add timestamp of moment when the file is included in a nonstop zone

nonstop/migrations/0009_track_added_to_nonstop_timestamp.py

+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('nonstop', '0008_track_uploader'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='track',
+            name='added_to_nonstop_timestamp',
+            field=models.DateTimeField(null=True),
+        ),
+    ]

nonstop/models.py

@@ -5,6 +5,7 @@ import mutagen
 from django.conf import settings
 from django.core.urlresolvers import reverse
 from django.db import models
+from django.utils.timezone import now
 from django.utils.translation import ugettext_lazy as _
 
 REMOTE_BASE_PATH = '/srv/soma/nonstop/'
@@ -58,6 +59,7 @@ class Track(models.Model):
     nonstop_zones = models.ManyToManyField('emissions.Nonstop', blank=True)
 
     creation_timestamp = models.DateTimeField(auto_now_add=True, null=True)
+    added_to_nonstop_timestamp = models.DateTimeField(null=True)
     uploader = models.ForeignKey(settings.AUTH_USER_MODEL, null=True)
 
     class Meta:
@@ -80,11 +82,19 @@ class Track(models.Model):
             return False
 
     def sync_nonstop_zones(self):
+        current_zones = self.nonstop_zones.all()
+        if current_zones.count():
+            if not self.added_to_nonstop_timestamp:
+                self.added_to_nonstop_timestamp = now()
+                self.save()
+        else:
+            self.added_to_nonstop_timestamp = None
+            self.save()
+
         if not self.file_exists():
             return
         nonstop_file = self.nonstopfile_set.order_by('creation_timestamp').last()
         filename = nonstop_file.filename
-        current_zones = self.nonstop_zones.all()
         from emissions.models import Nonstop
 
         for zone in Nonstop.objects.all():