<# 
.Synopsis   
    Adds node(s) to a RD Connection Broker(CB) Fail-Over cluster that has already been created.
	Creates a RD Connection Broker(CB) Fail-Over cluster if '-Create' switch has been specified.
	
.Description 
    Adds node(s) to a RD Connection Broker(CB) Fail-Over cluster that has already been created.
	Creates a RD Connection Broker(CB) Fail-Over cluster if '-Create' switch is specified. While creating a RD Connection Broker(CB) Fail-Over cluster, it also installs the required roles/features. 
	
	NOTE: 
	1. To add a node to an existing RD Connection Broker Fail-Over cluster, the script should be executed on the ownernode of the cluster.
	2. To create a RD Connection Broker Fail-Over cluster, the script should be executed on one of the nodes that is intended to be part of the cluster.
	3. The script should be executed with domain user credentials that has administrative privileges on all the nodes of the cluster.
   
.Parameter ClusterName
    Name of the RD Connection Broker Fail-Over cluster.

.Parameter ClientAccessName
    Client access Name of RD Connection Broker Fail-Over cluster. Client access name can be found in the services and applications pane of the Fail-Over cluster manager.

.Parameter Node
    Names of the servers that are a part of the RD Connection Broker Fail-Over cluster.
	
.Parameter Create
	Switch: If provided, the RD Connection Broker Fail-Over cluster is created.

.Example 
    PS C:\> Set-ConnectionBrokerCluster.ps1 -Node cb1,cb2 -ClusterName "My-Cluster" -ClientAccessName "HA-CB" -Create
    Creates the RD Connection Broker Fail-Over cluster "My-Cluster" with nodes cb1 and cb2.
	
.Example 
    PS C:\> Set-ConnectionBrokerCluster.ps1 -Node cb1,cb2 -ClusterName "My-Cluster" -ClientAccessName "HA-CB"
    Adds nodes cb1 and cb2 to already created cluster(with the current machine as one of the nodes).

.Notes 
    Name     : Set-ConnectionBrokerCluster.ps1
    
#>

param(
	[ValidateNotNullOrEmpty()]
    [Parameter(Mandatory=$TRUE, HelpMessage="Name of the RD Connection Broker Fail-Over cluster.")]
    [System.String]$ClusterName,
    
    [ValidateNotNullOrEmpty()]
    [Parameter(Mandatory=$TRUE, HelpMessage="Client access Name of RD Connection Broker Fail-Over cluster. Client access name can be found in the services and applications pane of the Fail-Over cluster manager.")]
    [System.String]$ClientAccessName,
    
    [ValidateNotNullOrEmpty()]
    [Parameter(Mandatory=$TRUE, HelpMessage="Names of the servers that are a part of the RD Connection Broker Fail-Over cluster.")]
    [System.String[]]$Node,
	
	[ValidateNotNullOrEmpty()]
    [Parameter(Mandatory=$FALSE, HelpMessage="Switch to specify if the RD Connection Broker Fail-Over cluster needs to be created.")]
    [Switch]$Create
)

function Get-HostName([Bool]$IsFqdn)
{
	$WmiObj = Get-WmiObject -Class Win32_ComputerSystem -Property Name,Domain
	if($IsFqdn)
	{
		return $WmiObj.Name + "." + $WmiObj.Domain
	}
	else
	{
		return $WmiObj.Name
	}
}

function Print-Error([System.String]$Msg)
{
	Write-Host -ForegroundColor Red -BackgroundColor White $Msg
	Exit(1)
}

function Invoke-MyCommand([System.String]$Computer, [System.Management.Automation.ScriptBlock]$ScriptBlock, [System.Object[]]$ArgumentList)
{
	$RetVal = @()
    
	$RetVal = [System.Object[]](Invoke-Command -ComputerName $Computer -ScriptBlock $ScriptBlock -ArgumentList $ArgumentList)
	
	return $RetVal
}

function Ping-Comp([System.String]$Computer)
{
	$RetVal = $null
	$RetVal = Invoke-MyCommand $Computer {"Ping"}
	if($RetVal)
	{
		return $TRUE
	}
	else
	{
		return $FALSE
	}
}

function Validate-AccessName([String]$AccessName)
{
	if( ($AccessName.Split(".").Length) -gt 1 )
	{
		return $FALSE
	}
	else
	{
		return $TRUE
	}
}

# Check if the script is being executed with appropriate privileges
$LoggedInUser = New-Object -TypeName System.Security.Principal.WindowsPrincipal -ArgumentList ([System.Security.Principal.WindowsIdentity]::GetCurrent())
if(!($LoggedInUser.IsInRole([System.Security.Principal.WindowsBuiltInRole]::Administrator)))
{
	Print-Error "Please execute the script with administrative privileges."
}

if(!($LoggedInUser.IsInRole("Domain Users")))
{
	Print-Error "Please execute the script with domain user credentials that has administrative privileges on all the nodes of the cluster."
}

if( -not (Validate-AccessName $ClusterName) )
{
	Print-Error "Please provide the Cluster Name of RD Connection Broker Fail-Over cluster, not it's FQDN."
}

if( -not (Validate-AccessName $ClientAccessName) )
{
	Print-Error "Please provide the Client access Name of RD Connection Broker Fail-Over cluster, not it's FQDN."
}

if( $ClusterName -eq  $ClientAccessName )
{
	Print-Error "The 'ClientAccessName' should not be the same as the 'ClusterName'."
}

#Check if the node list contains the localhost.
$AllComputers = [String[]]($Node)

