#---------define Functions----------

###############################################################
# GetPools() #
# Gets an array of pools from the GTM.
# The F5 must be initialized before calling this script. #
# $return string[]
###############################################################

function GetPools() {
	$list = (Get-F5.iControl).GlobalLBPool.get_list();
	return $list;
}

###############################################################
# GetMembers() #
# Gets the Members in the Pool provided and returns an Array of Members #
# @param string $Pool Name of the Pool to get Members
# @return iControl.CommonIPPortDefinition[] #
###############################################################

function GetMembers() {
	param([string]$Pool);
	$Members = (get-f5.icontrol).GlobalLBPool.get_member((,$Pool));

	$MemberA = $Members[0]; return $MemberA;
}

###############################################################
# GetMemberState() #
# Pass in a member. Then it receives the state of that member. #
# @param iControl.CommonIPPortDefinition[] Member, string Pool
# @return string #
###############################################################

function GetMemberState() {
param([iControl.CommonIPPortDefinition[]]$Member, [string]$Pool);

	$PoolA = (, $Pool); #Set Pool [iControl.CommonIPPortDefinition[][]]
	$MemberAofA = [iControl.CommonIPPortDefinition[][]](, $Member); #Set Object F5 is expecting
	$EnabledStateAofA = (Get-F5.iControl).GlobalLBPoolMember.get_enabled_state($PoolA, $MemberAofA)
	$EnabledStateA = $EnabledStateAofA[0]; #Get first object value

	foreach($EnabledState in $EnabledStateA) {
		$state = $EnabledState.state; #loop through Memers and get State
	}
	return [string]$state #return the state of the member passed in
}

#-----------Main Application-------------

$SnapinSet = Get-PSSnapin | select-string -Quiet -Pattern "iControlSnapin"

if(!$SnapinSet) { #check to see iControlSnapin has been added
	#if it hasn't been added then add it
	Add-PSSnapin iControlSnapin
}

#attempt to initilize connection to the correct IP
if(Initialize-f5.icontrol -hostname 1.1.1.1 -Username username -password password) {
	start-transcript -Path "Log.txt" -Append -Force #log output

	$Pools = GetPools

	$DisabledState = $FALSE
          $DisabledNodes = @()

	foreach($Pool in $Pools) #loop through pools {
		$Pool = [string]$Pool

		$Members = GetMembers -Pool $Pool

		#loop through members in a pool
		foreach($Mem in $Members) {
			$addr = $Mem.member.address;
			$port = $Mem.member.port;

			$MemberDef = New-Object -TypeName iControl.CommonIPPortDefinition;
			#set object
			$MemberDef.address = $addr
			$MemberDef.port = $port
			[iControl.CommonIPPortDefinition[]]$MembersA = [iControl.CommonIPPortDefinition[]](, $MemberDef)
			$state = GetMemberState -Member $MembersA -Pool $Pool
			#get state of the member
			if($state -eq "STATE_DISABLED") {
				#if member is disabled add it to the output to send in an email
				$Node = "${addr}:${port}"
				$DisabledNodes += "$Pool -> $Node"
				$DisabledState = $TRUE
			}
		}
	}

	if($DisabledState) {
		#if a disabled member has been found
		$Content = "The following nodes are disabled:"
		write-host "the following are disabled"

		foreach($Node in $DisabledNodes) {
			write-host $Node $Content += "$Node " #create html content to send in an email
		}

		#send email
		Send-MailMessage -To "<a href="mailto:to@example.com">to@example.com</a>" -From "<a href="mailto:from@example.com">from@example.com</a>" -subject "Nodes Disabled In GTM" -body "$Content" -bodyashtml -smtpServer 1.1.1.1

	}
	stop-transcript #stop logging
}
else {
	write-host "Critical Error Has Occurred. Cannot Initialize iControl" #if connection to F5 fails produce error
}