move Session.php to Modules

Modules/Session/Session.php

@@ -0,0 +1,84 @@
+<?php
+
+final class Session
+{
+    public static function start_session()
+    {
+        if (session_status() !== PHP_SESSION_ACTIVE) {
+            session_start();
+        }
+    }
+
+    public static function resume_session()
+    {
+        if(self::has_session_cookie()){
+            self::start_session();
+            return true;
+        }
+        return false;
+    }
+
+    public static function destroy_session()
+    {
+        self::start_session();
+        session_destroy();
+    }
+
+    /*
+        Reason: start_session() automatically sets a cookie,
+        we want a way to know if the user have a session without setting a cookie
+        (e.g to not set a cookie on every page to set the header, which change if you are logged-in)
+    */
+    public static function has_session_cookie()
+    {
+        return isset($_COOKIE[session_name()]);
+    }
+    
+    public static function is_login()
+    {
+        if (!self::resume_session()) {
+            return false;
+        }
+        if (!isset($_SESSION)) {
+            return false;
+        }
+        if (!isset($_SESSION["ID"])) {
+            return False;
+        }
+        
+        // ensure account has not been deleted/disabled in the meantime
+        $O_userModel = new UserModel();
+        $B_userActive = $O_userModel->isUserActive($_SESSION["ID"]);
+        return $B_userActive;
+    }
+
+    public static function set_login($I_id){
+        self::start_session();
+        $_SESSION["ID"] = $I_id;
+    }
+
+    public static function login_or_die()
+    {
+        if (!self::is_login()) {
+            header("Location: /user/login?return_uri=".$_SERVER["REQUEST_URI"]);
+            die();
+        }
+    }
+
+    public static function is_admin(){
+        if (!self::is_login()) return false;
+
+        $O_userModel = new UserModel();
+        return $O_userModel->isUserAdmin($_SESSION["ID"]);
+    }
+    
+    public static function admin_or_die(){
+        Session::login_or_die();
+
+        if (!self::is_admin()) {
+            header("Location: /");
+            die();
+        }
+    }
+
+}