DSCResources/MSFT_xExchMaintenanceMode/MSFT_xExchMaintenanceMode.psm1

function Get-TargetResource
{
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSDSCUseVerboseMessageInDSCResource", "")]
    [CmdletBinding()]
    [OutputType([System.Collections.Hashtable])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.Boolean]
        $Enabled,

        [Parameter(Mandatory = $true)]
        [System.Management.Automation.PSCredential]
        [System.Management.Automation.Credential()]
        $Credential,

        [Parameter()]
        [System.String[]]
        $AdditionalComponentsToActivate,

        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [ValidateSet('None', 'Lossless', 'GoodAvailability', 'BestAvailability', 'BestEffort')]
        [System.String]
        $MountDialOverride = 'None',

        [Parameter()]
        [System.Boolean]
        $MovePreferredDatabasesBack = $false,

        [Parameter()]
        [System.Boolean]
        $SetInactiveComponentsFromAnyRequesterToActive = $false,

        [Parameter()]
        [System.Boolean]
        $SkipActiveCopyChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipAllChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipClientExperienceChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipCpuChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipHealthChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipLagChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipMaximumActiveDatabasesChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipMoveSuppressionChecks = $false,

        [Parameter()]
        [System.String]
        $UpgradedServerVersion
    )

    Write-FunctionEntry -Parameters @{'Enabled' = $Enabled} -Verbose:$VerbosePreference

    # Load TransportMaintenanceMode Helper
    Import-Module "$((Get-Item -LiteralPath "$($PSScriptRoot)"))\TransportMaintenance.psm1" -Verbose:0

    # Establish remote PowerShell session
    Get-RemoteExchangeSession -Credential $Credential -CommandsToLoad 'Get-*' -Verbose:$VerbosePreference

    $maintenanceModeStatus = Get-MaintenanceModeStatus -EnteringMaintenanceMode $Enabled -DomainController $DomainController
    $atDesiredVersion = Test-ExchangeAtDesiredVersion -DomainController $DomainController -UpgradedServerVersion $UpgradedServerVersion

    if ($null -ne $maintenanceModeStatus)
    {
        # Determine which components are Active
        $activeComponents = $maintenanceModeStatus.ServerComponentState | Where-Object -FilterScript {$_.State -eq "Active"}

        [System.String[]] $activeComponentsList = @()

        if ($null -ne $activeComponents)
        {
            foreach ($activeComponent in $activeComponents)
            {
                $activeComponentsList += $activeComponent.Component
            }
        }

        $activeComponentCount = $activeComponentsList.Count

        # Figure out what our Enabled state should really be in case UpgradedServerVersion was passed
        $isEnabled = $Enabled

        if ($Enabled -eq $true -and $atDesiredVersion -eq $true)
        {
            $isEnabled = $false
        }

        $returnValue = @{
            Enabled              = [System.Boolean] $isEnabled
            ActiveComponentCount = [System.Int32] $activeComponentCount
            ActiveComponentsList = [System.String[]] $activeComponentsList
            ActiveDBCount        = [System.Int32] (Get-ActiveDBCount -MaintenanceModeStatus $maintenanceModeStatus -DomainController $DomainController)
            ActiveUMCallCount    = [System.Int32] (Get-UMCallCount -MaintenanceModeStatus $maintenanceModeStatus -DomainController $DomainController)
            ClusterState         = [System.String] $maintenanceModeStatus.ClusterNode.State
            QueuedMessageCount   = [System.Int32] (Get-QueueMessageCount -MaintenanceModeStatus $maintenanceModeStatus)
        }
    }

    $returnValue
}

function Set-TargetResource
{
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSUseShouldProcessForStateChangingFunctions", "")]
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.Boolean]
        $Enabled,

        [Parameter(Mandatory = $true)]
        [System.Management.Automation.PSCredential]
        [System.Management.Automation.Credential()]
        $Credential,

        [Parameter()]
        [System.String[]]
        $AdditionalComponentsToActivate,

        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [ValidateSet('None', 'Lossless', 'GoodAvailability', 'BestAvailability', 'BestEffort')]
        [System.String]
        $MountDialOverride = 'None',

        [Parameter()]
        [System.Boolean]
        $MovePreferredDatabasesBack = $false,

        [Parameter()]
        [System.Boolean]
        $SetInactiveComponentsFromAnyRequesterToActive = $false,

        [Parameter()]
        [System.Boolean]
        $SkipActiveCopyChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipAllChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipClientExperienceChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipCpuChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipHealthChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipLagChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipMaximumActiveDatabasesChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipMoveSuppressionChecks = $false,

        [Parameter()]
        [System.String]
        $UpgradedServerVersion
    )

    Write-FunctionEntry -Parameters @{'Enabled' = $Enabled} -Verbose:$VerbosePreference

    # Load TransportMaintenanceMode Helper
    Import-Module "$((Get-Item -LiteralPath "$($PSScriptRoot)"))\TransportMaintenance.psm1" -Verbose:0

    # Get ready for calling DAG maintenance scripts later
    $scriptsFolder = Join-Path -Path ((Get-ItemProperty HKLM:\SOFTWARE\Microsoft\ExchangeServer\v15\Setup).MsiInstallPath) -ChildPath "Scripts"
    $startDagServerMaintenanceScript = Join-Path -Path "$($scriptsFolder)" -ChildPath "StartDagServerMaintenance.ps1"
    $stopDagServerMaintenanceScript = Join-Path -Path "$($scriptsFolder)" -ChildPath "StopDagServerMaintenance.ps1"

    # Override Write-Host, as it is used by the target scripts, and causes a DSC error since the session is not interactive
    New-Alias Write-Host Write-Verbose

    # Check if setup is running.
    $setupRunning = Test-ExchangeSetupRunning

    if ($setupRunning -eq $true)
    {
        Write-Verbose -Message 'Exchange Setup is currently running. Skipping maintenance mode checks.'
        return
    }

