module Devise
  class TaggedLogging
    def initialize(app)
      @app = app
    end

    def call(env)
      if logger.respond_to?(:tagged)
        logger.tagged(compute_devise_tags(env)) { @app.call(env) }
      else
        @app.call(env)
      end
    end

    private

    def compute_devise_tags(env)
      warden = env['warden']
      Devise.mappings.keys.map do |scope|
        if record = warden.user(scope: scope)
          ["current #{scope}", record.to_key].join(": ")
        end
      end.compact
    end

    def logger
      Rails.logger
    end
  end
end