class Aws::Rest::Request::Body

def apply(http_req, params)
  body = build_body(params)
  # for rest-json, ensure we send at least an empty object
  # don't send an empty object for streaming? case.
  if body.nil? &&
     json_builder? &&
     modeled_body? &&
     !streaming?
    body = '{}'
  end
  http_req.body = body
end

def body_params(params)
  @rules.shape.members.inject({}) do |hash, (member_name, member_ref)|
    if !member_ref.location && params.key?(member_name)
      hash[member_name] = params[member_name]
    end
    hash
  end
end

def build_body(params)
  if streaming?
    params[@rules[:payload]]
  elsif @rules[:payload]
    params = params[@rules[:payload]]
    if params
      if xml_builder? &&
         @rules.shape.member?(@rules[:payload_member].location_name)
        # serializing payload member name for rest-xml is as follows:
        # 1. Use the member locationName if the member value doesn't match the member's name (default)
        # 2. Use the value of the locationName on the member's target if present
        # 3. Use the shape name of the member's target
        serialize(@rules[:payload_member], params, location_name: payload_location_name)
      else
        serialize(@rules[:payload_member], params)
      end
    end
  else
    params = body_params(params)
    serialize(@rules, params) unless params.empty?
  end
end

def initialize(serializer_class, rules)
  @serializer_class = serializer_class
  @rules = rules
end

def json_builder?
  @serializer_class == Json::Builder
end

def modeled_body?
  return true if @rules[:payload]
  @rules.shape.members.each do |member|
    _name, shape = member
    return true if shape.location.nil?
  end
  false
end

def payload_location_name
  @rules[:payload_member].shape['locationName'] ||
    @rules[:payload_member].shape.name
end

def serialize(rules, params, location_name: nil)
  @serializer_class.new(rules, location_name: location_name).serialize(params)
end

def streaming?
  @rules[:payload] && (
    BlobShape === @rules[:payload_member].shape ||
    StringShape === @rules[:payload_member].shape
  )
end

def xml_builder?
  @serializer_class == Xml::Builder
end