Framework/Abstracts/SVTBase.ps1

<#
.Description
# SVTBase class for all service classes.
# Provides functionality to create context object for resources, load controls for resource,
#>

Set-StrictMode -Version Latest
class SVTBase: AzSKRoot
{
    #Region: Properties
    hidden [string] $ResourceId = ""
    [ResourceContext] $ResourceContext = $null;
    hidden [SVTConfig] $SVTConfig
    hidden [PSObject] $ControlSettings

    hidden [ControlStateExtension] $ControlStateExt;
    
    hidden [ControlState[]] $ResourceState;
    hidden [ControlState[]] $DirtyResourceStates;

    hidden [ControlItem[]] $ApplicableControls = $null;
    hidden [ControlItem[]] $FeatureApplicableControls = $null;
    [string[]] $ChildResourceNames = $null;
    [System.Net.SecurityProtocolType] $currentSecurityProtocol;
    #User input parameters for controls
    [string[]] $FilterTags = @();
    [string[]] $ExcludeTags = @();
    [string[]] $ControlIds = @();
    [string[]] $Severity = @();
    [string[]] $ExcludeControlIds = @();
    [hashtable] $ResourceTags = @{}
    [bool] $GenerateFixScript = $false;

    [bool] $IncludeUserComments = $false;
    [string] $PartialScanIdentifier = [string]::Empty
    [ComplianceStateTableEntity[]] $ComplianceStateData = @();
    [PSObject[]] $ChildSvtObjects = @();
    #EndRegion

    SVTBase([string] $subscriptionId):
        Base($subscriptionId)
    {        

    }
    SVTBase([string] $subscriptionId, [SVTResource] $svtResource):
    Base($subscriptionId, [SVTResource] $svtResource)
    {        
        $this.CreateInstance($svtResource);
    }


    #Create instance for resource scan
    hidden [void] CreateInstance([SVTResource] $svtResource)
    {
        [Helpers]::AbstractClass($this, [SVTBase]);

        #Region: validation for resource object
        if(-not $svtResource)
        {
            throw [System.ArgumentException] ("The argument 'svtResource' is null");
        }

        if([string]::IsNullOrEmpty($svtResource.ResourceGroupName))
        {
            throw [System.ArgumentException] ("The argument 'ResourceGroupName' is null or empty");
        }

        if([string]::IsNullOrEmpty($svtResource.ResourceName))
        {
            throw [System.ArgumentException] ("The argument 'ResourceName' is null or empty");
        }
        #EndRegion

        #<TODO Framework: ResourceTypeMapping is already part of svtResource and populated from Resolver. Below validation is redudant.
        if(-not $svtResource.ResourceTypeMapping)
        {
            $svtResource.ResourceTypeMapping = [SVTMapping]::Mapping |
                                        Where-Object { $_.ClassName -eq $this.GetType().Name } |
                                        Select-Object -First 1
        }

        if (-not $svtResource.ResourceTypeMapping)
        {
            throw [System.ArgumentException] ("No ResourceTypeMapping found");
        }

        if ([string]::IsNullOrEmpty($svtResource.ResourceTypeMapping.JsonFileName))
        {
            throw [System.ArgumentException] ("JSON file name is null or empty");
        }

        $this.ResourceId = $svtResource.ResourceId;

        $this.LoadSvtConfig($svtResource.ResourceTypeMapping.JsonFileName);

        $this.ResourceContext = [ResourceContext]@{
            ResourceGroupName = $svtResource.ResourceGroupName;
            ResourceName = $svtResource.ResourceName;
            ResourceType = $svtResource.ResourceTypeMapping.ResourceType;
            ResourceTypeName = $svtResource.ResourceTypeMapping.ResourceTypeName;
            ResourceId = $svtResource.ResourceId
            ResourceDetails = $svtResource.ResourceDetails
        };
        
        #<TODO Framework: Fetch resource group details from resolver itself>
        $this.ResourceContext.ResourceGroupTags = $this.ResourceTags;
    }

       hidden [void] LoadSvtConfig([string] $controlsJsonFileName)
    {
        $this.ControlSettings = $this.LoadServerConfigFile("ControlSettings.json");

        if (-not $this.SVTConfig) {
            $this.SVTConfig =  [ConfigurationManager]::GetSVTConfig($controlsJsonFileName);
            
            $this.SVTConfig.Controls | Foreach-Object {

                #Expand description and recommendation string if any dynamic values defined field using control settings
                $_.Description = $global:ExecutionContext.InvokeCommand.ExpandString($_.Description)
                $_.Recommendation = $global:ExecutionContext.InvokeCommand.ExpandString($_.Recommendation)
                
                $ControlSeverity = $_.ControlSeverity
                #Check if ControlSeverity is customized/overridden using controlsettings configurations
                if([Helpers]::CheckMember($this.ControlSettings,"ControlSeverity.$ControlSeverity"))
                {
                    $_.ControlSeverity = $this.ControlSettings.ControlSeverity.$ControlSeverity
                }

                #<TODO Framework: Do we really need to trim method name as it is defined by developer>
                if(-not [string]::IsNullOrEmpty($_.MethodName))
                {
                    $_.MethodName = $_.MethodName.Trim();
                }

