Make the broadcast flow talk to the API

This commit removes the code the puts areas into the session and instead
creates and then updates a draft broadcast in the database.

This is so we can avoid session-related bugs, and potentially having a
large session when we start adding personalisation etc.

Once a broadcast is ready to go it is set to `broadcasting` straight
away with no approval. We’ll revisit this as we learn more about how
users might want to manage who can create and approve broadcasts.

The tests are a bit light in terms of checking what’s on the page, but
clicking through the pages is probably good enough for now.

app/main/views/broadcast.py

@@ -1,11 +1,9 @@
-from flask import redirect, render_template, request, session, url_for
-from notifications_utils.broadcast_areas import broadcast_area_libraries
-from notifications_utils.template import BroadcastPreviewTemplate
-from orderedset import OrderedSet
+from flask import redirect, render_template, request, url_for
 
 from app import current_service
 from app.main import main
 from app.main.forms import BroadcastAreaForm, SearchByNameForm
+from app.models.broadcast_message import BroadcastMessage
 from app.utils import service_has_permission, user_has_permissions
 
 
@@ -18,63 +16,63 @@ def broadcast_dashboard(service_id):
     )
 
 
-@main.route('/services/<uuid:service_id>/broadcast')
+@main.route('/services/<uuid:service_id>/broadcast/<uuid:template_id>')
 @user_has_permissions('send_messages')
 @service_has_permission('broadcast')
-def broadcast(service_id):
-    if 'broadcast_areas' in session:
-        session.pop('broadcast_areas')
+def broadcast(service_id, template_id):
     return redirect(url_for(
         '.preview_broadcast_areas',
         service_id=current_service.id,
+        broadcast_message_id=BroadcastMessage.create(
+            service_id=service_id,
+            template_id=template_id,
+        ).id,
     ))
 
 
-@main.route('/services/<uuid:service_id>/broadcast/areas')
+@main.route('/services/<uuid:service_id>/broadcast/<uuid:broadcast_message_id>/areas')
 @user_has_permissions('send_messages')
 @service_has_permission('broadcast')
-def preview_broadcast_areas(service_id):
-    selected_areas_ids = session.get('broadcast_areas', [])
+def preview_broadcast_areas(service_id, broadcast_message_id):
     return render_template(
         'views/broadcast/preview-areas.html',
-        selected=list(broadcast_area_libraries.get_areas(
-            *selected_areas_ids
-        )),
-        area_polygons=broadcast_area_libraries.get_polygons_for_areas_lat_long(
-            *selected_areas_ids
-        )
-    )
-
-
-@main.route('/services/<uuid:service_id>/broadcast/libraries')
-@user_has_permissions('send_messages')
-@service_has_permission('broadcast')
-def choose_broadcast_library(service_id):
-    return render_template(
-        'views/broadcast/libraries.html',
-        libraries=broadcast_area_libraries,
-        selected=broadcast_area_libraries.get_areas(
-            *session.get('broadcast_areas', [])
+        broadcast_message=BroadcastMessage.from_id(
+            broadcast_message_id,
+            service_id=current_service.id,
         ),
     )
 
 
-@main.route('/services/<uuid:service_id>/broadcast/libraries/<library_slug>', methods=['GET', 'POST'])
+@main.route('/services/<uuid:service_id>/broadcast/<uuid:broadcast_message_id>/libraries')
 @user_has_permissions('send_messages')
 @service_has_permission('broadcast')
-def choose_broadcast_area(service_id, library_slug):
-    library = broadcast_area_libraries.get(library_slug)
+def choose_broadcast_library(service_id, broadcast_message_id):
+    return render_template(
+        'views/broadcast/libraries.html',
+        libraries=BroadcastMessage.libraries,
+        broadcast_message_id=broadcast_message_id,
+    )
+
+
+@main.route(
+    '/services/<uuid:service_id>/broadcast/<uuid:broadcast_message_id>/libraries/<library_slug>',
+    methods=['GET', 'POST'],
+)
+@user_has_permissions('send_messages')
+@service_has_permission('broadcast')
+def choose_broadcast_area(service_id, broadcast_message_id, library_slug):
+    broadcast_message = BroadcastMessage.from_id(
+        broadcast_message_id,
+        service_id=current_service.id,
+    )
+    library = BroadcastMessage.libraries.get(library_slug)
     form = BroadcastAreaForm.from_library(library)
     if form.validate_on_submit():
-        if not session.get('broadcast_areas'):
-            session['broadcast_areas'] = []
-        session['broadcast_areas'] = session['broadcast_areas'] + form.areas.data
-        session['broadcast_areas'] = list(OrderedSet(
-            session['broadcast_areas']
-        ))
+        broadcast_message.add_areas(*form.areas.data)
         return redirect(url_for(
             '.preview_broadcast_areas',
             service_id=current_service.id,
+            broadcast_message_id=broadcast_message.id,
         ))
     return render_template(
         'views/broadcast/areas.html',
@@ -85,35 +83,41 @@ def choose_broadcast_area(service_id, library_slug):
     )
 
 
-@main.route('/services/<uuid:service_id>/broadcast/remove/<area_slug>')
+@main.route('/services/<uuid:service_id>/broadcast/<uuid:broadcast_message_id>/remove/<area_slug>')
 @user_has_permissions('send_messages')
 @service_has_permission('broadcast')
-def remove_broadcast_area(service_id, area_slug):
-    session['broadcast_areas'] = list(filter(
-        lambda saved_area_id: saved_area_id != area_slug,
-        session.get('broadcast_areas', []),
-    ))
-
+def remove_broadcast_area(service_id, broadcast_message_id, area_slug):
+    BroadcastMessage.from_id(
+        broadcast_message_id,
+        service_id=current_service.id,
+    ).remove_area(
+        area_slug
+    )
     return redirect(url_for(
         '.preview_broadcast_areas',
         service_id=current_service.id,
+        broadcast_message_id=broadcast_message_id,
     ))
 
 
-@main.route('/services/<uuid:service_id>/broadcast/preview', methods=['GET', 'POST'])
+@main.route(
+    '/services/<uuid:service_id>/broadcast/<uuid:broadcast_message_id>/preview',
+    methods=['GET', 'POST'],
+)
 @user_has_permissions('send_messages')
 @service_has_permission('broadcast')
-def preview_broadcast_message(service_id):
+def preview_broadcast_message(service_id, broadcast_message_id):
+    broadcast_message = BroadcastMessage.from_id(
+        broadcast_message_id,
+        service_id=current_service.id,
+    )
     if request.method == 'POST':
-        return 'OK'
-    selected_areas = session.get('broadcast_areas', [])
+        broadcast_message.start_broadcast()
+        return redirect(url_for(
+            '.broadcast_dashboard',
+            service_id=current_service.id,
+        ))
     return render_template(
         'views/broadcast/preview-message.html',
-        selected=list(broadcast_area_libraries.get_areas(
-            *selected_areas
-        )),
-        template=BroadcastPreviewTemplate({
-            'content': 'Message here',
-            'template_type': 'broadcast',
-        })
+        broadcast_message=broadcast_message,
     )