OV - Youtube upload by sort fix #1

gistfile1.cs

using Google.Apis.Auth.OAuth2;
using Google.Apis.Json;
using Google.Apis.Services;
using Google.Apis.Util.Store;
using Google.Apis.YouTube.v3;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace OnlineVideos.Sites
{
  public class YouTubeV3Util : SiteUtilBase, IFilter
  {
    #region Helper classes

    private class YouTubeUserdataStore : IDataStore
    {
      const string PREFIX = "YouTubeV3apiStore.";

      public Task StoreAsync<T>(string key, T value)
      {
        var serialized = NewtonsoftJsonSerializer.Instance.Serialize(value);
        OnlineVideoSettings.Instance.UserStore.SetValue(PREFIX + key, serialized, true);
        return TaskEx.Delay(0);
      }

      public Task DeleteAsync<T>(string key)
      {
        OnlineVideoSettings.Instance.UserStore.SetValue(PREFIX + key, null);
        return TaskEx.Delay(0);
      }

      public Task<T> GetAsync<T>(string key)
      {
        TaskCompletionSource<T> tcs = new TaskCompletionSource<T>();
        var serialized = OnlineVideoSettings.Instance.UserStore.GetValue(PREFIX + key, true);
        if (!string.IsNullOrWhiteSpace(serialized))
        {
          try
          {
            tcs.SetResult(NewtonsoftJsonSerializer.Instance.Deserialize<T>(serialized));
          }
          catch (Exception ex)
          {
            tcs.SetException(ex);
          }
        }
        else
        {
          tcs.SetResult(default(T));
        }
        return tcs.Task;
      }

      public Task ClearAsync()
      {
        return TaskEx.Delay(0);
      }
    }

    private class YouTubeVideo : VideoInfo
    {
      internal string ChannelId { get; set; }
      internal string ChannelTitle { get; set; }
      internal string PlaylistItemId { get; set; }
    }

    private class YouTubeCategory : RssLink
    {
      internal enum CategoryKind { Other, Channel, Playlist, GuideCategory, VideoCategory };
      internal CategoryKind Kind { get; set; }
      internal string Id { get; set; }
      internal bool IsMine { get; set; }
    }

    #endregion

    public enum VideoQuality { Low, Medium, High, HD, FullHD };

    public enum VideoFormat { flv, mp4, webm };

    const string CLIENT = @"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";

    [Category("OnlineVideosConfiguration"), Description("Add some dynamic categories found at startup to the list of configured ones.")]
    bool useDynamicCategories = true;

    [Category("OnlineVideosUserConfiguration"), LocalizableDisplayName("Preferred Format"), Description("Prefer this format when there are more than one for the desired quality.")]
    VideoFormat preferredFormat = VideoFormat.mp4;
    [Category("OnlineVideosUserConfiguration"), LocalizableDisplayName("Undesired Format"), Description("Try to avoid this format when there are more than one for the desired quality.")]
    VideoFormat undesiredFormat = VideoFormat.webm;
    [Category("OnlineVideosUserConfiguration"), LocalizableDisplayName("Video Quality", TranslationFieldName = "VideoQuality"), Description("Defines the maximum quality for the video to be played.")]
    VideoQuality videoQuality = VideoQuality.High;
    [Category("OnlineVideosUserConfiguration"), LocalizableDisplayName("Videos per Page"), Description("Defines the default number of videos to display per page.")]
    int pageSize = 26;
    [Category("OnlineVideosUserConfiguration"), LocalizableDisplayName("Enable Login"), Description("Will popup a browser on first use to select your YouTube account.")]
    bool enableLogin = false;

    string hl = CultureInfo.CurrentUICulture.TwoLetterISOLanguageName;
    string regionCode = RegionInfo.CurrentRegion.TwoLetterISORegionName;
    YouTubeService service;
    Func<List<VideoInfo>> nextPageVideosQuery;
    SearchResource.ListRequest.OrderEnum currentSearchOrder = SearchResource.ListRequest.OrderEnum.Relevance;
    string currentVideosTitle;
    string userFavoritesPlaylistId;

    public override int DiscoverDynamicCategories()
    {
      if (useDynamicCategories)
      {
        Settings.Categories = new BindingList<Category>();

        var guideCatgeory = new Category() { Name = "YouTube Guide", HasSubCategories = true };
        guideCatgeory.Other = (Func<List<Category>>)(() => QueryGuideCategories(guideCatgeory));
        Settings.Categories.Add(guideCatgeory);

        var videoCategory = new Category() { Name = "Video Categories", HasSubCategories = true };
        videoCategory.Other = (Func<List<Category>>)(() => QueryVideoCategories(videoCategory));
        Settings.Categories.Add(videoCategory);
        if (enableLogin)
        {
          try
          {
            QueryUserChannel().ForEach(c => Settings.Categories.Add(c));
          }
          catch (Exception ex)
          {
            throw new OnlineVideosException(ex.Message);
          }
        }

