FOUNDATIONS: Retrieve ReaderBook By Id

LibraryManagement.Api/Services/Foundations/ReaderBooks/IReaderBookService.cs

@@ -0,0 +1,14 @@
+//-----------------------------------------------------------
+// Copyright (c) Coalition of Good-Hearted Engineers
+// Free To Use To Build Reliable Library Management Solutions
+//-----------------------------------------------------------
+
+using LibraryManagement.Api.Models.Foundations.ReaderBooks;
+
+namespace LibraryManagement.Api.Services.Foundations.ReaderBooks
+{
+    public interface IReaderBookService
+    {
+        ValueTask<ReaderBook> RetrieveReaderBookByIdAsync(Guid readerId);
+    }
+}

LibraryManagement.Api/Services/Foundations/ReaderBooks/ReaderBookService.cs

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+//-----------------------------------------------------------
+// Copyright (c) Coalition of Good-Hearted Engineers
+// Free To Use To Build Reliable Library Management Solutions
+//-----------------------------------------------------------
+
+using LibraryManagement.Api.Models.Foundations.Books;
+using LibraryManagement.Api.Models.Foundations.ReaderBooks;
+using LibraryManagement.Api.Models.Foundations.Readers;
+using LibraryManagement.Api.Services.Foundations.Books;
+using LibraryManagement.Api.Services.Foundations.Readers;
+
+namespace LibraryManagement.Api.Services.Foundations.ReaderBooks
+{
+    public class ReaderBookService : IReaderBookService
+    {
+        private readonly IReaderService readerService;
+        private readonly IBookService bookService;
+
+        public ReaderBookService(
+            IReaderService readerService,
+            IBookService bookService)
+        {
+            this.readerService = readerService;
+            this.bookService = bookService;
+        }
+
+        public async ValueTask<ReaderBook> RetrieveReaderBookByIdAsync(Guid readerId)
+        {
+            Reader reader =
+                await this.readerService.RetrieveReaderByIdAsync(readerId);
+
+            IQueryable<Book> allBooks =
+                this.bookService.RetrieveAllBooks();
+
+            List<Book> booksForReader = allBooks
+                .Where(book => book.ReaderId == readerId)
+                .ToList();
+
+            return new ReaderBook
+            {
+                Reader = reader,
+                Books = booksForReader
+            };
+        }
+    }
+}