# Description: 
# Set's the Working Location for a VM. This location will hold the vswap and snapshot delta files.

# Usage: 
# First, connect to a virtual server server (Connect-VIServer)
#
# Set snapshot location for one vm (folder must already exist on datastore):
# Set-VMSnapshotLocation -vm VM001 -Location "[BigAssDatastore] Snapshots"
#
# For all vms at once (no folder specified will put all in the root of the datastore):
# Get-VM | ForEach-Object {Set-VMSnapshotLocation -vm $_ -Location "[BigAssDatastore]"}
#
# Reset the location to the original location (with the vmx file):
# Set-VMSnapshotLocation -vm VM001 -Reset

Function Set-VMSnapshotLocation
	{
	param($vm, [string]$Location, [switch]$Reset=$False)
	
	#Region Input Validation
	# Check vm parameter
	If (!$vm)
		{
		Throw "No VM specified."
		}
	# Check Location parameter. 
	# Can be empty when using Reset, can be "[datastore]" or can be "[datastore] folder" (folder must exist).
	If (!$Reset -and $Location -notmatch "\[\S+\](\s\w+)?")
		{
		Throw "Invalid location specified. Syntax: [Datastore] Folder"
		}
	# Specifying Reset will set Location to empty, which causes the original location to be used (same location as vmx file).
	If ($Reset)
		{
		$Location = ""
		}
	# Make sure to get a vm object to work with.
	# This allows both using a vm name when targeting one vm (Set-VMSnapshotLocation -vm VM001 -Reset); 
	# AND piping a collection of vm's (Get-VM | ForEach (Set-VMSnapshotLocation -vm $_ -Location "[BigAssDatastore] Snapshots" ).
	If ($vm.GetType().Name -eq "String")
		{
		$oVM = Get-VM $vm
		}
	ElseIf ($vm.GetType().Name -eq "VirtualMachineImpl")
		{
		$oVM = $vm
		}
	Else 
		{
		Throw "Parameter vm is of an invalid type."
		}
	#EndRegion InputValidation
	
	#Region Main
	# Get advanced properties of vm
	$vmView = $oVM | Get-View
	# Create object containing new properties
	$vmConfigSpec = New-Object VMware.Vim.VirtualMachineConfigSpec
	$vmConfigSpec.Files = New-Object VMware.Vim.VirtualMachineFileInfo
	$vmConfigSpec.Files.SnapshotDirectory = $Location
	# Reconfigure VM using new properties
	$vmView.ReconfigVM($vmConfigSpec)
	#EndRegion Main
	}