module Percy
  module Capybara
    module Loaders
      class BaseLoader
        # Modified version of Diego Perini's URL regex. https://gist.github.com/dperini/729294
        URL_REGEX = Regexp.new(
          # protocol identifier
          "((?:https?:)?//)" +
          "(" +
            # IP address exclusion
            # private & local networks
            "(?!(?:10|127)(?:\\.\\d{1,3}){3})" +
            "(?!(?:169\\.254|192\\.168)(?:\\.\\d{1,3}){2})" +
            "(?!172\\.(?:1[6-9]|2\\d|3[0-1])(?:\\.\\d{1,3}){2})" +
            # IP address dotted notation octets
            # excludes loopback network 0.0.0.0
            # excludes reserved space >= 224.0.0.0
            # excludes network & broacast addresses
            # (first & last IP address of each class)
            "(?:[1-9]\\d?|1\\d\\d|2[01]\\d|22[0-3])" +
            "(?:\\.(?:1?\\d{1,2}|2[0-4]\\d|25[0-5])){2}" +
            "(?:\\.(?:[1-9]\\d?|1\\d\\d|2[0-4]\\d|25[0-4]))" +
          "|" +
            # host name
            "(?:(?:[a-z\\u00a1-\\uffff0-9]-*)*[a-z\\u00a1-\\uffff0-9]+)" +
            # domain name
            "(?:\\.(?:[a-z\\u00a1-\\uffff0-9]-*)*[a-z\\u00a1-\\uffff0-9]+)*" +
          ")" +
          # port number
          "(:\\d{2,5})?" +
          # resource path
          "(/[^\\s\"']*)?"
        )

        attr_reader :page

        # @param [Capybara::Session] page The Capybara page.
        def initialize(options = {})
          @page = options[:page]
        end

        def build_resources
          raise NotImplementedError.new('subclass must implement abstract method')
        end

        def snapshot_resources
          raise NotImplementedError.new('subclass must implement abstract method')
        end

        # @private
        def root_html_resource
          Percy::Client::Resource.new(
            current_path, is_root: true, mimetype: 'text/html', content: page.html)
        end

        # Transformed version of the current URL to be a relative path.
        # This important because Rack::Test uses "www.example.com" as the actual current URL,
        # which would force Percy to actually render example.com instead of the page. By always
        # using a URL path as the resource URL, we guarantee that Percy will render what it's given.
        #
        # @private
        def current_path
          current_url = page.current_url
          url_match = URL_REGEX.match(current_url)
          return url_match[4] if url_match
          current_url
        end
      end
    end
  end
end