    # Establish remote PowerShell session
    Get-RemoteExchangeSession -Credential $Credential -CommandsToLoad '*' -Verbose:$VerbosePreference

    # If the request is to put the server in maintenance mode, make sure we aren't already at the (optional) requested Exchange Server version
    $atDesiredVersion = Test-ExchangeAtDesiredVersion -DomainController $DomainController -UpgradedServerVersion $UpgradedServerVersion

    if ($Enabled -eq $true -and $atDesiredVersion -eq $true)
    {
        Write-Verbose -Message "Server is already at or above the desired upgrade version of '$UpgradedServerVersion'. Skipping putting server into maintenance mode."
        return
    }

    # Continue on with setting the maintenance mode state
    $maintenanceModeStatus = Get-MaintenanceModeStatus -EnteringMaintenanceMode $Enabled -DomainController $DomainController

    if ($null -ne $maintenanceModeStatus)
    {
        # Set vars relevant to both 'Enabled' code paths
        $htStatus = $MaintenanceModeStatus.ServerComponentState | Where-Object -FilterScript {$_.Component -eq "HubTransport"}
        $haStatus = $MaintenanceModeStatus.ServerComponentState | Where-Object -FilterScript {$_.Component -eq "HubTransport"}

        # Put the server into maintenance mode
        if ($Enabled -eq $true)
        {
            # Block DB activation on this server
            if ($maintenanceModeStatus.MailboxServer.DatabaseCopyAutoActivationPolicy -ne "Blocked")
            {
                Write-Verbose -Message 'Setting DatabaseCopyAutoActivationPolicy to Blocked'
                Set-MailboxServerInternal -Identity $env:COMPUTERNAME -DomainController $DomainController -AdditionalParams @{"DatabaseCopyAutoActivationPolicy" = "Blocked"}
            }

            # Set UM to draining before anything else
            $changedUM = Update-ComponentState -Component "UMCallRouter" -Requester "Maintenance" -ServerComponentState $maintenanceModeStatus.ServerComponentState -State "Draining" -SetInactiveComponentsFromAnyRequesterToActive $SetInactiveComponentsFromAnyRequesterToActive -DomainController $DomainController

            # Start HT maintenance if required
            if ($htStatus.State -ne "Inactive")
            {
                Write-Verbose -Message 'Entering Transport Maintenance'
                [System.String[]] $transportExclusions = Get-ExclusionsForMessageRedirection -DomainController $DomainController
                Start-TransportMaintenance -LoadLocalShell $false -MessageRedirectExclusions $transportExclusions -Verbose
            }

            # Wait for remaining UM calls to drain
            if ($changedUM)
            {
                Wait-ForUMToDrain -DomainController $DomainController
            }

            # Run StartDagServerMaintenance script to put cluster offline and failover DB's
            if ($maintenanceModeStatus.ClusterNode.State -eq "Up" -or
                $maintenanceModeStatus.MailboxServer.DatabaseCopyAutoActivationPolicy -ne "Blocked" -or
                (Get-ActiveDBCount -MaintenanceModeStatus $maintenanceModeStatus -DomainController $DomainController) -ne 0)
            {
                Write-Verbose -Message 'Running StartDagServerMaintenance.ps1'

                $dagMemberCount = Get-DAGMemberCount

                # Setup parameters for StartDagServerMaintenance.ps1
                $startDagScriptParams = @{
                    serverName = $env:COMPUTERNAME
                    Verbose = $true
                }

                if ((Get-ExchangeVersionYear) -in '2016', '2019')
                {
                    $startDagScriptParams.Add('pauseClusterNode', $true)
                }

                if ($dagMemberCount -ne 0 -and $dagMemberCount -le 2)
                {
                    $startDagScriptParams.Add('overrideMinimumTwoCopies', $true)
                }

                if ($SkipAllChecks -or $SkipMoveSuppressionChecks)
                {
                    $startDagScriptParams.Add("Force", 'true')
                }

                # Execute StartDagServerMaintenance.ps1
                Invoke-DotSourcedScript `
                    -ScriptPath $startDagServerMaintenanceScript `
                    -ScriptParams $startDagScriptParams `
                    -SnapinsToRemove 'Microsoft.Exchange.Management.Powershell.E2010' `
                    -Verbose:$VerbosePreference
            }

            # Set remaining components to offline
            Update-ComponentState -Component "ServerWideOffline" -Requester "Maintenance" -ServerComponentState $maintenanceModeStatus.ServerComponentState -State "Inactive" -SetInactiveComponentsFromAnyRequesterToActive $SetInactiveComponentsFromAnyRequesterToActive -DomainController $DomainController | Out-Null

            # Check whether we are actually in maintenance mode
            $testResults = Test-TargetResource @PSBoundParameters

            if ($testResults -eq $false)
            {
                throw "Server is not fully in maintenance mode after running through steps to enable maintenance mode."
            }
        }
        # Take the server out of maintenance mode
        else
        {
            # Bring ServerWideOffline and UMCallRouter back online
            Update-ComponentState -Component "ServerWideOffline" -Requester "Maintenance" -ServerComponentState $maintenanceModeStatus.ServerComponentState -State "Active" -SetInactiveComponentsFromAnyRequesterToActive $SetInactiveComponentsFromAnyRequesterToActive -DomainController $DomainController | Out-Null
            Update-ComponentState -Component "UMCallRouter" -Requester "Maintenance" -ServerComponentState $maintenanceModeStatus.ServerComponentState -State "Active" -SetInactiveComponentsFromAnyRequesterToActive $SetInactiveComponentsFromAnyRequesterToActive -DomainController $DomainController | Out-Null

