Now that we have a working chat system, we just need to build a layout, which works dynamically and looks decent along with not having the page always reload when sending a message.

Now including start.sh to start a php server using the router.php so no webserver is needed.

.gitignore

@@ -6,3 +6,15 @@
 
 ./.idea 
 ./.idea/*
+./.crush
+/AGENTS.md
+/composer.lock
+/.idea/copilot.data.migration.agent.xml
+/.idea/copilot.data.migration.ask.xml
+/.idea/copilot.data.migration.ask2agent.xml
+/.idea/copilot.data.migration.edit.xml
+/.idea/php.xml
+/.idea/phpunit.xml
+/PROFILES_README.md
+/.idea/vcs.xml
+/.idea/workspace.xml

application/_installation/04-create-table-messages.sql

@@ -0,0 +1,20 @@
+CREATE TABLE IF NOT EXISTS `messages` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  `sender_id` int(11) NOT NULL,
+  `receiver_id` int(11) DEFAULT NULL,
+  `group_type` enum('admins','moderators','all_users') DEFAULT NULL,
+  `subject` varchar(255) NOT NULL,
+  `message` text NOT NULL,
+  `is_read` tinyint(1) NOT NULL DEFAULT 0,
+  `created_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `updated_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+  PRIMARY KEY (`id`),
+  KEY `sender_id` (`sender_id`),
+  KEY `receiver_id` (`receiver_id`),
+  KEY `is_read` (`is_read`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
+
+-- Foreign key constraints
+ALTER TABLE `messages`
+  ADD CONSTRAINT `messages_ibfk_1` FOREIGN KEY (`sender_id`) REFERENCES `users` (`user_id`) ON DELETE CASCADE,
+  ADD CONSTRAINT `messages_ibfk_2` FOREIGN KEY (`receiver_id`) REFERENCES `users` (`user_id`) ON DELETE CASCADE;

application/_installation/04-create-table-user-groups.sql

@@ -0,0 +1,15 @@
+CREATE TABLE IF NOT EXISTS `huge`.`user_groups` (
+  `group_id` TINYINT(1) NOT NULL COMMENT 'numeric user group id, matches users.user_account_type',
+  `group_name` VARCHAR(64) COLLATE utf8_unicode_ci NOT NULL COMMENT 'human readable group name',
+  PRIMARY KEY (`group_id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci COMMENT='user groups lookup';
+
+INSERT INTO `huge`.`user_groups` (`group_id`, `group_name`) VALUES
+  (1, 'Gast'),
+  (2, 'Benutzer'),
+  (3, 'Gruppe 3'),
+  (4, 'Gruppe 4'),
+  (5, 'Gruppe 5'),
+  (6, 'Gruppe 6'),
+  (7, 'Admin')
+ON DUPLICATE KEY UPDATE `group_name` = VALUES(`group_name`);

application/controller/AdminController.php

@@ -20,7 +20,9 @@ class AdminController extends Controller
     public function index()
     {
         $this->View->render('admin/index', array(
-                'users' => UserModel::getPublicProfilesOfAllUsers())
+                'users' => UserModel::getPublicProfilesOfAllUsers(),
+                'groups' => GroupModel::getAllGroups()
+            )
         );
     }
 
@@ -33,24 +35,9 @@ class AdminController extends Controller
         Redirect::to("admin");
     }
 
-    public function registerUser()
+    public function changeUserGroup()
     {
-        // Ensure the user is logged in and is an admin
-        if (!LoginModel::isUserLoggedIn() || !LoginModel::isAdmin()) {
-            Session::add('feedback_negative', Text::get('FEEDBACK_ADMIN_ONLY'));
-            Redirect::to('admin/index');
-            return;
-        }
-
-        // Validate and register the new user
-        $registration_successful = RegistrationModel::registerNewUser(true);
-
-        if ($registration_successful) {
-            Session::add('feedback_positive', Text::get('FEEDBACK_USER_REGISTERED_SUCCESSFULLY'));
-        } else {
-            Session::add('feedback_negative', Text::get('FEEDBACK_USER_REGISTRATION_FAILED'));
-        }
-
-        Redirect::to('admin/index');
+        GroupModel::setUserGroup(Request::post('user_id'), Request::post('group_id'));
+        Redirect::to("admin");
     }
 }

application/controller/DirectoryController.php

@@ -0,0 +1,16 @@
+<?php
+
+class DirectoryController extends Controller
+{
+    public function __construct()
+    {
+        parent::__construct();
+    }
+
+    public function index()
+    {
+        $this->View->render('directory/index', [
+            'users' => UserModel::getUsersWithGroups()
+        ]);
+    }
+}

