<#
.SYNOPSIS 
GroupChecker : check a Mult-IP group client count, and send an email if greater than previous count.
(c)2013 Radio IP Software inc. 
Version 1.0 - DO NOT DISTRIBUTE

.EXAMPLE
C:\PS>.\GroupChecker.ps1 -to myemail@mydomain.com -from multip1@mydomain.com -delay 60 -smtpserver exchg.mydomain.com


.DESCRIPTION
Running the GroupChecker.ps1 script will send an email when the client count of a specified group
is greater than the previous count. This script loops indifinitly.
Use the -detail option of get-help to see help on parameters.
#>

[cmdletbinding()]
param (
    #Provide the mailbox name for the source (From) email address 
    [parameter(Mandatory=$true)][string]$from, 
    #Provide the mailbox name for the destination (To) email address
    [parameter(Mandatory=$true)][string]$to,
    #Provie the mail server name or IP adress
    [parameter(Mandatory=$true)][string]$smtpServer, 
    #Provide the group to check (default is 'Quarantine')
    [parameter(Mandatory=$false)][string]$group = "Quarantine", 
    #Provide the delay, in seconds, between each checking loop (default = 30 seconds)
    [int32]$delay = 30,   
    #Send a test email, and do not check the group client count.
    [parameter(Mandatory=$false)][switch]$test=$false
)

$thisComputer = $env:COMPUTERNAME;

if($test)
{
$body = @"
This message has been sent by the GroupChecker Powershell script, from server '$thisComputer'.
Please disregard this message.

Regards.
"@
    send-mailmessage -from $from -to $to -subject "Test: New Client(s) in '$group'" -Body $body -smtpserver $smtpServer;
    exit;
}

# Connect to Mult-IP Server
try
{
    $a = new-object -com radioip.therock;
    $a.OpenSession($null,$null,$null);
}
catch
{
    write-Host "Can't find Mult-IP Gateway";
    exit;
}

#Initialize variables
$Qcount = 0;
$PrevQcount = 0;
$firstLoop = $true;

while($true) 
{
    $Qcount = $a.groups.item($group).clients.count;

	if($Qcount -ne $PrevQcount)
	{
	    write-debug "$Qcount Client(s) In $group";
        if($Qcount -gt $PrevQcount)
        {
            $diff = $PrevQcount - $Qcount;
            $clients = $a.groups.item($group).clients;
            $out = "";
            $clients | ForEach-Object { $name = $_.ClientName; $out += "`t$name`n"; }

            if($firstLoop)
            {
                $subject = "GroupChecker script started on $thisComputer - $QCount clients in '$group'"
                $body = @"
GroupChecker script started successfully on server $thisComputer.
There are currently $Qcount Mult-IP clients in the '$group' group:
$out
"@;
            }
            else
            {
                $subject = "$thisComputer - $diff New Client(s) in '$group'";
                $body = @"
$diff Mult-IP clients were added to the '$group' group, for a total of $Qcount clients:
$out
"@;
            }


	        send-mailmessage -from $from -to $to -subject $subject -body $body -smtpserver $smtpServer;
	        Write-Debug "Mail was sent";
        }
        $PrevQcount = $Qcount;
	}
    start-sleep -seconds $delay;
}