            # Run StopDagServerMaintenance.ps1 if required
            if ($maintenanceModeStatus.ClusterNode.State -ne "Up" -or `
                $maintenanceModeStatus.MailboxServer.DatabaseCopyAutoActivationPolicy -ne "Unrestricted" -or`
                $haStatus.State -ne "Active")
            {
                Write-Verbose -Message 'Running StopDagServerMaintenance.ps1'

                # Run StopDagServerMaintenance.ps1 in try/catch, so if an exception occurs, we can at least finish
                # doing the rest of the steps to take the server out of maintenance mode
                try
                {
                    $stopScriptParams = @{
                        serverName = $env:COMPUTERNAME
                        Verbose    = $true
                    }

                    Invoke-DotSourcedScript `
                        -ScriptPath $stopDagServerMaintenanceScript `
                        -ScriptParams $stopScriptParams `
                        -SnapinsToRemove 'Microsoft.Exchange.Management.Powershell.E2010' `
                        -Verbose:$VerbosePreference
                }
                catch
                {
                    Write-Error "Caught exception running StopDagServerMaintenance.ps1: $($_.Exception.Message)"
                }
            }

            # End Transport Maintenance
            if ($htStatus.State -ne "Active")
            {
                Write-Verbose -Message 'Ending Transport Maintenance'
                Stop-TransportMaintenance -LoadLocalShell $false -Verbose
            }

            # Bring components online that may have been taken offline by a failed setup run
            Update-ComponentState -Component "Monitoring" -Requester "Functional" -ServerComponentState $maintenanceModeStatus.ServerComponentState -State "Active" -SetInactiveComponentsFromAnyRequesterToActive $SetInactiveComponentsFromAnyRequesterToActive -DomainController $DomainController | Out-Null
            Update-ComponentState -Component "RecoveryActionsEnabled" -Requester "Functional" -ServerComponentState $maintenanceModeStatus.ServerComponentState -State "Active" -SetInactiveComponentsFromAnyRequesterToActive $SetInactiveComponentsFromAnyRequesterToActive -DomainController $DomainController | Out-Null

            # Bring online any specifically requested components
            if ($null -ne $AdditionalComponentsToActivate)
            {
                foreach ($component in $AdditionalComponentsToActivate)
                {
                    if ((Test-ComponentCheckedByDefault -ComponentName $component) -eq $false)
                    {
                        $status = $null
                        $status = $MaintenanceModeStatus.ServerComponentState | Where-Object -FilterScript {$_.Component -like "$($component)"}

                        if ($null -ne $status -and $status.State -ne 'Active')
                        {
                            Update-ComponentState -Component $component -Requester "Functional" -ServerComponentState $maintenanceModeStatus.ServerComponentState -State "Active" -SetInactiveComponentsFromAnyRequesterToActive $SetInactiveComponentsFromAnyRequesterToActive -DomainController $DomainController | Out-Null
                        }
                    }
                }
            }

            if ($MovePreferredDatabasesBack -eq $true)
            {
                Move-PrimaryDatabasesBack -DomainController $DomainController -MountDialOverride $MountDialOverride -SkipActiveCopyChecks $SkipActiveCopyChecks -SkipAllChecks $SkipAllChecks -SkipClientExperienceChecks $SkipClientExperienceChecks -SkipCpuChecks $SkipCpuChecks -SkipHealthChecks $SkipHealthChecks -SkipLagChecks $SkipLagChecks -SkipMaximumActiveDatabasesChecks $SkipMaximumActiveDatabasesChecks -SkipMoveSuppressionChecks $SkipMoveSuppressionChecks
            }
        }
    }
    else
    {
        throw "Failed to retrieve maintenance mode status of server."
    }

    Remove-Item Alias:Write-Host -ErrorAction SilentlyContinue
}

function Test-TargetResource
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.Boolean]
        $Enabled,

        [Parameter(Mandatory = $true)]
        [System.Management.Automation.PSCredential]
        [System.Management.Automation.Credential()]
        $Credential,

        [Parameter()]
        [System.String[]]
        $AdditionalComponentsToActivate,

        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [ValidateSet('None', 'Lossless', 'GoodAvailability', 'BestAvailability', 'BestEffort')]
        [System.String]
        $MountDialOverride = 'None',

        [Parameter()]
        [System.Boolean]
        $MovePreferredDatabasesBack = $false,

        [Parameter()]
        [System.Boolean]
        $SetInactiveComponentsFromAnyRequesterToActive = $false,

        [Parameter()]
        [System.Boolean]
        $SkipActiveCopyChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipAllChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipClientExperienceChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipCpuChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipHealthChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipLagChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipMaximumActiveDatabasesChecks = $false,

        [Parameter()]
        [System.Boolean]
        $SkipMoveSuppressionChecks = $false,

        [Parameter()]
        [System.String]
        $UpgradedServerVersion
    )

    Write-FunctionEntry -Parameters @{'Enabled' = $Enabled} -Verbose:$VerbosePreference

    # Load TransportMaintenanceMode Helper
    Import-Module "$((Get-Item -LiteralPath "$($PSScriptRoot)"))\TransportMaintenance.psm1" -Verbose:0

    $setupRunning = Test-ExchangeSetupRunning

    if ($setupRunning -eq $true)
    {
        Write-Verbose -Message 'Exchange Setup is currently running. Skipping maintenance mode checks.'
        return $true
    }

    # Establish remote PowerShell session
    Get-RemoteExchangeSession -Credential $Credential -CommandsToLoad 'Get-*' -Verbose:$VerbosePreference

    $serverVersion = Get-ExchangeVersionYear

    $maintenanceModeStatus = Get-MaintenanceModeStatus -EnteringMaintenanceMode $Enabled -DomainController $DomainController

    $testResults = $true

    if ($null -eq $maintenanceModeStatus)
    {
        Write-Error -Message "Failed to retrieve maintenance mode status for server."

