Recreating the Load method using repositories and pattern matching

Kyoo.Common/Controllers/ILibraryManager.cs

@@ -61,11 +61,11 @@ namespace Kyoo.Controllers
 		Task<Studio> GetStudio(Expression<Func<Studio, bool>> where);
 		Task<People> GetPerson(Expression<Func<People, bool>> where);
 
-		Task Load<T, T2>([NotNull] T obj, Expression<Func<T, T2>> member)
+		Task Load<T, T2>([NotNull] T obj, [CanBeNull] Expression<Func<T, T2>> member)
 			where T : class, IResource
-			where T2 : class;
+			where T2 : class, IResource;
 		
-		Task Load<T, T2>([NotNull] T obj, Expression<Func<T, IEnumerable<T2>>> member)
+		Task Load<T, T2>([NotNull] T obj, [CanBeNull] Expression<Func<T, ICollection<T2>>> member)
 			where T : class, IResource
 			where T2 : class;
 		

Kyoo.Common/Controllers/IRepository.cs

@@ -20,7 +20,7 @@ namespace Kyoo.Controllers
 			AfterID = afterID;
 		}
 		
-		public static implicit operator Pagination(int limit) => new Pagination(limit);
+		public static implicit operator Pagination(int limit) => new(limit);
 	}
 
 	public struct Sort<T>
@@ -67,7 +67,7 @@ namespace Kyoo.Controllers
 
 		public Sort<TValue> To<TValue>()
 		{
-			return new Sort<TValue>(Key.Convert<Func<TValue, object>>(), Descendant);
+			return new(Key.Convert<Func<TValue, object>>(), Descendant);
 		}
 	}
 	
@@ -207,5 +207,26 @@ namespace Kyoo.Controllers
 		) => GetFromPeople(showSlug, where, new Sort<ShowRole>(sort), limit);
 	}
 
-	public interface IProviderRepository : IRepository<ProviderID> {}
+	public interface IProviderRepository : IRepository<ProviderID>
+	{
+		Task<ICollection<MetadataID>> GetFromShow(int showID,
+			Expression<Func<MetadataID, bool>> where = null, 
+			Sort<MetadataID> sort = default,
+			Pagination limit = default);
+		Task<ICollection<MetadataID>> GetFromShow(int showID,
+			[Optional] Expression<Func<MetadataID, bool>> where, 
+			Expression<Func<MetadataID, object>> sort = default,
+			Pagination limit = default
+		) => GetFromShow(showID, where, new Sort<MetadataID>(sort), limit);
+		
+		Task<ICollection<MetadataID>> GetFromShow(string showSlug,
+			Expression<Func<MetadataID, bool>> where = null, 
+			Sort<MetadataID> sort = default,
+			Pagination limit = default);
+		Task<ICollection<MetadataID>> GetFromShow(string showSlug,
+			[Optional] Expression<Func<MetadataID, bool>> where, 
+			Expression<Func<MetadataID, object>> sort = default,
+			Pagination limit = default
+		) => GetFromShow(showSlug, where, new Sort<MetadataID>(sort), limit);
+	}
 }

Kyoo.Common/Controllers/Implementations/LibraryManager.cs

@@ -6,7 +6,7 @@ using Kyoo.Models;
 
 namespace Kyoo.Controllers
 {
-	public class ALibraryManager : ILibraryManager
+	public class LibraryManager : ILibraryManager
 	{
 		public ILibraryRepository LibraryRepository { get; }
 		public ILibraryItemRepository LibraryItemRepository { get; }
@@ -20,7 +20,7 @@ namespace Kyoo.Controllers
 		public IPeopleRepository PeopleRepository { get; }
 		public IProviderRepository ProviderRepository { get; }
 
-		protected ALibraryManager(ILibraryRepository libraryRepository, 
+		protected LibraryManager(ILibraryRepository libraryRepository, 
 			ILibraryItemRepository libraryItemRepository,
 			ICollectionRepository collectionRepository, 
 			IShowRepository showRepository, 
@@ -235,19 +235,63 @@ namespace Kyoo.Controllers
 			return PeopleRepository.Get(where);
 		}
 