        Settings.DynamicCategoriesDiscovered = true;
      }
      return Settings.Categories.Count;
    }

    public override int DiscoverSubCategories(Category parentCategory)
    {
      var method = parentCategory.Other as Func<List<Category>>;
      if (method != null)
      {
        parentCategory.SubCategories = method.Invoke();
        parentCategory.SubCategoriesDiscovered = true;
        return parentCategory.SubCategories.Count;
      }
      return 0;
    }

    public override int DiscoverNextPageCategories(NextPageCategory category)
    {
      var method = category.Other as Func<List<Category>>;
      if (method != null)
      {
        var newCategories = method.Invoke();
        category.ParentCategory.SubCategories.Remove(category);
        category.ParentCategory.SubCategories.AddRange(newCategories);
        return newCategories.Count;
      }
      return 0;
    }

    public override string GetCurrentVideosTitle()
    {
      return currentVideosTitle;
    }

    public override List<VideoInfo> GetVideos(Category category)
    {
      currentVideosTitle = null; // use default title for videos retrieved via this method (which is the Category Name)
      base.HasNextPage = false;
      nextPageVideosQuery = null;
      var method = category.Other as Func<List<VideoInfo>>;
      if (method != null)
      {
        return method.Invoke();
      }
      return new List<VideoInfo>();
    }

    public override List<String> GetMultipleVideoUrls(VideoInfo video, bool inPlaylist = false)
    {
      video.PlaybackOptions = Hoster.HosterFactory.GetHoster("Youtube").GetPlaybackOptions(video.VideoUrl);
      if (video.PlaybackOptions != null && video.PlaybackOptions.Count > 0)
      {
        if (video.PlaybackOptions.Count == 1)
        {
          // nothing to chose from, only one option available
          return new List<string>() { video.PlaybackOptions.First().Value };
        }
        else
        {
          KeyValuePair<string, string> foundQuality = default(KeyValuePair<string, string>);
          switch (videoQuality)
          {
            case VideoQuality.Low:		//use first available option
              foundQuality = video.PlaybackOptions.First(); break;
            case VideoQuality.Medium:	//first above 320 that is not 3D
              foundQuality = video.PlaybackOptions.FirstOrDefault(q => !q.Key.Contains("320") && !q.Key.Contains("3D")); break;
            case VideoQuality.High:		//highest below the HD formats that is not 3D
              foundQuality = video.PlaybackOptions.LastOrDefault(q => !q.Key.Contains("1920") && !q.Key.Contains("1280") && !q.Key.Contains("3D")); break;
            case VideoQuality.HD:		//first below full HD that is not 3D
              foundQuality = video.PlaybackOptions.LastOrDefault(q => !q.Key.Contains("1920") && !q.Key.Contains("3D")); break;
            case VideoQuality.FullHD:	//use highest available quality that is not 3D
              foundQuality = video.PlaybackOptions.Last(q => !q.Key.Contains("3D")); break;
          }
          if (!string.IsNullOrEmpty(foundQuality.Key))
          {
            string resolution = foundQuality.Key.Substring(0, foundQuality.Key.IndexOf('|'));
            // try to find one that has the same resolution and the preferred format
            var bestMatch = video.PlaybackOptions.FirstOrDefault(q => q.Key.Contains(resolution) && !q.Key.Contains("3D") && q.Key.Contains(preferredFormat.ToString()));
            // try to find one that has the same resolution and not the undesired format
            if (string.IsNullOrEmpty(bestMatch.Key)) bestMatch = video.PlaybackOptions.FirstOrDefault(q => q.Key.Contains(resolution) && !q.Key.Contains("3D") && !q.Key.Contains(undesiredFormat.ToString()));
            if (!string.IsNullOrEmpty(bestMatch.Key)) foundQuality = bestMatch;
          }
          // fallback when no match was found -> use first choice
          if (string.IsNullOrEmpty(foundQuality.Key)) foundQuality = video.PlaybackOptions.First();
          if (inPlaylist) video.PlaybackOptions = null;
          return new List<string>() { foundQuality.Value };
        }
      }
      return null; // no playback options
    }

    #region Search

    public override bool CanSearch { get { return true; } }

    Dictionary<string, string> cachedSearchCategories = null;
    public override Dictionary<string, string> GetSearchableCategories()
    {
      if (cachedSearchCategories == null)
        QueryVideoCategories(null);
      return cachedSearchCategories;
    }

    public override List<SearchResultItem> Search(string query, string category = null)
    {
      base.HasNextPage = false;
      nextPageVideosQuery = null;
      return QuerySearchVideos(query, "videos", null, category, null).ConvertAll(v => (SearchResultItem)v);
    }

