module HTTP
  module Protocol
    class Request
      class RequestLineParser
        def self.call(*args)
          instance = new *args
          instance.()
        end

        ACTIONS = %w(OPTIONS GET HEAD POST PUT DELETE TRACE CONNECT PATCH)
        REQUEST_LINE_REGEX = %r{^(?<action>#{ACTIONS * "|"}) (?<path>.*) HTTP/1\.1\r}

        attr_reader :request_line

        def initialize(request_line)
          @request_line = request_line
        end

        def call
          action, path = match_line
          Request.new action, path
        end

        def match_line
          match = REQUEST_LINE_REGEX.match request_line
          unless match
            raise Error.new "Invalid request line #{request_line.inspect}"
          end
          match.to_a.tap &:shift
        end
      end
    end
  end
end