getting users stats

[CmdletBinding()]Param(
    [Parameter()][switch]$EstimatedLogon
)

function GetRealLogonDate{
    [CmdletBinding()]
    Param(
        [Parameter(Mandatory=$true,
                   Position=0)]
        [String]$sAMAccountName,

        [Parameter(Mandatory=$true,
           Position=1)]
        [String]$Domain
    )

    # Currenly not used, but may use some day.  The idea is to get the 'real' last logon time of an account
    # before we apply a bogus to it.

    try{
        $domainContext = New-Object System.DirectoryServices.ActiveDirectory.DirectoryContext('Domain',$Domain)
        $domainInfo    = [DirectoryServices.ActiveDirectory.Domain]::GetDomain($domainContext)
    }
    catch{
        throw('Unable to connect to {0}: {1}' -f $Domain,$_.exception.message)
    }

    [array]$dcList = $domainInfo.DomainControllers | foreach { $_.name }
    Write-Verbose -Message ('[GetRealLogonDate] Found {0} DCs in {1}' -f $dcList.count,$Domain)

    $queryBlock = {
        Param(
            [Parameter(Mandatory=$true,
                       Position=0)]
            [String]$sAMAccountName,

            [Parameter(Mandatory=$true,
               Position=1)]
            [String]$ComputerName
        )

        $searcher = new-object System.DirectoryServices.DirectorySearcher([ADSI]"LDAP://$ComputerName")
        $searcher.filter = "(&(objectClass=User)(lastlogon=*)(sAMAccountName=$sAMAccountName))"
        [void]$searcher.PropertiesToLoad.Add('lastlogon')
        try{
            $userObj = $searcher.FindOne()
        }
        catch{
            return $null
        }

        Write-Output $(New-Object -TypeName PSObject -Property @{DC=$ComputerName;sAMAccountName=$sAMAccountName;LastLogon=[int64]$($userObj.Properties.lastlogon | Out-String).trim()})
    }

    $queryQueue = New-Object System.Collections.ArrayList
    for($i = 0; $i -lt $dcList.count; $i++){
        Write-Verbose ('[GetRealLogonDate] Running jobs: {0}' -f (Get-Job -State Running).Count)
        While( (Get-Job -State Running).Count -ge 10 ){
            Start-Sleep -Seconds 3
        }

        Write-Verbose ('[GetRealLogonDate] Starting job for {0}' -f $dcList[$i])
        Start-Job -Name $dcList[$i] -ScriptBlock $queryBlock -ArgumentList $sAMAccountName,$dcList[$i] | Out-Null

        Get-Job -State Completed | Where { $_.Name -like "*.$Domain.*"} | Receive-Job -Wait -AutoRemoveJob | foreach { [void]$queryQueue.Add($_)}
    }

    Write-Verbose ('[GetRealLogonDate] Waiting for running jobs to finish')
    Get-Job | Wait-Job | Receive-Job -Wait -AutoRemoveJob | foreach { [void]$queryQueue.Add($_)}

    $log = 0
    for($q = 0; $q -lt $queryQueue.count; $q++){
        if($queryQueue[$q].LastLogon -like $null){continue}
        if($queryQueue[$q].LastLogon -gt $log){$log = $queryQueue[$q].LastLogon}
    }

    Write-Output $([datetime]::FromFileTime($log))
}


$users = Get-ADUser -Filter {Enabled -eq $true} -ResultSetSize 50000 -Properties displayName,description,PasswordLastSet,MemberOf,CanonicalName,LastLogonDate
$UserReport = New-Object System.Collections.ArrayList

foreach ($u in $users){
    if($EstimatedLogon){
        $lastLogon = $u.LastLogonDate
    }
    else{
        $lastLogon = GetRealLogonDate -sAMAccountName $u.sAMAccountName -Domain ($u.CanonicalName -split '/')[0]
    }

    $UserObject = New-Object -TypeName PSObject -Property @{
        sAMAccountName  = $u.sAMAccountName
        displayName     = $u.displayName
        description     = $u.description
        LastLogon       = $lastlogon
        PasswordLastSet = $u.PasswordLastSet
        Memberships     = [string]::Join(';',($u.Memberof | foreach { ($_ -split ',')[0] -replace 'CN=' } | sort))
    }

    [void]$UserReport.Add($UserObject)
}

Write-Output $UserReport