Switch to using the local copy of the MapIt Area data

To avoid having to fetch data from MapIt every time the server is
started, we can use the area JSON in the repository. (The MapIt
data changes very occasionally, and usually as a result of manual
intervention to update it or make a fix, so not getting a live
copy every time shouldn't cause problems.)

This also enables us to simplify the code quite significantly.

app.rb

@@ -22,7 +22,6 @@
 set :content_dir, File.join(__dir__, 'prose')
 set :datasource, ENV.fetch('DATASOURCE', 'https://github.com/everypolitician/everypolitician-data/raw/master/countries.json')
 set :index, EveryPolitician::Index.new(index_url: settings.datasource)
-set :mapit_url, 'http://nigeria.mapit.mysociety.org/areas/'
 set :twitter_user, 'NGShineyoureye'
 
 # Create a wrapper for the mappings between the various IDs we have
@@ -42,10 +41,10 @@
 
 # Create a wrapper that caches MapIt and EveryPolitician area data:
 mapit = Mapit::Wrapper.new(
-  mapit_url: settings.mapit_url,
   mapit_mappings: mapit_mappings,
   baseurl: '/place/',
-  area_types: %w(FED SEN STA)
+  area_types: %w(FED SEN STA),
+  data_directory: 'mapit'
 )
 
 # Assemble data on the members of the various legislatures we support:

lib/mapit/wrapper.rb

@@ -1,15 +1,14 @@
 # frozen_string_literal: true
-require 'net/http'
 require_relative 'place'
 
 module Mapit
   class Wrapper
 
-    def initialize(mapit_url:, mapit_mappings:, baseurl:, area_types:)
-      @mapit_url = mapit_url
+    def initialize(mapit_mappings:, baseurl:, area_types:, data_directory:)
       @baseurl = baseurl
       @area_types = area_types
       @mapit_mappings = mapit_mappings
+      @data_directory = data_directory
       cache_mapit_data
       set_up_parent_child_relationships
     end
@@ -29,20 +28,27 @@ def places_of_type(area_type)
 
     private
 
-    attr_reader :mapit_url,
-                :mapit_mappings,
+    attr_reader :mapit_mappings,
                 :baseurl,
                 :id_to_place,
                 :area_types,
-                :type_to_places
+                :type_to_places,
+                :data_directory
 
     def places(area_type)
       areas_data(area_type).map { |a| create_place(a) }
     end
 
+    def mapit_area_cache_filename(area_type)
+      File.join(data_directory, "#{area_type}.json")
+    end
+
+    def parse_json_file(filename)
+      JSON.parse(open(filename, &:read))
+    end
+
     def areas_data(area_type)
-      uri = URI(mapit_url + area_type)
-      JSON.parse(Net::HTTP.get(uri)).values
+      parse_json_file(mapit_area_cache_filename(area_type)).values
     end
 
     def cache_mapit_data

tests/mapit/wrapper.rb

@@ -4,10 +4,10 @@
 
 describe 'Mappit::Wrapper' do
   let(:mapit) { Mapit::Wrapper.new(
-    mapit_url: mapit_url,
     mapit_mappings: FakeMappings.new,
     baseurl: '/baseurl/',
-    area_types: %w(FED SEN STA)
+    area_types: %w(FED SEN STA),
+    data_directory: 'mapit'
   ) }
 
   describe 'when getting the states' do

tests/test_helper.rb

@@ -32,9 +32,6 @@ def app
       get_from_disk(DATASOURCE, countries_json)
       get_from_disk(reps_json_url, reps_json)
       get_from_disk(senate_json_url, senate_json)
-      get_from_disk("#{mapit_url}STA", mapit_data_for_area_type('STA'))
-      get_from_disk("#{mapit_url}FED", mapit_data_for_area_type('FED'))
-      get_from_disk("#{mapit_url}SEN", mapit_data_for_area_type('SEN'))
     end
 
     def new_tempfile(contents, filename = 'sye-tests')
@@ -48,10 +45,6 @@ def basic_document(filename)
       Document::MarkdownWithFrontmatter.new(filename: filename, baseurl: 'irrelevant')
     end
 
-    def mapit_url
-      'http://nigeria.mapit.mysociety.org/areas/'
-    end
-
     def nigeria_at_known_revision
       @ng ||= EveryPolitician::Index.new(index_url: DATASOURCE).country('Nigeria')
     end