private RestoreJobException toRestoreJobException()

in server/src/main/java/org/apache/cassandra/sidecar/restore/RestoreRangeTask.java [233:282]
40 lines of code
10 McCabe index (conditional complexity)

    private RestoreJobException toRestoreJobException(Throwable cause)
    {
        S3Exception s3Exception = ThrowableUtils.getCause(cause, S3Exception.class);
        if (s3Exception == null) // has non-null cause, but not S3Exception
        {
            return RestoreJobExceptions.ofFatal("Unexpected error when checking object existence", range, cause);
        }
        else if (s3Exception instanceof NoSuchKeyException)
        {
            return RestoreJobExceptions.of("Object not found", range, s3Exception.awsErrorDetails(), null);
        }
        // status code based handling
        else if (s3Exception.statusCode() == 400
                 && s3Exception.awsErrorDetails().errorCode().equalsIgnoreCase("ExpiredToken"))
        {
            metrics.tokenExpired.metric.update(1);
            // Fail the job if 400 and token has expired.
            // https://docs.aws.amazon.com/AmazonS3/latest/API/ErrorResponses.html#ErrorCodeList
            return RestoreJobExceptions.ofFatal("Token has expired", range, s3Exception.awsErrorDetails(), s3Exception);
        }
        else if (s3Exception.statusCode() == 403)
        {
            metrics.tokenUnauthorized.metric.update(1);
            // Fail immediately if 403 forbidden is returned.
            // There might be permission issue on accessing the object.
            return RestoreJobExceptions.ofFatal("Object access is forbidden", range, s3Exception.awsErrorDetails(), s3Exception);
        }
        else if (s3Exception.statusCode() == 404)
        {
            if (s3Exception.awsErrorDetails().errorCode().equalsIgnoreCase("NoSuchKey"))
            {
                return RestoreJobExceptions.of("Object not found", range, s3Exception.awsErrorDetails(), null);
            }
            else if (s3Exception.awsErrorDetails().errorCode().equalsIgnoreCase("NoSuchBucket"))
            {
                return RestoreJobExceptions.ofFatal("Bucket not found", range, s3Exception.awsErrorDetails(), null);
            }
        }
        else if (s3Exception.statusCode() == 412)
        {
            instanceMetrics.restore().sliceChecksumMismatches.metric.update(1);
            // When checksum/eTag does not match, it should be an unrecoverable error and fail immediately.
            // For such scenario, we expect "S3Exception: (Status Code: 412)". Also see,
            // https://docs.aws.amazon.com/AmazonS3/latest/API/API_HeadObject.html#API_HeadObject_RequestSyntax
            return RestoreJobExceptions.ofFatal("Object checksum mismatched", range, s3Exception.awsErrorDetails(), s3Exception);
        }

        // Retry the other S3Exceptions
        return RestoreJobExceptions.of("Unable to check object existence. ", range, s3Exception.awsErrorDetails(), s3Exception);
    }