        $testResults = $false
    }
    else
    {
        # Make sure server is fully in maintenance mode
        if ($Enabled -eq $true)
        {
            $atDesiredVersion = Test-ExchangeAtDesiredVersion -DomainController $DomainController -UpgradedServerVersion $UpgradedServerVersion

            if ($atDesiredVersion -eq $true)
            {
                Write-Verbose -Message "Server is already at or above the desired upgrade version of '$UpgradedServerVersion'. Skipping putting server into maintenance mode."
                return $true
            }
            else
            {
                if ($maintenanceModeStatus.MailboxServer.DatabaseCopyAutoActivationPolicy -ne "Blocked")
                {
                    Write-Verbose -Message 'DatabaseCopyAutoActivationPolicy is not set to Blocked'
                    $testResults = $false
                }

                if ($null -ne ($MaintenanceModeStatus.ServerComponentState | Where-Object -FilterScript {$_.State -ne "Inactive" -and $_.Component -ne "Monitoring" -and $_.Component -ne "RecoveryActionsEnabled"}))
                {
                    Write-Verbose -Message 'One or more components have a status other than Inactive'
                    $testResults = $false
                }

                if ($maintenanceModeStatus.ClusterNode.State -eq "Up")
                {
                    Write-Verbose -Message 'Cluster node has a status of Up'
                    $testResults = $false
                }

                if ((Test-ServerIsPAM -DomainController $DomainController) -eq $true)
                {
                    Write-Verbose -Message 'Server still has the Primary Active Manager role'
                    $testResults = $false
                }


                [int] $messagesQueued = Get-QueueMessageCount -MaintenanceModeStatus $maintenanceModeStatus

                if ($messagesQueued -gt 0)
                {
                    Write-Verbose -Message "Found $messagesQueued messages still in queue"
                    $testResults = $false
                }


                [int] $activeDBCount = Get-ActiveDBCount -MaintenanceModeStatus $maintenanceModeStatus -DomainController $DomainController

                if ($activeDBCount -gt 0)
                {
                    Write-Verbose -Message "Found $activeDBCount replicated databases still activated on this server"
                    $testResults = $false
                }


                [int] $umCallCount = Get-UMCallCount -MaintenanceModeStatus $maintenanceModeStatus -DomainController $DomainController

                if ($umCallCount -gt 0)
                {
                    Write-Verbose -Message "Found $umCallCount active UM calls on this server"
                    $testResults = $false
                }
            }
        }
        # Make sure the server is fully out of maintenance mode
        else
        {
            $activeComponents = $MaintenanceModeStatus.ServerComponentState | Where-Object -FilterScript {$_.State -eq "Active"}

            if ($null -eq $activeComponents)
            {
                Write-Verbose -Message 'No Components found with a status of Active'
                $testResults = $false
            }

            if ($null -eq ($activeComponents | Where-Object -FilterScript {$_.Component -eq "ServerWideOffline"}))
            {
                Write-Verbose -Message 'Component ServerWideOffline is not Active'
                $testResults = $false
            }

            if ($serverVersion -in '2013', '2016')
            {
                if ($null -eq ($activeComponents | Where-Object -FilterScript {$_.Component -eq "UMCallRouter"}))
                {
                    Write-Verbose -Message 'Component UMCallRouter is not Active'
                    $testResults = $false
                }
            }

            if ($null -eq ($activeComponents | Where-Object -FilterScript {$_.Component -eq "HubTransport"}))
            {
                Write-Verbose -Message 'Component HubTransport is not Active'
                $testResults = $false
            }

            if ($maintenanceModeStatus.ClusterNode.State -ne "Up")
            {
                Write-Verbose -Message "Cluster node has a status of $($maintenanceModeStatus.ClusterNode.State)"
                $testResults = $false
            }

            if ($maintenanceModeStatus.MailboxServer.DatabaseCopyAutoActivationPolicy -ne "Unrestricted")
            {
                Write-Verbose -Message "DatabaseCopyAutoActivationPolicy is set to $($maintenanceModeStatus.MailboxServer.DatabaseCopyAutoActivationPolicy)"
                $testResults = $false
            }

            if ($null -eq ($activeComponents | Where-Object -FilterScript {$_.Component -eq "Monitoring"}))
            {
                Write-Verbose -Message 'Component Monitoring is not Active'
                $testResults = $false
            }

            if ($null -eq ($activeComponents | Where-Object -FilterScript {$_.Component -eq "RecoveryActionsEnabled"}))
            {
                Write-Verbose -Message 'Component RecoveryActionsEnabled is not Active'
                $testResults = $false
            }

            if ($null -ne $AdditionalComponentsToActivate)
            {
                foreach ($component in $AdditionalComponentsToActivate)
                {
                    if ((Test-ComponentCheckedByDefault -ComponentName $component) -eq $false)
                    {
                        $status = $null
                        $status = $MaintenanceModeStatus.ServerComponentState | Where-Object -FilterScript {$_.Component -like "$($component)"}

                        if ($null -ne $status -and $Status.State -ne "Active")
                        {
                            Write-Verbose -Message "Component $component is not set to Active"
                            $testResults = $false
                        }
                    }
                }
            }
        }
    }

    return $testResults
}

# Gets a Hashtable containing various objects from Exchange that will be used to determine maintenance mode status
function Get-MaintenanceModeStatus
{
    [CmdletBinding()]
    [OutputType([System.Collections.Hashtable])]
    param
    (
        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [System.Boolean]
        $EnteringMaintenanceMode = $true
    )

    Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToKeep 'DomainController'

    $serverComponentState = Get-ServerComponentStateInternal -Identity $env:COMPUTERNAME -DomainController $DomainController
    $clusterNode = Get-ClusterNode -Name $env:COMPUTERNAME
    $dbCopyStatus = Get-MailboxDatabaseCopyStatusInternal -Server $env:COMPUTERNAME -DomainController $DomainController
    $umCalls = Get-UMActiveCallsInternal -Server $env:COMPUTERNAME -DomainController $DomainController
    $mailboxServer = Get-MailboxServerInternal -Identity $env:COMPUTERNAME -DomainController $DomainController
    $queues = Get-Queue -Server $env:COMPUTERNAME -ErrorAction SilentlyContinue

