Show monthly usage by SMS provider on Providers page

This adds a '% monthly traffic' column to the SMS table on the Providers page
to let us see how much traffic is being sent to each SMS provider.

app/main/views/providers.py

@@ -22,6 +22,8 @@ def view_providers():
         elif provider['notification_type'] == 'email':
             domestic_email_providers.append(provider)
 
+    add_monthly_traffic(domestic_sms_providers)
+
     return render_template(
         'views/providers/providers.html',
         email_providers=domestic_email_providers,
@@ -30,6 +32,17 @@ def view_providers():
     )
 
 
+def add_monthly_traffic(domestic_sms_providers):
+    total_sms_sent = sum(provider.get('current_month_billable_sms', 0) for provider in domestic_sms_providers)
+
+    for provider in domestic_sms_providers:
+        if provider.get('current_month_billable_sms'):
+            percentage = (provider['current_month_billable_sms'] / total_sms_sent * 100) if total_sms_sent else 0
+            provider['monthly_traffic'] = round(percentage)
+        else:
+            provider['monthly_traffic'] = 0
+
+
 @main.route("/provider/<provider_id>/edit", methods=['GET', 'POST'])
 @login_required
 @user_is_platform_admin

app/templates/views/providers/providers.html

@@ -17,7 +17,7 @@ Providers
       caption="Domestic SMS providers",
       caption_visible=False,
       empty_message='No domestic sms providers',
-      field_headings=['Provider', 'Priority', 'Active', 'Last Updated', 'Updated By'],
+      field_headings=['Provider', 'Priority', '% monthly traffic', 'Active', 'Last Updated', 'Updated By'],
       field_headings_visible=True
   ) %}
 
@@ -25,6 +25,8 @@ Providers
 
       {{ text_field(item.priority) }}
 
+      {{ text_field(item.monthly_traffic) }}
+
       {{ text_field(item.active) }}
 
       {% if item.updated_at %}