Update

app/Helpers/FirstParty/ImageHash/ImageHashService.php

@@ -0,0 +1,100 @@
+<?php
+
+namespace App\Helpers\FirstParty\ImageHash;
+
+use Illuminate\Support\Facades\Http;
+use Illuminate\Support\Facades\Log;
+use Jenssegers\ImageHash\ImageHash;
+use Jenssegers\ImageHash\Implementations\DifferenceHash;
+
+class ImageHashService
+{
+    private ImageHash $hasher;
+
+    public function __construct()
+    {
+        $this->hasher = new ImageHash(new DifferenceHash);
+    }
+
+    public function generateHashFromUrl(string $url): ?string
+    {
+        try {
+            $response = Http::timeout(30)->get($url);
+
+            if (! $response->successful()) {
+                Log::warning("Failed to download image from URL: {$url}");
+
+                return null;
+            }
+
+            $imageData = $response->body();
+
+            return $this->generateHashFromData($imageData);
+
+        } catch (\Exception $e) {
+            Log::error("Error generating hash from URL {$url}: ".$e->getMessage());
+
+            return null;
+        }
+    }
+
+    public function generateHashFromData(string $imageData): ?string
+    {
+        try {
+            $tempFile = tempnam(sys_get_temp_dir(), 'imagehash_');
+            file_put_contents($tempFile, $imageData);
+
+            $hash = $this->hasher->hash($tempFile);
+            unlink($tempFile);
+
+            return $hash->toHex();
+
+        } catch (\Exception $e) {
+            Log::error('Error generating hash from image data: '.$e->getMessage());
+
+            return null;
+        }
+    }
+
+    public function calculateHammingDistance(string $hash1, string $hash2): int
+    {
+        // Validate hashes are not empty
+        if (empty($hash1) || empty($hash2)) {
+            return PHP_INT_MAX; // Return max distance for invalid hashes
+        }
+
+        // Pad shorter hash with zeros to make them equal length
+        $maxLength = max(strlen($hash1), strlen($hash2));
+        $hash1 = str_pad($hash1, $maxLength, '0', STR_PAD_LEFT);
+        $hash2 = str_pad($hash2, $maxLength, '0', STR_PAD_LEFT);
+
+        $distance = 0;
+        for ($i = 0; $i < $maxLength; $i++) {
+            if ($hash1[$i] !== $hash2[$i]) {
+                $distance++;
+            }
+        }
+
+        return $distance;
+    }
+
+    public function areHashesSimilar(string $hash1, string $hash2, int $threshold = 5): bool
+    {
+        return $this->calculateHammingDistance($hash1, $hash2) <= $threshold;
+    }
+
+    public function findSimilarHashes(string $targetHash, array $hashes, int $threshold = 5): array
+    {
+        $similar = [];
+
+        foreach ($hashes as $id => $hash) {
+            if ($this->areHashesSimilar($targetHash, $hash, $threshold)) {
+                $similar[$id] = $this->calculateHammingDistance($targetHash, $hash);
+            }
+        }
+
+        asort($similar);
+
+        return $similar;
+    }
+}