                #Check if
                if($this.CheckBaselineControl($_.ControlID))
                {
                    $_.IsBaselineControl = $true
                }
                #AddPreviewBaselineFlag
                if($this.CheckPreviewBaselineControl($_.ControlID))
                {
                    $_.IsPreviewBaselineControl = $true
                }
            }
        }
    }
    #stub to be used when Baseline configuration exists
    hidden [bool] CheckBaselineControl($controlId)
    {
        return $false
    }
    #stub to be used when PreviewBaseline configuration exists
    hidden [bool] CheckPreviewBaselineControl($controlId)
    {
        return $false
    }


    #Check if service is under mentainance and display maintenance warning message
    [bool] ValidateMaintenanceState()
    {
        if ($this.SVTConfig.IsMaintenanceMode) {
            $this.PublishCustomMessage(([ConfigurationManager]::GetAzSKConfigData().MaintenanceMessage -f $this.SVTConfig.FeatureName), [MessageType]::Warning);
        }
        return $this.SVTConfig.IsMaintenanceMode;
    }

    hidden [ControlResult] CreateControlResult([string] $childResourceName, [VerificationResult] $verificationResult)
    {
        [ControlResult] $control = [ControlResult]@{
            VerificationResult = $verificationResult;
        };

        if(-not [string]::IsNullOrEmpty($childResourceName))
        {
            $control.ChildResourceName = $childResourceName;
        }

        [SessionContext] $sc = [SessionContext]::new();
        $sc.IsLatestPSModule = $this.RunningLatestPSModule;
        $control.CurrentSessionContext = $sc;

        return $control;
    }

    [ControlResult] CreateControlResult()
    {
        return $this.CreateControlResult("", [VerificationResult]::Manual);
    }

    hidden [ControlResult] CreateControlResult([FixControl] $fixControl)
    {
        $control = $this.CreateControlResult();
        if($this.GenerateFixScript -and $fixControl -and $fixControl.Parameters -and ($fixControl.Parameters | Get-Member -MemberType Properties | Measure-Object).Count -ne 0)
        {
            $control.FixControlParameters = $fixControl.Parameters | Select-Object -Property *;
        }
        return $control;
    }

    [ControlResult] CreateControlResult([string] $childResourceName)
    {
        return $this.CreateControlResult($childResourceName, [VerificationResult]::Manual);
    }

    [ControlResult] CreateChildControlResult([string] $childResourceName, [ControlResult] $controlResult)
    {
        $control = $this.CreateControlResult($childResourceName, [VerificationResult]::Manual);
        if($controlResult.FixControlParameters -and ($controlResult.FixControlParameters | Get-Member -MemberType Properties | Measure-Object).Count -ne 0)
        {
            $control.FixControlParameters = $controlResult.FixControlParameters | Select-Object -Property *;
        }
        return $control;
    }

    hidden [SVTEventContext] CreateSVTEventContextObject()
    {
        return [SVTEventContext]@{
            FeatureName = $this.SVTConfig.FeatureName;
            Metadata = [Metadata]@{
                Reference = $this.SVTConfig.Reference;
            };

            SubscriptionContext = $this.SubscriptionContext;
            ResourceContext = $this.ResourceContext;
            PartialScanIdentifier = $this.PartialScanIdentifier
            
        };
    }

    hidden [SVTEventContext] CreateErrorEventContext([System.Management.Automation.ErrorRecord] $exception)
    {
        [SVTEventContext] $arg = $this.CreateSVTEventContextObject();
        $arg.ExceptionMessage = $exception;

        return $arg;
    }

    hidden [void] ControlStarted([SVTEventContext] $arg)
    {
        $this.PublishEvent([SVTEvent]::ControlStarted, $arg);
    }

    hidden [void] ControlDisabled([SVTEventContext] $arg)
    {
        $this.PublishEvent([SVTEvent]::ControlDisabled, $arg);
    }

    hidden [void] ControlCompleted([SVTEventContext] $arg)
    {
        $this.PublishEvent([SVTEvent]::ControlCompleted, $arg);
    }

    hidden [void] ControlError([ControlItem] $controlItem, [System.Management.Automation.ErrorRecord] $exception)
    {
        $arg = $this.CreateErrorEventContext($exception);
        $arg.ControlItem = $controlItem;
        $this.PublishEvent([SVTEvent]::ControlError, $arg);
    }

    hidden [void] EvaluationCompleted([SVTEventContext[]] $arguments)
    {
        $this.PublishEvent([SVTEvent]::EvaluationCompleted, $arguments);
    }

    hidden [void] EvaluationStarted()
    {
        $this.PublishEvent([SVTEvent]::EvaluationStarted, $this.CreateSVTEventContextObject());
    }
    
    hidden [void] EvaluationError([System.Management.Automation.ErrorRecord] $exception)
    {
        $this.PublishEvent([SVTEvent]::EvaluationError, $this.CreateErrorEventContext($exception));
    }