application/controller/MessageController.php

@@ -0,0 +1,212 @@
+<?php
+
+class MessageController extends Controller
+{
+    public function __construct()
+    {
+        parent::__construct();
+        
+        // Require login for all message features
+        Auth::checkAuthentication();
+    }
+    
+    /**
+     * Send a message to a specific user via URL parameters
+     * URL format: message/send/{receiver_id}/{subject}/{message}
+     */
+    public function send()
+    {
+        // Handle POST request
+        if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+            $receiver_id = isset($_POST['receiver_id']) ? $_POST['receiver_id'] : null;
+            $subject = isset($_POST['subject']) ? $_POST['subject'] : 'No Subject';
+            $message = isset($_POST['message']) ? $_POST['message'] : null;
+            
+            if (!$receiver_id || !$message) {
+                Session::add('feedback_negative', 'Receiver and message are required');
+                Redirect::to('message');
+                return;
+            }
+            
+            // Send the message
+            $sender_id = Session::get('user_id');
+            $success = MessageModel::sendToUser($sender_id, $receiver_id, $subject, $message);
+            
+            if ($success) {
+                Session::add('feedback_positive', 'Message sent successfully');
+            } else {
+                Session::add('feedback_negative', 'Failed to send message');
+            }
+            
+            // If coming from conversation view, return there
+            if (isset($_SERVER['HTTP_REFERER']) && strpos($_SERVER['HTTP_REFERER'], 'conversation') !== false) {
+                Redirect::to('message/conversation/' . $receiver_id);
+            } else {
+                Redirect::to('message');
+            }
+            return;
+        }
+        
+        // Handle GET request
+        $url_parts = explode('/', trim($_SERVER['REQUEST_URI'], '/'));
+        $receiver_id = isset($url_parts[2]) ? $url_parts[2] : null;
+        $subject = isset($url_parts[3]) ? urldecode($url_parts[3]) : null;
+        $message = isset($url_parts[4]) ? urldecode($url_parts[4]) : null;
+        
+        if (!$receiver_id || !$subject || !$message) {
+            header('Content-Type: application/json');
+            echo json_encode(['success' => false, 'message' => 'Missing parameters. Use: message/send/{receiver_id}/{subject}/{message}']);
+            return;
+        }
+        
+        // Verify receiver exists
+        $receiver = UserModel::getPublicProfileOfUser($receiver_id);
+        if (!$receiver) {
+            header('Content-Type: application/json');
+            echo json_encode(['success' => false, 'message' => 'Receiver not found']);
+            return;
+        }
+        
+        // Send the message
+        $sender_id = Session::get('user_id');
+        $success = MessageModel::sendToUser($sender_id, $receiver_id, $subject, $message);
+        
+        header('Content-Type: application/json');
+        if ($success) {
+            echo json_encode(['success' => true, 'message' => 'Message sent successfully']);
+        } else {
+            echo json_encode(['success' => false, 'message' => 'Failed to send message']);
+        }
+    }
+    
+    /**
+     * Send a message to a group via URL parameters
+     * URL format: message/sendgroup/{group_type}/{subject}/{message}
+     * group_type can be: admins, moderators, all_users
+     */
+    public function sendgroup()
+    {
+        // Handle POST request
+        if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+            $group_type = isset($_POST['group_type']) ? $_POST['group_type'] : null;
+            $subject = isset($_POST['subject']) ? $_POST['subject'] : 'No Subject';
+            $message = isset($_POST['message']) ? $_POST['message'] : null;
+            
+            if (!$group_type || !$message) {
+                Session::add('feedback_negative', 'Group type and message are required');
+                Redirect::to('message');
+                return;
+            }
+            
+            // Validate group type
+            if (!in_array($group_type, ['admins', 'moderators', 'all_users'])) {
+                Session::add('feedback_negative', 'Invalid group type');
+                Redirect::to('message');
+                return;
+            }
+            
+            // Send the message
+            $sender_id = Session::get('user_id');
+            $success = MessageModel::sendToGroup($sender_id, $group_type, $subject, $message);
+            
+            if ($success) {
+                Session::add('feedback_positive', 'Message sent to group successfully');
+            } else {
+                Session::add('feedback_negative', 'Failed to send message to group');
+            }
+            
+            Redirect::to('message');
+            return;
+        }
+        
+        // Handle GET request
+        $url_parts = explode('/', trim($_SERVER['REQUEST_URI'], '/'));
+        $group_type = isset($url_parts[2]) ? $url_parts[2] : null;
+        $subject = isset($url_parts[3]) ? urldecode($url_parts[3]) : null;
+        $message = isset($url_parts[4]) ? urldecode($url_parts[4]) : null;
+        
+        if (!$group_type || !$subject || !$message) {
+            header('Content-Type: application/json');
+            echo json_encode(['success' => false, 'message' => 'Missing parameters. Use: message/sendgroup/{group_type}/{subject}/{message}']);
+            return;
+        }
+        
+        // Validate group type
+        if (!in_array($group_type, ['admins', 'moderators', 'all_users'])) {
+            header('Content-Type: application/json');
+            echo json_encode(['success' => false, 'message' => 'Invalid group type. Must be: admins, moderators, or all_users']);
+            return;
+        }
+        
+        // Send the message
+        $sender_id = Session::get('user_id');
+        $success = MessageModel::sendToGroup($sender_id, $group_type, $subject, $message);
+        
+        header('Content-Type: application/json');
+        if ($success) {
+            echo json_encode(['success' => true, 'message' => 'Message sent to group successfully']);
+        } else {
+            echo json_encode(['success' => false, 'message' => 'Failed to send message to group']);
+        }
+    }
+    
+    /**
+     * Show the messenger interface
+     */
+    public function index()
+    {
+        $user_id = Session::get('user_id');
+        
+        // Get conversations and unread count
+        $conversations = MessageModel::getConversations($user_id);
+        $unread_count = MessageModel::getUnreadCount($user_id);
+        
+        $this->View->render('message/index', array(
+            'conversations' => $conversations,
+            'unread_count' => $unread_count,
+            'all_users' => MessageModel::getAllUsers($user_id)
+        ));
+    }
+    
+    /**
+     * Show conversation with a specific user
+     */
+    public function conversation()
+    {
+        $user_id = Session::get('user_id');
+        $url_parts = explode('/', trim($_SERVER['REQUEST_URI'], '/'));
+        $other_user_id = isset($url_parts[2]) ? $url_parts[2] : null;
+        
+        if (!$other_user_id) {
+            Redirect::to('message');
+            return;
+        }
+        
+        // Get user info for the other person
+        $other_user = UserModel::getPublicProfileOfUser($other_user_id);
+        if (!$other_user) {
+            Redirect::to('message');
+            return;
+        }
+        
+        // Get messages
+        $messages = MessageModel::getMessagesWithUser($user_id, $other_user_id);
+        
+        $this->View->render('message/conversation', array(
+            'messages' => $messages,
+            'other_user' => $other_user
+        ));
+    }
+    
+    /**
+     * Get unread count as JSON
+     */
+    public function unreadcount()
+    {
+        $user_id = Session::get('user_id');
+        $unread_count = MessageModel::getUnreadCount($user_id);
+        
+        header('Content-Type: application/json');
+        echo json_encode(['unread_count' => $unread_count]);
+    }
+}

application/controller/ProfileController.php

@@ -16,8 +16,16 @@ class ProfileController extends Controller
      */
     public function index()
     {
+        $all_users = UserModel::getPublicProfilesOfAllUsers();
+        
+        // Remove current user from the list
+        $current_user_id = Session::get('user_id');
+        if ($current_user_id && isset($all_users[$current_user_id])) {
+            unset($all_users[$current_user_id]);
+        }
+        
         $this->View->render('profile/index', array(
-            'users' => UserModel::getPublicProfilesOfAllUsers())
+            'users' => $all_users)
         );
     }
 

application/controller/RegisterController.php

@@ -22,12 +22,8 @@ class RegisterController extends Controller
      */
     public function index()
     {
-        // Redirect non-logged-in users to the login page
-        if (!LoginModel::isUserLoggedIn()) {
-            Redirect::to('login/index');
-            return;
-        }
-
+        // only admins can access registration; reuse existing admin auth check
+        Auth::checkAdminAuthentication();
         $this->View->render('register/index');
     }
 
@@ -37,20 +33,12 @@ class RegisterController extends Controller
      */
     public function register_action()
     {
-        // Restrict registration to admins only
-        if (!LoginModel::isAdmin()) {
-            Session::add('feedback_negative', Text::get('FEEDBACK_ADMIN_ONLY'));
-            Redirect::to('login/index');
-            return;
-        }
+        // enforce admin-only for registration
+        Auth::checkAdminAuthentication();
 
-        $registration_successful = RegistrationModel::registerNewUser();
+        RegistrationModel::registerNewUser();
 
-        if ($registration_successful) {
-            Redirect::to('login/index');
-        } else {
-            Redirect::to('register/index');
-        }
+        Redirect::to('admin/index');
     }
 
     /**
@@ -76,7 +64,7 @@ class RegisterController extends Controller
      */
     public function showCaptcha()
     {
-        Session::add('feedback_negative', Text::get('FEEDBACK_CAPTCHA_NOT_USED'));
+        // Captcha no longer used
         Redirect::to('register/index');
     }
 }

application/core/Application.php

@@ -19,10 +19,13 @@ class Application
     private $action_name;
 
     /**
-     * Start the application, analyze URL elements, call according controller/method or relocate to fallback location
+     * Construct
      */
     public function __construct()
     {
+        // Reset header render flag
+        View::resetHeaderRendered();
+        
         // create array with URL parts in $url
         $this->splitUrl();
 

application/core/DatabaseFactory.php

@@ -21,44 +21,76 @@
  */
 class DatabaseFactory
 {
-    private static $factory;
-    private $database;
+  private static $factory;
+  private $database;
 
-    public static function getFactory()
-    {
-        if (!self::$factory) {
-            self::$factory = new DatabaseFactory();
-        }
-        return self::$factory;
+  public static function getFactory()
+  {
+    if (!self::$factory) {
+      self::$factory = new DatabaseFactory();
+    }
+    return self::$factory;
+  }
+
+  public function getConnectionWithMySQLI()
+  {
+    if (!$this->database) {
+      // Throw exceptions and prevent also throwing credentials.
+      mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
+
+      try {
+        $host = Config::get('DB_HOST');
+        $user = Config::get('DB_USER');
+        $pass = Config::get('DB_PASS');
+        $name = Config::get('DB_NAME');
+        $port = (int) Config::get('DB_PORT');
+        $charset = Config::get('DB_CHARSET') ? Config::get('DB_CHARSET') : 'utf8mb4';
+
+        $this->database = new mysqli($host, $user, $pass, $name, $port);
+
+        // Set charset (important for security + correct encoding)
+        $this->database->set_charset($charset);
+      } catch (mysqli_sql_exception $e) {
+        echo 'Database connection can not be estabilished. Please try again later.' . '<br>';
+        echo 'Error code: ' . $e->getCode();
+        exit;
+      }
     }
 
