/// <summary>
        /// Creates or updates a Settings, if a particular setting exists then updates it, else inserts it.
        /// Invalidates cache for the Settings when done.
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="settings"></param>
        /// <returns></returns>
        public async Task <T> UpsertSettingsAsync <T>(T settings) where T : class, ISettings, new()
        {
            var settingsCreate = new List <Meta>();
            var settingsUpdate = new List <Meta>();
            var allSettings    = await GetAllSettingsAsync();

            foreach (var property in typeof(T).GetProperties())
            {
                if (!property.CanRead || !property.CanWrite)
                {
                    continue;
                }

                var value    = property.GetValue(settings);
                var valueStr = TypeDescriptor.GetConverter(property.PropertyType).CanConvertFrom(typeof(string)) ?
                               TypeDescriptor.GetConverter(typeof(object)).ConvertToInvariantString(value) :
                               JsonConvert.SerializeObject(value);

                var key = (typeof(T).Name + "." + property.Name).ToLowerInvariant();
                if (allSettings == null || !allSettings.Any(s => s.Key == key))
                {
                    settingsCreate.Add(new Meta
                    {
                        Key   = key,
                        Value = valueStr
                    });
                }
                else
                {
                    var setting = await _repo.GetAsync(key);

                    if (setting != null && setting.Value != valueStr)
                    {
                        setting.Value = valueStr;
                        settingsUpdate.Add(setting);
                    }
                }
            }

            if (settingsCreate.Count > 0)
            {
                await _repo.CreateRangeAsync(settingsCreate);
            }
            if (settingsUpdate.Count > 0)
            {
                await _repo.UpdateAsync(settingsUpdate);
            }

            string cacheKey = typeof(T).Name;
            await _cache.RemoveAsync(cacheKey);

            await _cache.RemoveAsync(CACHE_KEY_ALL_SETTINGS);

            return(settings);
        }