Handling race conditions on create if not exists of every repositories

Kyoo/Controllers/Repositories/EpisodeRepository.cs

@@ -106,7 +106,17 @@ namespace Kyoo.Controllers
 			Episode old = await Get(obj.Slug);
 			if (old != null)
 				return old.ID;
-			return await Create(obj);
+			try
+			{
+				return await Create(obj);
+			}
+			catch (DuplicatedItemException)
+			{
+				old = await Get(obj.Slug);
+				if (old == null)
+					throw new SystemException("Unknown database state.");
+				return old.ID;
+			}
 		}
 
 		public async Task Edit(Episode edited, bool resetOld)

Kyoo/Controllers/Repositories/GenreRepository.cs

@@ -80,7 +80,17 @@ namespace Kyoo.Controllers
 			Genre old = await Get(obj.Slug);
 			if (old != null)
 				return old.ID;
-			return await Create(obj);
+			try
+			{
+				return await Create(obj);
+			}
+			catch (DuplicatedItemException)
+			{
+				old = await Get(obj.Slug);
+				if (old == null)
+					throw new SystemException("Unknown database state.");
+				return old.ID;
+			}
 		}
 
 		public async Task Edit(Genre edited, bool resetOld)

Kyoo/Controllers/Repositories/LibraryRepository.cs

@@ -84,10 +84,20 @@ namespace Kyoo.Controllers
 			if (obj == null)
 				throw new ArgumentNullException(nameof(obj));
 
-			Library old = await Get(obj.Name);
+			Library old = await Get(obj.Slug);
 			if (old != null)
 				return old.ID;
-			return await Create(obj);
+			try
+			{
+				return await Create(obj);
+			}
+			catch (DuplicatedItemException)
+			{
+				old = await Get(obj.Slug);
+				if (old == null)
+					throw new SystemException("Unknown database state.");
+				return old.ID;
+			}
 		}
 
 		public async Task Edit(Library edited, bool resetOld)

Kyoo/Controllers/Repositories/PeopleRepository.cs

@@ -86,7 +86,17 @@ namespace Kyoo.Controllers
 			People old = await Get(obj.Slug);
 			if (old != null)
 				return old.ID;
-			return await Create(obj);
+			try
+			{
+				return await Create(obj);
+			}
+			catch (DuplicatedItemException)
+			{
+				old = await Get(obj.Slug);
+				if (old == null)
+					throw new SystemException("Unknown database state.");
+				return old.ID;
+			}
 		}
 
 		public async Task Edit(People edited, bool resetOld)

Kyoo/Controllers/Repositories/ProviderRepository.cs

@@ -80,7 +80,17 @@ namespace Kyoo.Controllers
 			ProviderID old = await Get(obj.Name);
 			if (old != null)
 				return old.ID;
-			return await Create(obj);
+			try
+			{
+				return await Create(obj);
+			}
+			catch (DuplicatedItemException)
+			{
+				old = await Get(obj.Name);
+				if (old == null)
+					throw new SystemException("Unknown database state.");
+				return old.ID;
+			}
 		}
 
 		public async Task Edit(ProviderID edited, bool resetOld)

Kyoo/Controllers/Repositories/SeasonRepository.cs

@@ -99,7 +99,17 @@ namespace Kyoo.Controllers
 			Season old = await Get(obj.Slug);
 			if (old != null)
 				return old.ID;
-			return await Create(obj);
+			try
+			{
+				return await Create(obj);
+			}
+			catch (DuplicatedItemException)
+			{
+				old = await Get(obj.Slug);
+				if (old == null)
+					throw new SystemException("Unknown database state.");
+				return old.ID;
+			}
 		}
 
 		public async Task Edit(Season edited, bool resetOld)

Kyoo/Controllers/Repositories/ShowRepository.cs

@@ -103,7 +103,17 @@ namespace Kyoo.Controllers
 			Show old = await Get(obj.Slug);
 			if (old != null)
 				return old.ID;
-			return await Create(obj);
+			try
+			{
+				return await Create(obj);
+			}
+			catch (DuplicatedItemException)
+			{
+				old = await Get(obj.Slug);
+				if (old == null)
+					throw new SystemException("Unknown database state.");
+				return old.ID;
+			}
 		}
 
 		public async Task Edit(Show edited, bool resetOld)

Kyoo/Controllers/Repositories/StudioRepository.cs

@@ -79,7 +79,17 @@ namespace Kyoo.Controllers
 			Studio old = await Get(obj.Slug);
 			if (old != null)
 				return old.ID;
-			return await Create(obj);
+			try
+			{
+				return await Create(obj);
+			}
+			catch (DuplicatedItemException)
+			{
+				old = await Get(obj.Slug);
+				if (old == null)
+					throw new SystemException("Unknown database state.");
+				return old.ID;
+			}
 		}
 
 		public async Task Edit(Studio edited, bool resetOld)