-    public function getConnection() {
-        if (!$this->database) {
+    return $this->database;
+  }
 
-            /**
-             * Check DB connection in try/catch block. Also when PDO is not constructed properly,
-             * prevent to exposing database host, username and password in plain text as:
-             * PDO->__construct('mysql:host=127....', 'root', '12345678', Array)
-             * by throwing custom error message
-             */
-            try {
-                $options = array(PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_OBJ, PDO::ATTR_ERRMODE => PDO::ERRMODE_WARNING);
-                $this->database = new PDO(
-                   Config::get('DB_TYPE') . ':host=' . Config::get('DB_HOST') . ';dbname=' .
-                   Config::get('DB_NAME') . ';port=' . Config::get('DB_PORT') . ';charset=' . Config::get('DB_CHARSET'),
-                   Config::get('DB_USER'), Config::get('DB_PASS'), $options
-                   );
-            } catch (PDOException $e) {
+  public function getConnection()
+  {
+    if (!$this->database) {
 
-                // Echo custom message. Echo error code gives you some info.
-                echo 'Database connection can not be estabilished. Please try again later.' . '<br>';
-                echo 'Error code: ' . $e->getCode();
+      /**
+       * Check DB connection in try/catch block. Also when PDO is not constructed properly,
+       * prevent to exposing database host, username and password in plain text as:
+       * PDO->__construct('mysql:host=127....', 'root', '12345678', Array)
+       * by throwing custom error message
+       */
+      try {
+        $options = array(PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_OBJ, PDO::ATTR_ERRMODE => PDO::ERRMODE_WARNING);
+        $this->database = new PDO(
+          Config::get('DB_TYPE') . ':host=' . Config::get('DB_HOST') . ';dbname=' .
+            Config::get('DB_NAME') . ';port=' . Config::get('DB_PORT') . ';charset=' . Config::get('DB_CHARSET'),
+          Config::get('DB_USER'),
+          Config::get('DB_PASS'),
+          $options
+        );
+      } catch (PDOException $e) {
 
-                // Stop application :(
-                // No connection, reached limit connections etc. so no point to keep it running
-                exit;
-            }
-        }
-        return $this->database;
+        // Echo custom message. Echo error code gives you some info.
+        echo 'Database connection can not be estabilished. Please try again later.' . '<br>';
+        echo 'Error code: ' . $e->getCode();
+
+        // Stop application :(
+        // No connection, reached limit connections etc. so no point to keep it running
+        exit;
+      }
     }
+
+    return $this->database;
+  }
 }

application/core/Text.php

@@ -2,29 +2,16 @@
 
 class Text
 {
-    private static $texts;
+    public static $texts;
 
-    public static function get($key, $data = null)
+    public static function get($key)
     {
-        // if not $key
-        if (!$key) {
-            return null;
-        }
-
-        if ($data) {
-            foreach ($data as $var => $value) {
-                ${$var} = $value;
-            }
-        }
-
-        // load config file (this is only done once per application lifecycle)
         if (!self::$texts) {
             self::$texts = require(__DIR__ . '/../config/texts.php');
         }
 
-        // check if array key exists
         if (!array_key_exists($key, self::$texts)) {
-            return null;
+            return "TEXT NOT FOUND";
         }
 
         return self::$texts[$key];

application/core/View.php

@@ -17,6 +17,11 @@ class View
     public $avatar_file_path;
     public $user_account_type;
     
+    /**
+     * Static property to track if header has been rendered
+     */
+    private static $header_rendered = false;
+
     /**
      * simply includes (=shows) the view. this is done from the controller. In the controller, you usually say
      * $this->view->render('help/index'); to show (in this example) the view index.php in the folder help.
@@ -32,9 +37,15 @@ class View
             }
         }
 
-        require Config::get('PATH_VIEW') . '_templates/header.php';
-        require Config::get('PATH_VIEW') . $filename . '.php';
-        require Config::get('PATH_VIEW') . '_templates/footer.php';
+        if (!self::$header_rendered) {
+            self::$header_rendered = true;
+            
+            require Config::get('PATH_VIEW') . '_templates/header.php';
+            require Config::get('PATH_VIEW') . $filename . '.php';
+            require Config::get('PATH_VIEW') . '_templates/footer.php';
+        } else {
+            require Config::get('PATH_VIEW') . $filename . '.php';
+        }
     }
 
     /**
@@ -51,13 +62,17 @@ class View
             return false;
         }
 
-        if ($data) {
-            foreach ($data as $key => $value) {
-                $this->{$key} = $value;
-            }
-        }
+        if (!self::$header_rendered) {
+            self::$header_rendered = true;
             
-        require Config::get('PATH_VIEW') . '_templates/header.php';
+            if ($data) {
+                foreach ($data as $key => $value) {
+                    $this->{$key} = $value;
+                }
+            }
+
+            require Config::get('PATH_VIEW') . '_templates/header.php';
+        }
 
         foreach($filenames as $filename) {
             require Config::get('PATH_VIEW') . $filename . '.php';
@@ -92,6 +107,14 @@ class View
         echo json_encode($data);
     }
     
+    /**
+     * Reset header render flag at start of request
+     */
+    public static function resetHeaderRendered()
+    {
+        self::$header_rendered = false;
+    }
+
     /**
      * renders the feedback messages into the view
      */

application/model/GroupModel.php

@@ -0,0 +1,54 @@
+<?php
+
+class GroupModel
+{
+    public static function getAllGroups()
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        $sql = "SELECT group_id, group_name FROM user_groups ORDER BY group_id";
+        $query = $database->prepare($sql);
+        $query->execute();
+        return $query->fetchAll();
+    }
+
+    public static function getGroupNameById($group_id)
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        $sql = "SELECT group_name FROM user_groups WHERE group_id = :gid LIMIT 1";
+        $query = $database->prepare($sql);
+        $query->execute(array(':gid' => $group_id));
+        $row = $query->fetch();
+        return $row ? $row->group_name : null;
+    }
+
+    public static function setUserGroup($userId, $groupId)
+    {
+        if (!is_numeric($userId) || !is_numeric($groupId)) {
+            return false;
+        }
+
+        // Do not allow changing own group via admin UI to prevent lockout
+        if ((int)$userId === (int)Session::get('user_id')) {
+            Session::add('feedback_negative', Text::get('FEEDBACK_ACCOUNT_CANT_DELETE_SUSPEND_OWN'));
+            return false;
+        }
+
+        // Only allow groups that exist in lookup
+        $database = DatabaseFactory::getFactory()->getConnection();
+        $check = $database->prepare("SELECT 1 FROM user_groups WHERE group_id = :gid LIMIT 1");
+        $check->execute([':gid' => $groupId]);
+        if ($check->rowCount() !== 1) {
+            return false;
+        }
+
+        $query = $database->prepare("UPDATE users SET user_account_type = :gid WHERE user_id = :uid LIMIT 1");
+        $query->execute([':gid' => $groupId, ':uid' => $userId]);
+
+        if ($query->rowCount() === 1) {
+            Session::add('feedback_positive', 'Benutzergruppe aktualisiert.');
+            return true;
+        }
+
+        return false;
+    }
+}

