class Middleman::Extensions::AssetHash

def after_configuration
  # Allow specifying regexes to ignore, plus always ignore apple touch icons
  @ignore = Array(options.ignore) + [/^apple-touch-icon/]
  app.use Middleware, exts: options.exts, middleman_app: app, ignore: @ignore
end

def ignored_resource?(resource)
  @ignore.any? { |ignore| Middleman::Util.path_match(ignore, resource.destination_path) }
end

def initialize(app, options_hash={}, &block)
  super
  require 'digest/sha1'
  require 'rack/test'
  require 'uri'
end

def manipulate_resource_list(resources)
  @rack_client ||= ::Rack::Test::Session.new(app.class.to_rack_app)
  # Process resources in order: binary images and fonts, then SVG, then JS/CSS.
  # This is so by the time we get around to the text files (which may reference
  # images and fonts) the static assets' hashes are already calculated.
  resources.sort_by do |a|
    if %w(.svg).include? a.ext
      0
    elsif %w(.js .css).include? a.ext
      1
    else
      -1
    end
  end.each(&method(:manipulate_single_resource))
end

def manipulate_single_resource(resource)
  return unless options.exts.include?(resource.ext)
  return if ignored_resource?(resource)
  return if resource.ignored?
  # Render through the Rack interface so middleware and mounted apps get a shot
  response = @rack_client.get(URI.escape(resource.destination_path), {},  'bypass_asset_hash' => 'true')
  raise "#{resource.path} should be in the sitemap!" unless response.status == 200
  digest = Digest::SHA1.hexdigest(response.body)[0..7]
  resource.destination_path = resource.destination_path.sub(/\.(\w+)$/) { |ext| "-#{digest}#{ext}" }
end