class Aws::Rest::Response::Headers

def apply(http_resp, target)
  headers = http_resp.headers
  @rules.shape.members.each do |name, ref|
    case ref.location
    when 'header' then extract_header_value(headers, name, ref, target)
    when 'headers' then extract_header_map(headers, name, ref, target)
    end
  end
end

def cast_value(ref, value)
  value = extract_json_trait(value) if ref['jsonvalue']
  case ref.shape
  when StringShape then value
  when IntegerShape then value.to_i
  when FloatShape then value.to_f
  when BooleanShape then value == 'true'
  when ListShape then
    value.split(",").map { |v| cast_value(ref.shape.member, v) }
  when TimestampShape
    if value =~ /^\d+(\.\d*)/
      Time.at(value.to_f)
    elsif value =~ /^\d+$/
      Time.at(value.to_i)
    else
      begin
        Time.parse(value)
      rescue
        nil
      end
    end
  else raise "unsupported shape #{ref.shape.class}"
  end
end

def extract_header_map(headers, name, ref, data)
  data[name] = {}
  prefix = ref.location_name || ''
  headers.each do |header_name, header_value|
    if match = header_name.match(/^#{prefix}(.+)/i)
      data[name][match[1]] = header_value
    end
  end
end

def extract_header_value(headers, name, ref, data)
  if headers.key?(ref.location_name)
    data[name] = cast_value(ref, headers[ref.location_name])
  end
end

def extract_json_trait(value)
  Aws::Json.load(Base64.decode64(value))
end

def initialize(rules)
  @rules = rules
end