class ActiveFedora::CachingConnection

def cache
  old, @cache_enabled = @cache_enabled, true
  yield
ensure
  @cache_enabled = old
  clear_cache unless @cache_enabled
end

def cache_resource(url, &block)
  result =
    if @cache.key?(url)
       ActiveSupport::Notifications.instrument("ldp.active_fedora",
                                               id: url, name: "CACHE", ldp_service: object_id)
       @cache[url]
    else
      @cache[url] = log(url) { yield }
    end
  result.dup
end

def clear_cache
  @cache.clear
end

def disable_cache!
  @cache_enabled = false
end

def enable_cache!
  @cache_enabled = true
end

def get(url, options = {})
  if @cache_enabled
    cache_resource(url) { super }
  else
    super
  end
end

def initialize(host)
  super
  @cache = {}
  @cache_enabled = false
end

def log(url)
  ActiveSupport::Notifications.instrument("ldp.active_fedora",
           id: url, name: "Load LDP", ldp_service: object_id) { yield }
end

def patch(*)
  clear_cache if @cache_enabled
  super
end

def post(*)
  clear_cache if @cache_enabled
  super
end

def put(*)
  clear_cache if @cache_enabled
  super
end

def uncached
  old, @cache_enabled = @cache_enabled, false
  yield
ensure
  @cache_enabled = old
end