    [SVTEventContext[]] EvaluateAllControls()
    {
        [SVTEventContext[]] $resourceSecurityResult = @();
        if (-not $this.ValidateMaintenanceState()) {
            if($this.GetApplicableControls().Count -eq 0)
            {
                if($this.ResourceContext)
                {
                    $this.PublishCustomMessage("No controls have been found to evaluate for Resource [$($this.ResourceContext.ResourceName)]", [MessageType]::Warning);
                    $this.PublishCustomMessage("$([Constants]::SingleDashLine)");
                }
                else
                {
                    $this.PublishCustomMessage("No controls have been found to evaluate for Subscription", [MessageType]::Warning);
                }
            }
            else
            {
                $this.PostTelemetry();
                $this.EvaluationStarted();    
                $resourceSecurityResult += $this.GetAutomatedSecurityStatus();
                $resourceSecurityResult += $this.GetManualSecurityStatus();            
                $this.PostEvaluationCompleted($resourceSecurityResult);
                $this.EvaluationCompleted($resourceSecurityResult);
            }
        }
        return $resourceSecurityResult;
    }

    [SVTEventContext[]] ComputeApplicableControlsWithContext()
    {
        [SVTEventContext[]] $contexts = @();
        if (-not $this.ValidateMaintenanceState()) {
            $controls = $this.GetApplicableControls();
            if($controls.Count -gt 0)
            {
                foreach($control in $controls) {
                    [SVTEventContext] $singleControlResult = $this.CreateSVTEventContextObject();
                    $singleControlResult.ControlItem = $control;
                    $contexts += $singleControlResult;
                }
            }
        }
        return $contexts;
    }

    [void] PostTelemetry()
    {
        # Setting the protocol for databricks
        if([Helpers]::CheckMember($this.ResourceContext, "ResourceType") -and $this.ResourceContext.ResourceType -eq "Microsoft.Databricks/workspaces")
        {
            $this.currentSecurityProtocol = [Net.ServicePointManager]::SecurityProtocol
            [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
        }
        $this.PostFeatureControlTelemetry()
    }

    [void] PostFeatureControlTelemetry()
    {
        #todo add check for latest module version
        if($this.RunningLatestPSModule -and ($this.FeatureApplicableControls | Measure-Object).Count -gt 0)
        {
            [CustomData] $customData = [CustomData]::new();
            $customData.Name = "FeatureControlTelemetry";
            $ResourceObject = "" | Select ResourceContext, Controls, ChildResourceNames;
            $ResourceObject.ResourceContext = $this.ResourceContext;
            $ResourceObject.Controls = $this.FeatureApplicableControls;
            $ResourceObject.ChildResourceNames = $this.ChildResourceNames;
            $customData.Value = $ResourceObject;
            $this.PublishCustomData($customData);        
        }
    }

    [SVTEventContext[]] FetchStateOfAllControls()
    {
        [SVTEventContext[]] $resourceSecurityResult = @();
        if (-not $this.ValidateMaintenanceState()) {
            if($this.GetApplicableControls().Count -eq 0)
            {
                $this.PublishCustomMessage("No security controls match the input criteria specified", [MessageType]::Warning);
            }
            else
            {
                $this.EvaluationStarted();
                $resourceSecurityResult += $this.GetControlsStateResult();
                if(($resourceSecurityResult | Measure-Object).Count -gt 0)
                {
                    $this.EvaluationCompleted($resourceSecurityResult);
                }
            }
        }
        return $resourceSecurityResult;
    }

    [ControlItem[]] ApplyServiceFilters([ControlItem[]] $controls)
    {
        return $controls;
    }

    hidden [ControlItem[]] GetApplicableControls()
    {
        #Lazy load the list of the applicable controls
        if($null -eq $this.ApplicableControls)
        {
            $this.ApplicableControls = @();
            $this.FeatureApplicableControls = @();
            $filterControlsById = @();
            $filteredControls = @();

            #Apply service filters based on default set of controls
            $this.FeatureApplicableControls += $this.ApplyServiceFilters($this.SVTConfig.Controls);

            if($this.ControlIds.Count -ne 0)
            {
                $filterControlsById += $this.FeatureApplicableControls | Where-Object { $this.ControlIds -Contains $_.ControlId };
            }
            else
            {
                $filterControlsById += $this.FeatureApplicableControls
            }

            if($this.ExcludeControlIds.Count -ne 0)
            {
                $filterControlsById = $filterControlsById | Where-Object { $this.ExcludeControlIds -notcontains $_.ControlId };
            }

            #Filter controls based on filterstags and excludetags
            $filterTagsCount = ($this.FilterTags | Measure-Object).Count
            $excludeTagsCount = ($this.ExcludeTags | Measure-Object).Count

            #filters controls based on Severity
            if($this.Severity.Count -ne 0 -and ($filterControlsById | Measure-Object).Count -gt 0)
            {
                $filterControlsById = $filterControlsById | Where-Object {$_.ControlSeverity -in $this.Severity };                
            }

            
            $unfilteredControlsCount = ($filterControlsById | Measure-Object).Count

            if($unfilteredControlsCount -gt 0) #If we have any controls at this point...
            {
                #If FilterTags are specified, limit the candidate set to matching controls
                if ($filterTagsCount -gt 0)
                {
                    #Look at each candidate control's tags and see if there's a match in FilterTags
                    $filterControlsById | ForEach-Object {
                        Set-Variable -Name control -Value $_ -Scope Local
                        Set-Variable -Name filterMatch -Value $false -Scope Local
                        
                        $filterMatch = $false
                                                
                        $control.Tags | ForEach-Object {
                                                    Set-Variable -Name cTag -Value $_ -Scope Local