$LocalHostName = Get-HostName $false
$LocalHostFQDN = Get-HostName $true
$NotFound = $True
$MasterConfigNode = $null
foreach($Comp in $AllComputers)
{
	if( ($Comp -eq $LocalHostName) -or ($Comp -eq $LocalHostFQDN) )
	{
		$NotFound = $False
		$MasterConfigNode = $Comp
	}
}

if($NotFound -and $Create.IsPresent)
{
	Print-Error "The 'Node' list should contain the local computer as the parameter '-Create' is provided."
}

if(!$Create.IsPresent -and !$NotFound)
{
	Print-Error "The 'Node' list contains the local computer which is not a part of the already created cluster. Please use '-Create' switch to create a new cluster and add nodes to it. Please execute the script on the 'OwnerNode' of the cluster, if the node is to be added to an already created cluster."
}

#Check to see if all computers are accessible for Remote PowerShell script execution.
foreach($Comp in $AllComputers)
{
	if(!(Ping-Comp $Comp))
	{
		Print-Error "Unable to ping $Comp. Exiting..!"
	}
}

$ScriptBlock = {
    Import-Module -Name ServerManager -ErrorAction Stop
	$RetVal = $TRUE
	
	$HostName = hostname
	
	if(!(Get-WindowsFeature RDS-Connection-Broker).Installed)
	{
		Add-WindowsFeature -Name RDS-Connection-Broker
		if($?)
		{
			Write-Host "Installed RD Connection Broker role service on '$HostName'"
		}
		else
		{
			Write-Host -ForegroundColor Red -BackgroundColor White "Failed to install RD Connection Broker role service on '$HostName'"
			$RetVal = $FALSE
		}
		
	}
	
	if(!(Get-WindowsFeature Failover-Clustering).Installed)
	{
		Add-WindowsFeature -Name Failover-Clustering
		if($?)
		{
			Write-Host "Installed 'Fail-Over-Clustering' feature on '$HostName'"
		}
		else
		{
			Write-Host -ForegroundColor Red -BackgroundColor White "Failed to install 'Fail-Over-Clustering' feature on '$HostName'"
			$RetVal = $FALSE
		}
	}
	
	$RetVal
}

#Install RD Connection Broker role service and failover-cluster feature if not installed 
foreach($Comp in $Node)
{
	$ShouldStop = $FALSE
	$RetValue = Invoke-MyCommand $Comp $ScriptBlock
	
	if(!$RetValue)
	{
		Print-Error "Error on server: '$Comp'. Either the 'ServerManager' module could not be loaded or one of the roles/features failed to install. Exiting..!"
	}
}

#Add cluster resources

#Load the FailOverClusters module
Import-Module -Name FailoverClusters -ErrorAction Stop

if($Create.IsPresent)
{
	#Create a new cluster
	New-Cluster -Name $ClusterName -Node $Node -ErrorAction Stop
		
	#Add RD Connection Broker role service and create a resource group
	Add-ClusterGenericServiceRole -Name $ClientAccessName -ServiceName "Tssdis" -CheckpointKey "SOFTWARE\Microsoft\Windows NT\CurrentVersion\Terminal Server\Session Broker" -ErrorAction Stop

	#Also add publishing service to the group
	Add-ClusterResource -Name "RemoteApp and Desktop Connection Management" -Group $ClientAccessName -ResourceType "Generic Service" -ErrorAction Stop
	Get-ClusterResource -Name "RemoteApp and Desktop Connection Management" | Set-ClusterParameter -Name ServiceName -Value "TScPubRPC"
	Get-ClusterResource -Name "RemoteApp and Desktop Connection Management" | Set-ClusterParameter -Name StartupParameters -Value "-k NetworkServiceRemoteDesktopPublishing"

	#Stop & Start the cluster group on this node
	Stop-ClusterGroup -Name $ClientAccessName
	Start-ClusterGroup -Name $ClientAccessName -ErrorAction Stop

	#Move the resource across the nodes atleast once so that the services are stopped and started atleast once
	$OtherNodes = @()
	foreach($Comp in $AllComputers)
	{
		if( $Comp -ne $MasterConfigNode )
		{
			$OtherNodes += $Comp
		}
	}

	if($OtherNodes)
	{
		foreach($CurrNode in $OtherNodes)
		{
			Move-ClusterGroup -Name $ClientAccessName -Node $CurrNode
			if(!$?)
			{
				Write-Warning "Moving the cluster ownership to server '$CurrNode' failed!"
			}
			else
			{
				Write-Host "Moving the cluster ownership to server '$CurrNode' passed!"
			}
		}
	}

	Move-ClusterGroup -Name $ClientAccessName -Node $MasterConfigNode
	if(!$?)
	{
		Write-Warning "Moving the cluster ownership to server '$MasterConfigNode' failed!"
	}
	else
	{
		Write-Host "Moving the cluster ownership to server '$MasterConfigNode' passed!"
	}

	Write-Host "Successfully created cluster '$ClusterName'!"
}
else
{
	$ClusterObj = Get-Cluster -Name $ClusterName
	if(!$ClusterObj)
	{
		Print-Error "Cluster '$ClusterName' does not exist!"
	}
	
	foreach($Comp in $Node)
	{
		Add-ClusterNode -Cluster $ClusterName -Name $Comp
		if(!$?)
		{
			Print-Error "Failed to add '$Comp' to the cluster '$ClusterName'"
		}
		else
		{
			Write-Host "Successfully added '$Comp' to the cluster '$ClusterName'"
		}
	}
}