Add-Type -AssemblyName System.Windows.Forms

$workingDirectory = 'D:\v_ram'
$daysBeforeDelete = 3
$driveLetter      = 'S:'

$workFolder   = 'current'
$backupFolder = 'backup'
$dateFormat   = 'yyyy_MM_dd'

function Is-Empty {
    param (
        [string] $Path
    )
    return (Get-ChildItem $Path | Measure-Object).count -eq 0
}

function Show-Notify {
    param (
        [string] $Title,
        [string] $Message,
        [int] $Timeout = 10000
    )
    $path = (Get-Process -id $pid).Path
    $notify = New-Object System.Windows.Forms.NotifyIcon
    $notify.Icon = [System.Drawing.Icon]::ExtractAssociatedIcon($path)
    #$notify.BalloonTipIcon = [System.Windows.Forms.ToolTipIcon]::Warning
    $notify.BalloonTipTitle = $Title
    $notify.BalloonTipText = $Message
    $notify.Visible = $true
    $e_h = {
        param([object]$sender, [System.EventArgs]$e)
        $notify.Dispose()
    }
    $notify.add_BalloonTipClosed($e_h)
    $notify.ShowBalloonTip($Timeout)
}

# Make sure working directory exist
mkdir $workingDirectory -force
mkdir (Join-Path $workingDirectory $workFolder) -force
mkdir (Join-Path $workingDirectory $backupFolder) -force

# Move everything in work folder to backup folder
if (-not (Is-Empty (Join-Path $workingDirectory $workFolder))){
    $todayFolder = [IO.Path]::Combine($workingDirectory, $backupFolder, (get-date -f $dateFormat))
    mkdir $todayFolder -force

    Move-Item -Path ([IO.Path]::Combine($workingDirectory, $workFolder, '*')) -Destination $todayFolder
}

$deleteCount = 0
# Delete old backup
Get-ChildItem (Join-Path $workingDirectory $backupFolder) | foreach-object {
    # Get folder name and check is older enough to be deleted
    if ((new-timespan ([DateTime]::ParseExact($_.Name, 'yyyy_MM_dd', $null)) (get-date)).Days -gt $daysBeforeDelete) {
        rm -R -Force ([IO.Path]::Combine($workingDirectory, $backupFolder, $_.Name))
        $deleteCount++
    }
}

if ($deleteCount -gt 0) {
    Show-Notify "VRamdisk" "Permanently deleted $deleteCount backups"
}

# Mount folder as dirve
subst $driveLetter (Join-Path $workingDirectory $workFolder)