Retructured solution

LiteCharms.Features/Shop/CartPackages/Commands/Handlers/AddPackageItemCommandHandler.cs

@@ -0,0 +1,38 @@
+using LiteCharms.Features.Shop.Postgres;
+
+namespace LiteCharms.Features.CartPackages.Commands.Handlers;
+
+public class AddPackageItemCommandHandler(IDbContextFactory<ShopDbContext> contextFactory) : IRequestHandler<AddPackageItemCommand, Result<Guid>>
+{
+    public async ValueTask<Result<Guid>> Handle(AddPackageItemCommand request, CancellationToken cancellationToken)
+    {
+        try
+        {
+            using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            if (!await context.Packages.AnyAsync(p => p.Id == request.PackageId, cancellationToken))
+                return Result.Fail($"Could not find package by ID {request.PackageId}");
+
+            if (!await context.ProductPrices.AnyAsync(p => p.Id == request.ProductPriceId && p.Active == true, cancellationToken))
+                return Result.Fail($"Could not find an active product price by ID {request.ProductPriceId}");
+
+            if (await context.PackageItems.AnyAsync(p => p.ProductPriceId == request.ProductPriceId && p.PackageId == request.PackageId, cancellationToken))
+                return Result.Fail<Guid>($"Product price {request.ProductPriceId} is already added to this package {request.PackageId}");
+
+            var newPackageItem = context.PackageItems.Add(new Entities.PackageItem
+            {
+                PackageId = request.PackageId,
+                ProductPriceId = request.ProductPriceId,
+                Active = true
+            });
+
+            return await context.SaveChangesAsync(cancellationToken) > 0
+                ? Result.Ok(newPackageItem.Entity.Id)
+                : Result.Fail<Guid>($"Failed to add new package item by ID {request.ProductPriceId}");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<Guid>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+}