module Protobuf::Rpc::Connectors::Common

def any_callbacks?
  return [@complete_cb, @failure_cb, @success_cb].inject(false) do |reduction, cb|
    reduction = (reduction || !cb.nil?)
  end
end

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

def data_callback(data)
  log_debug { sign_message('Using data_callback') }
  @used_data_callback = true
  @data = data
end

def fail(code, message)
  @error =  ClientError.new
  @error.code = code.is_a?(Symbol) ? Protobuf::Socketrpc::ErrorReason.values[code] : code
  @error.message = message
  log_debug { sign_message("Server failed request (invoking on_failure): #{@error.inspect}") }
  @failure_cb.call(@error) unless @failure_cb.nil?
rescue => e
  log_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)
  fail(: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
  log_debug { sign_message("Parsing response from server (connection closed)") }
  # Parse out the raw response
  response_wrapper = Protobuf::Socketrpc::Response.new
  response_wrapper.parse_from_string(@response_data)
  # Determine success or failure based on parsed data
  if response_wrapper.has_field?(:error_reason)
    log_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)
    fail(response_wrapper.error_reason, response_wrapper.error)
  else
    log_debug { sign_message("Successful response parsed") }
    # Ensure client_response is an instance
    response_type = @options[:response_type].new
    parsed = response_type.parse_from_string(response_wrapper.response_proto.to_s)
    if parsed.nil? and not response_wrapper.has_field?(:error_reason)
      fail(: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
  fail(:RPC_ERROR, "Connection error: #{e.message}")
end

def rpc_request_data
  validate_request_type
  return Protobuf::Socketrpc::Request.new(
    :service_name => @options[:service].name,
    :method_name => @options[:method].to_s,
    :request_proto => @options[:request].serialize_to_string
  ).serialize_to_string
rescue => e
  fail(:INVALID_REQUEST_PROTO, "Could not set request proto: #{e.message}")
end

def setup_connection
  initialize_stats
  @request_data = rpc_request_data
end

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

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

def verify_callbacks
  if !any_callbacks?
    log_debug { sign_message("No callbacks set, using data_callback") }
    @success_cb = @failure_cb = self.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|
    fail(:RPC_ERROR, "Invalid client connection configuration. #{opt} must be a defined option.") if @options[opt].nil?
  end
end