    # If we're checking queues too soon after restarting Transport, Get-Queue may fail. Wait for bootloader to be active and try again.
    if ($null -eq $queues -and $EnteringMaintenanceMode -eq $true)
    {
        $endTime = [DateTime]::Now.AddMinutes(5)

        Write-Verbose -Message "Waiting up to 5 minutes for the Transport Bootloader to be ready before running Get-Queue. Wait started at $([DateTime]::Now)."

        while ($null -eq $queues -and [DateTime]::Now -lt $endTime)
        {
            Wait-BootLoaderReady -Server $env:COMPUTERNAME -TimeOut (New-TimeSpan -Seconds 15) -PollingFrequency (New-TimeSpan -Seconds 1) | Out-Null
            $queues = Get-Queue -Server $env:COMPUTERNAME -ErrorAction SilentlyContinue
        }
    }

    [System.Collections.Hashtable] $returnValue = @{
        ServerComponentState = $serverComponentState
        ClusterNode = $clusterNode
        Queues = $queues
        DBCopyStatus = $dbCopyStatus
        UMActiveCalls = $umCalls
        MailboxServer = $mailboxServer
    }

    return $returnValue
}

# Gets a count of messages in queues on the local server
function Get-QueueMessageCount
{
    [CmdletBinding()]
    [OutputType([System.UInt32])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.Collections.Hashtable]
        $MaintenanceModeStatus
    )

    [UInt32] $messageCount = 0

    if ($null -ne $MaintenanceModeStatus.Queues)
    {
        foreach ($queue in $MaintenanceModeStatus.Queues | Where-Object -FilterScript {$_.Identity -notlike "*\Shadow\*"})
        {
            Write-Verbose -Message "Found queue '$($queue.Identity)' with a message count of '$($queue.MessageCount)'."
            $messageCount += $queue.MessageCount
        }
    }
    else
    {
        Write-Warning "No Transport Queues were detected on this server. This can occur if the MSExchangeTransport service is not started, or if Get-Queue was run too quickly after restarting the service."
    }

    return [System.UInt32] $messageCount
}

# Gets a count of database that are replication enabled, and are still activated on the local server (even if they are dismounted)
function Get-ActiveDBCount
{
    [CmdletBinding()]
    [OutputType([System.UInt32])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.Collections.Hashtable]
        $MaintenanceModeStatus,

        [Parameter()]
        [System.String]
        $DomainController
    )

    [UInt32] $activeDBCount = 0

    # Get DB's with a status of Mounted, Mounting, Dismounted, or Dismounting
    $localDBs = $MaintenanceModeStatus.DBCopyStatus | Where-Object -FilterScript {$_.Status -like "Mount*" -or $_.Status -like "Dismount*"}

    # Ensure that any DB's we found actually have copies
    foreach ($db in $localDBs)
    {
        $dbProps = Get-MailboxDatabaseInternal -Identity "$($db.DatabaseName)" -DomainController $DomainController

        if ($dbProps.ReplicationType -ne "None")
        {
            Write-Verbose -Message "Found database '$($db.DatabaseName)' with a replication type of '$($dbProps.ReplicationType)' and a status of '$($db.Status)'."
            $activeDBCount++
        }
    }

    return [System.UInt32] $activeDBCount
}

# Gets a count of active UM calls on the local server
function Get-UMCallCount
{
    [CmdletBinding()]
    [OutputType([System.UInt32])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.Collections.Hashtable]
        $MaintenanceModeStatus,

        [Parameter()]
        [System.String]
        $DomainController
    )

    [Uint32] $umCallCount = 0

    $umCalls = Get-UMActiveCallsInternal -Server $env:COMPUTERNAME -DomainController $DomainController

    if ($null -ne $umCalls)
    {
        if ($null -eq $umCalls.Count)
        {
            $umCallCount = 1
        }
        else
        {
            $umCallCount = $umCalls.Count
        }
    }

    return [System.UInt32] $umCallCount
}

# Gets a list of servers in the DAG with HubTransport not set to Active, or DatabaseCopyAutoActivationPolicy set to Blocked
function Get-ExclusionsForMessageRedirection
{
    [CmdletBinding()]
    [OutputType([System.String[]])]
    param
    (
        [Parameter()]
        [System.String]
        $DomainController
    )

    [System.String[]] $exclusions = @()

    $mbxServer = Get-MailboxServerInternal -Identity $env:COMPUTERNAME -DomainController $DomainController

    if ($null -ne $mbxServer)
    {
        $dag = Get-DatabaseAvailabilityGroupInternal -Identity $($mbxServer.DatabaseAvailabilityGroup) -DomainController $DomainController

        if ($null -ne $dag)
        {
            foreach ($server in $dag.Servers)
            {
                if ($server.Name -notlike $env:COMPUTERNAME)
                {
                    $serverName = $server.Name.ToLower()

                    # Check whether HubTransport is active on the specified server
                    $htState = $null
                    $htState = Get-ServerComponentStateInternal -Identity $server.Name -Component "HubTransport" -DomainController $DomainController

                    if ($null -ne $htState -and $htState.State -notlike "Active")
                    {
                        if (($exclusions.Contains($serverName) -eq $false))
                        {
                            $exclusions += $serverName
                            continue
                        }
                    }

                    # Check whether the server is already blocked from database activation
                    $currentMbxServer = $null
                    $currentMbxServer = Get-MailboxServerInternal -Identity $server.Name -DomainController $DomainController

                    if ($null -ne $currentMbxServer -and $currentMbxServer.DatabaseCopyAutoActivationPolicy -like "Blocked")
                    {
                        if (($exclusions.Contains($serverName) -eq $false))
                        {
                            $exclusions += $serverName
                            continue
                        }
                    }
                }
            }
        }
    }

    return [System.String[]] $exclusions
}

# If UpgradedServerVersion was specified, checks to see whether the server is already at the desired version
function Test-ExchangeAtDesiredVersion
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [System.String]
        $UpgradedServerVersion
    )

