Valheim Data Backup Script

### Valheim data backup script
### Backs up the entire appdata folder including characters/world data

## Note: If you get errors running the script, run the following:
## Set-ExecutionPolicy -ExecutionPolicy Bypass -Scope CurrentUser

## Configuration
# How many backups to keep before pruning older copies
# 0 keeps all backups
$NumToKeep = 7

# Send pruned backups to recycle bin (false means permanent delete)
$UseRecycleBin = $true

# Where to save backups (default: yourdesktop\Valheim_Backups)
$BackupFolderPath = "$env:USERPROFILE\Desktop\Valheim_Backups"

# Name of each unique backup folder (default yyyyMMdd-HHmm, e.g. 20210212-1238)
$FolderName = Get-Date -Format "yyyyMMdd-HHmm"

## Main Script (modify at own risk)
$DestinationPath = "$BackupFolderPath\$FolderName"

# Create the backup directory
if ((Test-Path $DestinationPath) -eq $false) {
    New-Item `
        -Path $BackupFolderPath `
        -Name $FolderName `
        -ItemType "directory" | Out-Null
}

# Copy valheim appdata
Copy-Item `
    "$env:USERPROFILE\AppData\LocalLow\IronGate\Valheim\*" `
    -Destination $DestinationPath `
    -Force -Recurse

# Prune old backups
if ($NumToKeep -gt 0) {
    $ExistingBackups = Get-ChildItem -Path $BackupFolderPath -Directory | Sort-Object -Descending
    for ($i = 0; $i -lt $ExistingBackups.Count; $i++) {
        if ($i -gt ($NumToKeep - 1)) {
            if ($UseRecycleBin) {
                Add-Type -AssemblyName Microsoft.VisualBasic
                [Microsoft.VisualBasic.FileIO.FileSystem]::Deletedirectory(
                        $ExistingBackups[$i],
                        'OnlyErrorDialogs',
                        'SendToRecycleBin'
                        )
            } else {
                Remove-Item $ExistingBackups[$i] -Recurse -Force
            }
        }
    }
}