SF Personalisation - GetUserSegment()

public static Segment GetUserSegment() {
    Segment firstMatchingSegment = null;
    var personalizationService = new PersonalizationService();
    var personalizationConfig = Config.Get<PersonalizationConfig>();
    var personalizationManager = PersonalizationManager.GetManager();
    var activeSegments = personalizationManager.GetSegments().Where(o => o.IsActive).OrderBy(o => o.Priority).ToList();

    //Reflection... :(
    var validateModuleItemMethod = typeof(SystemManager).GetMethod("ValidateModuleItem", BindingFlags.Static | BindingFlags.NonPublic);
    var isCriteriaMatchMethod = personalizationService.GetType().GetMethod("IsCriteriaMatch", BindingFlags.Instance | BindingFlags.NonPublic);
    var buildTestContextMethod = personalizationService.GetType().GetMethod("BuildTestContext", BindingFlags.Instance | BindingFlags.NonPublic);
    var testContext = buildTestContextMethod.Invoke(personalizationService, null) as IPersonalizationTestContext;

    //Test Segment is easy
    if (testContext.IsInTestMode && testContext.SelectedSegmentId != Guid.Empty) {
        return personalizationManager.GetSegments().SingleOrDefault(o => o.Id == testContext.SelectedSegmentId);
    }

    //Validate which segments are valid for assessment
    var validSegments = activeSegments.Where(
        segment => segment.CriteriaGroups.All(
            criteriaGroup => criteriaGroup.Criteria.All(
                criteria => {
                    var item = personalizationConfig.Criteria[criteria.CriterionName];
                    return item == null ? false : (bool)validateModuleItemMethod.Invoke(null, new[] { item });
                }
            )
        )
    );

    //Pick first matching (priority is set in the Sitefinity UI)
    firstMatchingSegment = validSegments.FirstOrDefault(
        segment => segment.CriteriaGroups.All(
            criteriaGroup => criteriaGroup.Criteria.Any(
                criteria => (bool)isCriteriaMatchMethod.Invoke(personalizationService, new object[] { criteria, testContext })
            )
        )
    );

    return firstMatchingSegment;
}