Fix show.receiver statistics.

Use current time for calculations,
not the start-time of celery.

ogn/commands/showreceiver.py

@@ -1,26 +1,29 @@
 from datetime import datetime, timedelta
-
 from sqlalchemy.sql import func
 from sqlalchemy import distinct, and_
 
 from ogn.model import ReceiverBeacon, Receiver
-
 from ogn.commands.dbutils import session
 
-back_24h = datetime.utcnow() - timedelta(days=1)
-receiver_messages_per_24h = 24 * 60 / 5
-
 from manager import Manager
 manager = Manager()
 
+receiver_beacons_per_day = 24 * 60 / 5
+
 
 @manager.command
 def list_all():
     """Show a list of all receivers."""
-    sq = session.query(distinct(ReceiverBeacon.name).label('name'), func.max(ReceiverBeacon.timestamp).label('lastseen'), func.count(ReceiverBeacon.name).label('messages_count')).\
-        filter(ReceiverBeacon.timestamp > back_24h).\
-        group_by(ReceiverBeacon.name).\
-        subquery()
+
+    timestamp_24h_ago = datetime.utcnow() - timedelta(days=1)
+
+    sq = session.query(
+            distinct(ReceiverBeacon.name).label('name'),
+            func.max(ReceiverBeacon.timestamp).label('lastseen'),
+            func.count(ReceiverBeacon.name).label('messages_count')).\
+        filter(ReceiverBeacon.timestamp > timestamp_24h_ago).\
+            group_by(ReceiverBeacon.name).\
+            subquery()
 
     query = session.query(Receiver, sq.c.messages_count).\
         filter(Receiver.name == sq.c.name).\
@@ -28,14 +31,21 @@ def list_all():
 
     print('--- Receivers ---')
     for [receiver, messages_count] in query.all():
-        print('%9s (%2s): %3d%% avail, %s, %s ' % (receiver.name, receiver.country_code, 100.0*float(messages_count/receiver_messages_per_24h), receiver.version, receiver.platform))
+        print('%9s (%2s): %3d%% avail, %s, %s ' % (receiver.name,
+                                                   receiver.country_code,
+                                                   100.0 * float(messages_count / receiver_beacons_per_day),
+                                                   receiver.version,
+                                                   receiver.platform))
 
 
 @manager.command
 def software_stats():
     """Show some statistics of receiver software."""
+
+    timestamp_24h_ago = datetime.utcnow() - timedelta(days=1)
+
     sq = session.query(ReceiverBeacon.name, func.max(ReceiverBeacon.timestamp).label('lastseen')).\
-        filter(ReceiverBeacon.timestamp > back_24h).\
+        filter(ReceiverBeacon.timestamp > timestamp_24h_ago).\
         group_by(ReceiverBeacon.name).\
         subquery()
 
@@ -52,8 +62,11 @@ def software_stats():
 @manager.command
 def hardware_stats():
     """Show some statistics of receiver hardware."""
+
+    timestamp_24h_ago = datetime.utcnow() - timedelta(days=1)
+
     sq = session.query(ReceiverBeacon.name, func.max(ReceiverBeacon.timestamp).label('lastseen')).\
-        filter(ReceiverBeacon.timestamp > back_24h).\
+        filter(ReceiverBeacon.timestamp > timestamp_24h_ago).\
         group_by(ReceiverBeacon.name).\
         subquery()