Add logging & some better error handling

src/ImageResizer.php

@@ -3,10 +3,12 @@ error_reporting(E_ERROR | E_PARSE);
 
 require_once './vendor/autoload.php';
 
+use ImageResizer\Lib\FileLogger;
 use ImageResizer\Lib\Resizer;
 use ImageResizer\Lib\SqliteImageDb;
 use ImageResizer\Models\ResizeParams;
 
+$logger = new FileLogger("resizer.log");
 $dotenv = Dotenv\Dotenv::createImmutable([__DIR__, __DIR__ . "/.."]);
 $dotenv->load();
 
@@ -15,6 +17,12 @@ $imageDb = new SqliteImageDb(new PDO("sqlite:{$_ENV["db_name"]}"));
 $imgPath = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
 $params = new ResizeParams($_GET);
 
-$resizer = new Resizer($imageDb);
+$resizer = new Resizer($imageDb, $logger);
 
-echo $resizer->performResize($imgPath, $params);
+try {
+    $resizer->performResize($imgPath, $params);
+} catch (\Exception $e) {
+    $logger->error($e->getMessage());
+    http_response_code(500);
+    echo "Internal Server Error";
+}

src/Lib/FileLogger.php

@@ -0,0 +1,21 @@
+<?php declare(strict_types=1);
+
+namespace ImageResizer\Lib;
+
+use DateTime;
+use Psr\Log\AbstractLogger;
+use Stringable;
+
+class FileLogger extends AbstractLogger
+{
+    function __construct(private readonly string $filename = 'php://stdout') {}
+    public function log($level, Stringable|string $message, array $context = []): void
+    {
+        $timestamp = new DateTime();
+        $callingClass = debug_backtrace()[2]['class'];
+        $callingFunction = debug_backtrace()[2]['function'];
+        $log = $timestamp->format(DATE_ATOM) . " [$level] $callingClass::$callingFunction $message " . json_encode($context);
+        fwrite(fopen($this->filename, 'w'), $log . PHP_EOL);
+    }
+}
+

src/Lib/Resizer.php

@@ -6,10 +6,13 @@ namespace ImageResizer\Lib;
 
 use ImageResizer\Models\ResizeParams;
 use ImageResizer\Models\Image;
+use Psr\Log\AbstractLogger;
+
 class Resizer
 {
     public function __construct(
-        private readonly ImageDb $imageDb
+        private readonly ImageDb $imageDb,
+        private readonly AbstractLogger $logger,
     )
     {}
 
@@ -20,7 +23,7 @@ class Resizer
     {
         // Check if the image has already been processed
         if ($image = $this->imageDb->findImage($path, $params)) {
-
+            $this->logger->info("Found existing image", ['path'=>$path, 'params'=>$params]);
             header("Content-type: {${$image->getMime()}}");
             return base64_decode($image->encode(75));
         }
@@ -28,6 +31,7 @@ class Resizer
         // Fetch the image at the given URL
         $original_img = Image::fromUrl($_ENV['ROOT_DOMAIN'] . $path);
         $converted = $this->createVariant($original_img, $params);
+        $this->logger->info("Created variant", ['path'=>$path, 'params'=>$params]);
 
         // Store the image in the database
         $this->imageDb->saveImage(
@@ -35,6 +39,7 @@ class Resizer
             $params,
             $converted
         );
+        $this->logger->info("Saved image for $path");
 
         header("Content-type: {$original_img->getMime()}");
         return base64_decode($converted);