#!/bin/bash

for host in `xe host-list | grep ^uuid | awk '{print $NF}'`; do 
  for pif in `xe pif-list host-uuid=$host | grep -v VLAN.*-1 | grep -B 3 VLAN | grep ^uuid | awk '{print $NF}'`; do 
    networkuuid=`xe pif-list uuid=$pif | grep network-uuid | awk '{print $NF}'`; 
    count=`xe vif-list network-uuid=$networkuuid | grep ^uuid | wc -l`; 
    if [ $count -eq 0 ]; then
      vlan=`xe vlan-list | grep -B 2 $pif | grep ^uuid |  awk '{print $NF}'`; 
      if [ -n "$vlan" ]; then
        echo "Destroy free VLAN on host $host: $vlan";
        xe vlan-destroy uuid=$vlan 
      fi
    else
      for vm in `xe vif-list network-uuid=$networkuuid | grep vm-uuid | awk '{print $NF}'`; do
        resident=`xe vm-param-get param-name=resident-on uuid=$vm`;
        vlan=`xe vlan-list | grep -B 2 $pif | grep ^uuid | awk '{print $NF}'`;
        if [ "$resident" = "$host" ]; then
          echo "VLAN in used by vm $vm: $vlan";
        else
          echo "VLAN in used by vm $vm on host $resident: $vlan"; 
        fi
        break;
      done
    fi
    sleep 2; 
  done
done