module Sprockets::Server

def call(env)
  start_time = Time.now.to_f
  time_elapsed = lambda { ((Time.now.to_f - start_time) * 1000).to_i }
  msg = "Served asset #{env['PATH_INFO']} -"
  # Mark session as "skipped" so no `Set-Cookie` header is set
  env['rack.session.options'] ||= {}
  env['rack.session.options'][:defer] = true
  env['rack.session.options'][:skip] = true
  # Extract the path from everything after the leading slash
  path = unescape(env['PATH_INFO'].to_s.sub(/^\//, ''))
  # URLs containing a `".."` are rejected for security reasons.
  if forbidden_request?(path)
    return forbidden_response
  end
  # Strip fingerprint
  if fingerprint = path_fingerprint(path)
    path = path.sub("-#{fingerprint}", '')
  end
  # Look up the asset.
  asset = find_asset(path, :bundle => !body_only?(env))
  # `find_asset` returns nil if the asset doesn't exist
  if asset.nil?
    logger.info "#{msg} 404 Not Found (#{time_elapsed.call}ms)"
    # Return a 404 Not Found
    not_found_response
  # Check request headers `HTTP_IF_NONE_MATCH` against the asset digest
  elsif etag_match?(asset, env)
    logger.info "#{msg} 304 Not Modified (#{time_elapsed.call}ms)"
    # Return a 304 Not Modified
    not_modified_response(asset, env)
  else
    logger.info "#{msg} 200 OK (#{time_elapsed.call}ms)"
    # Return a 200 with the asset contents
    ok_response(asset, env)
  end
rescue Exception => e
  logger.error "Error compiling asset #{path}:"
  logger.error "#{e.class.name}: #{e.message}"
  case content_type_of(path)
  when "application/javascript"
    # Re-throw JavaScript asset exceptions to the browser
    logger.info "#{msg} 500 Internal Server Error\n\n"
    return javascript_exception_response(e)
  when "text/css"
    # Display CSS asset exceptions in the browser
    logger.info "#{msg} 500 Internal Server Error\n\n"
    return css_exception_response(e)
  else
    raise
  end
end