application/model/LoginModel.php

@@ -379,15 +379,4 @@ class LoginModel
     {
         return Session::userIsLoggedIn();
     }
-
-    /**
-     * Check if the logged-in user is an admin
-     *
-     * @return bool True if the user is an admin, false otherwise
-     */
-    public static function isAdmin()
-    {
-        $user_role = Session::get('user_role'); // Assuming user role is stored in session
-        return $user_role === 'admin';
-    }
 }

application/model/MessageModel.php

@@ -0,0 +1,186 @@
+<?php
+
+class MessageModel
+{
+    public static function sendMessage($sender_id, $receiver_id, $group_type, $subject, $message)
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        
+        $sql = "INSERT INTO messages (sender_id, receiver_id, group_type, subject, message) 
+                VALUES (:sender_id, :receiver_id, :group_type, :subject, :message)";
+        $query = $database->prepare($sql);
+        return $query->execute(array(
+            ':sender_id' => $sender_id,
+            ':receiver_id' => $receiver_id,
+            ':group_type' => $group_type,
+            ':subject' => $subject,
+            ':message' => $message
+        ));
+    }
+    
+    public static function sendToUser($sender_id, $receiver_id, $subject, $message)
+    {
+        return self::sendMessage($sender_id, $receiver_id, null, $subject, $message);
+    }
+    
+    public static function sendToGroup($sender_id, $group_type, $subject, $message)
+    {
+        return self::sendMessage($sender_id, null, $group_type, $subject, $message);
+    }
+    
+    public static function getUnreadCount($user_id)
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        
+        $sql = "SELECT COUNT(*) as count FROM messages 
+                WHERE receiver_id = :user_id AND is_read = 0";
+        $query = $database->prepare($sql);
+        $query->execute(array(':user_id' => $user_id));
+        $result = $query->fetch();
+        
+        return $result->count;
+    }
+    
+    public static function getUnreadCountForUser($user_id, $sender_id)
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        
+        $sql = "SELECT COUNT(*) as count FROM messages 
+                WHERE receiver_id = :user_id AND sender_id = :sender_id AND is_read = 0";
+        $query = $database->prepare($sql);
+        $query->execute(array(
+            ':user_id' => $user_id,
+            ':sender_id' => $sender_id
+        ));
+        $result = $query->fetch();
+        
+        return $result->count;
+    }
+    
+    public static function getConversations($user_id)
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        
+        $sql = "SELECT DISTINCT 
+                    CASE 
+                        WHEN sender_id = :user_id THEN receiver_id 
+                        ELSE sender_id 
+                    END as other_user_id,
+                    u.user_name,
+                    u.user_email,
+                    MAX(m.created_at) as last_message_time,
+                    (SELECT COUNT(*) FROM messages m2 
+                     WHERE ((m2.sender_id = :user_id AND m2.receiver_id = other_user_id) OR 
+                           (m2.receiver_id = :user_id AND m2.sender_id = other_user_id)) 
+                     AND m2.is_read = 0 AND m2.receiver_id = :user_id) as unread_count
+                FROM messages m
+                JOIN users u ON (CASE 
+                    WHEN sender_id = :user_id THEN receiver_id 
+                    ELSE sender_id 
+                END) = u.user_id
+                WHERE (sender_id = :user_id OR receiver_id = :user_id)
+                  AND receiver_id IS NOT NULL
+                GROUP BY other_user_id
+                ORDER BY last_message_time DESC";
+        
+        $query = $database->prepare($sql);
+        $query->execute(array(':user_id' => $user_id));
+        return $query->fetchAll();
+    }
+    
+    public static function getMessagesWithUser($user_id, $other_user_id)
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        
+        $sql = "SELECT m.*, u_sender.user_name as sender_name, 
+                       CASE 
+                           WHEN m.sender_id = :user_id THEN 'sent' 
+                           ELSE 'received' 
+                       END as message_type
+                FROM messages m
+                JOIN users u_sender ON m.sender_id = u_sender.user_id
+                WHERE ((m.sender_id = :user_id AND m.receiver_id = :other_user_id) OR 
+                       (m.receiver_id = :user_id AND m.sender_id = :other_user_id))
+                  AND m.group_type IS NULL
+                ORDER BY m.created_at ASC";
+        
+        $query = $database->prepare($sql);
+        $query->execute(array(
+            ':user_id' => $user_id,
+            ':other_user_id' => $other_user_id
+        ));
+        $messages = $query->fetchAll();
+        
+        // Mark received messages as read
+        self::markAsRead($user_id, $other_user_id);
+        
+        return $messages;
+    }
+    
+    public static function markAsRead($user_id, $sender_id)
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        
+        $sql = "UPDATE messages SET is_read = 1 
+                WHERE receiver_id = :user_id AND sender_id = :sender_id AND is_read = 0";
+        $query = $database->prepare($sql);
+        return $query->execute(array(
+            ':user_id' => $user_id,
+            ':sender_id' => $sender_id
+        ));
+    }
+    
+    public static function getGroupMessages($user_id)
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        
+        // Check user role to determine which group messages they should receive
+        $user_role = UserModel::getUserRole($user_id);
+        
+        $where_conditions = [];
+        $params = [':user_id' => $user_id];
+        
+        // All users receive all_users messages
+        $where_conditions[] = "group_type = 'all_users'";
+        
+        // Admins receive admin messages
+        if ($user_role === 'admin') {
+            $where_conditions[] = "group_type = 'admins'";
+        }
+        
+        // Moderators receive moderator messages (and admin messages if not already covered)
+        if ($user_role === 'moderator' || $user_role === 'admin') {
+            $where_conditions[] = "group_type = 'moderators'";
+        }
+        
+        if (empty($where_conditions)) {
+            return []; // User has no role that qualifies for group messages
+        }
+        
+        $where_clause = "(" . implode(" OR ", $where_conditions) . ")";
+        
+        $sql = "SELECT m.*, u.user_name as sender_name 
+                FROM messages m
+                JOIN users u ON m.sender_id = u.user_id
+                WHERE $where_clause AND m.receiver_id IS NULL
+                ORDER BY m.created_at DESC";
+        
+        $query = $database->prepare($sql);
+        $query->execute($params);
+        return $query->fetchAll();
+    }
+    
+    public static function getAllUsers($current_user_id)
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        
+        $sql = "SELECT user_id, user_name, user_email 
+                FROM users 
+                WHERE user_id != :current_user_id
+                ORDER BY user_name ASC";
+        
+        $query = $database->prepare($sql);
+        $query->execute(array(':current_user_id' => $current_user_id));
+        return $query->fetchAll();
+    }
+}

application/model/NoteModel.php

@@ -6,115 +6,114 @@
  */
 class NoteModel
 {
-    /**
-     * Get all notes (notes are just example data that the user has created)
-     * @return array an array with several objects (the results)
-     */
-    public static function getAllNotes()
-    {
-        $database = DatabaseFactory::getFactory()->getConnection();
+  /**
+   * Get all notes (notes are just example data that the user has created)
+   * @return array an array with several objects (the results)
+   */
+  public static function getAllNotes()
+  {
+    $database = DatabaseFactory::getFactory()->getConnection();
 
-        $sql = "SELECT user_id, note_id, note_text FROM notes WHERE user_id = :user_id";
-        $query = $database->prepare($sql);
-        $query->execute(array(':user_id' => Session::get('user_id')));
+    $sql = "SELECT user_id, note_id, note_text FROM notes WHERE user_id = :user_id";
+    $query = $database->prepare($sql);
+    $query->execute(array(':user_id' => Session::get('user_id')));
 
