class Middleman::CoreExtensions::Data

def after_configuration
  return unless @original_data_dir != app.config[:data_dir]
  @watcher.update_path(app.config[:data_dir])
end

def data
  extensions[:data].data_store
end

def initialize(app, config={}, &block)
  super
  @data_store = DataStore.new(app, DATA_FILE_MATCHER)
  app.config.define_setting :data_dir, 'data', 'The directory data files are stored in'
  app.add_to_instance(:data, &method(:data_store))
  app.add_to_config_context(:data, &method(:data_store))
  start_watching(app.config[:data_dir])
end

def start_watching(dir)
  @original_data_dir = dir
  # Tell the file watcher to observe the :data_dir
  @watcher = app.files.watch :data,
                             path: File.join(app.root, dir),
                             ignore: proc { |f| !DATA_FILE_MATCHER.match(f[:relative_path]) }
  # Setup data files before anything else so they are available when
  # parsing config.rb
  app.files.on_change(:data, &@data_store.method(:update_files))
end