done first ver. of MasterManager

MCTG/Model/Managers/MasterManager.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
+using System.Diagnostics;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
@@ -23,14 +24,52 @@ namespace Model.Managers
             CurrentConnectedUser = null;
         }
 
-        public bool LogIn(string mail, string password)
+        public bool Login(string mail, string password)
         {
-            if (Users is null)
-                throw new ArgumentNullException();
+            if (Users is null || Users.Count == 0)
+                throw new ArgumentNullException("There is no users registred.");
 
             User user = (User)(from u in Users
                                where u.Mail == mail
                                select u);
+
+            if (user is null || !user.psswMgr.VerifyPassword(user.Password, password))
+                return false;
+
+            CurrentConnectedUser = user;
+            return true;
+        }
+
+        public bool Logout()
+        {
+            if (CurrentConnectedUser is null)
+                return false;
+
+            CurrentConnectedUser = null;
+            return true;
+        }
+
+        public bool Register(User newuser)
+        {
+            try
+            {
+                User user = newuser;
+                DataMgr.Data[nameof(User)].Add(user);
+                Users = DataMgr.GetUsers();
+            }
+            catch (ArgumentException e)
+            {
+                Debug.WriteLine(e.Message);
+                return false;
+            }
+
+            return true;
+        }
+
+        public void AddRecipe(Recipe recipe)
+        {
+            DataMgr.Data[nameof(Recipe)].Add(recipe);
+            Recipes = DataMgr.GetRecipes();
         }
     }
 }