first pass at exercise

DesignPatternsSolution/Execise.Tests/UnitTests.cs

@@ -12,18 +12,28 @@ public void LibraryShouldBeSingleton()
         {
             //check that when you create a Library instance second time, 
             //you get exactly the same instance as for a very first time
+
+            Library lib1 = Library.getInstance();
+            Library lib2 = Library.getInstance();
+
+            Assert.AreSame(lib1, lib2);
         }
 
         //test that an book was registered successfully by checking the returned Id value is not -1
         [TestMethod]
         public void BookShouldRegister()
         {
+            int retVal = RegistrationRepository.Register(new Book("Author", "title", 2012, 42));
+
+            Assert.AreNotEqual(-1, retVal);
         }
 
         //test that an customer was registered successfully by checking the returned Id value is not -1
         [TestMethod]
         public void CustomerShouldRegister()
         {
+            int retVal = RegistrationRepository.Register(new Customer("Andrew", "123 fake st"));
+            Assert.AreNotEqual(-1, retVal);
         }
 
         //test that a book can be borrowed
@@ -32,6 +42,11 @@ public void CanBorrowBook()
         {
             //create a borrowable book with available amount more than one. 
             //Run BorrowOne method of the BookBorrowable instance. Check that total amount was reduced by one.
+            Book book = new Book("Author", "title", 2012, 42);
+            BookBorrowable borrowableBOok = new BookBorrowable(book, new BookDecorator());
+
+            borrowableBOok.BorrowOne();
+            Assert.AreEqual(41, book.AvailableAmount);
 
         }       
     }

DesignPatternsSolution/Exercise/BookBorrowable.cs

@@ -1,7 +1,28 @@
 namespace Exercise
 {
-    public class BookBorrowable 
+    public class BookBorrowable: Book
     {
-
+        private Book item;
+        private BookDecorator decorator;
+
+        public BookBorrowable(Book item, BookDecorator decorator) :
+            base(item.Author, item.NameOrTitle, item.YearCreated, item.AvailableAmount)
+        {
+            this.item = item;
+            this.decorator = decorator;
+        }
+
+        public void BorrowOne()
+        {
+            decorator.BorrowOne(item);
+        }
+    }
+
+    public class BookDecorator
+    {
+        public void BorrowOne(Item item)
+        {
+            item.AvailableAmount--;
+        }
     }
 }

DesignPatternsSolution/Exercise/Item.cs

@@ -8,15 +8,23 @@ public Item(int amount, int year)
             ObjType = ObjectType.Item;
             YearCreated = year;
         }
+
+
     }
 
-    public class Book : Item
+    public class Book : Item, IRegistarable
     {
         public Book(string author, string title, int year, int amount) : base(amount, year)
         {
             NameOrTitle = title;
             Author = author;
         }
+
         public string Author { get; set; }
+
+        public RegisteredObject GetRegistrationInfo()
+        {
+            return new RegisteredObject() { AvailableAmount = AvailableAmount, Info = NameOrTitle };
+        }
     }
 }

DesignPatternsSolution/Exercise/Library.cs

@@ -3,16 +3,19 @@
     public class Library
     {
         //implement Singleton to make sure only one library will exist
+        private static Library libraryInstance = new Library();
 
-
+        private Library() { }
+
+        public static Library getInstance()
+        {
+            return libraryInstance;
+        }
 
         //Implement Register method by utilizing RegistrationRepository (complete missing parts)
         public int Register()
         {
-            // return RegistrationRepository.Register();
-
-            //dummy, just to compile
-            return 0;
+            return RegistrationRepository.Register(new Book("andrew", "title",2017, 4));
         }
     }
 }

DesignPatternsSolution/Exercise/Person.cs

@@ -2,7 +2,7 @@
 
 namespace Exercise
 {
-    public class Customer : LibObject
+    public class Customer : LibObject, IRegistarable
     {
         public string Address { get; set; }
         public DateTime RegisteredAt { get; set; }
@@ -19,5 +19,14 @@ public void SetId(int id)
         {
             ObjectId = id;
         }
+
+        public RegisteredObject GetRegistrationInfo()
+        {
+            return new RegisteredObject()
+            {
+                AvailableAmount = 1,
+                Info = NameOrTitle
+            };
+        }
     }
 }