MT#18409 - /api/customerbalances add filter by domain

Change-Id: Iaffb91d261fdd39431c8563616113c223c9e1cd6

lib/NGCP/Panel/Controller/API/CustomerBalances.pm

@@ -73,6 +73,21 @@ sub query_params {
                 second => sub {},
             },
         },
+        {
+            param => 'domain',
+            description => 'Filter for contracts with subscribers belonging to a specific domain',
+            query => {
+                first => sub {
+                    my $q = shift;
+                    { 'domain.domain' => { '=' => $q } };
+                },
+                second => sub {
+                    { join => { voip_subscribers => 'domain' },
+                      distinct => 1,
+                    };
+                },
+            },
+        },
     ];
 }