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 decode_body(body)
  if body.respond_to?(:to_str) && body.length >= 2
     decode body, :symbolize_keys => true
  else
    body
  end
end

def initialize(response)
  @http_headers = response[:response_headers]
  message = parse_response(response)
  super(message)
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
    if error.kind_of?(Hash)
      error[:message]
    else
      error
    end
  elsif body[:message]
    body[:message]
  else
    ''
  end
end

def parse_response(response)
  body = parse_body(response[:body])
  "#{response[:method].to_s.upcase} #{response[:url].to_s}: #{response[:status]} #{body}"
end