namespace ASC.Feed.Aggregator.Service
{
    public class FeedCleanerService : FeedBaseService
    {
        protected override string LoggerName { get; set; } = "ASC.Feed.Cleaner";

        public FeedCleanerService(
            FeedSettings feedSettings,
            IServiceProvider serviceProvider,
            IOptionsMonitor<ILog> optionsMonitor)
            : base(feedSettings, serviceProvider, optionsMonitor)
        {
        }

        public override Task StartAsync(CancellationToken cancellationToken)
        {
            Logger.Info("Feed Cleaner Service running.");

            var cfg = FeedSettings;
            IsStopped = false;

            Timer = new Timer(RemoveFeeds, cfg.AggregateInterval, cfg.RemovePeriod, cfg.RemovePeriod);

            return Task.CompletedTask;
        }

        public override Task StopAsync(CancellationToken cancellationToken)
        {
            Logger.Info("Feed Cleaner Service stopping.");

            IsStopped = true;

            Timer?.Change(Timeout.Infinite, 0);

            return Task.CompletedTask;
        }

        private void RemoveFeeds(object interval)
        {
            if (!Monitor.TryEnter(LockObj))
            {
                return;
            }

            try
            {
                using var scope = ServiceProvider.CreateScope();
                var feedAggregateDataProvider = scope.ServiceProvider.GetService<FeedAggregateDataProvider>();

                Logger.DebugFormat("Start of removing old news");

                feedAggregateDataProvider.RemoveFeedAggregate(DateTime.UtcNow.Subtract((TimeSpan)interval));
            }
            catch (Exception ex)
            {
                Logger.Error(ex);
            }
            finally
            {
                Monitor.Exit(LockObj);
            }
        }
    }
}