-		public virtual Task Load<T, T2>(T obj, Expression<Func<T, T2>> member)
+		public async Task Load<T, T2>(T obj, Expression<Func<T, T2>> member)
 			where T : class, IResource
-			where T2 : class
+			where T2 : class, IResource
 		{
-			// TODO figure out why setting this method as abstract prevent the app from loading this assembly.
+			dynamic identifier = obj.ID > 0 ? obj.ID : obj.Slug;
-			throw new NotImplementedException();
+			switch (obj, (T2)default)
+			{
+				case (Show s, Studio): s.Studio = await StudioRepository.GetFromShow(identifier); break;
+				
+				case (Season s, Show): s.Show = await ShowRepository.GetFromSeason(identifier); break;
+				
+				case (Episode e, Show): e.Show = await ShowRepository.GetFromEpisode(identifier); break;
+				case (Episode e, Season): e.Season = await SeasonRepository.GetFromEpisode(identifier); break;
+				
+				case (Track t, Episode): t.Episode = await EpisodeRepository.GetFromTrack(identifier); break;
+				
+				default: throw new ArgumentException($"Couldn't find a way to load {member} of {typeof(T).Name}.");
+			}
 		}
 
-		public virtual Task Load<T, T2>(T obj, Expression<Func<T, IEnumerable<T2>>> member)
+		public async Task Load<T, T2>(T obj, Expression<Func<T, ICollection<T2>>> member)
 			where T : class, IResource
 			where T2 : class
 		{
-			throw new NotImplementedException();
+			dynamic identifier = obj.ID > 0 ? obj.ID : obj.Slug;
+			switch (obj, (T2)default)
+			{
+				case (Library l, ProviderID): l.Providers = await ProviderRepository.GetFromLibrary(identifier); break; 
+				case (Library l, Show): l.Shows = await ShowRepository.GetFromLibrary(identifier); break; 
+				case (Library l, Collection): l.Collections = await CollectionRepository.GetFromLibrary(identifier); break; 
+				
+				case (Collection c, Show): c.Shows = await ShowRepository.GetFromCollection(identifier); break; 
+				case (Collection c, Library): c.Libraries = await LibraryRepository.GetFromCollection(identifier); break; 
+				
+				case (Show s, MetadataID): s.ExternalIDs = await ProviderRepository.GetFromShow(identifier); break;
+				case (Show s, Genre): s.Genres = await GenreRepository.GetFromShow(identifier); break;
+				case (Show s, PeopleRole): s.People = await PeopleRepository.GetFromShow(identifier); break;
+				case (Show s, Season): s.Seasons = await SeasonRepository.GetFromShow(identifier); break;
+				case (Show s, Episode): s.Episodes = await EpisodeRepository.GetFromShow(identifier); break;
+				case (Show s, Library): s.Libraries = await LibraryRepository.GetFromShow(identifier); break;
+				case (Show s, Collection): s.Collections = await CollectionRepository.GetFromShow(identifier); break;
+				
+				case (Season s, MetadataID): s.ExternalIDs = await ProviderRepository.GetFromSeason(identifier); break;
+				case (Season s, Episode): s.Episodes = await EpisodeRepository.GetFromSeason(identifier); break;
+				
+				case (Episode e, MetadataID): e.ExternalIDs = await ProviderRepository.GetFromEpisode(identifier); break;
+				case (Episode e, Track): e.Tracks = await TrackRepository.GetFromEpisode(identifier); break;
+				
+				case (Genre g, Show): g.Shows = await ShowRepository.GetFromGenre(identifier); break;
+				
+				case (Studio s, Show): s.Shows = await ShowRepository.GetFromStudio(identifier); break;
+				
+				case (People p, MetadataID): p.ExternalIDs = await ProviderRepository.GetFromPeople(identifier); break;
+				case (People p, PeopleRole): p.Roles = await ShowRepository.GetFromPeople(identifier); break;
+
+				default: throw new ArgumentException($"Couldn't find a way to load {member} of {typeof(T).Name}.");
+			};
 		}
 		
 		public Task<ICollection<Library>> GetLibraries(Expression<Func<Library, bool>> where = null, 

Kyoo.Common/ExpressionRewrite.cs

@@ -43,26 +43,21 @@ namespace Kyoo
 			(string inner, _, ParameterExpression p) = _innerRewrites.FirstOrDefault(x => x.param == node.Expression);
 			if (inner != null)
 			{
-				Expression param = p;
+				Expression param = inner.Split('.').Aggregate<string, Expression>(p, Expression.Property);
-				foreach (string accessor in inner.Split('.'))
-					param = Expression.Property(param, accessor);
 				node = Expression.Property(param, node.Member.Name);
 			}
 			
