<#
.SYNOPSIS
This Powershell script will promote a slave repo to a master
 
.DESCRIPTION
	This Powershell script will promote a slave repo to a master
    This is to be used as a part of a disaster recovery process

    Assumtion: The Master is dead

	It will
		Disable replication on all servers
        Promote a slave to a master
        Reconfigure all slaves to be aware of the new master
        Enable replication

.PARAMETER  Repo
Name of the Repo to promote

.PARAMETER  NewMaster
Name of new the new master server

.PARAMETER	Servers
A list of server that are a part of the subverion network
These will be reconfigured to communicate with the new master

.EXAMPLE
PromoteSlave.ps1 -Repo MyRepo -NewMaster NewMaster -Servers Server1,Server2,Server3
 
.NOTES
Uses a number of cmdlets provided by VisualSVN.
 
#>
#

#

Param
(
    [ parameter (Mandatory=$true,
	             HelpMessage="Enter the name of the new Master Server")]
    [string] $Repo,
    [ parameter (Mandatory=$true,
				 HelpMessage="Enter the name of the Repository to be remastered")]
    [string] $NewMaster,
    [ parameter (Mandatory=$true) ]
    [string[]] $Servers
)


Function Promote-Slave( $REPO, $NEWMASTER, $SERVERS)
{
Write-Host 'REPO:' , $REPO
Write-Host 'NEWMASTER:' , $NEWMASTER
Write-Host 'SERVERS:' , $SERVERS
    # Init Data
    $ALLSERVERS = $SERVERS
    $serversOk = $true
    If ($ALLSERVERS -notcontains $NEWMASTER) { $ALLSERVERS += $NEWMASTER }

    #
    # Examine all the machines and ensure that they exist and that they are slaves
    #
    $ALLSERVERS | ForEach-Object {
    Write-Host "Examine:", $_
        $repoData = Get-SvnRepository -Name $REPO -CimSession $_ -ErrorAction SilentlyContinue
        If ( ! $repoData )
        {
            Write-Error "Unknown server: $_" -Category InvalidArgument
            $serversOk = $false
            Break
        }
        $repoType = $repoData.Type
        If ( $repoType -ne 'VdfsSlave' )
        {
            Write-Error "Repo on Server ($_) is not a Slave ($repoType)" -Category InvalidData
            $serversOk = $false
            Break
        }    
    }
    If (! $serversOk )
    { 
        return 
    }
    Write-Host "All servers Exist and are VdfsSlaves"


    #   Build up a list of replicators
    #       All the server names, remove the new master, append '$' so that its the machine name
    # 
    $REPLICATORS =  $ALLSERVERS | where { $_ -ne $NEWMASTER } | ForEach-Object { $_ + '$' }

    #
    # Display stuff
    #
    Write-Host "New Master:", $NEWMASTER
    Write-Host "Replicators: ", $REPLICATORS

    #
    # Do the hard part
    #
    $ALLSERVERS | ForEach-Object { 
        Suspend-SvnRepository -name $REPO -CimSession $_ 
    }

    Switch-SvnRepository -Name $REPO -Role Master -Confirm:$false -CimSession $NEWMASTER

    Set-SvnRepositoryReplication $REPO -Replicators $REPLICATORS -CimSession $NEWMASTER
    Set-SvnRepositoryReplication $REPO -Enabled $true -CimSession $NEWMASTER

    $ALLSERVERS | Where { $_ -ne $NEWMASTER } | ForEach-Object { 
        Set-SvnRepository $REPO -MasterServer $NEWMASTER  -Confirm:$false -CimSession $_
    }

    $ALLSERVERS | ForEach-Object { 
        Resume-SvnRepository -name $REPO -CimSession $_ 
    }
}

 #
 # Invoke the function
 #
#Write-Host "Repo:", $REPO, "NewMaster:", $NEWMASTER, "Servers:", $SERVERS
Promote-Slave $REPO $NEWMASTER $SERVERS