restore incorrectly deleted file (#2114)

ErsatzTV.Application/Libraries/Commands/CreateLocalLibraryHandler.cs

@@ -0,0 +1,76 @@
+using System.Threading.Channels;
+using ErsatzTV.Application.MediaSources;
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Locking;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using static ErsatzTV.Application.Libraries.Mapper;
+
+namespace ErsatzTV.Application.Libraries;
+
+public class CreateLocalLibraryHandler : LocalLibraryHandlerBase,
+    IRequestHandler<CreateLocalLibrary, Either<BaseError, LocalLibraryViewModel>>
+{
+    private readonly IDbContextFactory<TvContext> _dbContextFactory;
+    private readonly IEntityLocker _entityLocker;
+    private readonly ChannelWriter<IScannerBackgroundServiceRequest> _scannerWorkerChannel;
+
+    public CreateLocalLibraryHandler(
+        ChannelWriter<IScannerBackgroundServiceRequest> scannerWorkerChannel,
+        IEntityLocker entityLocker,
+        IDbContextFactory<TvContext> dbContextFactory)
+    {
+        _scannerWorkerChannel = scannerWorkerChannel;
+        _entityLocker = entityLocker;
+        _dbContextFactory = dbContextFactory;
+    }
+
+    public async Task<Either<BaseError, LocalLibraryViewModel>> Handle(
+        CreateLocalLibrary request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Validation<BaseError, LocalLibrary> validation = await Validate(dbContext, request);
+        return await validation.Apply(localLibrary => PersistLocalLibrary(dbContext, localLibrary));
+    }
+
+    private async Task<LocalLibraryViewModel> PersistLocalLibrary(
+        TvContext dbContext,
+        LocalLibrary localLibrary)
+    {
+        await dbContext.LocalLibraries.AddAsync(localLibrary);
+        await dbContext.SaveChangesAsync();
+
+        if (_entityLocker.LockLibrary(localLibrary.Id))
+        {
+            await _scannerWorkerChannel.WriteAsync(new ForceScanLocalLibrary(localLibrary.Id));
+        }
+
+        return ProjectToViewModel(localLibrary);
+    }
+
+    private static Task<Validation<BaseError, LocalLibrary>> Validate(
+        TvContext dbContext,
+        CreateLocalLibrary request) =>
+        MediaSourceMustExist(dbContext, request)
+            .BindT(localLibrary => NameMustBeValid(request, localLibrary))
+            .BindT(localLibrary => PathsMustBeValid(dbContext, localLibrary));
+
+    private static Task<Validation<BaseError, LocalLibrary>> MediaSourceMustExist(
+        TvContext dbContext,
+        CreateLocalLibrary request) =>
+        dbContext.LocalMediaSources
+            .OrderBy(lms => lms.Id)
+            .FirstOrDefaultAsync()
+            .Map(Optional)
+            .MapT(
+                lms => new LocalLibrary
+                {
+                    Name = request.Name,
+                    Paths = request.Paths.Map(p => new LibraryPath { Path = p }).ToList(),
+                    MediaKind = request.MediaKind,
+                    MediaSourceId = lms.Id
+                })
+            .Map(o => o.ToValidation<BaseError>("LocalMediaSource does not exist."));
+}