                                                    if( ($this.FilterTags | Where-Object { $_ -like $cTag} | Measure-Object).Count -ne 0)
                                                    {
                                                        $filterMatch = $true
                                                    }
                                                }

                        #Add if this control has a tag that matches FilterTags
                        if ($filterMatch) 
                        {
                            $filteredControls += $control
                        }   
                    }                     
                }
                else #No FilterTags specified, so all controls qualify
                {
                    $filteredControls = $filterControlsById
                }

                #Note: Candidate controls list is now in $filteredControls...we will use that to calculate $filteredControlsFinal
                $filteredControlsFinal = @()
                if ($excludeTagsCount -eq 0)
                {
                    #If exclude tags are not specified, then not much to do.
                    $filteredControlsFinal = $filteredControls
                }
                else 
                {
                    #ExludeTags _are_ specified, we need to check if candidate set has to be reduced...
                    
                    #Look at each candidate control's tags and see if there's a match in ExcludeTags
                    $filteredControls | ForEach-Object {
                        Set-Variable -Name control -Value $_ -Scope Local
                        Set-Variable -Name excludeMatch -Value $false -Scope Local
                        $excludeMatch = $false

                        $control.Tags | ForEach-Object {
                              Set-Variable -Name cTag -Value $_ -Scope Local

                              if(($this.ExcludeTags | Where-Object { $_ -like $cTag} | Measure-Object).Count -ne 0)
                              {
                                    $excludeMatch = $true
                              }
                        }
                        
                        #Add to final list if this control *does-not* have a tag that matches ExcludeTags
                        if (-not $excludeMatch) 
                        {
                            $filteredControlsFinal += $control
                        }   
                    }
                    $filteredControls = $filteredControlsFinal                
                } 
            }

            $this.ApplicableControls = $filteredControls;
            #this filtering has been done as the first step it self;
            #$this.ApplicableControls += $this.ApplyServiceFilters($filteredControls);
            
        }
        return $this.ApplicableControls;
    }

    hidden [SVTEventContext[]] GetManualSecurityStatus()
    {
        [SVTEventContext[]] $manualControlsResult = @();
        try
        {
            $this.GetApplicableControls() | Where-Object { $_.Automated -eq "No" -and $_.Enabled -eq $true } |
            ForEach-Object {
                $controlItem = $_;
                [SVTEventContext] $arg = $this.CreateSVTEventContextObject();

                $arg.ControlItem = $controlItem;
                [ControlResult] $control = [ControlResult]@{
                    VerificationResult = [VerificationResult]::Manual;
                };

                [SessionContext] $sc = [SessionContext]::new();
                $sc.IsLatestPSModule = $this.RunningLatestPSModule;
                $control.CurrentSessionContext = $sc;

                $arg.ControlResults += $control
                
                $this.PostProcessData($arg);

                $manualControlsResult += $arg;
            }
        }
        catch
        {
            $this.EvaluationError($_);
        }

        return $manualControlsResult;
    }

    hidden [SVTEventContext[]] GetAutomatedSecurityStatus()
    {
        [SVTEventContext[]] $automatedControlsResult = @();
        $this.DirtyResourceStates = @();
        try
        {
            $this.GetApplicableControls() | Where-Object { $_.Automated -ne "No" -and (-not [string]::IsNullOrEmpty($_.MethodName)) } |
            ForEach-Object {
                $eventContext = $this.RunControl($_);
                if($null -ne $eventContext -and $eventcontext.ControlResults.Length -gt 0)
                {
                    $automatedControlsResult += $eventContext;
                }
            };
        }
        catch
        {
            $this.EvaluationError($_);
        }

        return $automatedControlsResult;
    }
    
    hidden [SVTEventContext[]] GetControlsStateResult()
    {
        [SVTEventContext[]] $automatedControlsResult = @();
        $this.DirtyResourceStates = @();
        try
        {
            $this.GetApplicableControls() |
            ForEach-Object {
                $eventContext = $this.FetchControlState($_);
                #filter controls if there is no state found
                if($eventContext)
                {
                    $eventContext.ControlResults = $eventContext.ControlResults | Where-Object{$_.AttestationStatus -ne [AttestationStatus]::None}
                    if($eventContext.ControlResults)
                    {
                        $automatedControlsResult += $eventContext;
                    }
                }
            };
        }
        catch
        {
            $this.EvaluationError($_);
        }

        return $automatedControlsResult;
    }
    
    hidden [SVTEventContext] RunControl([ControlItem] $controlItem)
    {
        [SVTEventContext] $singleControlResult = $this.CreateSVTEventContextObject();
        $singleControlResult.ControlItem = $controlItem;

        $this.ControlStarted($singleControlResult);
        if($controlItem.Enabled -eq $false)
        {
            $this.ControlDisabled($singleControlResult);
        }
        else
        {
            $azskScanResult = $this.CreateControlResult($controlItem.FixControl);
            try
            {
                $methodName = $controlItem.MethodName;
                #$this.CurrentControlItem = $controlItem;
                $singleControlResult.ControlResults += $this.$methodName($azskScanResult);
            }
            catch
            {
                $azskScanResult.VerificationResult = [VerificationResult]::Error                
                $azskScanResult.AddError($_);
                $singleControlResult.ControlResults += $azskScanResult
                $this.ControlError($controlItem, $_);
            }
            $this.PostProcessData($singleControlResult);