    #endregion

    #region Paging

    public override List<VideoInfo> GetNextPageVideos()
    {
      var method = nextPageVideosQuery;
      base.HasNextPage = false;
      nextPageVideosQuery = null;
      if (method != null)
      {
        return method.Invoke();
      }
      return new List<VideoInfo>();
    }

    #endregion

    #region IFilter Members

    public List<VideoInfo> FilterVideos(Category category, int maxResults, string orderBy, string timeFrame)
    {
      return (category.Other as Func<List<VideoInfo>>).Invoke();
    }

    public List<VideoInfo> FilterSearchResults(string query, int maxResults, string orderBy, string timeFrame)
    {
      return FilterSearchResults(query, null, maxResults, orderBy, timeFrame);
    }

    public List<VideoInfo> FilterSearchResults(string query, string category, int maxResults, string orderBy, string timeFrame)
    {
      Enum.TryParse<SearchResource.ListRequest.OrderEnum>(orderBy, out currentSearchOrder);
      return QuerySearchVideos(query, "videos", null, category, null);
    }

    public List<int> GetResultSteps() { return new List<int>() { 10, 20, 30, 40, 50 }; }

    public Dictionary<string, string> GetOrderByOptions() { return Enum.GetNames(typeof(SearchResource.ListRequest.OrderEnum)).ToDictionary(o => o); }

    public Dictionary<string, string> GetTimeFrameOptions() { return new Dictionary<string, string>(); }

    #endregion

    #region Context Menu

    public override List<ContextMenuEntry> GetContextMenuEntries(Category selectedCategory, VideoInfo selectedItem)
    {
      List<ContextMenuEntry> result = new List<ContextMenuEntry>();
      var ytVideo = selectedItem as YouTubeVideo;
      var ytCategory = selectedCategory as YouTubeCategory;
      if (selectedItem == null && ytCategory != null)
      {
        if (ytCategory.Kind == YouTubeCategory.CategoryKind.Playlist && ytCategory.IsMine && !string.IsNullOrEmpty(ytCategory.Id))
        {
          result.Add(new ContextMenuEntry() { DisplayText = Translation.Instance.DeletePlaylist, Action = ContextMenuEntry.UIAction.Execute });
        }
      }
      if (ytVideo != null)
      {
        result.Add(new ContextMenuEntry() { DisplayText = Translation.Instance.RelatedVideos, Action = ContextMenuEntry.UIAction.Execute });

        if (!string.IsNullOrEmpty(ytVideo.ChannelTitle) && !string.IsNullOrEmpty(ytVideo.ChannelId))
        {
          result.Add(new ContextMenuEntry() { DisplayText = Translation.Instance.UploadsBy + " [" + ytVideo.ChannelTitle + "]", Action = ContextMenuEntry.UIAction.Execute });
          result.Add(new ContextMenuEntry() { DisplayText = Translation.Instance.Playlists + " [" + ytVideo.ChannelTitle + "]", Action = ContextMenuEntry.UIAction.Execute });
        }
        if (!string.IsNullOrEmpty(userFavoritesPlaylistId))
        {
          if (ytCategory != null && ytCategory.Kind == YouTubeCategory.CategoryKind.Playlist && ytCategory.Id == userFavoritesPlaylistId && !string.IsNullOrEmpty(ytVideo.PlaylistItemId))
          {
            result.Add(new ContextMenuEntry() { DisplayText = Translation.Instance.RemoveFromFavorites + " (" + Settings.Name + ")", Action = ContextMenuEntry.UIAction.Execute });
          }
          else
          {
            result.Add(new ContextMenuEntry() { DisplayText = Translation.Instance.AddToFavourites + " (" + Settings.Name + ")", Action = ContextMenuEntry.UIAction.Execute });
          }
        }
        if (ytCategory != null && ytCategory.Kind == YouTubeCategory.CategoryKind.Playlist && ytCategory.IsMine && !string.IsNullOrEmpty(ytCategory.Id) && !string.IsNullOrEmpty(ytVideo.PlaylistItemId))
        {
          result.Add(new ContextMenuEntry() { DisplayText = Translation.Instance.RemoveFromPlaylist, Action = ContextMenuEntry.UIAction.Execute });
        }
        if (enableLogin)
        {
          var plCtx = new ContextMenuEntry() { DisplayText = Translation.Instance.AddToPlaylist, Action = ContextMenuEntry.UIAction.ShowList };
          plCtx.SubEntries.Add(new ContextMenuEntry() { DisplayText = Translation.Instance.CreateNewPlaylist, Action = ContextMenuEntry.UIAction.GetText });
          foreach (var pl in QueryChannelPlaylists(new YouTubeCategory() { IsMine = true }, null))
          {
            if (pl is YouTubeCategory)
              plCtx.SubEntries.Add(new ContextMenuEntry() { DisplayText = pl.Name, Other = (pl as YouTubeCategory).Id });
          }
          result.Add(plCtx);
        }
      }
      return result;
    }

