module Sprockets::Loader

def load(uri)
  unloaded = UnloadedAsset.new(uri, self)
  if unloaded.params.key?(:id)
    unless asset = asset_from_cache(unloaded.asset_key)
      id = unloaded.params.delete(:id)
      uri_without_id = build_asset_uri(unloaded.filename, unloaded.params)
      asset = load_from_unloaded(UnloadedAsset.new(uri_without_id, self))
      if asset[:id] != id
        @logger.warn "Sprockets load error: Tried to find #{uri}, but latest was id #{asset[:id]}"
      end
    end
  else
    asset = fetch_asset_from_dependency_cache(unloaded) do |paths|
      # When asset is previously generated, its "dependencies" are stored in the cache.
      # The presence of `paths` indicates dependencies were stored.
      # We can check to see if the dependencies have not changed by "resolving" them and
      # generating a digest key from the resolved entries. If this digest key has not
      # changed the asset will be pulled from cache.
      #
      # If this `paths` is present but the cache returns nothing then `fetch_asset_from_dependency_cache`
      # will confusingly be called again with `paths` set to nil where the asset will be
      # loaded from disk.
      if paths
        digest = DigestUtils.digest(resolve_dependencies(paths))
        if uri_from_cache = cache.get(unloaded.digest_key(digest), true)
          asset_from_cache(UnloadedAsset.new(uri_from_cache, self).asset_key)
        end
      else
        load_from_unloaded(unloaded)
      end
    end
  end
  Asset.new(self, asset)
end