class Github::Error::ServiceError

def self.errors
  @errors ||= Hash[
    descendants.map { |klass| [klass.new({}).http_status_code, klass] }
  ]
end

def self.http_status_code(code)
  define_method(:http_status_code) { code }
end

def create_message(response)
  "#{response[:method].to_s.upcase} #{response[:url]}: #{@status} #{@body}"
end

def decode_body(body)
  if body.respond_to?(:to_str) && body.length >= MIN_BODY_LENGTH
    JSON.parse(body, symbolize_names: true)
  else
    body
  end
end

def initialize(response)
  @http_headers = response[:response_headers]
  @body         = parse_body(response[:body])
  @status       = response[:status]
  super(create_message(response))
end

def parse_body(body)
  body = decode_body(body)
  return '' if body.nil? || body.empty?
  if body[:error]
    body[:error]
  elsif body[:errors]
    error = Array(body[:errors]).first
    error.is_a?(Hash) ? error[:message] : error
  elsif body[:message]
    body[:message]
  else
    ''
  end
end