module Yrpc
  module Controllers

    class Request

      attr_reader :message
      # @var [GRPC::ActiveCall] active_call
      attr_reader :active_call
      # @var [Symbol] method_key
      attr_reader :method_key
      # @var [Grpc::Controllers::Request::Type] type
      attr_reader :type
      # @var [Class] service
      attr_reader :service

      delegate :metadata, to: :active_call
      delegate :messages, :client_streamer?, :server_streamer?, :bidi_streamer?, :request_response?, to: :type

      ##
      # Abstract representation of a gRPC request type
      #
      class Type
        delegate :client_streamer?, :server_streamer?, :bidi_streamer?, :request_response?, to: :@rpc_desc

        ##
        # Initialize a new request type object
        #
        # @param [GRPC::RpcDesc] rpc_desc The RPC descriptor for the request type
        #
        def initialize(rpc_desc)
          @rpc_desc = rpc_desc
        end
      end

      ##

      #struct GRPC::RpcDesc
      def initialize(method_key:, service:, rpc_desc:, active_call:, message:)
        @method_key = method_key
        @service = service
        @active_call = active_call
        @message = message
        @rpc_desc = rpc_desc
        @type = Type.new(rpc_desc)
      end


      def service_key
        @service.name.underscore.tr('/', '.').gsub('.service', '')
      end

      def method_missing(method_id, *arguments, &block)
        method_message = *arguments.join
        if (method_id.to_s =~ /^raise_[\w]+/) == 0
          error_type = method_id.to_s.split('raise_')[1].upcase!
          code = "Yrpc::Response::Code::#{error_type}".constantize
          message = method_message
          raise Yrpc::Error::ResponseError.new(code, message)
        else
          super
        end
      end


      def response_class
        @rpc_desc.output
      end


      def request_class
        @rpc_desc.input
      end

      # grpc 中的 service.method
      def method_name
        "#{service_key}.#{method_key}"
      end

      # 返回这个request的所有mesage 要根据stremer类型来判断
      def messages
        if client_streamer?
          message.call { |msg| yield msg }
        elsif bidi_streamer?
          message
        else
          [message]
        end
      end
    end
  end
end