Archean-backup.ps1

# A simple PowerShell script to backup Archean save files
# Twitter: @Kerbo_
#

# EDIT TO SUIT YOUR INSTALL AND PREFERRED BACKUP LOCATION
$archeanDir = "C:\Program Files (x86)\Steam\steamapps\common\Archean\Archean-data\server\worlds"
$archeanBackupDir = "C:\savegames\Archean"
# Keep this many backups
$maxBackups = 10

$dateString = $(get-date -f yyy-MM-dd_HH-mm)

# Create backup directory if it doesn't exist
New-Item -ItemType Directory -Force -Path $archeanBackupDir | Out-Null

Push-Location $archeanDir
$saves = Get-ChildItem -Directory
foreach($save in $saves) {
    # Examine latest backup
    Push-Location $archeanBackupDir
    $backup = gci "$save-*" | select -last 1
    if (-not ([string]::IsNullOrEmpty($backup))) {
        # New temp dir
        $parent = [System.IO.Path]::GetTempPath()
        [string] $name = [System.Guid]::NewGuid()
        $tempDir = New-Item -ItemType Directory -Path (Join-Path $parent $name)
        # Extract and get hash
        Expand-Archive -Path $backup -DestinationPath $tempDir
        $backup_hash = Get-FileHash $tempDir\state.worldstate
        # Remove temp dir
        Remove-Item -LiteralPath $tempDir -Force -Recurse
    }
    Pop-Location

    if(Test-Path -Path "$save\state.worldstate" -PathType Leaf) {
        $current_hash = Get-FileHash "$save\state.worldstate"
        if ( $backup_hash.Hash -eq $current_hash.Hash ) {
            Write-Host "$save matches latest backup, no backup needed"
        } else {
            Write-Host "Backing up to $archeanBackupDir\$save-$dateString.zip"
            Compress-Archive -Path $save\* -DestinationPath "$archeanBackupDir\$save-$dateString.zip"
        }
    }

    # Keep only latest $maxBackups backups
    Push-Location $archeanBackupDir
    $c = Get-ChildItem "$save-*" | measure
    $count = $c.Count
    Write-Host "Using $count out of $maxBackups backups for $save"
    If($count -gt $maxBackups) {
        $delcount = $count - $maxBackups
        Write-Host "Cleaning up $delcount old backups for $save"
        Get-ChildItem "$save-*" -Recurse | sort CreationTime -desc | select -Skip $maxBackups | Remove-Item -Force
    }
    Pop-Location
}
Pop-Location
Write-Host "Done"
Start-Sleep -Seconds 5