    public override ContextMenuExecutionResult ExecuteContextMenuEntry(Category selectedCategory, VideoInfo selectedItem, ContextMenuEntry choice)
    {
      ContextMenuExecutionResult result = new ContextMenuExecutionResult();
      try
      {
        if (choice.DisplayText == Translation.Instance.AddToFavourites + " (" + Settings.Name + ")")
        {
          var query = Service.PlaylistItems.Insert(
              new Google.Apis.YouTube.v3.Data.PlaylistItem()
              {
                Snippet = new Google.Apis.YouTube.v3.Data.PlaylistItemSnippet()
                {
                  Title = selectedItem.Title,
                  PlaylistId = userFavoritesPlaylistId,
                  ResourceId = new Google.Apis.YouTube.v3.Data.ResourceId()
                  {
                    VideoId = selectedItem.VideoUrl,
                    Kind = "youtube#video"
                  }
                }
              },
              "snippet");
          var response = query.Execute();
          result.ExecutionResultMessage = string.Format("{0} {1}", Translation.Instance.Success, Translation.Instance.AddingToFavorites);
        }
        else if (choice.DisplayText == Translation.Instance.RemoveFromFavorites + " (" + Settings.Name + ")")
        {
          var query = Service.PlaylistItems.Delete((selectedItem as YouTubeVideo).PlaylistItemId);
          var response = query.Execute();
          result.RefreshCurrentItems = true;
        }
        else if (choice.DisplayText == Translation.Instance.RelatedVideos)
        {
          base.HasNextPage = false;
          nextPageVideosQuery = null;
          currentVideosTitle = Translation.Instance.RelatedVideos + " [" + selectedItem.Title + "]";
          result.ResultItems = QuerySearchVideos(null, "videos", null, null, (selectedItem as YouTubeVideo).VideoUrl).ConvertAll<SearchResultItem>(v => v as SearchResultItem);
        }
        else if (choice.DisplayText.StartsWith(Translation.Instance.UploadsBy))
        {
          base.HasNextPage = false;
          nextPageVideosQuery = null;
          currentVideosTitle = Translation.Instance.UploadsBy + " [" + (selectedItem as YouTubeVideo).ChannelTitle + "]";
          result.ResultItems = QuerySearchVideos(null, "videos", (selectedItem as YouTubeVideo).ChannelId, null, null).ConvertAll<SearchResultItem>(v => v as SearchResultItem);
        }
        else if (choice.DisplayText.StartsWith(Translation.Instance.Playlists))
        {
          var parentCategory = new YouTubeCategory() { Name = Translation.Instance.Playlists + " [" + (selectedItem as YouTubeVideo).ChannelTitle + "]" };
          parentCategory.SubCategories = QueryChannelPlaylists(parentCategory, (selectedItem as YouTubeVideo).ChannelId);
          result.ResultItems = parentCategory.SubCategories.ConvertAll<SearchResultItem>(v => v as SearchResultItem);
        }
        else if (choice.DisplayText == Translation.Instance.RemoveFromPlaylist)
        {
          var query = Service.PlaylistItems.Delete((selectedItem as YouTubeVideo).PlaylistItemId);
          var response = query.Execute();
          result.RefreshCurrentItems = true;
          if ((selectedCategory as YouTubeCategory).EstimatedVideoCount != null) (selectedCategory as YouTubeCategory).EstimatedVideoCount--;
        }
        else if (choice.DisplayText == Translation.Instance.DeletePlaylist)
        {
          var query = Service.Playlists.Delete((selectedCategory as YouTubeCategory).Id);
          var response = query.Execute();
          selectedCategory.ParentCategory.SubCategoriesDiscovered = false;
          result.RefreshCurrentItems = true;
        }
        else if (choice.ParentEntry != null && choice.ParentEntry.DisplayText == Translation.Instance.AddToPlaylist)
        {
          if (choice.Other == null)
          {
            // create new playlist first
            var query = Service.Playlists.Insert(
                new Google.Apis.YouTube.v3.Data.Playlist()
                {
                  Snippet = new Google.Apis.YouTube.v3.Data.PlaylistSnippet() { Title = choice.UserInputText }
                },
                "snippet");
            var response = query.Execute();
            choice.Other = response.Id;
          }
          var queryItem = Service.PlaylistItems.Insert(
              new Google.Apis.YouTube.v3.Data.PlaylistItem()
              {
                Snippet = new Google.Apis.YouTube.v3.Data.PlaylistItemSnippet()
                {
                  Title = selectedItem.Title,
                  PlaylistId = choice.Other as string,
                  ResourceId = new Google.Apis.YouTube.v3.Data.ResourceId()
                  {
                    VideoId = selectedItem.VideoUrl,
                    Kind = "youtube#video"
                  }
                }
              },
              "snippet");
          var responseItem = queryItem.Execute();
          // force re-discovery of dynamic subcategories for my playlists category (as either a new catgeory was added or the count changed)
          var playlistsCategory = Settings.Categories.FirstOrDefault(c => (c is YouTubeCategory) && (c as YouTubeCategory).IsMine && c.Name.EndsWith(Translation.Instance.Playlists));
          if (playlistsCategory != null) playlistsCategory.SubCategoriesDiscovered = false;
        }

