class Google::Cloud::Error

def self.from_error error
  klass = if error.respond_to? :code
            grpc_error_class_for error.code
          elsif error.respond_to? :status_code
            gapi_error_class_for error.status_code
          else
            self
          end
  klass.new error.message
end

def self.gapi_error_class_for http_status_code
  # The http status codes mapped to their error classes.
  {
    400 => InvalidArgumentError, # FailedPreconditionError/OutOfRangeError
    401 => UnauthenticatedError,
    403 => PermissionDeniedError,
    404 => NotFoundError,
    409 => AlreadyExistsError, # AbortedError
    412 => FailedPreconditionError,
    429 => ResourceExhaustedError,
    499 => CanceledError,
    500 => InternalError, # UnknownError/DataLossError
    501 => UnimplementedError,
    503 => UnavailableError,
    504 => DeadlineExceededError
  }[http_status_code] || self
end

def self.grpc_error_class_for grpc_error_code
  # The gRPC status code 0 is for a successful response.
  # So there is no error subclass for a 0 status code, use current class.
  [
    self, CanceledError, UnknownError, InvalidArgumentError,
    DeadlineExceededError, NotFoundError, AlreadyExistsError,
    PermissionDeniedError, ResourceExhaustedError,
    FailedPreconditionError, AbortedError, OutOfRangeError,
    UnimplementedError, InternalError, UnavailableError, DataLossError,
    UnauthenticatedError
  ][grpc_error_code] || self
end

def body
  return nil unless cause && cause.respond_to?(:body)
  cause.body
end

def code
  return nil unless cause && cause.respond_to?(:code)
  cause.code
end

def details
  return nil unless cause && cause.respond_to?(:details)
  cause.details
end

def header
  return nil unless cause && cause.respond_to?(:header)
  cause.header
end

def initialize msg = nil
  super
  @cause = $ERROR_INFO
end

def metadata
  return nil unless cause && cause.respond_to?(:metadata)
  cause.metadata
end

def status_code
  return nil unless cause && cause.respond_to?(:status_code)
  cause.status_code
end

def status_details
  return nil unless cause && cause.respond_to?(:status_details)
  cause.status_details
end