Podcatcher.PodcastSqlModel.addEpisodeToPlayHistory C# (CSharp) Method

        public void addEpisodeToPlayHistory(PodcastEpisodeModel episode)
        {
            if (episode == null)
            {
                Debug.WriteLine("Warning: Trying to add NULL episode to play history.");
                return;
            }

            LastPlayedEpisodeModel existingItem = (from LastPlayedEpisodeModel e in PlayHistory
                                                   where e.LastPlayedEpisodeId == episode.EpisodeId
                                                   select e).FirstOrDefault();

            // Episode is already in play history. Just update the timestamp instead of adding a duplicate one.
            if (existingItem != null)
            {
                Debug.WriteLine("Found episode already in history. Updating timestamp. Name: " + episode.EpisodeName);
                existingItem.TimeStamp = DateTime.Now;
                existingItem.LastPlayedEpisodeId = episode.EpisodeId;
                SubmitChanges();
                return;
            }

            // Clean old history items (if we have more than 10).
            if (PlayHistory.Count() >= 10)
            {
                var oldestHistoryItems = (from LastPlayedEpisodeModel e in PlayHistory
                                         orderby e.TimeStamp descending
                                         select e).Skip(10);

                if (oldestHistoryItems != null)
                {
                    Debug.WriteLine("Cleaning old episode from history.");
                    PlayHistory.DeleteAllOnSubmit(oldestHistoryItems);
                }
            }

            // Add a new item.
            LastPlayedEpisodeModel newHistoryItem = new LastPlayedEpisodeModel();
            newHistoryItem.LastPlayedEpisodeId = episode.EpisodeId;
            newHistoryItem.TimeStamp = DateTime.Now;

            Debug.WriteLine("Inserting episode to history: " + episode.EpisodeName);

            PlayHistory.InsertOnSubmit(newHistoryItem);
            SubmitChanges();
        }