-        // fetchAll() is the PDO method that gets all result rows
-        return $query->fetchAll();
+    // fetchAll() is the PDO method that gets all result rows
+    return $query->fetchAll();
+  }
+
+  /**
+   * Get a single note
+   * @param int $note_id id of the specific note
+   * @return object a single object (the result)
+   */
+  public static function getNote($note_id)
+  {
+    $database = DatabaseFactory::getFactory()->getConnectionWithMySQLI();
+
+    $sql = "SELECT user_id, note_id, note_text FROM notes WHERE user_id = :user_id AND note_id = :note_id LIMIT 1";
+    $query = $database->prepare($sql);
+    $query->execute(array(':user_id' => Session::get('user_id'), ':note_id' => $note_id));
+
+    return $query;
+  }
+
+  /**
+   * Set a note (create a new one)
+   * @param string $note_text note text that will be created
+   * @return bool feedback (was the note created properly ?)
+   */
+  public static function createNote($note_text)
+  {
+    if (!$note_text || strlen($note_text) == 0) {
+      Session::add('feedback_negative', Text::get('FEEDBACK_NOTE_CREATION_FAILED'));
+      return false;
     }
 
-    /**
-     * Get a single note
-     * @param int $note_id id of the specific note
-     * @return object a single object (the result)
-     */
-    public static function getNote($note_id)
-    {
-        $database = DatabaseFactory::getFactory()->getConnection();
+    $database = DatabaseFactory::getFactory()->getConnection();
 
-        $sql = "SELECT user_id, note_id, note_text FROM notes WHERE user_id = :user_id AND note_id = :note_id LIMIT 1";
-        $query = $database->prepare($sql);
-        $query->execute(array(':user_id' => Session::get('user_id'), ':note_id' => $note_id));
+    $sql = "INSERT INTO notes (note_text, user_id) VALUES (:note_text, :user_id)";
+    $query = $database->prepare($sql);
+    $query->execute(array(':note_text' => $note_text, ':user_id' => Session::get('user_id')));
 
-        // fetch() is the PDO method that gets a single result
-        return $query->fetch();
+    if ($query->rowCount() == 1) {
+      return true;
     }
 
-    /**
-     * Set a note (create a new one)
-     * @param string $note_text note text that will be created
-     * @return bool feedback (was the note created properly ?)
-     */
-    public static function createNote($note_text)
-    {
-        if (!$note_text || strlen($note_text) == 0) {
-            Session::add('feedback_negative', Text::get('FEEDBACK_NOTE_CREATION_FAILED'));
-            return false;
-        }
+    // default return
+    Session::add('feedback_negative', Text::get('FEEDBACK_NOTE_CREATION_FAILED'));
+    return false;
+  }
 
-        $database = DatabaseFactory::getFactory()->getConnection();
-
-        $sql = "INSERT INTO notes (note_text, user_id) VALUES (:note_text, :user_id)";
-        $query = $database->prepare($sql);
-        $query->execute(array(':note_text' => $note_text, ':user_id' => Session::get('user_id')));
-
-        if ($query->rowCount() == 1) {
-            return true;
-        }
-
-        // default return
-        Session::add('feedback_negative', Text::get('FEEDBACK_NOTE_CREATION_FAILED'));
-        return false;
+  /**
+   * Update an existing note
+   * @param int $note_id id of the specific note
+   * @param string $note_text new text of the specific note
+   * @return bool feedback (was the update successful ?)
+   */
+  public static function updateNote($note_id, $note_text)
+  {
+    if (!$note_id || !$note_text) {
+      return false;
     }
 
-    /**
-     * Update an existing note
-     * @param int $note_id id of the specific note
-     * @param string $note_text new text of the specific note
-     * @return bool feedback (was the update successful ?)
-     */
-    public static function updateNote($note_id, $note_text)
-    {
-        if (!$note_id || !$note_text) {
-            return false;
-        }
+    $database = DatabaseFactory::getFactory()->getConnection();
 
-        $database = DatabaseFactory::getFactory()->getConnection();
+    $sql = "UPDATE notes SET note_text = :note_text WHERE note_id = :note_id AND user_id = :user_id LIMIT 1";
+    $query = $database->prepare($sql);
+    $query->execute(array(':note_id' => $note_id, ':note_text' => $note_text, ':user_id' => Session::get('user_id')));
 
-        $sql = "UPDATE notes SET note_text = :note_text WHERE note_id = :note_id AND user_id = :user_id LIMIT 1";
-        $query = $database->prepare($sql);
-        $query->execute(array(':note_id' => $note_id, ':note_text' => $note_text, ':user_id' => Session::get('user_id')));
-
-        if ($query->rowCount() == 1) {
-            return true;
-        }
-
-        Session::add('feedback_negative', Text::get('FEEDBACK_NOTE_EDITING_FAILED'));
-        return false;
+    if ($query->rowCount() == 1) {
+      return true;
     }
 
-    /**
-     * Delete a specific note
-     * @param int $note_id id of the note
-     * @return bool feedback (was the note deleted properly ?)
-     */
-    public static function deleteNote($note_id)
-    {
-        if (!$note_id) {
-            return false;
-        }
+    Session::add('feedback_negative', Text::get('FEEDBACK_NOTE_EDITING_FAILED'));
+    return false;
+  }
 
-        $database = DatabaseFactory::getFactory()->getConnection();
-
-        $sql = "DELETE FROM notes WHERE note_id = :note_id AND user_id = :user_id LIMIT 1";
-        $query = $database->prepare($sql);
-        $query->execute(array(':note_id' => $note_id, ':user_id' => Session::get('user_id')));
-
-        if ($query->rowCount() == 1) {
-            return true;
-        }
-
-        // default return
-        Session::add('feedback_negative', Text::get('FEEDBACK_NOTE_DELETION_FAILED'));
-        return false;
+  /**
+   * Delete a specific note
+   * @param int $note_id id of the note
+   * @return bool feedback (was the note deleted properly ?)
+   */
+  public static function deleteNote($note_id)
+  {
+    if (!$note_id) {
+      return false;
     }
+
+    $database = DatabaseFactory::getFactory()->getConnection();
+
+    $sql = "DELETE FROM notes WHERE note_id = :note_id AND user_id = :user_id LIMIT 1";
+    $query = $database->prepare($sql);
+    $query->execute(array(':note_id' => $note_id, ':user_id' => Session::get('user_id')));
+
+    if ($query->rowCount() == 1) {
+      return true;
+    }
+
+    // default return
+    Session::add('feedback_negative', Text::get('FEEDBACK_NOTE_DELETION_FAILED'));
+    return false;
+  }
 }

application/model/RegistrationModel.php

@@ -19,28 +19,35 @@ class RegistrationModel
         $user_name = strip_tags(Request::post('user_name'));
         $user_email = strip_tags(Request::post('user_email'));
         // Use 'user_password' if provided (admin registration), otherwise 'user_password_new'
-        $user_password_new = $isAdmin ? Request::post('user_password') : Request::post('user_password_new');
+        $user_password_new = $isAdmin ? Request::post('user_password_new') : Request::post('user_password_new');
+        $user_password_repeat = $user_password_new; // no repeat field
 
-        // validate input (skip captcha validation)
-        $validation_result = self::registrationInputValidation($user_name, $user_password_new, $user_email);
-        if (!$validation_result) {
-            return false;
-        }
+        // validate using existing validators and messages
+        $valid = true;
+        if (!self::validateUserName($user_name)) { $valid = false; }
+        if (!self::validateUserEmail($user_email, $user_email)) { $valid = false; }
+        if (!self::validateUserPassword($user_password_new, $user_password_repeat)) { $valid = false; }
+        if (!$valid) { return false; }
 
         // hash the password
         $user_password_hash = password_hash($user_password_new, PASSWORD_DEFAULT);
 
