Delete files older than 30 and save 1 - powershell

Question

I need to have a clean-up script that remove all files older than 30 days but if file is older than 30 days it should save the last one. Possible? :)
I have tried a couple of parameters but cannot really get it to work.. guess I need a if/else clause?
Would appreciate any guide and help with this, thanks
$Daysback = "-30"
$CurrentDate = Get-Date
$DatetoDelete = $CurrentDate.AddDays($Daysback)
$path = "C:\Data\*"
$save1 = Get-ChildItem -Path $path | Where-Object {($_.Name -like "Test*.zip")} | sort LastWriteTime -Descending | select -First
Get-ChildItem $path -Recurse
{($_.CreationTime -le $(Get-Date).AddDays($Daysback))}
{
Remove-Item -Recurse -Force
}
elseif ($save1)
{
Remove-Item -Recurse -Force
}
}

Answer 1

Something like this should work.
$Daysback = "-30"
$CurrentDate = Get-Date
$DatetoDelete = $CurrentDate.AddDays($Daysback)
$path = "C:\Data\*"
$Items=Get-ChildItem -Path $path -Recurse | Where-Object {($_.Name -like "Test*.zip") -and ($_.LastWriteTime -le ($DatetoDelete))}| Sort-Object LastWriteTime -Descending
$Items|Select-Object -Skip 1 |Remove-Item -Recurse -Force -Path $_.fullname
Get-ChildItem -> Filter, only get the items that name starts with Test and ends with .Zip that were written over 30 days ago. Sort them.
In the delete line, we use -Skip 1 to skip over the first item in the sorted list and remove the items by using their path.

Answer 2

This can be simplified. The below block will grab all files in C:\Data that meet the filter (faster than Where-Object significantly), then further reduces those based on their CreationTime, skips 1, and deletes the rest.
Get-ChildItem -Path 'C:\Data' -Filter 'Test*.zip' -Recurse |
Where-Object { -not $_.PSIsContainer -and
$_.CreationTime -le (Get-Date).AddDays(-30) } |
Sort-Object -Property 'LastWriteTime' -Descending |
Select-Object -Skip 1 |
Remove-Item -Force -WhatIf