-File -FilePath $treeFile -Encoding UTF8 -Append
Write-Host "[$(NowTag)] Tree view exported: $treeFile" -ForegroundColor Green

# Summary
Write-Host "`nOU STRUCTURE SUMMARY:" -ForegroundColor Cyan
Write-Host "  Total OUs: $ouCount"
Write-Host "  Protected OUs: $(($ouDetails | Where-Object ProtectedFromAccidentalDeletion).Count)"
Write-Host "  OUs with GPO Inheritance Blocked: $(($ouDetails | Where-Object GPOInheritanceBlocked).Count)"
Write-Host "  OUs with Linked GPOs: $(($ouDetails | Where-Object { $_.LinkedGPOCount -gt 0 }).Count)"

Write-Host "`n[$(NowTag)] Export complete! Output folder: $OutputFolder"