## check for parameters
param(
	[string]$AlertName = $(throw write-host "You did not specify the -AlertName parameter."),
	[string]$NotificationRecipientName = $(throw write-host "You did not specify the -NotificationRecipientName parameter. Use the Get-NotificationRecipient command to get a list of all registered notification recipients")
	)

$RMS = "RootManagementServerName"

write-Host 
write-Host "Executing Set-NotificationForAlert.ps1 ..."
write-Host 

## prepare OpsMgr shell

if ((Get-PSSnapin | Where-Object {$_.Name -eq 'Microsoft.EnterpriseManagement.OperationsManager.Client'}) -eq $null) 
{
	Write-Host
	Write-Host "File OpsMgrV3.ps1 loaded."
	Write-Host "Initializing shell for operations manager..."
	Write-Host "Add Microsoft.EnterpriseManagement.OperationsManager.Client snap in."
	Add-PSSnapin Microsoft.EnterpriseManagement.OperationsManager.Client -ErrorAction SilentlyContinue -ErrorVariable Err

	if ($Err) { $(throw write-Host $Err) }
}

if ((Get-ManagementGroupConnection | Where-Object {$_.ManagementServerName -eq $RMS}) -eq $null) 
{
	Write-Host "Connect to Management Server: $RMS"
	New-ManagementGroupConnection $RMS -ErrorAction SilentlyContinue -ErrorVariable Err
	if ($Err) { $(throw write-Host $Err) }
}

if ((Get-PSDrive | Where-Object {$_.Name -eq 'Monitoring'}) -eq $null) 
{
	Write-Host "Create Monitoring drive from Provider."
	New-PSDrive -Name: Monitoring -PSProvider: OperationsManagerMonitoring -Root: \ -ErrorAction SilentlyContinue -ErrorVariable Err
	if ($Err) { $(throw write-Host $Err) }
	Write-Host "Operations manager shell initialized."
	Write-Host
}

Set-Location Monitoring:\$RMS

$Alerts = Get-Alert | where {$_.Name -eq $AlertName}
if ($Alerts.ProblemId -eq $null)
{
	if ($Alerts.Count -gt 0) 
	{
		$ProblemID = $Alerts[0].ProblemId.ToString()
	}
else
	{
		throw write-host "No alert was found with the specified name"
	}
}
else
{
	$ProblemId = $Alerts.ProblemId.ToString()
}


## load SDK assemblies
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.EnterpriseManagement")
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.EnterpriseManagement.Configuration")
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.EnterpriseManagement.ConnectorFramework")
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.EnterpriseManagement.Monitoring")

## connect to management group
$ManagementGroup = New-Object Microsoft.EnterpriseManagement.ManagementGroup($RMS)
$ManagementGroup.Reconnect()

$smtpAction = $ManagementGroup.GetNotificationAction("DefaultSmtpAction")
$recipient = $ManagementGroup.GetNotificationRecipient($NotificationRecipientName)
$config = New-Object Microsoft.EnterpriseManagement.Administration.AlertChangedSubscriptionConfiguration([Microsoft.EnterpriseManagement.Administration.AlertSubscriptionConfigurationType]::Any)

$config.Criteria = "<SimpleExpression><ValueExpression><Property>ProblemId</Property></ValueExpression><Operator>Equal</Operator><ValueExpression><Value>$ProblemId</Value></ValueExpression></SimpleExpression>"

$config.ExpirationStartTime = Get-Date
$config.PollingIntervalMinutes = 1

$NewGuid = [System.Guid]::NewGuid()
$NewGuid = $NewGuid.ToString().Replace('-', '_')

$Subscription = New-Object Microsoft.EnterpriseManagement.Administration.AlertNotificationSubscription("STACustomSubscription$NewGuid", $config)

$Subscription.DisplayName = $NotificationRecipientName + " - " + $AlertName
$Subscription.ToRecipients.Add($recipient)
$Subscription.Actions.Add($smtpAction)
$ManagementGroup.InsertNotificationSubscription($Subscription)