feat: Reimplement order and invoice management with new service and repository layers, introduce compression middleware, and update database schema.

app/Http/Middleware/CompressionMiddleware.php

@@ -0,0 +1,90 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use Closure;
+use Illuminate\Http\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+class CompressionMiddleware
+{
+    /**
+     * Handle an incoming request.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @param  \Closure(\Illuminate\Http\Request): (\Symfony\Component\HttpFoundation\Response)  $next
+     * @return \Symfony\Component\HttpFoundation\Response
+     */
+    public function handle(Request $request, Closure $next): Response
+    {
+        $response = $next($request);
+
+        // Chỉ nén response cho JSON API
+        if (!$this->shouldCompress($request, $response)) {
+            return $response;
+        }
+
+        $content = $response->getContent();
+        
+        // Chỉ nén nếu content size > 1KB
+        if (strlen($content) < 1024) {
+            return $response;
+        }
+
+        $acceptEncoding = $request->header('Accept-Encoding', '');
+        
+        // Kiểm tra client hỗ trợ gzip
+        if (str_contains($acceptEncoding, 'gzip') && function_exists('gzencode')) {
+            $compressed = gzencode($content, 6); // Level 6 compression
+            
+            if ($compressed !== false) {
+                $response->setContent($compressed);
+                $response->headers->set('Content-Encoding', 'gzip');
+                $response->headers->set('Content-Length', strlen($compressed));
+                $response->headers->set('Vary', 'Accept-Encoding');
+            }
+        }
+        // Fallback to deflate if gzip not supported
+        elseif (str_contains($acceptEncoding, 'deflate') && function_exists('gzdeflate')) {
+            $compressed = gzdeflate($content, 6);
+            
+            if ($compressed !== false) {
+                $response->setContent($compressed);
+                $response->headers->set('Content-Encoding', 'deflate');
+                $response->headers->set('Content-Length', strlen($compressed));
+                $response->headers->set('Vary', 'Accept-Encoding');
+            }
+        }
+
+        return $response;
+    }
+
+    /**
+     * Determine if the response should be compressed.
+     */
+    private function shouldCompress(Request $request, Response $response): bool
+    {
+        // Chỉ nén JSON responses
+        $contentType = $response->headers->get('Content-Type', '');
+        if (!str_contains($contentType, 'application/json')) {
+            return false;
+        }
+
+        // Không nén nếu đã có Content-Encoding
+        if ($response->headers->has('Content-Encoding')) {
+            return false;
+        }
+
+        // Không nén file downloads
+        if ($response->headers->has('Content-Disposition')) {
+            return false;
+        }
+
+        // Chỉ nén response thành công
+        if ($response->getStatusCode() >= 400) {
+            return false;
+        }
+
+        return true;
+    }
+}