-        // check if username or email already exists
-        if (UserModel::doesUsernameAlreadyExist($user_name) || UserModel::doesEmailAlreadyExist($user_email)) {
-            Session::add('feedback_negative', Text::get('FEEDBACK_USERNAME_OR_EMAIL_TAKEN'));
-            return false;
+        $return = true;
+        if (UserModel::doesUsernameAlreadyExist($user_name)) {
+            Session::add('feedback_negative', Text::get('FEEDBACK_USERNAME_ALREADY_TAKEN'));
+            $return = false;
         }
+        if (UserModel::doesEmailAlreadyExist($user_email)) {
+            Session::add('feedback_negative', Text::get('FEEDBACK_USER_EMAIL_ALREADY_TAKEN'));
+            $return = false;
+        }
+        if (!$return) return false;
 
-        // directly activate user (skip email verification)
-        $user_active = 1;
+        // directly activate user: set empty activation hash
+        $user_activation_hash = null;
 
         // write user data to database
-        if (!self::writeNewUserToDatabase($user_name, $user_password_hash, $user_email, time(), $user_active)) {
+        if (!self::writeNewUserToDatabase($user_name, $user_password_hash, $user_email, time(), $user_activation_hash)) {
             Session::add('feedback_negative', Text::get('FEEDBACK_ACCOUNT_CREATION_FAILED'));
             return false;
         }
@@ -141,11 +148,7 @@ class RegistrationModel
             return false;
         }
 
-        if (strlen($user_password_new) < 6) {
-            Session::add('feedback_negative', Text::get('FEEDBACK_PASSWORD_TOO_SHORT'));
-            return false;
-        }
-
+        // no minimum length restriction
         return true;
     }
 
@@ -164,9 +167,9 @@ class RegistrationModel
     {
         $database = DatabaseFactory::getFactory()->getConnection();
 
-        // write new users data into database
-        $sql = "INSERT INTO users (user_name, user_password_hash, user_email, user_creation_timestamp, user_activation_hash, user_provider_type)
-                    VALUES (:user_name, :user_password_hash, :user_email, :user_creation_timestamp, :user_activation_hash, :user_provider_type)";
+        // write new users data into database; set user_active=1 and user_activation_hash to provided value (can be null)
+        $sql = "INSERT INTO users (user_name, user_password_hash, user_email, user_creation_timestamp, user_activation_hash, user_provider_type, user_active)
+                    VALUES (:user_name, :user_password_hash, :user_email, :user_creation_timestamp, :user_activation_hash, :user_provider_type, 1)";
         $query = $database->prepare($sql);
         try {
             $query->execute(array(
@@ -178,8 +181,7 @@ class RegistrationModel
                 ':user_provider_type' => 'DEFAULT'
             ));
         } catch (PDOException $e) {
-            error_log("Database error during user creation: " . $e->getMessage());
-            Session::add('feedback_negative', "Database error: " . $e->getMessage());
+            // only one feedback message on failure
             return false;
         }
         $count =  $query->rowCount();

application/model/UserModel.php

@@ -19,7 +19,7 @@ class UserModel
     {
         $database = DatabaseFactory::getFactory()->getConnection();
 
-        $sql = "SELECT user_id, user_name, user_email, user_active, user_has_avatar, user_deleted FROM users";
+        $sql = "SELECT user_id, user_name, user_email, user_active, user_has_avatar, user_deleted, user_account_type FROM users";
         $query = $database->prepare($sql);
         $query->execute();
 
@@ -39,11 +39,46 @@ class UserModel
             $all_users_profiles[$user->user_id]->user_active = $user->user_active;
             $all_users_profiles[$user->user_id]->user_deleted = $user->user_deleted;
             $all_users_profiles[$user->user_id]->user_avatar_link = (Config::get('USE_GRAVATAR') ? AvatarModel::getGravatarLinkByEmail($user->user_email) : AvatarModel::getPublicAvatarFilePathOfUser($user->user_has_avatar, $user->user_id));
+            $all_users_profiles[$user->user_id]->user_account_type = $user->user_account_type;
         }
 
         return $all_users_profiles;
     }
 
+    /**
+     * Gets list of users including their group name via user_groups lookup.
+     * @return array
+     */
+    public static function getUsersWithGroups()
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+
+        $sql = "SELECT u.user_id, u.user_name, u.user_email, u.user_active, u.user_has_avatar, u.user_deleted, u.user_account_type,
+                       g.group_name
+                  FROM users u
+             LEFT JOIN user_groups g ON g.group_id = u.user_account_type";
+        $query = $database->prepare($sql);
+        $query->execute();
+
+        $result = [];
+        foreach ($query->fetchAll() as $user) {
+            array_walk_recursive($user, 'Filter::XSSFilter');
+
+            $obj = new stdClass();
+            $obj->user_id = $user->user_id;
+            $obj->user_name = $user->user_name;
+            $obj->user_email = $user->user_email;
+            $obj->user_active = $user->user_active;
+            $obj->user_deleted = $user->user_deleted;
+            $obj->user_account_type = $user->user_account_type;
+            $obj->group_name = $user->group_name;
+            $obj->user_avatar_link = (Config::get('USE_GRAVATAR') ? AvatarModel::getGravatarLinkByEmail($user->user_email) : AvatarModel::getPublicAvatarFilePathOfUser($user->user_has_avatar, $user->user_id));
+
+            $result[] = $obj;
+        }
+        return $result;
+    }
+
     /**
      * Gets a user's profile data, according to the given $user_id
      * @param int $user_id The user's id
@@ -340,4 +375,31 @@ class UserModel
         // return one row (we only have one result or nothing)
         return $query->fetch();
     }
+    
+    /**
+     * Gets the user role type based on account type
+     *
+     * @param $user_id int user id
+     *
+     * @return string The user role (admin, moderator, user)
+     */
+    public static function getUserRole($user_id)
+    {
+        $database = DatabaseFactory::getFactory()->getConnection();
+        
+        $sql = "SELECT user_account_type FROM users WHERE user_id = :user_id LIMIT 1";
+        $query = $database->prepare($sql);
+        $query->execute(array(':user_id' => $user_id));
+        $result = $query->fetch();
+        
+        // Map account type to role
+        switch ($result->user_account_type) {
+            case 7: // admin
+                return 'admin';
+            case 2: // moderator (example value, adjust according to your system)
+                return 'moderator';
+            default:
+                return 'user';
+        }
+    }
 }

application/view/_templates/header.php

@@ -24,6 +24,9 @@
             <li <?php if (View::checkForActiveController($filename, "profile")) { echo ' class="active" '; } ?> >
                 <a href="<?php echo Config::get('URL'); ?>profile/index">Profiles</a>
             </li>
+            <li <?php if (View::checkForActiveController($filename, "directory")) { echo ' class="active" '; } ?> >
+                <a href="<?php echo Config::get('URL'); ?>directory/index">Benutzer</a>
+            </li>
             <?php if (Session::userIsLoggedIn()) { ?>
                 <li <?php if (View::checkForActiveController($filename, "dashboard")) { echo ' class="active" '; } ?> >
                     <a href="<?php echo Config::get('URL'); ?>dashboard/index">Dashboard</a>
@@ -31,6 +34,17 @@
                 <li <?php if (View::checkForActiveController($filename, "note")) { echo ' class="active" '; } ?> >
                     <a href="<?php echo Config::get('URL'); ?>note/index">My Notes</a>
                 </li>
+                <li <?php if (View::checkForActiveController($filename, "message")) { echo ' class="active" '; } ?> >
+                    <a href="<?php echo Config::get('URL'); ?>message/index">Messages</a>
+                    <?php if (Session::userIsLoggedIn()) {
+                        // Get unread message count
+                        $user_id = Session::get('user_id');
+                        $unread_count = MessageModel::getUnreadCount($user_id);
+                        if ($unread_count > 0) {
+                            echo '<span class="message-badge">' . $unread_count . '</span>';
+                        }
+                    } ?>
+                </li>
             <?php } else { ?>
                 <!-- for not logged in users -->
                 <li <?php if (View::checkForActiveControllerAndAction($filename, "login/index")) { echo ' class="active" '; } ?> >

