$SyncPath = "$env:USERPROFILE\Saved Games\FromSoftware"     # The path your save files will be copied to, preferably Google Drive or something like that
$CheckGameState = $true                                     # Check if game is running before performing a backup?
$IntervalInSeconds = 300                                    # How often to attempt a backup
$NumberToKeep = 20                                          # Number of backups to keep

function New-SaveFile([String]$Game, [String]$Version, [System.Array]$Process, [String]$Directory, [String]$File) {
    [PSCustomObject]@{
        Game = $Game
        Version = $Version
        Process = $Process
        Directory = $Directory
        File = $File
    }
}

# Custom objects representing each save file
$SaveFiles = @(New-SaveFile `
                -Game "Dark Souls" `
                -Version "1" `
                -Process "DarkSouls","DarkSoulsRemastered" `
                -File "DRAKS0005.sl2" `
                -Directory "$env:USERPROFILE\Documents\NBGI\DARK SOULS REMASTERED\17627925")
$SaveFiles += (New-SaveFile `
                -Game "Dark Souls" `
                -Version "2" `
                -Process "DarkSoulsII" `
                -File "DS2SOFS0000.sl2" `
                -Directory "$env:APPDATA\DarkSoulsII\01100001010cfb15")
$SaveFiles += (New-SaveFile `
                -Game "Dark Souls" `
                -Version "3" `
                -Process "DarkSoulsIII" `
                -File "DS30000.sl2" `
                -Directory "$env:APPDATA\DarkSoulsIII\01100001010cfb15")

If ($CheckGameState -eq $false) {$NumberToKeep *= 10}       # If we are doing backups more frequently, allow more backups to be kept

While (1) {

    ForEach ($SaveFile In $SaveFiles) {

        $FileName = $SaveFile.File
        $SourceFile = Get-Item -Path "$($SaveFile.Directory)\$FileName"

        If (Test-Path -Path $SourceFile) {

            $Game = $SaveFile.Game
            $Version = $SaveFile.Version
            $TargetDir = "$SyncPath\$Game\$Version"

            $OKToRun = ($CheckGameState -eq $false) -or ($null -eq (Get-Process -Name $SaveFile.Process -ErrorAction SilentlyContinue))

            If (!(Test-Path $TargetDir)) {
                New-Item -ItemType Directory -Force -Path $TargetDir
            }

            If ($OKToRun) {
                $LastBackup = Get-ChildItem -Path $TargetDir | Sort-Object LastWriteTime | Select-Object -Last 1
                If ($LastBackup.LastWriteTime -ne $SourceFile.LastWriteTime) {
                    Copy-Item $SourceFile "$SyncPath\$Game\$Version\$FileName.$(Get-Date -f yyyy-MM-dd_HH-mm-ss)" -Force
                }

                While ((Get-ChildItem -Path $TargetDir).Count -gt $NumberToKeep) {
                    Get-ChildItem -Path $TargetDir | Sort-Object LastWriteTime | Select-Object -First 1 | Remove-Item
                }
            }
        }
    }

    Start-Sleep -Seconds $IntervalInSeconds
}