    $atDesiredVersion = $false

    if (!([System.String]::IsNullOrEmpty($UpgradedServerVersion)))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToKeep 'DomainController'

        $server = Get-ExchangeServerInternal -Identity $env:COMPUTERNAME -DomainController $DomainController

        if ($null -ne $server)
        {
            [System.String[]] $versionParts = $UpgradedServerVersion.Split('.')

            if ($null -ne $versionParts -and $versionParts.Length -eq 4)
            {
                if (([int]::Parse($server.AdminDisplayVersion.Major) -ge [int]::Parse($versionParts[0])) -and
                    ([int]::Parse($server.AdminDisplayVersion.Minor) -ge [int]::Parse($versionParts[1])) -and
                    ([int]::Parse($server.AdminDisplayVersion.Build) -ge [int]::Parse($versionParts[2])) -and
                    ([int]::Parse($server.AdminDisplayVersion.Revision) -ge [int]::Parse($versionParts[3])))
                {
                    $atDesiredVersion = $true
                }
                else
                {
                    Write-Verbose -Message "Desired server version '$UpgradedServerVersion' is greater than the actual server version '$($server.AdminDisplayVersion)'"
                }
            }
            else
            {
                throw "Invalid version format for `$UpgradedServerVersion. Should be in the format ##.#.####.#"
            }
        }
    }

    return $atDesiredVersion
}

# Checks to see whether the specified component is one that is already checked by default
function Test-ComponentCheckedByDefault
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        $ComponentName
    )

    [System.Boolean] $checkedByDefault = $false

    if ($ComponentName -like "ServerWideOffline" -or $ComponentName -like "UMCallRouter" -or $ComponentName -like "HubTransport" -or $ComponentName -like "Monitoring" -or $ComponentName -like "RecoveryActionsEnabled")
    {
        $checkedByDefault = $true
    }

    return $checkedByDefault
}

# Gets a count of members in this servers DAG
function Get-DAGMemberCount
{
    [CmdletBinding()]
    [OutputType([System.Int32])]
    param
    (
        [Parameter()]
        [System.String]
        $DomainController
    )

    [System.Int32] $count = 0

    $server = Get-MailboxServerInternal -Identity $env:COMPUTERNAME -DomainController $DomainController

    if ($null -ne $server -and ![System.String]::IsNullOrEmpty($server.DatabaseAvailabilityGroup))
    {
        $dag = Get-DatabaseAvailabilityGroupInternal -Identity "$($server.DatabaseAvailabilityGroup)" -DomainController $DomainController

        if ($null -ne $dag)
        {
            $count = $dag.Servers.Count
        }
    }

    return $count
}

function Test-ServerIsPAM
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [Parameter()]
        [System.String]
        $DomainController
    )

    $isPAM = $false

    $server = Get-MailboxServerInternal -Identity $env:COMPUTERNAME -DomainController $DomainController

    if ($null -ne $server -and ![System.String]::IsNullOrEmpty($server.DatabaseAvailabilityGroup))
    {
        $dag = Get-DatabaseAvailabilityGroupInternal -Identity "$($server.DatabaseAvailabilityGroup)" -DomainController $DomainController

        if ($null -ne $dag -and $dag.PrimaryActiveManager -like $env:COMPUTERNAME)
        {
            $isPAM = $true
        }
    }

    return $isPAM
}

# Waits up the the specified WaitMinutes for existing UM calls to finish. Returns True if no more UM calls are active.
function Wait-ForUMToDrain
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [System.UInt32]
        $SleepSeconds = 15,

        [Parameter()]
        [System.UInt32]
        $WaitMinutes = 5
    )

    [System.Boolean] $umDrained = $false

    $endTime = [DateTime]::Now.AddMinutes($WaitMinutes)

    Write-Verbose -Message "Waiting up to $WaitMinutes minutes for active UM calls to finish"

    while ($fullyInMaintenanceMode -eq $false -and [DateTime]::Now -lt $endTime)
    {
        Write-Verbose -Message "Checking whether all UM calls are finished at $([DateTime]::Now)."

        $umCalls = $null

        Get-UMActiveCallsInternal -Server $env:COMPUTERNAME -DomainController $DomainController

        if ($null -eq $umCalls -or $umCalls.Count -eq 0)
        {
            $umDrained = $true
        }
        else
        {
            Write-Verbose -Message "There are still active UM calls as of $([DateTime]::Now). Sleeping for $SleepSeconds seconds. Will continue checking until $endTime."
            Start-Sleep -Seconds $SleepSeconds
        }
    }

    return $umDrained
}

<#
    Checks whether a Component is at the specified State, if not, changes the component to the state.
    Returns whether a change was made to the component state
#>

function Update-ComponentState
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        $Component,

        [Parameter(Mandatory = $true)]
        [System.String]
        $Requester,

        [Parameter(Mandatory = $true)]
        $ServerComponentState,

        [Parameter(Mandatory = $true)]
        [System.String]
        $State,

        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [System.Boolean]
        $SetInactiveComponentsFromAnyRequesterToActive = $false
    )

    [System.Boolean] $madeChange = $false

    $componentState = $MaintenanceModeStatus.ServerComponentState | Where-Object -FilterScript {$_.Component -like "$($Component)"}

    if ($null -ne $componentState)
    {
        # If we're already Inactive don't bother setting to Draining.
        if ($State -like "Draining" -and $componentState.State -like "Inactive")
        {
            return $false
        }
        elseif ($componentState.State -notlike "$($State)")
        {
            Write-Verbose -Message "Setting $($componentState.Component) component to $State for requester $Requester"

            Set-ServerComponentStateInternal -Component $componentState.Component -State $State -Requester $Requester -DomainController $DomainController