            # Check for the control which requires elevated permission to modify 'Recommendation' so that user can know it is actually automated if they have the right permission
            if($singleControlResult.ControlItem.Automated -eq "Yes")
            {
                $singleControlResult.ControlResults |
                    ForEach-Object {
                    $currentItem = $_;
                    if($_.VerificationResult -eq [VerificationResult]::Manual -and $singleControlResult.ControlItem.Tags.Contains([Constants]::OwnerAccessTagName))
                    {
                        $singleControlResult.ControlItem.Recommendation = [Constants]::RequireOwnerPermMessage + $singleControlResult.ControlItem.Recommendation
                    }
                }
            }
        }

        $this.ControlCompleted($singleControlResult);

        return $singleControlResult;
    }
    
    # Policy compliance methods begin
    hidden [ControlResult] ComputeFinalScanResult([ControlResult] $azskScanResult, [ControlResult] $policyScanResult)
    {
        if($policyScanResult.VerificationResult -ne [VerificationResult]::Failed -and $azskScanResult.VerificationResult -ne [VerificationResult]::Passed)
        {
            return $azskScanResult
        }
        else
        {
            return $policyScanResult;
        }
    }
    
    hidden [SVTEventContext] FetchControlState([ControlItem] $controlItem)
    {
        [SVTEventContext] $singleControlResult = $this.CreateSVTEventContextObject();
        $singleControlResult.ControlItem = $controlItem;

        $controlState = @();
        $controlStateValue = @();
        try
        {
            $resourceStates = $this.GetResourceState();
            if(($resourceStates | Measure-Object).Count -ne 0)
            {
                $controlStateValue += $resourceStates | Where-Object { $_.InternalId -eq $singleControlResult.ControlItem.Id };
                $controlStateValue | ForEach-Object {
                    $currentControlStateValue = $_;
                    if($null -ne $currentControlStateValue)
                    {
                        #assign expiry date
                        $expiryIndays = $this.CalculateExpirationInDays($singleControlResult,$currentControlStateValue);
                        if($expiryIndays -ne -1)
                        {
                            $currentControlStateValue.State.ExpiryDate = ($currentControlStateValue.State.AttestedDate.AddDays($expiryIndays)).ToString("MM/dd/yyyy");
                        }
                        $controlState += $currentControlStateValue;
                    }
                }
            }
        }
        catch
        {
            $this.EvaluationError($_);
        }
        if(($controlState|Measure-Object).Count -gt 0)
        {
            $this.ControlStarted($singleControlResult);
            if($controlItem.Enabled -eq $false)
            {
                $this.ControlDisabled($singleControlResult);
            }
            else
            {
                $controlResult = $this.CreateControlResult($controlItem.FixControl);
                $singleControlResult.ControlResults += $controlResult;          
                $singleControlResult.ControlResults | 
                ForEach-Object {
                    try
                    {
                        $currentItem = $_;

                        if($controlState.Count -ne 0)
                        {
                            # Process the state if it's available
                            $childResourceState = $controlState | Where-Object { $_.ChildResourceName -eq  $currentItem.ChildResourceName } | Select-Object -First 1;
                            if($childResourceState)
                            {
                                $currentItem.StateManagement.AttestedStateData = $childResourceState.State;
                                $currentItem.AttestationStatus = $childResourceState.AttestationStatus;
                                $currentItem.ActualVerificationResult = $childResourceState.ActualVerificationResult;
                                $currentItem.VerificationResult = [VerificationResult]::NotScanned
                            }
                        }
                    }
                    catch
                    {
                        $this.EvaluationError($_);
                    }
                };

            }
            $this.ControlCompleted($singleControlResult);
        }

        return $singleControlResult;
    }
    hidden [void] PostEvaluationCompleted([SVTEventContext[]] $ControlResults)
    {
        # If ResourceType is Databricks, reverting security protocol
        if([Helpers]::CheckMember($this.ResourceContext, "ResourceType") -and $this.ResourceContext.ResourceType -eq "Microsoft.Databricks/workspaces")
        {
          [Net.ServicePointManager]::SecurityProtocol = $this.currentSecurityProtocol 
        }
        $this.UpdateControlStates($ControlResults);
    }

    hidden [void] UpdateControlStates([SVTEventContext[]] $ControlResults)
    {
        if($null -ne $this.ControlStateExt -and $this.ControlStateExt.HasControlStateWriteAccessPermissions() -and ($ControlResults | Measure-Object).Count -gt 0 -and ($this.ResourceState | Measure-Object).Count -gt 0)
        {
            $effectiveResourceStates = @();
            if(($this.DirtyResourceStates | Measure-Object).Count -gt 0)
            {
                $this.ResourceState | ForEach-Object {
                    $controlState = $_;
                    if(($this.DirtyResourceStates | Where-Object { $_.InternalId -eq $controlState.InternalId -and $_.ChildResourceName -eq $controlState.ChildResourceName } | Measure-Object).Count -eq 0)
                    {
                        $effectiveResourceStates += $controlState;
                    }
                }
            }
            else
            {
                #If no dirty states found then no action needed.
                return;
            }

