Improved system prompt with LLM-based prompt engineering

README.md

@@ -2,7 +2,8 @@
 
 A Laravel application that analyzes Amazon product reviews to detect fake reviews using AI. The service fetches reviews via the Unwrangle API, analyzes them with OpenAI, and provides authenticity scores.
 
-Visit [nullfake.com](https://nullfake.com) to try it out.
+# Visit [nullfake.com](https://nullfake.com) to try it out.
+# Read our [blog post about how nullfake works](https://shift8web.ca/from-fakespot-to-null-fake-navigating-the-evolving-landscape-of-fake-reviews/)
 
 ## How It Works
 
@@ -54,3 +55,8 @@ The model calculates:
 ## License
 
 MIT
+
+## Shift8
+
+This was developed in Toronto Canada by [Shift8 Web](https://shift8web.ca)
+

app/Exceptions/ReviewServiceException.php

@@ -4,4 +4,4 @@
 
 class ReviewServiceException extends \Exception
 {
-} 
+}

app/Http/Controllers/Controller.php

@@ -8,5 +8,6 @@
 
 class Controller extends BaseController
 {
-    use AuthorizesRequests, ValidatesRequests;
+    use AuthorizesRequests;
+    use ValidatesRequests;
 }

app/Http/Controllers/UrlExpansionController.php

@@ -0,0 +1,148 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use Illuminate\Http\Request;
+use Illuminate\Http\JsonResponse;
+use GuzzleHttp\Client;
+use GuzzleHttp\Exception\GuzzleException;
+use App\Services\LoggingService;
+
+class UrlExpansionController extends Controller
+{
+    /**
+     * Expand a shortened URL to its final destination
+     */
+    public function expandUrl(Request $request): JsonResponse
+    {
+        $request->validate([
+            'url' => 'required|url'
+        ]);
+
+        $shortUrl = $request->input('url');
+
+        // Only expand Amazon short URLs for security
+        if (!$this->isAmazonShortUrl($shortUrl)) {
+            return response()->json([
+                'success' => false,
+                'error' => 'Only Amazon URLs are supported'
+            ], 400);
+        }
+
+        try {
+            LoggingService::log('Expanding short URL', [
+                'short_url' => $shortUrl
+            ]);
+
+            // Follow redirects manually to get final URL
+            $finalUrl = $this->followRedirects($shortUrl);
+
+            LoggingService::log('URL expansion successful', [
+                'short_url' => $shortUrl,
+                'final_url' => $finalUrl
+            ]);
+
+            return response()->json([
+                'success' => true,
+                'original_url' => $shortUrl,
+                'expanded_url' => $finalUrl
+            ]);
+
+        } catch (GuzzleException $e) {
+            LoggingService::log('URL expansion failed', [
+                'short_url' => $shortUrl,
+                'error' => $e->getMessage()
+            ]);
+
+            return response()->json([
+                'success' => false,
+                'error' => 'Unable to expand URL: ' . $e->getMessage()
+            ], 500);
+        }
+    }
+
+    /**
+     * Follow redirects manually to get final URL without validating the final destination
+     */
+    private function followRedirects(string $url, int $maxRedirects = 5): string
+    {
+        $client = new Client([
+            'timeout' => 5,
+            'connect_timeout' => 2,
+            'allow_redirects' => false,
+            'headers' => [
+                'User-Agent' => 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'
+            ]
+        ]);
+
+        $currentUrl = $url;
+        $redirectCount = 0;
+
+        while ($redirectCount < $maxRedirects) {
+            try {
+                $response = $client->get($currentUrl);
+                $statusCode = $response->getStatusCode();
+
+                LoggingService::log('Redirect step', [
+                    'url' => $currentUrl,
+                    'status' => $statusCode,
+                    'redirect_count' => $redirectCount
+                ]);
+
+                if (in_array($statusCode, [301, 302, 303, 307, 308])) {
+                    $locationHeaders = $response->getHeader('Location');
+                    if (empty($locationHeaders)) {
+                        LoggingService::log('No location header found, stopping redirects');
+                        break;
+                    }
+
+                    $newUrl = $locationHeaders[0];
+
+                    // If we've reached an Amazon product URL, stop here - don't try to validate it
+                    if (strpos($newUrl, 'amazon.com/dp/') !== false || strpos($newUrl, 'amazon.com/gp/product/') !== false) {
+                        LoggingService::log('Reached Amazon product URL, stopping redirects', [
+                            'final_url' => $newUrl
+                        ]);
+                        return $newUrl;
+                    }
+
+                    $currentUrl = $newUrl;
+                    $redirectCount++;
+                } else {
+                    // Got a non-redirect response, stop here
+                    break;
+                }
+            } catch (\Exception $e) {
+                LoggingService::log('Redirect failed', [
+                    'url' => $currentUrl,
+                    'error' => $e->getMessage()
+                ]);
+                break;
+            }
+        }
+
+        return $currentUrl;
+    }
+
+    /**
+     * Check if URL is an Amazon short URL
+     */
+    private function isAmazonShortUrl(string $url): bool
+    {
+        $amazonShortDomains = [
+            'a.co',
+            'amzn.to',
+            'amazon.com'
+        ];
+
+        $host = parse_url($url, PHP_URL_HOST);
+
+        foreach ($amazonShortDomains as $domain) {
+            if ($host === $domain || str_ends_with($host, '.' . $domain)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+} 

app/Http/Kernel.php

@@ -53,16 +53,16 @@ class Kernel extends HttpKernel
      * @var array<string, class-string|string>
      */
     protected $middlewareAliases = [
-        'auth' => \App\Http\Middleware\Authenticate::class,
-        'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
-        'auth.session' => \Illuminate\Session\Middleware\AuthenticateSession::class,
-        'cache.headers' => \Illuminate\Http\Middleware\SetCacheHeaders::class,
-        'can' => \Illuminate\Auth\Middleware\Authorize::class,
-        'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,
+        'auth'             => \App\Http\Middleware\Authenticate::class,
+        'auth.basic'       => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
+        'auth.session'     => \Illuminate\Session\Middleware\AuthenticateSession::class,
+        'cache.headers'    => \Illuminate\Http\Middleware\SetCacheHeaders::class,
+        'can'              => \Illuminate\Auth\Middleware\Authorize::class,
+        'guest'            => \App\Http\Middleware\RedirectIfAuthenticated::class,
         'password.confirm' => \Illuminate\Auth\Middleware\RequirePassword::class,
-        'precognitive' => \Illuminate\Foundation\Http\Middleware\HandlePrecognitiveRequests::class,
-        'signed' => \App\Http\Middleware\ValidateSignature::class,
-        'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,
-        'verified' => \Illuminate\Auth\Middleware\EnsureEmailIsVerified::class,
+        'precognitive'     => \Illuminate\Foundation\Http\Middleware\HandlePrecognitiveRequests::class,
+        'signed'           => \App\Http\Middleware\ValidateSignature::class,
+        'throttle'         => \Illuminate\Routing\Middleware\ThrottleRequests::class,
+        'verified'         => \Illuminate\Auth\Middleware\EnsureEmailIsVerified::class,
     ];
 }

app/Http/Middleware/RedirectIfAuthenticated.php

@@ -13,7 +13,7 @@ class RedirectIfAuthenticated
     /**
      * Handle an incoming request.
      *
-     * @param  \Closure(\Illuminate\Http\Request): (\Symfony\Component\HttpFoundation\Response)  $next
+     * @param \Closure(\Illuminate\Http\Request): (\Symfony\Component\HttpFoundation\Response) $next
      */
     public function handle(Request $request, Closure $next, string ...$guards): Response
     {