[UK] Fix broken boundary in May 2016 Boundary-Line

mapit_gb/management/commands/mapit_UK_fix_2016-05.py

@@ -0,0 +1,47 @@
+# This script is to be run as a one-off to fix up some geometries in the May
+# 2016 edition of Boundary-Line that are incorrect.
+
+from optparse import make_option
+from django.core.management.base import NoArgsCommand
+from mapit.models import Area, CodeType, Generation, Geometry
+
+
+class Command(NoArgsCommand):
+    help = 'Fix the UK Boundary-Line import for May 2016'
+    option_list = NoArgsCommand.option_list + (
+        make_option('--commit', action='store_true', dest='commit', help='Actually update the database'),
+    )
+
+    code_version = CodeType.objects.get(code='gss')
+
+    def get_area(self, code):
+        area = Area.objects.get(codes__code=code, codes__type=self.code_version)
+        assert area.polygons.count() == 1
+        return area
+
+    def get_generation_prior_to_current(self):
+        latest_on = Generation.objects.filter(active=True).order_by('-id')
+        if latest_on:
+            return latest_on[1]
+        return None
+
+    def handle_noargs(self, **options):
+        # The area that has been included as Cheriton and Bishops Sutton should
+        # be part of Alresford & Itchen Valley.
+        area_to_add_to = self.get_area('E05010995')  # Alresford & Itchen Valley
+        area_to_remove = self.get_area('E05004654')  # Cheriton and Bishops Sutton
+
+        self.stdout.write('Copying the area of %s to %s' % (area_to_remove, area_to_add_to))
+        polygon = area_to_remove.polygons.all()[0]
+        polygon_copy = Geometry(area=area_to_add_to, polygon=polygon.polygon)
+
+        lower_generation = self.get_generation_prior_to_current()
+        self.stdout.write('Setting the generation_high of %s to %s' % (area_to_remove, lower_generation))
+        area_to_remove.generation_high = lower_generation
+        if lower_generation is None:
+            self.stdout.write('Only one generation, so setting generation_low to None too')
+            area_to_remove.generation_low = None
+
+        if options['commit']:
+            polygon_copy.save()
+            area_to_remove.save()