Add a cancel job button

If you schedule a job you might change your mind or circumstances might
change. So you need to be able to cancel it. This commit adds a button
on the job page which hits the `…/cancel` API endpoint for a job.

app/main/views/jobs.py

@@ -12,7 +12,8 @@ from flask import (
     jsonify,
     request,
     url_for,
-    current_app
+    current_app,
+    redirect
 )
 from flask_login import login_required
 from werkzeug.datastructures import MultiDict
@@ -147,6 +148,14 @@ def view_job_csv(service_id, job_id):
     )
 
 
+@main.route("/services/<service_id>/jobs/<job_id>", methods=['POST'])
+@login_required
+@user_has_permissions('send_texts', 'send_emails', 'send_letters', admin_override=True)
+def cancel_job(service_id, job_id):
+    job_api_client.cancel_job(service_id, job_id)
+    return redirect(url_for('main.service_dashboard', service_id=service_id))
+
+
 @main.route("/services/<service_id>/jobs/<job_id>.json")
 @login_required
 @user_has_permissions('view_activity', admin_override=True)

app/notify_client/job_api_client.py

@@ -77,3 +77,18 @@ class JobApiClient(BaseAPIClient):
             job['data']['notifications_requested'] = stats['requested']
 
         return job
+
+    def cancel_job(self, service_id, job_id):
+
+        job = self.post(
+            url='/service/{}/job/{}/cancel'.format(service_id, job_id),
+            data={}
+        )
+
+        stats = self.__convert_statistics(job['data'])
+        job['data']['notifications_sent'] = stats['delivered'] + stats['failed']
+        job['data']['notifications_delivered'] = stats['delivered']
+        job['data']['notifications_failed'] = stats['failed']
+        job['data']['notifications_requested'] = stats['requested']
+
+        return job

app/templates/partials/jobs/notifications.html

@@ -1,4 +1,5 @@
 {% from "components/table.html" import list_table, field, right_aligned_field_heading, date_field, row_heading %}
+{% from "components/page-footer.html" import page_footer %}
 
 <div class="ajax-block-container">
   {% if job.job_status == 'scheduled' %}
@@ -6,6 +7,14 @@
     <p>
       Sending will start at {{ job.scheduled_for|format_time }}
     </p>
+    <div class="page-footer">
+      <form method="post">
+        {{ page_footer(
+          button_text="Cancel sending",
+          destructive=True
+        ) }}
+      </form>
+    </div>
 
   {% else %}