Cleanup-Workflows.ps1

#region functions
function Write-Log 
{ 
    [CmdletBinding()] 
    Param 
    ( 
        [Parameter(Mandatory=$true, 
                   ValueFromPipelineByPropertyName=$true)] 
        [ValidateNotNullOrEmpty()] 
        [Alias("LogContent")] 
        [string]$Message, 
 
        [Parameter(Mandatory=$false)] 
        [Alias('LogPath')] 
        [string]$Path='D:\Cleanup-Workflows.log', 
         
        [Parameter(Mandatory=$false)] 
        [ValidateSet("Error","Warn","Info")] 
        [string]$Level="Info", 
         
        [Parameter(Mandatory=$false)] 
        [switch]$NoClobber 
    ) 
 
    Begin 
    { 
        # Set VerbosePreference to Continue so that verbose messages are displayed. 
        $VerbosePreference = 'Continue' 
    } 
    Process 
    { 
         
        # If the file already exists and NoClobber was specified, do not write to the log. 
        if ((Test-Path $Path) -AND $NoClobber) { 
            Write-Error "Log file $Path already exists, and you specified NoClobber. Either delete the file or specify a different name." 
            Return 
            } 
 
        # If attempting to write to a log file in a folder/path that doesn't exist create the file including the path. 
        elseif (!(Test-Path $Path)) { 
            Write-Verbose "Creating $Path." 
            $NewLogFile = New-Item $Path -Force -ItemType File 
            } 
 
        else { 
            # Nothing to see here yet. 
            } 
 
        # Format Date for our Log File 
        $FormattedDate = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
 
        # Write message to error, warning, or verbose pipeline and specify $LevelText 
        switch ($Level) { 
            'Error' { 
                Write-Error $Message 
                $LevelText = 'ERROR:' 
                } 
            'Warn' { 
                Write-Warning $Message 
                $LevelText = 'WARNING:' 
                } 
            'Info' { 
                Write-Verbose $Message 
                $LevelText = 'INFO:' 
                } 
            } 
         
        # Write log entry to $Path 
        "$FormattedDate $LevelText $Message" | Out-File -FilePath $Path -Append 
    } 
    End 
    { 
    } 
}
#endregion

#region variables
#$LogPath = ($PSScriptRoot + "\Cleanup-Workflows.log")
$LogPath = "D:\Cleanup-Workflows.log"
Write-Log -Level Info -Path $LogPath -Message "Starting Workflow Cleanup"
#endregion

#region main
Write-Log -Level Info -Path $LogPath -Message "Searching all MPRs"
$MPRs = Search-Resources -XPath "/ManagementPolicyRule" -ExpectedObjectType ManagementPolicyRule

Write-Log -Level Info -Path $LogPath -Message "Searching all WFs"
$WFs = Search-Resources -XPath "/WorkflowDefinition" -ExpectedObjectType WorkflowDefinition

Write-Log -Level Info -Path $LogPath -Message ("Checking usage of " + ($WFs | Measure-Object).Count + " WFs")
$Unused_WFs = foreach($WF in $WFs){
    $Usage = $false
    
    if($MPRs.ActionWorkflowDefinition.Value -contains $WF.ObjectID.Value){
        $Usage = $true
    }

    if($MPRs.AuthenticationWorkflowDefinition.Value -contains $WF.ObjectID.Value){
        $Usage = $true
    }

    if($MPRs.AuthorizationWorkflowDefinition.Value -contains $WF.ObjectID.Value){
        $Usage = $true
    }

    if(-not $Usage){
        Write-Log -Level Info -Path $LogPath -Message ("Found unused WF: " + $WF.DisplayName)
        $WF
    }

}
Write-Log -Level Info -Path $LogPath -Message ("Found " + ($Unused_WFs | Measure-Object).Count + " unused WFs")

Write-Output "Please select the unused workflows to be deleted."

$Delete_WFs = $Unused_WFs | Select-Object -Property DisplayName,Description,CreatedTime,RequestPhase,RunOnPolicyUpdate,ObjectID |Out-GridView -PassThru -Title "Select WFs to delete"

Write-Log -Level Info -Path $LogPath -Message ("Selected: " + ($Delete_WFs | Measure-Object).Count + " unused WFs to be deleted")

$choice = ""
while ($choice -notmatch "[y|n]"){
    $choice = Read-Host "Please confirm the deletion? (Y/N)"
}

if ($choice -eq "y"){
    Write-Log -Level Info -Path $LogPath -Message ("Deleting: " + ($Delete_WFs | Measure-Object).Count + " WFs")
    foreach($WF in $Delete_WFs){
        Remove-Resource -ID $WF.ObjectID.Value
    }
}else{
    Write-Log -Level Info -Path $LogPath -Message ("Deletion refused")    
}
Write-Log -Level Info -Path $LogPath -Message ("Finished") 
#endregion