Create Report for Average Mailbox Size and Item Count per Database in Microsoft Exchange 2010

Function Get-OSCEXMailboxDBReport 
{ 
    [CmdletBinding()] 
    Param 
    ( 
        #Define parameters 
        [Parameter(Mandatory=$true,Position=1,ValueFromPipeline=$true)] 
        [string]$Database, 
        [Parameter(Mandatory=$false,Position=2)] 
        [string[]]$DataBaseProperty, 
        [Parameter(Mandatory=$true,Position=3)] 
        [string[]]$MailboxStatisticsProperty, 
        [Parameter(Mandatory=$false,Position=4)] 
        [switch]$IncludeDisconnectedMailbox     
    ) 
    Process 
    { 
        $reports = @() 
        $mailboxDBProperties = @{} 
        #Get Mailbox Database 
        $mailboxDB = Get-MailboxDatabase -Identity $Database -Status -Verbose:$false 
        #If specific database could be found, keep on processing 
        if ($mailboxDB -ne $null) { 
            #Save the property names to a variable, it will be used to validate the property names which are provided by administrators 
            $mailboxDB | Get-Member -MemberType Property | %{$mailboxDBProperties.Add($_.Name,"")} 
            #Prepare the report 
            $report = New-Object PSObject 
            $report | Add-Member -MemberType NoteProperty -Name "ServerName" -Value $($mailboxDB.ServerName) 
            $report | Add-Member -MemberType NoteProperty -Name "DatabaseName" -Value $($mailboxDB.Name) 
            $report | Add-Member -MemberType NoteProperty -Name "DatabaseSize" -Value $($mailboxDB.DatabaseSize) 
            $report | Add-Member -MemberType NoteProperty -Name "AvailableNewMailboxSpace" -Value $($mailboxDB.AvailableNewMailboxSpace) 
            #Handle additional properties 
            if ($DataBaseProperty -ne $null) { 
                foreach ($dbProperty in $DataBaseProperty) { 
                    if ($mailboxDBProperties.ContainsKey($dbProperty)) { 
                        $report | Add-Member -MemberType NoteProperty -Name $dbProperty -Value $($mailboxDB.$dbProperty) 
                    } else { 
                        $warningMsg = $Messages.PropertyNameIsNotValid 
                        $warningMsg = $warningMsg -replace "Placeholder01",$dbProperty 
                        $pscmdlet.WriteWarning($warningMsg) 
                    } 
                } 
            } 
            #Get mailbox statistics 
            $mailboxDBStatProperties = @{} 
            if ($IncludeDisconnectedMailbox) { 
                $mailboxStat = Get-MailboxStatistics -Database $Database -Verbose:$false 
            } else { 
                $mailboxStat = Get-MailboxStatistics -Database $Database -Verbose:$false | Where-Object {$_.DisconnectDate -ne $null} 
            } 
            if ($mailboxStat -is [array]) { 
                $mailboxStat | Get-Member -MemberType Property | %{$mailboxDBStatProperties.Add($_.Name,"")} 
                $report | Add-Member -MemberType NoteProperty -Name "Mailbox(Count)" -Value $($mailboxStat.Count) 
                foreach ($mbxStatProperty in $MailboxStatisticsProperty) { 
                    #Use regular expression to capture measure method 
                    $measureMethod = [regex]::Match($mbxStatProperty,"(?<=\()\w+") 
                    $measuredProperty = [regex]::Replace($mbxStatProperty,"\($measureMethod\)","") 
                    if (($mailboxDBStatProperties.ContainsKey($measuredProperty)) -and ($measuredProperty -match "Count|Size") -and ($measuredProperty -notmatch "LastLoggedOnUserAccount")) { 
                        Switch ($measureMethod) { 
                            "Average" { 
                                if ($measuredProperty -match "Size") { 
                                    $measuredValue = $mailboxStat | Select *,@{Name="$measuredProperty";Expression={$_.$measuredProperty.Value.ToBytes()}} -ExcludeProperty $measuredProperty | Measure-Object -Property $measuredProperty -Average 
                                } else { 
                                    $measuredValue = $mailboxStat | Measure-Object -Property $measuredProperty -Average 
                                } 
                                $report | Add-Member -MemberType NoteProperty -Name "$measuredProperty(Average)" -Value $measuredValue.Average 
                            } 
                            "Sum" { 
                                if ($measuredProperty -match "Size") { 
                                    $measuredValue = $mailboxStat | Select *,@{Name="$measuredProperty";Expression={$_.$measuredProperty.Value.ToBytes()}} -ExcludeProperty $measuredProperty | Measure-Object -Property $measuredProperty -Sum 
                                } else { 
                                    $measuredValue = $mailboxStat | Measure-Object -Property $measuredProperty -Sum 
                                } 
                                $report | Add-Member -MemberType NoteProperty -Name "$measuredProperty(Sum)" -Value $measuredValue.Sum 
                            } 
                            "Maximum" { 
                                if ($measuredProperty -match "Size") { 
                                    $measuredValue = $mailboxStat | Select *,@{Name="$measuredProperty";Expression={$_.$measuredProperty.Value.ToBytes()}} -ExcludeProperty $measuredProperty | Measure-Object -Property $measuredProperty -Maximum 
                                } else { 
                                    $measuredValue = $mailboxStat | Measure-Object -Property $measuredProperty -Maximum 
                                } 
                                $report | Add-Member -MemberType NoteProperty -Name "$measuredProperty(Maximum)" -Value $measuredValue.Maximum 
                            } 
                            "Minimum" { 
                                if ($measuredProperty -match "Size") { 
                                    $measuredValue = $mailboxStat | Select *,@{Name="$measuredProperty";Expression={$_.$measuredProperty.Value.ToBytes()}} -ExcludeProperty $measuredProperty | Measure-Object -Property $measuredProperty -Minimum 
                                } else { 
                                    $measuredValue = $mailboxStat | Measure-Object -Property $measuredProperty -Minimum 
                                } 
                                $report | Add-Member -MemberType NoteProperty -Name "$measuredProperty(Minimum)" -Value $measuredValue.Minimum 
                            } 
                            Default { 
                                $warningMsg = $Messages.MeasureMethodIsNotValid 
                                $warningMsg = $warningMsg -replace "Placeholder01",$measureMethod 
                                $pscmdlet.WriteWarning($warningMsg)                                     
                            } 
                        } 
                    } else { 
                        $warningMsg = $Messages.PropertyNameIsNotValidForMeasuring 
                        $warningMsg = $warningMsg -replace "Placeholder01",$measuredProperty 
                        $pscmdlet.WriteWarning($warningMsg) 
                    } 
                    $measuredValue = $null 
                } 
            } else { 
                #If the mailbox database does not contain any user mailboxes,SystemMailbox will be excluded from the result. 
                $warningMsg = $Messages.CannotFindAnyMailboxStat 
                $warningMsg = $warningMsg -replace "Placeholder01",$Database 
                $pscmdlet.WriteWarning($warningMsg) 
            } 
        } 
        return $report 
    } 
}