Recyle AppPool Interactive

[CmdletBinding()]
param
(
    [Parameter(Mandatory, HelpMessage = "Enter a comma separated list of servers to query for IIS websites.")]
    [string[]] $Servers
)

function GetPoolList([string[]]$serverList)
{
    # Create PSSession for each server in the list.
    $PSSessions = $serverList | ForEach-Object {
        New-PSSession -ComputerName $_
    }

    $i = 1                   # The display list will start at #1
    $lookup = [ordered]@{}   # New lookup table with the key as the number that is displayed to the user for choosing.
    # We do an OrderedDictionary above so that when we perform a 'foreach' on it, the items inside will be processed in the correct order.
    # ... otherwise the displayed list will be backwards.
    foreach ($session in $PSSessions)
    {
        $webSites = @(
            Invoke-Command -Session $session -ScriptBlock {
                Import-Module IISAdministration
                Get-IISSite | Select-Object Name -Unique | Sort-Object Name | Select-Object -ExpandProperty Name
            }
        )

        foreach ($site in $webSites)
        {
            # $i is turned into a string here, because an ordered dictionary can be indexed by numbers.
            # If we didn't stringify it, all of the user's choices would actually indicate the next website in the list
            # e.g. - 1, 3, 6 -- would be recycle the 2nd, 4th, and 7th websites in the list.
            [void]$lookup.Add("$i", [pscustomobject]@{
                Site = $site
                ListDisplay = ("{0}: {1} - {2}" -f $i, $session.ComputerName, $site) # This is the display line that will be presented to the user
                Session = $session
            })
            $i++
        }
    }

    , $lookup   # return the lookup table
}

Write-Host "`nChoose a website from the following list:`n" -f Yellow
$allSitesInfo = GetPoolList -serverList $Servers
foreach ($kvp in $allSitesInfo.GetEnumerator())
{
    Write-Host $kvp.Value.ListDisplay -f Cyan
}
# The list websites and servers have now been displayed.

[string[]]$RecyclePools = (read-host "`nSelect website numbers to recycle (separated by comma)") -split ',' | Get-Unique
# We explicitly define the entered numbers above as "strings", otherwise PowerShell might try to convert them back to Int32.
# Also, we do Get-Unique above just in case somebody puts the same number multiple times (we don't need to recycle that much...)

Write-Host "`n" # Just an extra line break

# For each number they've entered...
# ... retrieve the website to get each AppPool and then recycle them.
foreach ($number in $RecyclePools)
{
    $siteToRecycle = $allSitesInfo[$number].Site
    $sessionToUse = $allSitesInfo[$number].Session

    Write-Host "Recycling all app pools for $siteToRecycle on $($sessionToUse.ComputerName)..." -f Green

    Invoke-Command -Session $sessionToUse -ScriptBlock {
        $iisSite = Get-IISSite -Name $using:siteToRecycle
        foreach ($appPool in $iisSite.Applications)
        {
            $(Get-IISAppPool -Name $appPool.ApplicationPoolName).Recycle()
        }
    }
}

foreach ($obj in $allSitesInfo.GetEnumerator())
{
    $obj.Value.Session | Remove-PSSession
}