function Get-GPOZaurrOrganizationalUnit {
    [CmdletBinding()]
    param(
        [alias('ForestName')][string] $Forest,
        [string[]] $ExcludeDomains,
        [alias('Domain', 'Domains')][string[]] $IncludeDomains,
        [System.Collections.IDictionary] $ExtendedForestInformation,

        [ValidateSet('OK', 'Unlink', 'Delete')][string[]] $Option,
        [alias('ExcludeOU', 'Exclusions')][string[]] $ExcludeOrganizationalUnit
    )
    $CachedOu = [ordered] @{}
    $CachedGPO = [ordered] @{}

    $ForestInformation = Get-WinADForestDetails -Extended -Forest $Forest -IncludeDomains $IncludeDomains -ExcludeDomains $ExcludeDomains -ExtendedForestInformation $ExtendedForestInformation
    $DefaultFolders = Get-WellKnownFolders -Forest $Forest -IncludeDomains $IncludeDomains -ExcludeDomains $ExcludeDomains -ExtendedForestInformation $ExtendedForestInformation
    $GroupPolicies = Get-GPOZaurrAD -Forest $Forest -IncludeDomains $IncludeDomains -ExcludeDomains $ExcludeDomains -ExtendedForestInformation $ExtendedForestInformation
    foreach ($GPO in $GroupPolicies) {
        $CachedGPO[$GPO.GPODistinguishedName] = $GPO
    }
    foreach ($Domain in $ForestInformation.Domains) {
        Write-Verbose "Get-GPOZaurrOrganizationalUnit - Processing $($Domain)"
        $CountTop = 0
        $TopOrganizationalUnits = Get-ADOrganizationalUnit -Filter * -Properties LinkedGroupPolicyObjects, DistinguishedName, ntSecurityDescriptor -Server $ForestInformation['QueryServers'][$Domain]['hostname'][0] -SearchScope OneLevel
        foreach ($TopOU in $TopOrganizationalUnits) {
            $CountTop++
            Write-Verbose "Get-GPOZaurrOrganizationalUnit - Processing $($Domain) / $($TOPOU.DistinguishedName) [$CountTop/$($TopOrganizationalUnits.Count)]"
            # cache top ou
            if ($TopOU.LinkedGroupPolicyObjects) {
                $LinkedGPOs = $CachedGPO[$TopOU.LinkedGroupPolicyObjects]
            } else {
                $LinkedGPOs = $null
            }
            $CachedOu[$TopOU.DistinguishedName] = [ordered]@{
                'LinkedGroupPolicyObjects' = $TopOU.LinkedGroupPolicyObjects
                'LinkedGroupPolicy'        = $LinkedGPOs
                'Objects'                  = [ordered] @{}
                'ObjectsClasses'           = [ordered] @{}
                'ObjectsCountDirect'       = 0
                'ObjectsCountIndirect'     = 0
                'ObjectsCountTotal'        = 0
                'Level'                    = 'Top'
                'RootLevel'                = $TopOU.Name
                'Domain'                   = $Domain
            }

            # cache children OUs
            $OUs = Get-ADOrganizationalUnit -SearchScope Subtree -SearchBase $TopOU.DistinguishedName -Server $ForestInformation['QueryServers'][$Domain]['hostname'][0] -Properties LinkedGroupPolicyObjects, DistinguishedName -Filter *
            Write-Verbose "Get-GPOZaurrOrganizationalUnit - Processing $($Domain) / $($TOPOU.DistinguishedName) [$CountTop/$($TopOrganizationalUnits.Count)], found $($OUs.Count) OU's to process."
            foreach ($OU in $OUs) {
                if (-not $CachedOu[$OU.DistinguishedName]) {
                    if ($OU.LinkedGroupPolicyObjects) {
                        $LinkedGPOs = $CachedGPO[$OU.LinkedGroupPolicyObjects]
                    } else {
                        $LinkedGPOs = $null
                    }
                    $CachedOu[$OU.DistinguishedName] = [ordered]@{
                        'LinkedGroupPolicyObjects' = $OU.LinkedGroupPolicyObjects
                        'LinkedGroupPolicy'        = $LinkedGPOs
                        'Objects'                  = [ordered] @{}
                        'ObjectsClasses'           = [ordered] @{}
                        'ObjectsCountDirect'       = 0
                        'ObjectsCountIndirect'     = 0
                        'ObjectsCountTotal'        = 0
                        'Level'                    = 'Child'
                        'RootLevel'                = $TopOU.Name
                        'Domain'                   = $Domain
                    }
                }
            }
            # Find all objects in those OUs
            $ObjectsInOu = Get-ADObject -LDAPFilter "(|(ObjectClass=user)(ObjectClass=contact)(ObjectClass=computer)(ObjectClass=group)(objectClass=inetOrgPerson))" -SearchBase $TopOU.distinguishedName -Server $ForestInformation['QueryServers'][$Domain]['hostname'][0]
            Write-Verbose "Get-GPOZaurrOrganizationalUnit - Processing $($Domain) / $($TOPOU.DistinguishedName) [$CountTop/$($TopOrganizationalUnits.Count)], found $($ObjectsInOu.Count) objects to process."
            foreach ($Object in $ObjectsInOu) {
                $Place = ConvertFrom-DistinguishedName -ToOrganizationalUnit -DistinguishedName $Object.DistinguishedName
                $AllOUs = ConvertFrom-DistinguishedName -ToMultipleOrganizationalUnit -IncludeParent -DistinguishedName $Place
                foreach ($OU in $AllOUs) {
                    if ($OU -eq $Place) {
                        $CachedOu[$OU]['Objects'][$Object.DistinguishedName] = $Object
                        $CachedOu[$OU]['ObjectsClasses'][$Object.ObjectClass] = ''
                        $CachedOu[$OU]['ObjectsCountDirect']++
                    } else {
                        $CachedOu[$OU]['ObjectsClasses'][$Object.ObjectClass] = ''
                        $CachedOu[$OU]['ObjectsCountIndirect']++
                    }
                    $CachedOu[$OU]['ObjectsCountTotal']++
                }
            }
        }
    }
    foreach ($OU in $CachedOu.Keys) {
        $ObjectClasses = [string[]] $CachedOu[$OU]['ObjectsClasses'].Keys