            $madeChange = $true

            if ($State -eq "Active" -and $SetInactiveComponentsFromAnyRequesterToActive -eq $true)
            {
                $additionalRequesters = $null
                $additionalRequesters = $componentState.LocalStates | Where-Object -FilterScript {$_.Requester -notlike "$($Requester)" -and $_.State -notlike "Active"}

                if ($null -ne $additionalRequesters)
                {
                    foreach ($additionalRequester in $additionalRequesters)
                    {
                        Write-Verbose -Message "Setting $($componentState.Component) component to Active for requester $($additionalRequester.Requester)"

                        Set-ServerComponentStateInternal -Component $componentState.Component -State Active -Requester $additionalRequester.Requester -DomainController $DomainController
                    }
                }
            }
        }
    }

    return $madeChange
}

# Finds all databases which have an Activation Preference of 1 for this server, which are not currently hosted on this server, and moves them back
function Move-PrimaryDatabasesBack
{
    [CmdletBinding()]
    param
    (
        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [ValidateSet('None', 'Lossless', 'GoodAvailability', 'BestAvailability', 'BestEffort')]
        [System.String]
        $MountDialOverride,

        [Parameter()]
        [System.Boolean]
        $SkipActiveCopyChecks,

        [Parameter()]
        [System.Boolean]
        $SkipAllChecks,

        [Parameter()]
        [System.Boolean]
        $SkipClientExperienceChecks,

        [Parameter()]
        [System.Boolean]
        $SkipCpuChecks,

        [Parameter()]
        [System.Boolean]
        $SkipHealthChecks,

        [Parameter()]
        [System.Boolean]
        $SkipLagChecks,

        [Parameter()]
        [System.Boolean]
        $SkipMaximumActiveDatabasesChecks,

        [Parameter()]
        [System.Boolean]
        $SkipMoveSuppressionChecks
    )

    $databases = Get-MailboxDatabaseInternal -Server $env:COMPUTERNAME -Status -DomainController $DomainController

    [System.String[]] $databasesWithActivationPrefOneNotOnThisServer = @()

    if ($null -ne $databases)
    {
        foreach ($database in $databases)
        {
            if ($null -ne $database.ActivationPreference)
            {
                foreach ($ap in $database.ActivationPreference)
                {
                    if ($ap.Key.Name -like $env:COMPUTERNAME -and $ap.Value -eq 1)
                    {
                        $copyStatus = $null
                        $copyStatus = Get-MailboxDatabaseCopyStatusInternal -Identity "$($database.Name)\$($env:COMPUTERNAME)" -DomainController $DomainController

                        if ($null -ne $copyStatus -and $copyStatus.Status -eq "Healthy")
                        {
                            $databasesWithActivationPrefOneNotOnThisServer += $database.Name
                        }
                    }
                }
            }
        }
    }

    if ($databasesWithActivationPrefOneNotOnThisServer.Count -gt 0)
    {
        Write-Verbose -Message "Found $($databasesWithActivationPrefOneNotOnThisServer.Count) Healthy databases with Activation Preference 1 that should be moved to this server."

        foreach ($database in $databasesWithActivationPrefOneNotOnThisServer)
        {
            Write-Verbose -Message "Attempting to move database '$database' back to this server."

            # Do the move in a try/catch block so we can log the error, but not have it prevent other databases from attempting to move
            try
            {
                Move-ActiveMailboxDatabaseInternal -Identity $database -ActivateOnServer $env:COMPUTERNAME -DomainController $DomainController -MountDialOverride $MountDialOverride -SkipActiveCopyChecks $SkipActiveCopyChecks -SkipAllChecks $SkipAllChecks -SkipClientExperienceChecks $SkipClientExperienceChecks -SkipCpuChecks $SkipCpuChecks -SkipHealthChecks $SkipHealthChecks -SkipLagChecks $SkipLagChecks -SkipMaximumActiveDatabasesChecks $SkipMaximumActiveDatabasesChecks -SkipMoveSuppressionChecks $SkipMoveSuppressionChecks
            }
            catch
            {
                Write-Error "$($_.Exception.Message)"
            }
        }
    }
    else
    {
        Write-Verbose -Message 'Found 0 Healthy databases with Activation Preference 1 for this server that are currently not hosted on this server'
    }
}

#region Exchange Cmdlet Wrappers
function Get-ExchangeServerInternal
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        $Identity,

        [Parameter()]
        [System.String]
        $DomainController
    )

    if ([System.String]::IsNullOrEmpty($DomainController))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'DomainController'
    }

    return (Get-ExchangeServer @PSBoundParameters)
}

function Get-DatabaseAvailabilityGroupInternal
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        $Identity,

        [Parameter()]
        [System.String]
        $DomainController
    )

    if ([System.String]::IsNullOrEmpty($DomainController))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'DomainController'
    }

    return (Get-DatabaseAvailabilityGroup @PSBoundParameters -Status)
}

function Get-ServerComponentStateInternal
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        $Identity,

        [Parameter()]
        [System.String]
        $Component,

        [Parameter()]
        [System.String]
        $DomainController
    )

    if ([System.String]::IsNullOrEmpty($Component))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'Component'
    }

    if ([System.String]::IsNullOrEmpty($DomainController))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'DomainController'
    }

    return (Get-ServerComponentState @PSBoundParameters)
}

function Set-ServerComponentStateInternal
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        $Component,

        [Parameter(Mandatory = $true)]
        [System.String]
        $Requester,

        [Parameter(Mandatory = $true)]
        [System.String]
        $State,

        [Parameter()]
        [System.String]
        $DomainController
    )

    if ([System.String]::IsNullOrEmpty($DomainController))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'DomainController'
    }

    Set-ServerComponentState -Identity $env:COMPUTERNAME @PSBoundParameters
}

function Get-MailboxDatabaseInternal
{
    [CmdletBinding()]
    param
    (
        [Parameter()]
        [System.String]
        $Identity,