            #get the uniqueid from the first control result. Here we can take first as it would come here for each resource.
            $id = $ControlResults[0].GetUniqueId();

            $this.ControlStateExt.SetControlState($id, $effectiveResourceStates, $true)
        }
    }

    hidden [void] PostProcessData([SVTEventContext] $eventContext)
    {
        $tempHasRequiredAccess = $true;
        $controlState = @();
        $controlStateValue = @();
        try
        {
            # Get policy compliance if org-level flag is enabled and policy is found
            #TODO: set flag in a variable once and reuse it
            
            if([FeatureFlightingManager]::GetFeatureStatus("EnableAzurePolicyBasedScan",$($this.SubscriptionContext.SubscriptionId)) -eq $true)
            {
                if(-not [string]::IsNullOrWhiteSpace($eventContext.ControlItem.PolicyDefinitionGuid))
                {
                    #create default controlresult
                    $policyScanResult = $this.CreateControlResult($eventContext.ControlItem.FixControl);
                    #update default controlresult with policy compliance state
                    $policyScanResult = $this.CheckPolicyCompliance($eventContext.ControlItem, $policyScanResult);
                    #todo: currently excluding child controls
                    if($eventContext.ControlResults.Count -eq 1 -and $Null -ne $policyScanResult)
                    {
                        $finalScanResult = $this.ComputeFinalScanResult($eventContext.ControlResults[0],$policyScanResult)
                        $eventContext.ControlResults[0] = $finalScanResult
                    }
                }
            }
            
            $this.GetDataFromSubscriptionReport($eventContext);

            $resourceStates = $this.GetResourceState()            
            if(($resourceStates | Measure-Object).Count -ne 0)
            {
                $controlStateValue += $resourceStates | Where-Object { $_.InternalId -eq $eventContext.ControlItem.Id };
                $controlStateValue | ForEach-Object {
                    $currentControlStateValue = $_;
                    if($null -ne $currentControlStateValue)
                    {
                        if($this.IsStateActive($eventContext, $currentControlStateValue))
                        {
                            $controlState += $currentControlStateValue;
                        }
                        else
                        {
                            #add to the dirty state list so that it can be removed later
                            $this.DirtyResourceStates += $currentControlStateValue;
                        }
                    }
                }
            }
            elseif($null -eq $resourceStates)
            {
                $tempHasRequiredAccess = $false;
            }
        }
        catch
        {
            $this.EvaluationError($_);
        }

        $eventContext.ControlResults |
        ForEach-Object {
            try
            {
                $currentItem = $_;
                # Copy the current result to Actual Result field
                $currentItem.ActualVerificationResult = $currentItem.VerificationResult;

                #Logic to append the control result with the permissions metadata
                [SessionContext] $sc = $currentItem.CurrentSessionContext;
                $sc.Permissions.HasAttestationWritePermissions = $this.ControlStateExt.HasControlStateWriteAccessPermissions();
                $sc.Permissions.HasAttestationReadPermissions = $this.ControlStateExt.HasControlStateReadAccessPermissions();
                # marking the required access as false if there was any error reading the attestation data
                $sc.Permissions.HasRequiredAccess = $sc.Permissions.HasRequiredAccess -and $tempHasRequiredAccess;

                # Disable the fix control feature
                if(-not $this.GenerateFixScript)
                {
                    $currentItem.EnableFixControl = $false;
                }

                if($currentItem.StateManagement.CurrentStateData -and $currentItem.StateManagement.CurrentStateData.DataObject -and $eventContext.ControlItem.DataObjectProperties)
                {
                    $currentItem.StateManagement.CurrentStateData.DataObject = [Helpers]::SelectMembers($currentItem.StateManagement.CurrentStateData.DataObject, $eventContext.ControlItem.DataObjectProperties);
                }

                if($controlState.Count -ne 0)
                {
                    # Process the state if its available
                    $childResourceState = $controlState | Where-Object { $_.ChildResourceName -eq  $currentItem.ChildResourceName } | Select-Object -First 1;
                    if($childResourceState)
                    {
                        # Skip passed ones from State Management
                        if($currentItem.ActualVerificationResult -ne [VerificationResult]::Passed)
                        {
                            #compare the states
                            if(($childResourceState.ActualVerificationResult -eq $currentItem.ActualVerificationResult) -and $childResourceState.State)
                            {
                                $currentItem.StateManagement.AttestedStateData = $childResourceState.State;

                                # Compare dataobject property of State
                                if($null -ne $childResourceState.State.DataObject)
                                {
                                    if($currentItem.StateManagement.CurrentStateData -and $null -ne $currentItem.StateManagement.CurrentStateData.DataObject)
                                    {
                                        $currentStateDataObject = [JsonHelper]::ConvertToJsonCustom($currentItem.StateManagement.CurrentStateData.DataObject) | ConvertFrom-Json

                                        try
                                        {
                                            # Objects match, change result based on attestation status
                                            if($eventContext.ControlItem.AttestComparisionType -and $eventContext.ControlItem.AttestComparisionType -eq [ComparisionType]::NumLesserOrEqual)
                                            {
                                                if([Helpers]::CompareObject($childResourceState.State.DataObject, $currentStateDataObject, $true,$eventContext.ControlItem.AttestComparisionType))
                                                {
                                                    $this.ModifyControlResult($currentItem, $childResourceState);
                                                }
                                                