      }
      catch (Google.GoogleApiException apiEx)
      {
        throw new OnlineVideosException(string.Format("{0} {1}", apiEx.HttpStatusCode, apiEx.Message));
      }
      catch (Exception ex)
      {
        throw new OnlineVideosException(ex.Message);
      }
      return result;
    }

    #endregion

    #region YouTube service wrapper methods

    /// <summary>
    /// Gets a (cached) instance of the <see cref="YouTubeService"/> used to query the API.
    /// When authorization is enabled, upon first creation a user token will be retrieved using a browser popup.
    /// </summary>
    YouTubeService Service
    {
      get
      {
        if (service == null)
        {
          UserCredential credential = null;
          if (enableLogin)
          {
            using (var stream = new System.IO.MemoryStream(Convert.FromBase64String(CLIENT)))
            {
              credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
                  GoogleClientSecrets.Load(stream).Secrets,
                  new[] { YouTubeService.Scope.Youtube },
                  "user",
                  CancellationToken.None,
                  new YouTubeUserdataStore()
              ).Result;
            }
          }
          service = new YouTubeService(new BaseClientService.Initializer()
          {
            ApiKey = "AIzaSyDzL_VrmG4Q2K4unBafZEoOv3UCAUTB7e4",
            ApplicationName = "OnlineVideos",
            HttpClientInitializer = credential,
          });
        }
        return service;
      }
    }

    /// <summary>Returns a list of categories for the authenticated user (Watch Later, Watch History, Subscriptions, Playlists)</summary>
    List<Category> QueryUserChannel()
    {
      var query = Service.Channels.List("snippet, contentDetails");
      query.Mine = true;
      var response = query.Execute();
      var userChannel = response.Items.FirstOrDefault();
      var results = new List<Category>();
      if (userChannel != null)
      {
        var userName = userChannel.Snippet.Title;
        if (!string.IsNullOrWhiteSpace(userName))
        {
          userFavoritesPlaylistId = userChannel.ContentDetails.RelatedPlaylists.Favorites;
          results.Add(new Category() { Name = string.Format("{0}'s {1}", userName, "Watch Later"), Thumb = userChannel.Snippet.Thumbnails.High.Url, Other = (Func<List<VideoInfo>>)(() => QueryPlaylistVideos(userChannel.ContentDetails.RelatedPlaylists.WatchLater)) });
          results.Add(new Category() { Name = string.Format("{0}'s {1}", userName, "Watch History"), Thumb = userChannel.Snippet.Thumbnails.High.Url, Other = (Func<List<VideoInfo>>)(() => QueryPlaylistVideos(userChannel.ContentDetails.RelatedPlaylists.WatchHistory)) });

          var subscriptionsCategory = new Category() { Name = string.Format("{0}'s {1}", userName, Translation.Instance.Subscriptions), Thumb = userChannel.Snippet.Thumbnails.High.Url, HasSubCategories = true };
          subscriptionsCategory.Other = (Func<List<Category>>)(() => QueryMySubscriptions(subscriptionsCategory));
          results.Add(subscriptionsCategory);

          var playlistsCategory = new YouTubeCategory() { Name = string.Format("{0}'s {1}", userName, Translation.Instance.Playlists), Thumb = userChannel.Snippet.Thumbnails.High.Url, HasSubCategories = true, IsMine = true };
          playlistsCategory.Other = (Func<List<Category>>)(() => QueryChannelPlaylists(playlistsCategory, null));
          results.Add(playlistsCategory);
        }
      }
      return results;
    }

