broadcast-areas: create broadcast areas in groups

Signed-off-by: Toby Lorne <toby.lornewelch-richards@digital.cabinet-office.gov.uk>

notifications_utils/broadcast_areas/create-broadcast-areas-db.py

@@ -1,15 +1,26 @@
 #!/usr/bin/env python
 
 from copy import deepcopy
+import sqlite3
 import geojson
 from pathlib import Path
 import shapely.geometry as sgeom
 
+from notifications_utils.safe_string import make_string_safe_for_id
+
 from repo import BroadcastAreasRepository
 
 package_path = Path(__file__).resolve().parent
 
 
+def convert_shape_to_feature(shape):
+    return {
+        "type": "Feature",
+        "properties": {},
+        "geometry": sgeom.mapping(shape),
+    }
+
+
 def simplify_polygon(series):
     polygon, *_holes = series  # discard holes
 
@@ -26,7 +37,7 @@ def simplify_polygon(series):
         simplified_polygon = [[c[0], c[1]] for c in simplified_polygon.exterior.coords]
 
         num_polys = len(simplified_polygon)
-        simplify_degrees *= 1.5
+        simplify_degrees *= 1.75
         if num_polys <= 125:
             break
 
@@ -53,22 +64,30 @@ repo.delete_db()
 repo.create_tables()
 
 simple_datasets = [
-    ("Countries", "ctry19nm"),
-    ("Regions of England", "rgn18nm"),
-    ("Counties and Unitary Authorities in England and Wales", "ctyua16nm"),
+    ("Countries", "ctry19cd", "ctry19nm"),
+    ("Regions of England", "rgn18cd", "rgn18nm"),
+    ("Counties and Unitary Authorities in England and Wales", "ctyua16cd", "ctyua16nm"),
 ]
-for dataset_name, name_field in simple_datasets:
+for dataset_name, id_field, name_field in simple_datasets:
     filepath = package_path / "{}.geojson".format(dataset_name)
+
+    dataset_id = make_string_safe_for_id(dataset_name)
     dataset_geojson = geojson.loads(filepath.read_text())
 
-    repo.insert_broadcast_area_library(dataset_name)
+    repo.insert_broadcast_area_library(dataset_id, dataset_name, False)
 
     for feature in dataset_geojson["features"]:
+        f_id = dataset_id + "-" + feature["properties"][id_field]
         f_name = feature["properties"][name_field]
 
         simple_feature = deepcopy(feature)
         simple_feature["geometry"] = simplify_geometry(simple_feature["geometry"])
-        repo.insert_broadcast_areas([[f_name, dataset_name, feature, simple_feature]])
+
+        repo.insert_broadcast_areas([[
+            f_id, f_name,
+            dataset_id, None,
+            feature, simple_feature,
+        ]])
 
 # https://geoportal.statistics.gov.uk/datasets/wards-may-2020-boundaries-uk-bgc
 # Converted to geojson manually from SHP because of GeoJSON download limits
@@ -81,28 +100,73 @@ ward_code_to_la_mapping = {
     f["properties"]["WD19CD"]: f["properties"]["LAD19NM"]
     for f in geojson.loads(las_filepath.read_text())["features"]
 }
+ward_code_to_la_id_mapping = {
+    f["properties"]["WD19CD"]: f["properties"]["LAD19CD"]
+    for f in geojson.loads(las_filepath.read_text())["features"]
+}
 
 dataset_name = "Electoral Wards of the United Kingdom"
-repo.insert_broadcast_area_library(dataset_name)
+dataset_id = make_string_safe_for_id(dataset_name)
+repo.insert_broadcast_area_library(dataset_id, dataset_name, True)
+
+for f in geojson.loads(las_filepath.read_text())["features"]:
+    group_id = dataset_id + "-" + f["properties"]["LAD19CD"]
+    group_name = f["properties"]["LAD19NM"]
+
+    try:
+        repo.insert_broadcast_area_library_group(group_id, group_name, dataset_id)
+    except sqlite3.IntegrityError:
+        # Already exists
+        pass
 
 areas_to_add = []
 
 for f in geojson.loads(wards_filepath.read_text())["features"]:
-
     ward_code = f["properties"]["wd20cd"]
     ward_name = f["properties"]["wd20nm"]
+    ward_id = dataset_id + "-" + ward_code
 
     try:
+        la_id = dataset_id + "-" + ward_code_to_la_id_mapping[ward_code]
         la_name = ward_code_to_la_mapping[ward_code]
 
-        f_name = "{} - {}".format(la_name, ward_name)
-
         sf = deepcopy(f)
         sf["geometry"] = simplify_geometry(sf["geometry"])
 
-        areas_to_add.append([f_name, dataset_name, f, sf])
+        areas_to_add.append([
+            ward_id, ward_name,
+            dataset_id, la_id,
+            f, sf
+        ])
 
     except KeyError:
         print("Skipping", ward_code, ward_name)  # noqa: T001
 
 repo.insert_broadcast_areas(areas_to_add)
+areas_to_add = []
+
+for group_id, group_name in repo.get_all_groups_for_library(dataset_id):
+    areas = repo.get_all_areas_for_group(group_id)
+
+    features = [geojson.loads(f) for _, _, f, _ in areas]
+    shapes = [sgeom.shape(f["geometry"]) for f in features]
+
+    if len(shapes) == 0:
+        continue
+
+    print(group_id, group_name, "union")
+    shape = shapes[0]
+    for other in shapes[1:]:
+        shape = shape.buffer(0).union(other.buffer(0))
+
+    feature = convert_shape_to_feature(shape)
+    simple_feature = deepcopy(feature)
+    simple_feature["geometry"] = simplify_geometry(simple_feature["geometry"])
+
+    areas_to_add.append([
+        group_id, group_name,
+        dataset_id, None,
+        feature, simple_feature
+    ])
+
+repo.insert_broadcast_areas(areas_to_add)