private async Task _Refresh()
{
if (!IsNeedRefresh) { return; }
Debug.WriteLine($"{Label} starting update feed.");
var updateTime = DateTime.Now;
var latestItems = new List<FeedItem>();
foreach (var feedSource in _FeedSourceList)
{
var items = await feedSource.GetLatestItems(HohoemaApp);
foreach (var item in items)
{
latestItems.Add(item);
}
}
var latestOrderedItems = latestItems
.OrderByDescending(x => x.SubmitDate)
.Take(MaxFeedItemsCount)
.ToList();
foreach (var item in latestOrderedItems)
{
item.CheckedTime = updateTime;
}
var exceptItems = latestOrderedItems.Except(FeedItems, FeedItemComparer.Default).ToList();
var addedItems = exceptItems.Where(x => x.CheckedTime == updateTime);
var removedItems = FeedItems
.Except(latestOrderedItems, FeedItemComparer.Default)
.Where(x => x.CheckedTime != updateTime)
.ToList();
foreach (var addItem in addedItems)
{
addItem.IsUnread = true;
// 投稿日時が初期化されていない場合はThumbnailInfoから拾ってくる
// ユーザー動画取得の場合に投稿時刻が取れないことが原因
// 追加されたアイテムだけのThumbnailを取得することで無駄な処理を減らす
if (addItem.SubmitDate == default(DateTime))
{
try
{
var nicoVideo = await HohoemaApp.MediaManager.GetNicoVideoAsync(addItem.VideoId);
addItem.SubmitDate = nicoVideo.PostedAt;
}
catch (Exception ex)
{
Debug.Fail("UserFeedItem 更新中、NicoVideoオブジェクトの取得に失敗しました。", ex.Message);
}
}
FeedItems.Add(addItem);
}
foreach (var removedItem in removedItems)
{
var item = FeedItems.SingleOrDefault(x => x.VideoId == removedItem.VideoId);
if (item != null)
{
item.IsDeleted = true;
FeedItems.Remove(item);
}
}
FeedItems.Sort(FeedItemComparer.Default);
UpdateTime = updateTime;
await FeedManager.SaveOne(this);
Completed?.Invoke(this);
IsNeedRefresh = false;
Debug.WriteLine($"{Label} update feed done.");
}