application/view/admin/index.php

@@ -22,6 +22,7 @@
                     <td>User's email</td>
                     <td>Activated ?</td>
                     <td>Link to user's profile</td>
+                    <td>Group</td>
                     <td>suspension Time in days</td>
                     <td>Soft delete</td>
                     <td>Submit</td>
@@ -41,6 +42,19 @@
                         <td>
                             <a href="<?= Config::get('URL') . 'profile/showProfile/' . $user->user_id; ?>">Profile</a>
                         </td>
+                        <td>
+                            <form action="<?= Config::get('URL'); ?>admin/changeUserGroup" method="post">
+                                <input type="hidden" name="user_id" value="<?= $user->user_id; ?>" />
+                                <select name="group_id">
+                                    <?php foreach ($this->groups as $group) { ?>
+                                        <option value="<?= $group->group_id; ?>" <?= (isset($user->user_account_type) && (int)$user->user_account_type === (int)$group->group_id ? 'selected' : '') ?>>
+                                            <?= (int)$group->group_id; ?> - <?= htmlspecialchars($group->group_name, ENT_QUOTES, 'UTF-8'); ?>
+                                        </option>
+                                    <?php } ?>
+                                </select>
+                                <input type="submit" value="Save" />
+                            </form>
+                        </td>
                         <form action="<?= config::get("URL"); ?>admin/actionAccountSettings" method="post">
                             <td><input type="number" name="suspension" /></td>
                             <td><input type="checkbox" name="softDelete" <?php if ($user->user_deleted) { ?> checked <?php } ?> /></td>
@@ -56,10 +70,10 @@
 
         <h3>Register a new user</h3>
 
-        <form method="post" action="<?php echo Config::get('URL'); ?>admin/registerUser">
+        <form method="post" action="<?php echo Config::get('URL'); ?>register/register_action">
             <input type="text" name="user_name" placeholder="Username" required />
             <input type="email" name="user_email" placeholder="Email address" required />
-            <input type="password" name="user_password" placeholder="Password" required />
+            <input type="password" name="user_password_new" placeholder="Password" required autocomplete="off" />
             <input type="submit" value="Register User" />
         </form>
 

application/view/directory/index.php

@@ -0,0 +1,54 @@
+<div class="container">
+    <h1>Benutzerverzeichnis</h1>
+
+    <div class="box">
+        <?php $this->renderFeedbackMessages(); ?>
+
+        <table id="users-table" class="overview-table" style="width:100%">
+            <thead>
+                <tr>
+                    <td>Id</td>
+                    <td>Avatar</td>
+                    <td>Benutzername</td>
+                    <td>Email</td>
+                    <td>Aktiv?</td>
+                    <td>Gruppe</td>
+                    <td>Profil</td>
+                </tr>
+            </thead>
+            <tbody>
+            <?php foreach ($this->users as $user) { ?>
+                <tr class="<?= ($user->user_active == 0 ? 'inactive' : 'active'); ?>">
+                    <td><?= $user->user_id; ?></td>
+                    <td class="avatar">
+                        <?php if (isset($user->user_avatar_link)) { ?>
+                            <img src="<?= $user->user_avatar_link; ?>"/>
+                        <?php } ?>
+                    </td>
+                    <td><?= $user->user_name; ?></td>
+                    <td><?= $user->user_email; ?></td>
+                    <td><?= ($user->user_active == 0 ? 'Nein' : 'Ja'); ?></td>
+                    <td><?= htmlspecialchars($user->group_name ?: $user->user_account_type, ENT_QUOTES, 'UTF-8'); ?></td>
+                    <td><a href="<?= Config::get('URL') . 'profile/showProfile/' . $user->user_id; ?>">Profil</a></td>
+                </tr>
+            <?php } ?>
+            </tbody>
+        </table>
+    </div>
+</div>
+
+<!-- jQuery & DataTables CDN -->
+<link rel="stylesheet" href="https://cdn.datatables.net/1.13.8/css/jquery.dataTables.min.css">
+<script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>
+<script src="https://cdn.datatables.net/1.13.8/js/jquery.dataTables.min.js"></script>
+<script>
+    $(document).ready(function(){
+        $('#users-table').DataTable({
+            pageLength: 10,
+            order: [[ 0, 'asc' ]],
+            language: {
+                url: 'https://cdn.datatables.net/plug-ins/1.13.8/i18n/de-DE.json'
+            }
+        });
+    });
+</script>

application/view/message/conversation.php

@@ -0,0 +1,115 @@
+<div class="container">
+  <div class="row">
+    <!-- Back to Messenger -->
+    <div class="col-md-12">
+      <a href="<?= Config::get('URL') ?>message" class="btn btn-default">
+        <span class="glyphicon glyphicon-arrow-left"></span> Back to Messenger
+      </a>
+      <hr>
+    </div>
+  </div>
+
+  <div class="row">
+    <!-- Chat Area -->
+    <div class="col-md-12">
+      <div class="panel panel-default">
+        <div class="panel-heading">
+          Conversation with <?= htmlspecialchars($this->other_user->user_name) ?>
+        </div>
+        <div class="panel-body message-container">
+          <?php if (empty($this->messages)): ?>
+            <div class="text-center">
+              <em>No messages yet. Start a conversation!</em>
+            </div>
+          <?php else: ?>
+            <?php foreach ($this->messages as $msg): ?>
+              <div class="message <?= $msg->message_type ?>">
+                <div class="message-bubble">
+                  <?= htmlspecialchars($msg->message) ?>
+                </div>
+                <div class="message-time">
+                  <?= date('M j, Y H:i', strtotime($msg->created_at)) ?>
+                </div>
+              </div>
+            <?php endforeach; ?>
+          <?php endif; ?>
+        </div>
+
+        <!-- Reply Form -->
+        <div class="panel-footer">
+          <form action="<?= Config::get('URL') ?>message/send" method="post" id="reply-form">
+            <input type="hidden" name="receiver_id" value="<?= $this->other_user->user_id ?>">
+            <div class="input-group">
+              <input type="text" name="message" class="form-control" placeholder="Type your message..." required>
+              <span class="input-group-btn">
+                <button type="submit" class="btn btn-primary">Send</button>
+              </span>
+            </div>
+          </form>
+        </div>
+      </div>
+    </div>
+  </div>
+</div>
+
+<style>
+  .message-container {
+    height: 400px;
+    overflow-y: auto;
+    background-color: #f5f5f5;
+    padding: 15px;
+  }
+
+  .message {
+    margin-bottom: 15px;
+    clear: both;
+  }
+
+  .message.sent {
+    text-align: right;
+  }
+
+  .message.received {
+    text-align: left;
+  }
+
+  .message-bubble {
+    display: inline-block;
+    max-width: 70%;
+    padding: 10px 15px;
+    border-radius: 18px;
+    position: relative;
+    word-wrap: break-word;
+  }
+
+  .message.sent .message-bubble {
+    background-color: #007bff;
+    color: white;
+  }
+
+  .message.received .message-bubble {
+    background-color: #e5e5ea;
+    color: black;
+  }
+
+  .message-time {
+    font-size: 0.8em;
+    color: #666;
+    margin-top: 5px;
+  }
+
+  /* Scroll to bottom of messages on load */
+  .message-container {
+    scroll-behavior: smooth;
+  }
+</style>
+
+<script>
+  // Scroll to bottom of messages
+  document.addEventListener('DOMContentLoaded', function() {
+    const container = document.querySelector('.message-container');
+    container.scrollTop = container.scrollHeight;
+  });
+</script>
+
+<?php $this->render('_templates/footer'); ?>

