implement functions

Administration.cs

@@ -2,7 +2,7 @@ namespace Bücherwurm
 {
     class Administration
     {
-        private Catalogue Books {get; set;}
+        private Catalogue Catalogue {get; set;}
 
         private Inventory Inventory {get; set;}
 
@@ -10,7 +10,7 @@ namespace Bücherwurm
         
         public Administration()
         {
-            Books = new Catalogue();
+            Catalogue = new Catalogue();
             Inventory = new Inventory();
             Lendings = new Lend_Administration();
         }

Catalogue.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 
 namespace Bücherwurm
@@ -6,14 +7,30 @@ namespace Bücherwurm
     {
         private List<Book> Books {get; set;}
 
+        private int NextId {get; set;}
+
         public Catalogue()
         {
             Books = new List<Book>();
+            NextId = 0;
         }
 
         public void Import(string JsonString)
         {
             //TODO: implement!
         }
+
+        public void Add(string Title, string Author,
+            string Country, string ILink, string Link,
+            string Language, int Pages, int Year)
+        {
+            Books.Add(new Book(NextId, Title, Author, Country, ILink, Link, Language, Pages, Year));
+            NextId = NextId++;
+        }
+
+        public void Remove(int BookID)
+        {
+            Books.RemoveAll(book => book.BookId == BookID);
+        }
     }
 }

Inventory.cs

@@ -6,18 +6,22 @@ namespace Bücherwurm
     {
         private List<Item> InventoryList {get; set;}
 
+        private int NextId {get; set;}
+
         public Inventory(){
             InventoryList = new List<Item>();
+            NextId = 0;
         }
 
         public void Add(Book Book)
         {
-            //TODO: implement!
+            InventoryList.Add(new Item(NextId, Book.BookId));
+            NextId = NextId++;
         }
 
         public void Remove(int Id)
         {
-            //TODO: implement!
+            InventoryList.RemoveAll(item => item.ItemId == Id);
         }
     }
 }

Lend_Administration.cs

@@ -6,19 +6,27 @@ namespace Bücherwurm
     {
         private List<Lending> Lendings {get; set;}
 
+        private List<int> ActiveLendings {get; set;}
+
+        private int NextId {get; set;}
+
         public Lend_Administration()
         {
             Lendings = new List<Lending>();
+            ActiveLendings = new List<int>();
+            NextId = 0;
         }
 
-        public void Lend(int[] ItemsIds, string Customer)
+        public void Lend(int[] ItemIds, string Customer)
         {
-            //TODO: implement!
+            Lendings.Add(new Lending(NextId, ItemIds, Customer));
+            ActiveLendings.Add(NextId);
+            NextId = NextId++;
         }
 
         public void Return(int LendID)
         {
-            //TODO: implement!
+            ActiveLendings.RemoveAll(id => id == LendID);
         }
     }
 }

Program.cs

@@ -6,7 +6,7 @@ namespace Bücherwurm
     {
         static void Main(string[] args)
         {
-            Console.WriteLine("Hello World!");
+            var Admin = new Administration();
         }
     }
 }

diagrams/classes.drawio

@@ -1 +1 @@
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