                                            }
                                            else
                                            {
                                                if([Helpers]::CompareObject($childResourceState.State.DataObject, $currentStateDataObject, $true))
                                                {
                                                        $this.ModifyControlResult($currentItem, $childResourceState);
                                                }
                                            }
                                        }
                                        catch
                                        {
                                            $this.EvaluationError($_);
                                        }
                                    }
                                }
                                else
                                {
                                    if($currentItem.StateManagement.CurrentStateData)
                                    {
                                        if($null -eq $currentItem.StateManagement.CurrentStateData.DataObject)
                                        {
                                            # No object is persisted, change result based on attestation status
                                            $this.ModifyControlResult($currentItem, $childResourceState);
                                        }
                                    }
                                    else
                                    {
                                        # No object is persisted, change result based on attestation status
                                        $this.ModifyControlResult($currentItem, $childResourceState);
                                    }
                                }
                            }
                        }
                        else
                        {
                            #add to the dirty state list so that it can be removed later
                            $this.DirtyResourceStates += $childResourceState
                        }
                    }
                }
            }
            catch
            {
                $this.EvaluationError($_);
            }
        };
    }

    # State Machine implementation of modifying verification result
    hidden [void] ModifyControlResult([ControlResult] $controlResult, [ControlState] $controlState)
    {
        # No action required if Attestation status is None OR verification result is Passed
        if($controlState.AttestationStatus -ne [AttestationStatus]::None -or $controlResult.VerificationResult -ne [VerificationResult]::Passed)
        {
            $controlResult.AttestationStatus = $controlState.AttestationStatus;
            $controlResult.VerificationResult = [Helpers]::EvaluateVerificationResult($controlResult.VerificationResult, $controlState.AttestationStatus);
        }
    }

    hidden [ControlState[]] GetResourceState()
    {
        if($null -eq $this.ResourceState)
        {
            $this.ResourceState = @();
            if($this.ControlStateExt -and $this.ControlStateExt.HasControlStateReadAccessPermissions())
            {
                $resourceStates = $this.ControlStateExt.GetControlState($this.ResourceId)
                if($null -ne $resourceStates)
                {
                    $this.ResourceState += $resourceStates
                }
                else
                {
                    return $null;
                }                
            }
        }

        return $this.ResourceState;
    }

    #Function to validate attestation data expiry validation
    hidden [bool] IsStateActive([SVTEventContext] $eventcontext,[ControlState] $controlState)
    {
        try
        {
            $expiryIndays = $this.CalculateExpirationInDays([SVTEventContext] $eventcontext,[ControlState] $controlState);
            #Validate if expiry period is passed
            #Added a condition so as to expire attested controls that were in 'Error' state.
            if(($expiryIndays -ne -1 -and $controlState.State.AttestedDate.AddDays($expiryIndays) -lt [DateTime]::UtcNow) -or ($controlState.ActualVerificationResult -eq [VerificationResult]::Error))
            {
                return $false
            }
            else
            {
                $controlState.State.ExpiryDate = ($controlState.State.AttestedDate.AddDays($expiryIndays)).ToString("MM/dd/yyyy");
                return $true
            }
        }
        catch
        {
            #if any exception occurs while getting/validating expiry period, return true.
            $this.EvaluationError($_);
            return $true
        }
    }

    hidden [int] CalculateExpirationInDays([SVTEventContext] $eventcontext,[ControlState] $controlState)
    {
        try
        {
            #For exempt controls, either the no. of days for expiry were provided at the time of attestation or a default of 6 motnhs was already considered,
            #therefore skipping this flow and calculating days directly using the expiry date already saved.
            if($controlState.AttestationStatus -ne [AttestationStatus]::ApprovedException)
            {
                #Get controls expiry period. Default value is zero
                $controlAttestationExpiry = $eventcontext.controlItem.AttestationExpiryPeriodInDays
                $controlSeverity = $eventcontext.controlItem.ControlSeverity
                $controlSeverityExpiryPeriod = 0
                $defaultAttestationExpiryInDays = [Constants]::DefaultControlExpiryInDays;
                $expiryInDays=-1;
    