    /// <summary>Returns a list of categories that can be associated with YouTube channels.</summary>
    /// <remarks>
    /// A guide category identifies a category that YouTube algorithmically assigns based on a channel's content or other indicators, such as the channel's popularity. 
    /// The list is similar to video categories, with the difference being that a video's uploader can assign a video category but only YouTube can assign a channel category.
    /// </remarks>
    List<Category> QueryGuideCategories(Category parentCategory)
    {
      var query = Service.GuideCategories.List("snippet");
      query.RegionCode = regionCode;
      query.Hl = hl;
      var response = query.Execute();
      var results = new List<Category>();
      foreach (var item in response.Items)
      {
        var category = new YouTubeCategory() { Name = item.Snippet.Title, HasSubCategories = true, ParentCategory = parentCategory, Kind = YouTubeCategory.CategoryKind.GuideCategory, Id = item.Id };
        category.Other = (Func<List<Category>>)(() => QueryChannelsForGuideCategory(category, item.Id));
        results.Add(category);
      }
      return results;
    }

    /// <summary>Returns a list of categories that can be associated with YouTube videos.</summary>
    List<Category> QueryVideoCategories(Category parentCategory)
    {
      var query = Service.VideoCategories.List("snippet");
      query.RegionCode = regionCode;
      query.Hl = hl;
      var response = query.Execute();
      var results = new List<Category>();
      cachedSearchCategories = new Dictionary<string, string>();
      foreach (var item in response.Items)
      {
        if (item.Snippet.Assignable == true)
        {
          var category = new YouTubeCategory() { Name = item.Snippet.Title, ParentCategory = parentCategory, Kind = YouTubeCategory.CategoryKind.VideoCategory, Id = item.Id };
          category.Other = (Func<List<VideoInfo>>)(() => QueryCategoryVideos(item.Id));
          results.Add(category);
          cachedSearchCategories.Add(item.Snippet.Title, item.Id);
        }
      }
      return results;
    }

    /// <summary>Returns a list of channels for the given guide category.</summary>
    /// <param name="guideCategoryId">The guide category to use as filter in the query.</param>
    List<Category> QueryChannelsForGuideCategory(Category parentCategory, string guideCategoryId, string pageToken = null)
    {
      var query = Service.Channels.List("snippet, statistics");
      query.CategoryId = guideCategoryId;
      query.Hl = hl;
      query.MaxResults = pageSize;
      query.PageToken = pageToken;
      var response = query.Execute();
      var results = new List<Category>();
      foreach (var item in response.Items)
      {
        var category = new YouTubeCategory()
        {
          Name = item.Snippet.Localized.Title,
          Description = item.Snippet.Localized.Description,
          Thumb = item.Snippet.Thumbnails != null ? item.Snippet.Thumbnails.High.Url : null,
          EstimatedVideoCount = (uint)(item.Statistics.VideoCount ?? 0),
          HasSubCategories = true,
          ParentCategory = parentCategory,
          Kind = YouTubeCategory.CategoryKind.Channel,
          Id = item.Id
        };
        category.Other = (Func<List<Category>>)(() => QueryChannelPlaylists(category, item.Id));
        results.Add(category);
      }
      if (!string.IsNullOrEmpty(response.NextPageToken))
      {
        results.Add(new NextPageCategory() { ParentCategory = parentCategory, Other = (Func<List<Category>>)(() => QueryChannelsForGuideCategory(parentCategory, guideCategoryId, response.NextPageToken)) });
      }
      return results;
    }

    /// <summary>Returns a list of playlists for the given channel.</summary>
    /// <param name="channelId">The channel to use as filter in the query.</param>
    List<Category> QueryChannelPlaylists(YouTubeCategory parentCategory, string channelId, string pageToken = null)
    {
      var query = Service.Playlists.List("snippet, contentDetails");
      if (string.IsNullOrEmpty(channelId))
        query.Mine = true;
      else
        query.ChannelId = channelId;
      query.Hl = hl;
      query.MaxResults = pageSize;
      query.PageToken = pageToken;
      var response = query.Execute();
      var results = new List<Category>();
      if (!string.IsNullOrEmpty(channelId) && pageToken == null && parentCategory.EstimatedVideoCount > 0)
      {
        var resultsUploaded = new List<Category>();
        // before all playlists add a category that will list all uploads of the channel
        results.Add(new YouTubeCategory()
        {
          Name = string.Format("{0} {1}", Translation.Instance.UploadsBy, parentCategory.Name),
          Thumb = parentCategory.Thumb,
          EstimatedVideoCount = parentCategory.EstimatedVideoCount,
          ParentCategory = parentCategory,
          Kind = YouTubeCategory.CategoryKind.Channel,
          Id = channelId,
          Other = (Func<List<VideoInfo>>)(() => QuerySearchVideos(null, "videos", parentCategory.Id, null, null, true, null))
        });
      }
      foreach (var item in response.Items)
      {
        if ((long)(item.ContentDetails.ItemCount ?? 0) > 0 || parentCategory.IsMine) // hide empty playlists when not listing the authenticated user's
          results.Add(new YouTubeCategory()
          {
            Name = item.Snippet.Localized.Title,
            Description = item.Snippet.Localized.Description,
            Thumb = item.Snippet.Thumbnails != null ? item.Snippet.Thumbnails.High.Url : null,
            EstimatedVideoCount = (uint)(item.ContentDetails.ItemCount ?? 0),
            ParentCategory = parentCategory,
            Kind = YouTubeCategory.CategoryKind.Playlist,
            Id = item.Id,
            IsMine = parentCategory.IsMine,
            Other = (Func<List<VideoInfo>>)(() => QueryPlaylistVideos(item.Id))
          });
      }
      if (!string.IsNullOrEmpty(response.NextPageToken))
      {
        results.Add(new NextPageCategory() { ParentCategory = parentCategory, Other = (Func<List<Category>>)(() => QueryChannelPlaylists(parentCategory, channelId, response.NextPageToken)) });
      }
      return results;
    }

