Added a way to get the Author by productId

LiteCharms.Features.MidrandBooks/Authors/AuthorService.cs

@@ -8,6 +8,29 @@ namespace LiteCharms.Features.MidrandBooks.Authors;
 
 public sealed class AuthorService(IDbContextFactory<MidrandBooksDbContext> contextFactory) : IService
 {
+    public async ValueTask<Result<Author>> GetAuthorByProductIdAsync(long productId, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
+
+            var author = await context.Books
+                .AsNoTracking()
+                .Include(i => i.Author)
+                .Where(b => b.ProductId == productId)                
+                .FirstOrDefaultAsync(cancellationToken);
+
+            if (author is null)
+                return Result.Fail<Author>(new Error($"No author association discovered for Product ID {productId}"));
+
+            return Result.Ok(author.Author!.ToModel());
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail<Author>(new Error(ex.Message).CausedBy(ex));
+        }
+    }
+
     public async ValueTask<Result> UpdateAuthorStatusAsync(long authorId, bool isEnabled, CancellationToken cancellationToken = default)
     {
         try

LiteCharms.Features.MidrandBooks/Products/ProductService.cs

@@ -153,7 +153,9 @@ public sealed class ProductService(IDbContextFactory<MidrandBooksDbContext> cont
         {
             await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
 
-            var query = context.Products.AsQueryable();
+            var query = context.Products
+                .Include(i => i.Price)
+                .AsQueryable();
 
             var cultureInfo = CultureInfo.InvariantCulture;
 
@@ -304,7 +306,9 @@ public sealed class ProductService(IDbContextFactory<MidrandBooksDbContext> cont
         {
             await using var context = await contextFactory.CreateDbContextAsync(cancellationToken);
 
-            var product = await context.Products.AsNoTracking().FirstOrDefaultAsync(p => p.Id == productId, cancellationToken);
+            var product = await context.Products
+                .Include(i => i.Price)
+                .AsNoTracking().FirstOrDefaultAsync(p => p.Id == productId, cancellationToken);
 
             return product is null
                 ? Result.Fail<Product>(new Error($"Product with ID {productId} not found."))