From 96111842f4de0dad161868cfeece38b7d65147f1 Mon Sep 17 00:00:00 2001
From: Richard Schmidt <richard.schmidt@informatik.hs-fulda>
Date: Wed, 7 Feb 2024 14:39:41 +0100
Subject: [PATCH] Added logic for checking if username / password exist

---
 src/main/java/LoginGUI.java | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/main/java/LoginGUI.java b/src/main/java/LoginGUI.java
index 4df5634..d19db0e 100644
--- a/src/main/java/LoginGUI.java
+++ b/src/main/java/LoginGUI.java
@@ -43,12 +43,29 @@ public class LoginGUI extends JFrame implements ActionListener {
             String username = usernameField.getText();
             String password = new String(passwordField.getPassword());
 
-            	//Add login functionality
-                JOptionPane.showMessageDialog(this, "Login");
+            if (authenticateUser(username, password)) {
+            JOptionPane.showMessageDialog(this, "Login successful!");
+            // Perform actions after successful login
+            } else {
+            JOptionPane.showMessageDialog(this, "Invalid username or password", "Login Error", JOptionPane.ERROR_MESSAGE);
+            }
                 
             
         }
     }
+    
+ // Function to authenticate the user by comparing the entered username and password with the saved user data
+    private boolean authenticateUser(String username, String password) {
+        List<CreateUser> userList = CreateUser.readUserListFromJsonFile("user.json");
+        if (userList != null) {
+            for (CreateUser user : userList) {
+            if (user.getUserName().equals(username) && user.getPassword().equals(password)) {
+            return true; //Success
+           }
+            }
+        }
+        return false; // Fail
+    }
 
 
     public static void main(String[] args) {