    /// <summary>Returns a list of the authenticated user's subscriptions (channels).</summary>
    List<Category> QueryMySubscriptions(Category parentCategory, string pageToken = null)
    {
      var query = Service.Subscriptions.List("snippet, contentDetails");
      query.Mine = true;
      query.MaxResults = pageSize;
      query.PageToken = pageToken;
      var response = query.Execute();
      var results = new List<Category>();

      // before all channels add a category that will list all uploads
      results.Add(new YouTubeCategory()
      {
        Name = "Latest Videos",
        Thumb = parentCategory.Thumb,
        ParentCategory = parentCategory,
        Kind = YouTubeCategory.CategoryKind.Other,
        Other = (Func<List<VideoInfo>>)(() => QueryNewestSubscriptionVideos())
      });

      foreach (var item in response.Items)
      {
        var category = new YouTubeCategory()
        {
          Name = item.Snippet.Title,
          Description = item.Snippet.Description,
          Thumb = item.Snippet.Thumbnails != null ? item.Snippet.Thumbnails.High.Url : null,
          EstimatedVideoCount = (uint)(item.ContentDetails.TotalItemCount ?? 0),
          ParentCategory = parentCategory,
          HasSubCategories = true,
          Kind = YouTubeCategory.CategoryKind.Channel,
          Id = item.Snippet.ResourceId.ChannelId,
          IsMine = true
        };
        category.Other = (Func<List<Category>>)(() => QueryChannelPlaylists(category, item.Snippet.ResourceId.ChannelId));
        results.Add(category);
      }
      if (!string.IsNullOrEmpty(response.NextPageToken))
      {
        results.Add(new NextPageCategory() { ParentCategory = parentCategory, Other = (Func<List<Category>>)(() => QueryMySubscriptions(parentCategory, response.NextPageToken)) });
      }
      return results;
    }

    List<VideoInfo> QueryNewestSubscriptionVideos(string pageToken = null)
    {
      var query = Service.Activities.List("snippet, contentDetails");
      query.Home = true;
      query.RegionCode = regionCode;
      query.MaxResults = pageSize;
      query.PageToken = pageToken;
      var response = query.Execute();
      var results = response.Items.Where(i => i.Snippet.Type == "upload").Select(i => new YouTubeVideo()
      {
        Title = i.Snippet.Title,
        Description = i.Snippet.Description,
        Thumb = i.Snippet.Thumbnails != null ? i.Snippet.Thumbnails.High.Url : null,
        Airdate = i.Snippet.PublishedAt != null ? i.Snippet.PublishedAt.Value.ToString("g", OnlineVideoSettings.Instance.Locale) : i.Snippet.PublishedAtRaw,
        VideoUrl = i.ContentDetails.Upload.VideoId,
        ChannelId = i.Snippet.ChannelId,
        ChannelTitle = i.Snippet.ChannelTitle
      }).ToList<VideoInfo>();
      if (!string.IsNullOrEmpty(response.NextPageToken))
      {
        base.HasNextPage = true;
        nextPageVideosQuery = () => QueryNewestSubscriptionVideos(response.NextPageToken);
      }
      return results;
    }