        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [System.String]
        $Server,

        [Parameter()]
        [switch]
        $Status
    )

    if ([System.String]::IsNullOrEmpty($Identity))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'Identity'
    }

    if ([System.String]::IsNullOrEmpty($DomainController))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'DomainController'
    }

    if ([System.String]::IsNullOrEmpty($Server))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'Server'
    }

    return (Get-MailboxDatabase @PSBoundParameters)
}

function Get-MailboxDatabaseCopyStatusInternal
{
    [CmdletBinding()]
    param
    (
        [Parameter()]
        [System.String]
        $Identity,

        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [System.String]
        $Server
    )

    if ([System.String]::IsNullOrEmpty($Identity))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'Identity'
    }

    if ([System.String]::IsNullOrEmpty($DomainController))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'DomainController'
    }

    if ([System.String]::IsNullOrEmpty($Server))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'Server'
    }

    return (Get-MailboxDatabaseCopyStatus @PSBoundParameters)
}

function Get-MailboxServerInternal
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        $Identity,

        [Parameter()]
        [System.String]
        $DomainController
    )

    if ([System.String]::IsNullOrEmpty($DomainController))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'DomainController'
    }

    return (Get-MailboxServer @PSBoundParameters)
}

function Set-MailboxServerInternal
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        $Identity,

        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [System.Collections.Hashtable]
        $AdditionalParams
    )

    if ([System.String]::IsNullOrEmpty($DomainController))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'DomainController'
    }

    Add-ToPSBoundParametersFromHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToAdd $AdditionalParams
    Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'AdditionalParams'

    Set-MailboxServer @PSBoundParameters
}

function Get-UMActiveCallsInternal
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        $Server,

        [Parameter()]
        [System.String]
        $DomainController
    )

    $umActiveCalls = $null

    $serverVersion = Get-ExchangeVersionYear

    if ($serverVersion -in '2013', '2016')
    {
        if ([System.String]::IsNullOrEmpty($DomainController))
        {
            Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'DomainController'
        }

        $umActiveCalls = Get-UMActiveCalls @PSBoundParameters
    }

    return $umActiveCalls
}

function Move-ActiveMailboxDatabaseInternal
{
    [CmdletBinding()]
    param
    (
        [Parameter()]
        [System.String]
        $ActivateOnServer,

        [Parameter()]
        [System.String]
        $Identity,

        [Parameter()]
        [System.String]
        $DomainController,

        [Parameter()]
        [ValidateSet('None', 'Lossless', 'GoodAvailability', 'BestAvailability', 'BestEffort')]
        [System.String]
        $MountDialOverride,

        [Parameter()]
        [System.String]
        $MoveComment,

        [Parameter()]
        [System.String]
        $Server = $env:COMPUTERNAME,

        [Parameter()]
        [System.Boolean]
        $SkipActiveCopyChecks,

        [Parameter()]
        [System.Boolean]
        $SkipAllChecks,

        [Parameter()]
        [System.Boolean]
        $SkipClientExperienceChecks,

        [Parameter()]
        [System.Boolean]
        $SkipCpuChecks,

        [Parameter()]
        [System.Boolean]
        $SkipHealthChecks,

        [Parameter()]
        [System.Boolean]
        $SkipLagChecks,

        [Parameter()]
        [System.Boolean]
        $SkipMaximumActiveDatabasesChecks,

        [Parameter()]
        [System.Boolean]
        $SkipMoveSuppressionChecks
    )

    if ([System.String]::IsNullOrEmpty($ActivateOnServer))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'ActivateOnServer'
    }

    if ([System.String]::IsNullOrEmpty($DomainController))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'DomainController'
    }

    if ([System.String]::IsNullOrEmpty($Identity))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'Identity'
    }

    if ([System.String]::IsNullOrEmpty($MoveComment))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'MoveComment'
    }

    if ([System.String]::IsNullOrEmpty($Server))
    {
        Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'Server'
    }

    # Setup parameters in a format Move-ActiveMailboxDatabase expects
    $moveDBParams = @{
        Confirm     = $false
        Erroraction = 'Stop'
    }

    if ($SkipActiveCopyChecks)
    {
        $moveDBParams.Add("SkipActiveCopyChecks", $true)
    }

    if ($SkipClientExperienceChecks)
    {
        $moveDBParams.Add("SkipClientExperienceChecks", $true)
    }

    if ($SkipHealthChecks)
    {
        $moveDBParams.Add("SkipHealthChecks", $true)
    }

    if ($SkipLagChecks)
    {
        $moveDBParams.Add("SkipLagChecks", $true)
    }

    if ($SkipMaximumActiveDatabasesChecks)
    {
        $moveDBParams.Add("SkipMaximumActiveDatabasesChecks", $true)
    }

    if ((Get-ExchangeVersionYear) -in '2016', '2019')
    {
        if ($SkipAllChecks)
        {
            $moveDBParams.Add("SkipAllChecks", $true)
        }

        if ($SkipCpuChecks)
        {
            $moveDBParams.Add("SkipCpuChecks", $true)
        }

        if ($SkipMoveSuppressionChecks)
        {
            $moveDBParams.Add("SkipMoveSuppressionChecks", $true)
        }
    }

    # Remove the PSBoundParameters we just re-formatted
    Remove-FromPSBoundParametersUsingHashtable -PSBoundParametersIn $PSBoundParameters -ParamsToRemove 'SkipActiveCopyChecks', 'SkipClientExperienceChecks', 'SkipLagChecks', 'SkipMaximumActiveDatabasesChecks', 'SkipMoveSuppressionChecks', 'SkipHealthChecks', 'SkipCpuChecks', 'SkipAllChecks'

    # Execute mailbox DB move
    Move-ActiveMailboxDatabase @PSBoundParameters @moveDBParams
}
#endregion

Export-ModuleMember -Function *-TargetResource