 			// Can't use node.Member directly because we want to support attribute override
-			MemberInfo member = node.Expression.Type.GetProperty(node.Member.Name) ?? node.Member;
+			MemberInfo member = node.Expression!.Type.GetProperty(node.Member.Name) ?? node.Member;
 			ExpressionRewriteAttribute attr = member!.GetCustomAttribute<ExpressionRewriteAttribute>();
 			if (attr == null)
 				return base.VisitMember(node);
 
-			Expression property = node.Expression;
+			Expression property = attr.Link.Split('.').Aggregate(node.Expression, Expression.Property);
-			foreach (string child in attr.Link.Split('.'))
-				property = Expression.Property(property, child);
-			
 			if (property is MemberExpression expr)
 				Visit(expr.Expression);
 			_inner = attr.Inner;
-			return property;
+			return property!;
 		}
 
 		protected override Expression VisitLambda<T>(Expression<T> node)

Kyoo.Common/Utility.cs

@@ -17,7 +17,7 @@ namespace Kyoo
 {
 	public static class Utility
 	{
-		public static bool IsPropertyExpression<T, T2>(Expression<Func<T, T2>> ex)
+		public static bool IsPropertyExpression(LambdaExpression ex)
 		{
 			return ex == null ||
 			       ex.Body is MemberExpression ||
@@ -490,6 +490,18 @@ namespace Kyoo
 			return first.SequenceEqual(second, new LinkComparer<T, T1, T2>());
 		}
 
+		public static string GetMemberName([NotNull] Expression expression)
+		{
+			var t = ExpressionRewrite.Rewrite(expression);
+			return ExpressionRewrite.Rewrite(expression) switch
+			{
+				MemberExpression member => member.Member.Name,
+				LambdaExpression lambda when IsPropertyExpression(lambda) => GetMemberName(lambda.Body),
+				null => throw new ArgumentNullException(nameof(expression)),
+				_ => throw new ArgumentException($"Can't get member.")
+			};
+		}
+
 		public static Expression<T> Convert<T>([CanBeNull] this Expression expr)
 			where T : Delegate
 		{

Kyoo.CommonAPI/LibraryManager.cs

@@ -1,58 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq.Expressions;
-using System.Threading.Tasks;
-using Microsoft.EntityFrameworkCore;
-
-namespace Kyoo.Controllers
-{
-	public class LibraryManager : ALibraryManager
-	{
-		private readonly DbContext _database;
-		
-		public LibraryManager(ILibraryRepository libraryRepository,
-			ILibraryItemRepository libraryItemRepository,
-			ICollectionRepository collectionRepository,
-			IShowRepository showRepository,
-			ISeasonRepository seasonRepository,
-			IEpisodeRepository episodeRepository,
-			ITrackRepository trackRepository,
-			IGenreRepository genreRepository,
-			IStudioRepository studioRepository,
-			IProviderRepository providerRepository,
-			IPeopleRepository peopleRepository,
-			DbContext database)
-			: base(libraryRepository,
-				libraryItemRepository,
-				collectionRepository,
-				showRepository,
-				seasonRepository,
-				episodeRepository,
-				trackRepository,
-				genreRepository,
-				studioRepository,
-				providerRepository,
-				peopleRepository)
-		{
-			_database = database;
-		}
-		
-		public override Task Load<T, T2>(T obj, Expression<Func<T, IEnumerable<T2>>> member)
-		{
-			if (obj == null)
-				throw new ArgumentNullException(nameof(obj));
-			if (!Utility.IsPropertyExpression(member) || member == null)
-				throw new ArgumentException($"{nameof(member)} is not a property.");
-			return _database.Entry(obj).Collection(member).LoadAsync();
-		}
-		
-		public override Task Load<T, T2>(T obj, Expression<Func<T, T2>> member)
-		{
-			if (obj == null)
-				throw new ArgumentNullException(nameof(obj));
-			if (!Utility.IsPropertyExpression(member) || member == null)
-				throw new ArgumentException($"{nameof(member)} is not a property.");
-			return _database.Entry(obj).Reference(member).LoadAsync();
-		}
-	}
-}