        if ($CachedOu[$OU]['ObjectsCountTotal'] -eq 0 -and $CachedOu[$OU]['LinkedGroupPolicyObjects'].Count -gt 0) {
            $Status = "Unlink GPO", 'Delete OU'
        } elseif ($CachedOu[$OU]['ObjectsCountTotal'] -eq 0 -and $CachedOu[$OU]['LinkedGroupPolicyObjects'].Count -eq 0) {
            $Status = 'Delete OU'
        } elseif ($CachedOU[$Ou]['ObjectsCountTotal'] -gt 0 -and $CachedOu[$OU]['LinkedGroupPolicyObjects'].Count -gt 0 -and $ObjectClasses -notcontains 'User' -and $ObjectClasses -notcontains 'Computer' ) {
            $Status = "Unlink GPO"
        } else {
            $Status = 'OK'
        }

        if ($Option) {
            $Found = $false
            if ($Option -contains 'Ok' -and $Status -contains 'OK') {
                $Found = $true
            } elseif ($Option -contains 'Unlink' -and $Status -contains 'Unlink GPO') {
                $Found = $true
            } elseif ($Option -contains 'Delete' -and $Status -contains 'Delete OU') {
                $Found = $true
            }
            if ($ExcludeOrganizationalUnit) {
                foreach ($ExcludedOU in $ExcludeOrganizationalUnit) {
                    if ($OU -like $ExcludedOU) {
                        $Found = $false
                        break
                    }
                }
            }
            foreach ($Exclude in $DefaultFolders) {
                if ($OU -eq "$Exclude") {
                    $Found = $false
                    break
                }
            }
            if (-not $Found) {
                continue
            }
        } else {
            if ($ExcludeOrganizationalUnit) {
                foreach ($ExcludedOU in $ExcludeOrganizationalUnit) {
                    if ($OU -like $ExcludedOU) {
                        $Status = 'Excluded'
                        break
                    }
                }
            }
            foreach ($Exclude in $DefaultFolders) {
                if ($OU -eq "$Exclude") {
                    $Status = 'Excluded, Default OU'
                    break
                }
            }
        }

        [PSCustomObject] @{
            Organizationalunit  = $OU
            Level               = $CachedOu[$OU]['Level']
            RootLevel           = $CachedOu[$OU]['RootLevel']
            DomainName          = $CachedOu[$OU]['Domain']
            Status              = $Status
            GPOCount            = $CachedOu[$OU]['LinkedGroupPolicyObjects'].Count
            ObjectCountDirect   = $CachedOu[$OU]['ObjectsCountDirect']
            ObjectCountIndirect = $CachedOu[$OU]['ObjectsCountIndirect']
            ObjectCountTotal    = $CachedOu[$OU]['ObjectsCountTotal']
            ObjectClasses       = $ObjectClasses
            GPONames            = $CachedOu[$OU]['LinkedGroupPolicy'].DisplayName
            Objects             = $CachedOu[$OU]['Objects'].Values.Name
            GPO                 = $CachedOu[$OU]['LinkedGroupPolicy']
        }
    }
}