application/view/message/index.php

@@ -0,0 +1,175 @@
+<div class="container">
+  <h1>Messenger</h1>
+
+  <div class="row">
+    <!-- Conversations List -->
+    <div class="col-md-4">
+      <div class="panel panel-default">
+        <div class="panel-heading">
+          Conversations
+          <?php if ($this->unread_count > 0): ?>
+            <span class="badge pull-right"><?= $this->unread_count ?></span>
+          <?php endif; ?>
+        </div>
+        <div class="panel-body" style="padding: 0; max-height: 500px; overflow-y: auto;">
+          <div class="list-group">
+            <?php if (empty($this->conversations)): ?>
+              <div class="list-group-item">
+                <em>No conversations yet</em>
+              </div>
+            <?php else: ?>
+              <?php foreach ($this->conversations as $conv): ?>
+                <a href="<?= Config::get('URL') ?>message/conversation/<?= $conv->other_user_id ?>"
+                  class="list-group-item <?= $conv->unread_count > 0 ? 'active' : '' ?>">
+                  <h5 class="list-group-item-heading">
+                    <?= htmlspecialchars($conv->user_name) ?>
+                    <?php if ($conv->unread_count > 0): ?>
+                      <span class="badge"><?= $conv->unread_count ?></span>
+                    <?php endif; ?>
+                  </h5>
+                  <p class="list-group-item-text">
+                    <small><?= date('M j, Y', strtotime($conv->last_message_time)) ?></small>
+                  </p>
+                </a>
+              <?php endforeach; ?>
+            <?php endif; ?>
+          </div>
+        </div>
+      </div>
+
+      <!-- New Message -->
+      <div class="panel panel-default">
+        <div class="panel-heading">New Message</div>
+        <div class="panel-body">
+          <form action="<?= Config::get('URL') ?>message/send" method="post">
+            <div class="form-group">
+              <label for="receiver_id">To:</label>
+              <select name="receiver_id" id="receiver_id" class="form-control" required>
+                <option value="">Select user</option>
+                <?php foreach ($this->all_users as $user): ?>
+                  <option value="<?= $user->user_id ?>"><?= htmlspecialchars($user->user_name) ?></option>
+                <?php endforeach; ?>
+              </select>
+            </div>
+            <div class="form-group">
+              <label for="subject">Subject:</label>
+              <input type="text" name="subject" id="subject" class="form-control" required>
+            </div>
+            <div class="form-group">
+              <label for="message">Message:</label>
+              <textarea name="message" id="message" class="form-control" rows="3" required></textarea>
+            </div>
+            <button type="submit" class="btn btn-primary">Send Message</button>
+          </form>
+        </div>
+      </div>
+
+      <!-- Send to Group -->
+      <div class="panel panel-default">
+        <div class="panel-heading">Send to Group</div>
+        <div class="panel-body">
+          <form action="<?= Config::get('URL') ?>message/sendgroup" method="post">
+            <div class="form-group">
+              <label for="group_type">Group:</label>
+              <select name="group_type" id="group_type" class="form-control" required>
+                <option value="">Select group</option>
+                <option value="all_users">All Users</option>
+                <option value="admins">Administrators</option>
+                <option value="moderators">Moderators</option>
+              </select>
+            </div>
+            <div class="form-group">
+              <label for="group_subject">Subject:</label>
+              <input type="text" name="subject" id="group_subject" class="form-control" required>
+            </div>
+            <div class="form-group">
+              <label for="group_message">Message:</label>
+              <textarea name="message" id="group_message" class="form-control" rows="3" required></textarea>
+            </div>
+            <button type="submit" class="btn btn-warning">Send to Group</button>
+          </form>
+        </div>
+      </div>
+    </div>
+
+    <!-- Chat Area -->
+    <div class="col-md-8">
+      <div class="panel panel-default">
+        <div class="panel-heading">
+          Chat Area
+          <span class="pull-right">Select a conversation to start messaging</span>
+        </div>
+        <div class="panel-body" style="height: 500px; background-color: #f5f5f5; text-align: center; padding-top: 200px;">
+          <em>Select a conversation from the left to view messages</em>
+        </div>
+      </div>
+    </div>
+  </div>
+</div>
+
+<style>
+  .message-container {
+    height: 400px;
+    overflow-y: auto;
+    background-color: #f5f5f5;
+    padding: 15px;
+    border-radius: 5px;
+    margin-bottom: 15px;
+  }
+
+  .message {
+    margin-bottom: 10px;
+    clear: both;
+  }
+
+  .message.sent {
+    text-align: right;
+  }
+
+  .message.received {
+    text-align: left;
+  }
+
+  .message-bubble {
+    display: inline-block;
+    max-width: 70%;
+    padding: 10px 15px;
+    border-radius: 18px;
+    position: relative;
+  }
+
+  .message.sent .message-bubble {
+    background-color: #007bff;
+    color: white;
+    float: right;
+  }
+
+  .message.received .message-bubble {
+    background-color: #e5e5ea;
+    color: black;
+    float: left;
+  }
+
+  .message-time {
+    font-size: 0.8em;
+    color: #666;
+    margin-top: 5px;
+    clear: both;
+  }
+
+  .badge {
+    background-color: #d9534f;
+  }
+
+  .list-group-item.active {
+    background-color: #d9edf7;
+    border-color: #bce8f1;
+    color: #31708f;
+  }
+
+  .list-group-item.active .badge {
+    background-color: #d9534f;
+  }
+</style>
+
+<?php $this->render('_templates/footer'); ?>

application/view/profile/index.php

@@ -35,6 +35,16 @@
                         <td><?= ($user->user_active == 0 ? 'No' : 'Yes'); ?></td>
                         <td>
                             <a href="<?= Config::get('URL') . 'profile/showProfile/' . $user->user_id; ?>">Profile</a>
+                            <?php 
+                            // Show unread message count for each user
+                            if (Session::userIsLoggedIn()) {
+                                $current_user_id = Session::get('user_id');
+                                $unread_count = MessageModel::getUnreadCountForUser($current_user_id, $user->user_id);
+                                if ($unread_count > 0) {
+                                    echo ' <span class="badge" style="background-color: #d9534f; color: white; padding: 2px 5px; border-radius: 50%;">' . $unread_count . '</span>';
+                                }
+                            }
+                            ?>
                         </td>
                     </tr>
                 <?php } ?>

application/view/register/index.php

@@ -11,9 +11,7 @@
         <form method="post" action="<?php echo Config::get('URL'); ?>register/register_action">
             <input type="text" pattern="[a-zA-Z0-9]{2,64}" name="user_name" placeholder="Username (letters/numbers, 2-64 chars)" required />
             <input type="text" name="user_email" placeholder="email address (a real address)" required />
-            <input type="text" name="user_email_repeat" placeholder="repeat email address (to prevent typos)" required />
             <input type="password" name="user_password_new" pattern=".{6,}" placeholder="Password (6+ characters)" required autocomplete="off" />
-            <input type="password" name="user_password_repeat" pattern=".{6,}" required placeholder="Repeat your password" autocomplete="off" />
             <input type="submit" value="Register" />
         </form>
     </div>

public/css/style.css

@@ -266,3 +266,17 @@ body {
 .red-text {
     color: red;
 }
+
+/* Message badge */
+.message-badge {
+    display: inline-block;
+    background-color: #d9534f;
+    color: white;
+    font-size: 10px;
+    font-weight: bold;
+    padding: 2px 5px;
+    border-radius: 50%;
+    margin-left: 5px;
+    position: relative;
+    top: -2px;
+}