first commit

backend/includes/Database.php

@@ -0,0 +1,49 @@
+<?php
+/**
+ * Database Singleton — PDO Connection
+ */
+
+require_once __DIR__ . '/../config.php';
+
+class Database
+{
+    private static ?PDO $instance = null;
+
+    private function __construct()
+    {
+        try {
+            $dsn = sprintf(
+                'mysql:host=%s;dbname=%s;charset=utf8mb4',
+                DB_HOST,
+                DB_NAME
+            );
+
+            self::$instance = new PDO($dsn, DB_USER, DB_PASS, [
+                PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
+                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
+                PDO::ATTR_EMULATE_PREPARES   => false,
+                PDO::MYSQL_ATTR_INIT_COMMAND => "SET time_zone = '+03:00'",
+            ]);
+        } catch (PDOException $e) {
+            error_log('Database connection failed: ' . $e->getMessage());
+            http_response_code(500);
+            echo json_encode(['success' => false, 'message' => 'database_error']);
+            exit;
+        }
+    }
+
+    public static function getInstance(): PDO
+    {
+        if (self::$instance === null) {
+            new self();
+        }
+        return self::$instance;
+    }
+
+    /** Prevent cloning */
+    private function __clone() {}
+    public function __wakeup()
+    {
+        throw new \Exception("Cannot unserialize singleton");
+    }
+}