                if(($eventcontext.ControlResults |Measure-Object).Count -gt 0)    
                {
                    $isControlInGrace=$eventcontext.ControlResults.IsControlInGrace;
                }
                else
                {
                    $isControlInGrace=$true;
                }
                if([Helpers]::CheckMember($this.ControlSettings,"AttestationExpiryPeriodInDays") `
                        -and [Helpers]::CheckMember($this.ControlSettings.AttestationExpiryPeriodInDays,"Default") `
                        -and $this.ControlSettings.AttestationExpiryPeriodInDays.Default -gt 0)
                {
                    $defaultAttestationExpiryInDays = $this.ControlSettings.AttestationExpiryPeriodInDays.Default
                }            
                #Expiry in the case of WillFixLater or StateConfirmed/Recurring Attestation state will be based on Control Severity.
                if($controlState.AttestationStatus -eq [AttestationStatus]::NotAnIssue -or $controlState.AttestationStatus -eq [AttestationStatus]::NotApplicable)
                {
                    $expiryInDays=$defaultAttestationExpiryInDays;
                }
                else
                {
                    # Expire WillFixLater if GracePeriod has expired
                    if(-not($isControlInGrace) -and $controlState.AttestationStatus -eq [AttestationStatus]::WillFixLater)
                    {
                        $expiryInDays=0;
                    }
                    else
                    {
                        if($controlAttestationExpiry -ne 0)
                        {
                            $expiryInDays = $controlAttestationExpiry
                        }
                        elseif([Helpers]::CheckMember($this.ControlSettings,"AttestationExpiryPeriodInDays"))
                        {
                            $controlsev = $this.ControlSettings.ControlSeverity.PSobject.Properties | Where-Object Value -eq $controlSeverity | Select-Object -First 1
                            $controlSeverity = $controlsev.name                                    
                            #Check if control severity has expiry period
                            if([Helpers]::CheckMember($this.ControlSettings.AttestationExpiryPeriodInDays.ControlSeverity,$controlSeverity) )
                            {
                                $expiryInDays = $this.ControlSettings.AttestationExpiryPeriodInDays.ControlSeverity.$controlSeverity
                            }
                            #If control item and severity does not contain expiry period, assign default value
                            else
                            {
                                $expiryInDays = $defaultAttestationExpiryInDays
                            }
                        }
                        #Return -1 when expiry is not defined
                        else
                        {
                            $expiryInDays = -1
                        }
                    }
                }                
            }
            else
            {                
                #Calculating the expiry in days for exempt controls
                
                $expiryDate = [DateTime]$controlState.State.ExpiryDate
                #Adding 1 explicitly to the days since the differnce below excludes the expiryDate and that also needs to be taken into account.
                $expiryInDays = ($expiryDate - $controlState.State.AttestedDate).Days + 1
            }                                
        }
        catch
        {
            #if any exception occurs while getting/validating expiry period, return -1.
            $this.EvaluationError($_);
            $expiryInDays = -1
        }
        return $expiryInDays
    }


    hidden AddResourceMetadata([PSObject] $metadataObj)
    {
        [hashtable] $resourceMetadata = New-Object -TypeName Hashtable;
            $metadataObj.psobject.properties |
                ForEach-Object {
                    $resourceMetadata.Add($_.name, $_.value)
                }

        if([Helpers]::CheckMember($this.ControlSettings, 'AllowedResourceTypesForMetadataCapture') )
        {
            if( $this.ResourceContext.ResourceTypeName -in $this.ControlSettings.AllowedResourceTypesForMetadataCapture)
            {
                $this.ResourceContext.ResourceMetadata = $resourceMetadata
            }
            else
            {
                $this.ResourceContext.ResourceMetadata = $null
            }
        }
        else 
        {
            $this.ResourceContext.ResourceMetadata = $resourceMetadata
        }

    }

    hidden [SVTResource] CreateSVTResource([string] $ConnectionResourceId,[string] $ResourceGroupName, [string] $ConnectionResourceName, [string] $ResourceType, [string] $Location, [string] $MappingName)
    {
        $svtResource = [SVTResource]::new();
        $svtResource.ResourceId = $ConnectionResourceId; 
        $svtResource.ResourceGroupName = $ResourceGroupName;
        $svtResource.ResourceName = $ConnectionResourceName
        $svtResource.ResourceType = $ResourceType; #
        $svtResource.Location = $Location;
        $svtResource.ResourceTypeMapping = ([SVTMapping]::Mapping |
                        Where-Object { $_.ResourceTypeName -eq $MappingName } |
                        Select-Object -First 1);

        return $svtResource;
    }
  
    #stub to be used when ComplianceState
    hidden [void] GetDataFromSubscriptionReport($singleControlResult)
       { 
        
    }

    [int] hidden CalculateGraceInDays([SVTEventContext] $context)
    {
        
        $controlResult=$context.ControlResults;
        $computedGraceDays=15;
        $ControlBasedGraceExpiryInDays=0;
        $currentControlItem=$context.controlItem;
        $controlSeverity=$currentControlItem.ControlSeverity;
        if([Helpers]::CheckMember($this.ControlSettings,"NewControlGracePeriodInDays"))
        {
            if([Helpers]::CheckMember($this.ControlSettings,"ControlSeverity"))
            {
                $controlsev = $this.ControlSettings.ControlSeverity.PSobject.Properties | Where-Object Value -eq $controlSeverity | Select-Object -First 1
                $controlSeverity = $controlsev.name
                $computedGraceDays=$this.ControlSettings.NewControlGracePeriodInDays.ControlSeverity.$ControlSeverity;
            }
            else
            {
                $computedGraceDays=$this.ControlSettings.NewControlGracePeriodInDays.ControlSeverity.$ControlSeverity;
            }
        }
        if($null -ne $currentControlItem.GraceExpiryDate)
        {
            if($currentControlItem.GraceExpiryDate -gt [DateTime]::UtcNow )
            {
                $ControlBasedGraceExpiryInDays=$currentControlItem.GraceExpiryDate.Subtract($controlResult.FirstScannedOn).Days
                if($ControlBasedGraceExpiryInDays -gt $computedGraceDays)
                {
                    $computedGraceDays = $ControlBasedGraceExpiryInDays
                }
            }            
        }

      return $computedGraceDays;
    }    
}