feat: Implement DownloadController for secure down

app/Http/Controllers/DownloadController.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Models\DownloadableProduct;
+use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Storage;
+use Symfony\Component\HttpFoundation\StreamedResponse;
+
+class DownloadController extends Controller
+{
+    public function generateSecureLink(Request $request, $productId)
+    {
+        $downloadableProduct = DownloadableProduct::where('product_id', $productId)->firstOrFail();
+        if (!$this->checkDownloadLimits($downloadableProduct) || !$this->authorizeDownload($request->user(), $downloadableProduct)) {
+            abort(403, 'Download limit reached or not authorized.');
+        }
+        $temporaryUrl = Storage::disk('local')->temporaryUrl(
+            $downloadableProduct->file_url, now()->addMinutes(5)
+        );
+        return response()->json(['url' => $temporaryUrl]);
+    }
+
+    private function checkDownloadLimits(DownloadableProduct $downloadableProduct)
+    {
+        return $downloadableProduct->download_limit > $downloadableProduct->downloads_count && (!$downloadableProduct->expiration_time || $downloadableProduct->expiration_time->isFuture());
+    }
+
+    public function serveFile(Request $request, $productId)
+    {
+        $downloadableProduct = DownloadableProduct::where('product_id', $productId)->firstOrFail();
+        if (!$this->checkDownloadLimits($downloadableProduct) || !$this->authorizeDownload($request->user(), $downloadableProduct)) {
+            abort(403, 'Download limit reached or not authorized.');
+        }
+        $downloadableProduct->increment('downloads_count');
+        return Storage::disk('local')->download($downloadableProduct->file_url);
+    }
+
+    private function authorizeDownload($user, DownloadableProduct $downloadableProduct)
+    {
+        // Implement logic to verify user's purchase
+        return true; // Placeholder for purchase verification logic
+    }
+}