module Protobuf::Rpc::Connectors::Common

def any_callbacks?
  [@complete_cb, @failure_cb, @success_cb].any?
end

def complete
  @stats.stop
  logger.info { @stats.to_s }
  logger.debug { sign_message('Response proceessing complete') }
  @complete_cb.call(self) unless @complete_cb.nil?
rescue => e
  logger.error { sign_message('Complete callback error encountered') }
  log_exception(e)
  raise
end

def data_callback(data)
  logger.debug { sign_message('Using data_callback') }
  @used_data_callback = true
  @data = data
end

def failure(code, message)
  @error = ClientError.new
  @error.code = Protobuf::Socketrpc::ErrorReason.fetch(code)
  @error.message = message
  logger.debug { sign_message("Server failed request (invoking on_failure): #{@error.inspect}") }
  @failure_cb.call(@error) unless @failure_cb.nil?
rescue => e
  logger.error { sign_message("Failure callback error encountered") }
  log_exception(e)
  raise
ensure
  complete
end

def initialize_stats
  @stats = ::Protobuf::Rpc::Stat.new(:CLIENT)
  @stats.server = [@options[:port], @options[:host]]
  @stats.service = @options[:service].name
  @stats.method_name = @options[:method].to_s
rescue => ex
  log_exception(ex)
  failure(:RPC_ERROR, "Invalid stats configuration. #{ex.message}")
end

def log_signature
  @_log_signature ||= "[client-#{self.class}]"
end

def parse_response
  # Close up the connection as we no longer need it
  close_connection
  logger.debug { sign_message("Parsing response from server (connection closed)") }
  # Parse out the raw response
  @stats.response_size = @response_data.size unless @response_data.nil?
  response_wrapper = Protobuf::Socketrpc::Response.decode(@response_data)
  # Determine success or failure based on parsed data
  if response_wrapper.field?(:error_reason)
    logger.debug { sign_message("Error response parsed") }
    # fail the call if we already know the client is failed
    # (don't try to parse out the response payload)
    failure(response_wrapper.error_reason, response_wrapper.error)
  else
    logger.debug { sign_message("Successful response parsed") }
    # Ensure client_response is an instance
    parsed = @options[:response_type].decode(response_wrapper.response_proto.to_s)
    if parsed.nil? && !response_wrapper.field?(:error_reason)
      failure(:BAD_RESPONSE_PROTO, 'Unable to parse response from server')
    else
      verify_callbacks
      succeed(parsed)
      return @data if @used_data_callback
    end
  end
end

def post_init
  send_data unless error?
rescue => e
  failure(:RPC_ERROR, "Connection error: #{e.message}")
end

def request_bytes
  validate_request_type!
  fields = { :service_name => @options[:service].name,
             :method_name => @options[:method].to_s,
             :request_proto => @options[:request],
             :caller => request_caller }
  return ::Protobuf::Socketrpc::Request.encode(fields)
rescue => e
  failure(:INVALID_REQUEST_PROTO, "Could not set request proto: #{e.message}")
end

def request_caller
  @options[:client_host] || ::Protobuf.client_host
end

def setup_connection
  initialize_stats
  @request_data = request_bytes
  @stats.request_size = request_bytes.size
end

def succeed(response)
  logger.debug { sign_message("Server succeeded request (invoking on_success)") }
  @success_cb.call(response) unless @success_cb.nil?
rescue => e
  logger.error { sign_message("Success callback error encountered") }
  log_exception(e)
  failure(:RPC_ERROR, "An exception occurred while calling on_success: #{e.message}")
ensure
  complete
end

def timeout
  if options[:timeout]
    options[:timeout]
  else
    300 # seconds
  end
end

def timeout_wrap(&block)
  ::Timeout.timeout(timeout, &block)
rescue ::Timeout::Error
  failure(:RPC_FAILED, "The server took longer than #{timeout} seconds to respond")
end

def validate_request_type!
  unless @options[:request].class == @options[:request_type]
    expected = @options[:request_type].name
    actual = @options[:request].class.name
    failure(:INVALID_REQUEST_PROTO, "Expected request type to be type of #{expected}, got #{actual} instead")
  end
end

def verify_callbacks
  unless any_callbacks?
    logger.debug { sign_message("No callbacks set, using data_callback") }
    @success_cb = @failure_cb = method(:data_callback)
  end
end

def verify_options!
  # Verify the options that are necessary and merge them in
  [:service, :method, :host, :port].each do |opt|
    failure(:RPC_ERROR, "Invalid client connection configuration. #{opt} must be a defined option.") if @options[opt].nil?
  end
end