Add network reporting method

urlchecker_network.py

 import socket
 import errno
+from peewee import fn
 
 TIMEOUT = 2
 
 
+def reportNetwork(db, ip=None, transport=None, port=None):
+    # http://charlesleifer.com/blog/techniques-for-querying-lists-of-objects-and-determining-the-top-related-item/
+    NetworkChangeAlias = db.NetworkChange.alias()
+
+    subquery = (
+        NetworkChangeAlias.select(
+            NetworkChangeAlias.ip,
+            NetworkChangeAlias.transport,
+            NetworkChangeAlias.port,
+            fn.MAX(NetworkChangeAlias.status_id).alias("max_status_id"),
+        )
+        .group_by(
+            NetworkChangeAlias.ip,
+            NetworkChangeAlias.transport,
+            NetworkChangeAlias.port,
+        )
+        .alias("network_change_max_subquery")
+    )
+
+    StatusAlias = db.Status.alias()
+
+    query = (
+        db.NetworkChange.select(db.NetworkChange, StatusAlias)
+        .join(StatusAlias)
+        .switch(db.NetworkChange)
+        .join(
+            subquery,
+            on=(
+                (db.NetworkChange.status_id == subquery.c.max_status_id)
+                & (db.NetworkChange.ip == subquery.c.ip)
+                & (db.NetworkChange.transport == subquery.c.transport)
+                & (db.NetworkChange.port == subquery.c.port)
+            ),
+        )
+        .order_by(
+            db.NetworkChange.ip.asc(),
+            db.NetworkChange.port.asc(),
+            db.NetworkChange.transport.asc(),
+        )
+    )
+
+    if transport is not None:
+        if type(transport) == list:
+            query = query.where(db.NetworkChange.transport << transport)
+        else:
+            query = query.where(db.NetworkChange.transport == transport)
+    if port is not None:
+        query = query.where(db.NetworkChange.port == port)
+    if ip is not None:
+        if type(ip) == list:
+            query = query.where(db.NetworkChange.ip << ip)
+        else:
+            query = query.where(db.NetworkChange.ip == ip)
+    return query
+
+
 def logNetwork(db, ip, transport, port, state, status_id):
 
     with db._db.atomic():
         try:
             # Check previous parameter value
-            previous_entry = (
-                db.NetworkChange.select()
-                .where(
-                    db.NetworkChange.ip == ip,
-                    db.NetworkChange.transport == transport,
-                    db.NetworkChange.port == port,
-                )
-                .order_by(db.NetworkChange.status.desc())
-                .get()
-            )
+            previous_entry = reportNetwork(
+                db, ip=ip, transport=transport, port=port
+            ).get()
         except db.NetworkChange.DoesNotExist:
             previous_entry = None