module RailsLiveReload
  ENV_FILE = Rails.root.join('.env').to_s
  ENV_SAMPLE_FILE = Rails.root.join('.env.sample').to_s
  INITIALIZER = Rails.root.join('config/initializers/hot_changes.rb').to_s
  CHECKSUMS = {} # rubocop:disable Style/MutableConstant

  # MonkeyPath Watcher
  class Watcher
    def initialize
      @files = {}
      @sockets = []

      # puts "Watching: #{root}"
      # RailsLiveReload.patterns.each do |pattern, rule|
      #   puts "  #{pattern} => #{rule}"
      # end

      build_tree
      start_socket
      start_listener
    end

    def reload_all
      before_reload(files)
      data = { event: RailsLiveReload::INTERNAL[:socket_events][:reload], files: }.to_json
      @sockets.each { |socket, _| socket.puts data } # rubocop:disable Style/HashEachMethods
    end

    private

    def before_reload(files)
      perform_when_change(files, ENV_SAMPLE_FILE) { Hot::Constants.load_definitions }
      perform_when_change(files, ENV_FILE) { Hot::Constants.load_values }
      perform_when_change(files, INITIALIZER) { load Rails.root.join('config', 'initializers', 'hot_changes.rb') }
    end

    def perform_when_change(files, key, &)
      return unless files.include?(key)

      current_checksum = files[key]
      return unless current_checksum != CHECKSUMS[key]

      yield
      CHECKSUMS[key] = current_checksum
    end
  end
end