Make a job model for individual jobs

This follows the pattern of what we’ve done with services, users and
events.

It gives us a better interface to the data we get back from the API than
dealing with the raw JSON directly.

Now is a good time to do this because we’re going to be making a bunch
of changes to the jobs pages, and those changes will be easier to code
and understand with a sesnsible model behind them.

app/models/job.py

@@ -0,0 +1,159 @@
+from datetime import datetime
+
+from notifications_utils.letter_timings import (
+    CANCELLABLE_JOB_LETTER_STATUSES,
+    get_letter_timings,
+    letter_can_be_cancelled,
+)
+from werkzeug.utils import cached_property
+
+from app.models import JSONModel
+from app.notify_client.job_api_client import job_api_client
+from app.notify_client.notification_api_client import notification_api_client
+from app.notify_client.service_api_client import service_api_client
+from app.utils import set_status_filters
+
+
+class Job(JSONModel):
+
+    ALLOWED_PROPERTIES = {
+        'id',
+        'service',
+        'template',
+        'template_version',
+        'original_file_name',
+        'created_at',
+        'notification_count',
+        'notifications_sent',
+        'notifications_requested',
+        'job_status',
+        'statistics',
+        'created_by',
+        'scheduled_for',
+    }
+
+    @classmethod
+    def from_id(cls, job_id, service_id):
+        return cls(job_api_client.get_job(service_id, job_id)['data'])
+
+    @property
+    def status(self):
+        return self.job_status
+
+    @property
+    def cancelled(self):
+        return self.status == 'cancelled'
+
+    @property
+    def scheduled(self):
+        return self.status == 'scheduled'
+
+    @property
+    def notification_count(self):
+        return self._dict.get('notification_count', 0)
+
+    @property
+    def notifications_delivered(self):
+        return self._dict.get('notifications_delivered', 0)
+
+    @property
+    def notifications_failed(self):
+        return self._dict.get('notifications_failed', 0)
+
+    @property
+    def notifications_processed(self):
+        return self.notifications_delivered + self.notifications_failed
+
+    @property
+    def notifications_sending(self):
+        if self.scheduled:
+            return 0
+        return (
+            self.notification_count -
+            self.notifications_delivered -
+            self.notifications_failed
+        )
+
+    @property
+    def notifications_created(self):
+        return notification_api_client.get_notification_count_for_job_id(
+            service_id=self.service, job_id=self.id
+        )
+
+    @property
+    def still_processing(self):
+        return (
+            self.status != 'finished' or
+            self.notifications_created < self.notification_count
+        )
+
+    @property
+    def template_id(self):
+        return self._dict['template']
+
+    @cached_property
+    def template(self):
+        return service_api_client.get_service_template(
+            service_id=self.service,
+            template_id=self.template_id,
+            version=self.template_version,
+        )['data']
+
+    @property
+    def template_type(self):
+        return self.template['template_type']
+
+    @property
+    def percentage_complete(self):
+        return self.notifications_requested / self.notification_count * 100
+
+    @property
+    def letter_job_can_be_cancelled(self):
+
+        if self.template['template_type'] != 'letter':
+            return False
+
+        if any(self.uncancellable_notifications):
+            return False
+
+        if not letter_can_be_cancelled(
+            'created', datetime.strptime(self.created_at[:-6], '%Y-%m-%dT%H:%M:%S.%f')
+        ):
+            return False
+
+        return True
+
+    @cached_property
+    def all_notifications(self):
+        return self.get_notifications(set_status_filters({}))['notifications']
+
+    @property
+    def uncancellable_notifications(self):
+        return (
+            n for n in self.all_notifications
+            if n['status'] not in CANCELLABLE_JOB_LETTER_STATUSES
+        )
+
+    @cached_property
+    def postage(self):
+        # There might be no notifications if the job has only just been
+        # created and the tasks haven't run yet
+        try:
+            return self.all_notifications[0]['postage']
+        except IndexError:
+            return self.template['postage']
+
+    @property
+    def letter_timings(self):
+        return get_letter_timings(self.created_at, postage=self.postage)
+
+    def get_notifications(self, status):
+        return notification_api_client.get_notifications_for_service(
+            self.service, self.id, status=status,
+        )
+
+    def cancel(self):
+        if self.template_type == 'letter':
+            return job_api_client.cancel_letter_job(self.service, self.id)
+        else:
+            return job_api_client.cancel_job(self.service, self.id)