Files
notifications-admin/app/models/broadcast_message.py
Chris Hill-Scott 969e7a6dbd Show how a broadcast will overspill selected area
Broadcasting is not a precise technology, because:
- cell towers are directional
- their range varies depending on whether they are 2, 3, 4, or 5G
  (the higher the bandwidth the shorter the range)
- in urban areas the towers are more densely packed, so a phone is
  likely to have a greater choice of tower to connect to, and will
  favour a closer one (which has a stronger signal)
- topography and even weather can affect the range of a tower

So it’s good for us to visually indicate that the broadcast is not as
precise as the boundaries of the area, because it gives the person
sending the message an indication of how the technology works.

At the same time we have a restriction on the number of polygons we
think and area can have, so we’ve done some work to make versions of
polygons which are simplified and buffered (see
https://github.com/alphagov/notifications-utils/pull/769 for context).

Serendipitously, the simplified and buffered polygons are larger and
smoother than the detailed polygons we’ve got from the GeoJSON files. So
they naturally give the impression of covering an area which is wider
and less precise.

So this commit takes those simple polygons and uses them to render the
blue fill. This makes the blue fill extend outside the black stroke,
which is still using the detailed polygons direct from the GeoJSON.
2020-08-13 11:20:49 +01:00

184 lines
4.9 KiB
Python

from datetime import datetime
from notifications_utils.template import BroadcastPreviewTemplate
from orderedset import OrderedSet
from shapely.geometry import MultiPolygon, Polygon
from shapely.ops import unary_union
from werkzeug.utils import cached_property
from app.broadcast_areas import broadcast_area_libraries
from app.models import JSONModel, ModelList
from app.models.user import User
from app.notify_client.broadcast_message_api_client import (
broadcast_message_api_client,
)
from app.notify_client.service_api_client import service_api_client
class BroadcastMessage(JSONModel):
ALLOWED_PROPERTIES = {
'id',
'service_id',
'template_id',
'template_name',
'template_version',
'service_id',
'created_by',
'personalisation',
'starts_at',
'finishes_at',
'created_at',
'approved_at',
'cancelled_at',
'updated_at',
'created_by_id',
'approved_by_id',
'cancelled_by_id',
}
libraries = broadcast_area_libraries
def __lt__(self, other):
return (
self.cancelled_at or self.finishes_at
) < (
other.cancelled_at or other.finishes_at
)
@classmethod
def create(cls, *, service_id, template_id):
return cls(broadcast_message_api_client.create_broadcast_message(
service_id=service_id,
template_id=template_id,
))
@classmethod
def from_id(cls, broadcast_message_id, *, service_id):
return cls(broadcast_message_api_client.get_broadcast_message(
service_id=service_id,
broadcast_message_id=broadcast_message_id,
))
@property
def areas(self):
return broadcast_area_libraries.get_areas(
*self._dict['areas']
)
@property
def initial_area_names(self):
return [
area.name for area in self.areas
][:10]
@property
def polygons(self):
return broadcast_area_libraries.get_polygons_for_areas_lat_long(
*self._dict['areas']
)
@property
def simple_polygons(self):
simple_polygons = broadcast_area_libraries.get_simple_polygons_for_areas_lat_long(
*self._dict['areas']
)
unioned_polygons = unary_union([
Polygon(i) for i in simple_polygons
])
if isinstance(unioned_polygons, MultiPolygon):
return [
[
[x, y] for x, y in p.exterior.coords
]
for p in unioned_polygons
]
return [[
[x, y] for x, y in unioned_polygons.exterior.coords
]]
@property
def template(self):
response = service_api_client.get_service_template(
self.service_id,
self.template_id,
version=self.template_version,
)
return BroadcastPreviewTemplate(response['data'])
@property
def status(self):
if (
self._dict['status']
and self._dict['status'] == 'broadcasting'
and self.finishes_at < datetime.utcnow().isoformat()
):
return 'completed'
return self._dict['status']
@cached_property
def created_by(self):
return User.from_id(self.created_by_id)
@cached_property
def approved_by(self):
return User.from_id(self.approved_by_id)
@cached_property
def cancelled_by(self):
return User.from_id(self.cancelled_by_id)
def add_areas(self, *new_areas):
self._update(areas=list(OrderedSet(
self._dict['areas'] + list(new_areas)
)))
def remove_area(self, area_to_remove):
self._update(areas=[
area for area in self._dict['areas']
if area != area_to_remove
])
def _set_status_to(self, status):
broadcast_message_api_client.update_broadcast_message_status(
status,
broadcast_message_id=self.id,
service_id=self.service_id,
)
def _update(self, **kwargs):
broadcast_message_api_client.update_broadcast_message(
broadcast_message_id=self.id,
service_id=self.service_id,
data=kwargs,
)
def request_approval(self, until):
self._update(
finishes_at=until,
)
self._set_status_to('pending-approval')
def approve_broadcast(self):
self._update(
starts_at=datetime.utcnow().isoformat(),
)
self._set_status_to('broadcasting')
def reject_broadcast(self):
self._set_status_to('rejected')
def cancel_broadcast(self):
self._set_status_to('cancelled')
class BroadcastMessages(ModelList):
model = BroadcastMessage
client_method = broadcast_message_api_client.get_broadcast_messages
def with_status(self, *statuses):
return [
broadcast for broadcast in self if broadcast.status in statuses
]