require 'rflow/message'

class RFlow
  class Connection
    attr_accessor :instance_uuid, :name, :configuration, :recv_callback

    # Attribute that holds the 
    attr_accessor :recv_callback
    
    def initialize(connection_instance_uuid, connection_name=nil, connection_configuration={})
      @instance_uuid = connection_instance_uuid
      @name = connection_name
      @configuration = connection_configuration
    end


    # Subclass and implement to be able to handle future 'recv'
    # methods.  Will only be called in the context of a running
    # EventMachine reactor
    def connect_input!
      raise NotImplementedError, "Raw connections do not support connect_input.  Please subclass and define a connect_output method."
    end


    # Subclass and implement to be able to handle future 'send'
    # methods.  Will only be called in the context of a running
    # EventMachine reactor
    def connect_output!
      raise NotImplementedError, "Raw connections do not support connect_output.  Please subclass and define a connect_output method."
    end

    
    # Subclass and implement to handle outgoing messages.  The message
    # will be a RFlow::Message object and the subclasses are expected
    # to marshal it up into something that will be unmarshalled on the
    # other side
    def send_message(message)
      raise NotImplementedError, "Raw connections do not support send_message.  Please subclass and define a send_message method."
    end

    # Parent component will set this attribute if it expects to
    # recieve messages.  Connection subclass should call it
    # (recv_callback.call(message)) when it gets a new message, which
    # will be transmitted back to the parent component's
    # process_message method.  Sublcass is responsible for
    # deserializing whatever was on the wire into a RFlow::Message object
    def recv_callback
      @recv_callback ||= Proc.new {|message|}
    end
    
  end # class Connection

  class Disconnection < Connection
    def send_message(message)
      RFlow.logger.debug "Attempting to send without a connection, doing nothing"
    end
  end
  
end # class RFlow