module Roda::RodaPlugins::Assets::RequestClassMethods

def _asset_regexp(type, key, digest)
  "#{key.sub(/\A#{type}/, '')}.#{digest}.#{type}"
end

def assets_matchers
  @assets_matchers ||= [:css, :js].map do |t|
    if regexp = assets_regexp(t)
      [t, regexp].freeze
    end
  end.compact.freeze
end

def assets_regexp(type)
  o = roda_class.assets_opts
  if compiled = o[:compiled]
    assets = compiled.
      select{|k,_| k =~ /\A#{type}/}.
      map{|k, md| _asset_regexp(type, k, md)}
    return if assets.empty?
    /#{o[:"compiled_#{type}_prefix"]}(#{Regexp.union(assets)})/
  else
    return unless assets = o[type]
    assets = unnest_assets_hash(assets)
    ts = o[:timestamp_paths]
    /#{o[:"#{type}_prefix"]}#{"\\d+#{ts}" if ts}(#{Regexp.union(assets.uniq)})#{o[:"#{type}_suffix"]}/
  end
end

def unnest_assets_hash(h)
  case h
  when Hash
    h.map do |k,v|
      assets = unnest_assets_hash(v)
      assets = assets.map{|x| "#{k}/#{x}"} if roda_class.assets_opts[:group_subdirs]
      assets
    end.flatten(1)
  else
    Array(h)
  end
end