    /// <summary>Returns a list of most popular videos for the given category.</summary>
    /// <param name="videoCategoryId">The category to use use as filter in the query.</param>
    List<VideoInfo> QueryCategoryVideos(string videoCategoryId, string pageToken = null)
    {
      var query = Service.Videos.List("snippet, contentDetails");
      query.Chart = VideosResource.ListRequest.ChartEnum.MostPopular;
      query.VideoCategoryId = videoCategoryId;
      query.RegionCode = regionCode;
      query.Hl = hl;
      query.MaxResults = pageSize;
      query.PageToken = pageToken;
      var response = query.Execute();
      var results = response.Items.Select(i => new YouTubeVideo()
      {
        Title = i.Snippet.Localized.Title,
        Description = i.Snippet.Localized.Description,
        Thumb = i.Snippet.Thumbnails != null ? i.Snippet.Thumbnails.High.Url : null,
        Airdate = i.Snippet.PublishedAt != null ? i.Snippet.PublishedAt.Value.ToString("g", OnlineVideoSettings.Instance.Locale) : i.Snippet.PublishedAtRaw,
        Length = System.Xml.XmlConvert.ToTimeSpan(i.ContentDetails.Duration).ToString(),
        VideoUrl = i.Id,
        ChannelId = i.Snippet.ChannelId,
        ChannelTitle = i.Snippet.ChannelTitle
      }).ToList<VideoInfo>();
      if (!string.IsNullOrEmpty(response.NextPageToken))
      {
        base.HasNextPage = true;
        nextPageVideosQuery = () => QueryCategoryVideos(videoCategoryId, response.NextPageToken);
      }
      return results;
    }

    /// <summary>Returns a list of videos for the given playlist.</summary>
    /// <param name="playlistId">The playlist to use as a filter in the query.</param>
    List<VideoInfo> QueryPlaylistVideos(string playlistId, string pageToken = null)
    {
      var query = Service.PlaylistItems.List("snippet");
      query.PlaylistId = playlistId;
      query.MaxResults = pageSize;
      query.PageToken = pageToken;
      var response = query.Execute();
      var results = response.Items.Where(i => i.Snippet.ResourceId.Kind == "youtube#video").Select(i => new YouTubeVideo()
      {
        Title = i.Snippet.Title,
        Description = i.Snippet.Description,
        Thumb = i.Snippet.Thumbnails != null ? i.Snippet.Thumbnails.High.Url : null,
        Airdate = i.Snippet.PublishedAt != null ? i.Snippet.PublishedAt.Value.ToString("g", OnlineVideoSettings.Instance.Locale) : i.Snippet.PublishedAtRaw,
        VideoUrl = i.Snippet.ResourceId.VideoId,
        ChannelId = i.Snippet.ChannelId,
        ChannelTitle = i.Snippet.ChannelTitle,
        PlaylistItemId = i.Id,
      }).ToList<VideoInfo>();
      if (!string.IsNullOrEmpty(response.NextPageToken))
      {
        base.HasNextPage = true;
        nextPageVideosQuery = () => QueryPlaylistVideos(playlistId, response.NextPageToken);
      }
      return results;
    }

    /// <summary>Returns a list of videos for the given search string.</summary>
    /// <param name="queryString">The search string to use as as filter in the query.</param>
    /// <param name="channelId">The channel id to use as filter in the query.</param>
    List<VideoInfo> QuerySearchVideos(string queryString, string searchType, string channelId, string categoryId, string relatedToVideoId, bool sortbyDate = false, string pageToken = null)
    {
      var query = Service.Search.List("snippet");
      if (!string.IsNullOrEmpty(channelId))
        query.ChannelId = channelId;
      if (!string.IsNullOrEmpty(queryString))
        query.Q = queryString;
      if (!string.IsNullOrEmpty(categoryId))
        query.VideoCategoryId = categoryId;
      if (!string.IsNullOrEmpty(relatedToVideoId))
        query.RelatedToVideoId = relatedToVideoId;
      if (sortbyDate)
      {
        query.Order = SearchResource.ListRequest.OrderEnum.Date;
      }
      else
      {
        query.Order = currentSearchOrder;
      }


      query.Type = searchType;

      query.MaxResults = pageSize;
      query.PageToken = pageToken;
      var response = query.Execute();
      var results = response.Items.Select(i => new YouTubeVideo()
      {
        Title = i.Snippet.Title,
        Description = i.Snippet.Description,
        Thumb = i.Snippet.Thumbnails != null ? i.Snippet.Thumbnails.High.Url : null,
        Airdate = i.Snippet.PublishedAt != null ? i.Snippet.PublishedAt.Value.ToString("g", OnlineVideoSettings.Instance.Locale) : i.Snippet.PublishedAtRaw,
        VideoUrl = i.Id.VideoId,
        ChannelId = i.Snippet.ChannelId,
        ChannelTitle = i.Snippet.ChannelTitle,
      }).ToList<VideoInfo>();
      if (!string.IsNullOrEmpty(response.NextPageToken))
      {
        base.HasNextPage = true;
        nextPageVideosQuery = () => QuerySearchVideos(queryString, searchType, channelId, categoryId, relatedToVideoId, sortbyDate, response.NextPageToken);
      }
      return results;
    }
    #endregion
  }
}