From a1be6ff62bead1903e3f0c27d0e969a77454780e Mon Sep 17 00:00:00 2001
From: James Cole <james@firefly-iii.org>
Date: Sun, 7 Apr 2024 16:12:41 +0200
Subject: [PATCH] Limit the number of error messages Firefly III will send.

---
 app/Jobs/MailError.php | 67 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 66 insertions(+), 1 deletion(-)

diff --git a/app/Jobs/MailError.php b/app/Jobs/MailError.php
index c06a617d03..4e170923a7 100644
--- a/app/Jobs/MailError.php
+++ b/app/Jobs/MailError.php
@@ -27,6 +27,7 @@ use Illuminate\Contracts\Queue\ShouldQueue;
 use Illuminate\Mail\Message;
 use Illuminate\Queue\InteractsWithQueue;
 use Illuminate\Queue\SerializesModels;
+use Illuminate\Support\Facades\Log;
 use Symfony\Component\Mailer\Exception\TransportException;
 
 /**
@@ -68,6 +69,14 @@ class MailError extends Job implements ShouldQueue
         $args['user']     = $this->userData;
         $args['ip']       = $this->ipAddress;
         $args['token']    = config('firefly.ipinfo_token');
+
+        // limit number of error mails that can be sent.
+        if ($this->reachedLimit()) {
+            Log::info('MailError: reached limit, not sending email.');
+            return;
+        }
+
+
         if ($this->attempts() < 3 && '' !== $email) {
             try {
                 \Mail::send(
@@ -79,7 +88,7 @@ class MailError extends Job implements ShouldQueue
                         }
                     }
                 );
-            } catch (\Exception|TransportException $e) { // @phpstan-ignore-line
+            } catch (\Exception | TransportException $e) { // @phpstan-ignore-line
                 $message = $e->getMessage();
                 if (str_contains($message, 'Bcc')) {
                     app('log')->warning('[Bcc] Could not email or log the error. Please validate your email settings, use the .env.example file as a guide.');
@@ -96,4 +105,60 @@ class MailError extends Job implements ShouldQueue
             }
         }
     }
+
+    /**
+     * @return bool
+     */
+    private function reachedLimit(): bool
+    {
+        Log::debug('reachedLimit()');
+        $types  = [
+            '5m'  => ['limit' => 5, 'reset' => 5 * 60],
+            '1h'  => ['limit' => 15, 'reset' => 60 * 60],
+            '24h' => ['limit' => 15, 'reset' => 24 * 60 * 60],
+        ];
+        $file   = storage_path('framework/cache/error-count.json');
+        $limits = [];
+        if(!is_writable($file)) {
+            Log::error(sprintf('MailError: cannot write to "%s", cannot rate limit errors!', $file));
+            return false;
+        }
+        if (!file_exists($file)) {
+            Log::debug(sprintf('Wrote new file in "%s"', $file));
+            file_put_contents($file, json_encode($limits, JSON_PRETTY_PRINT));
+        }
+        if (file_exists($file)) {
+            Log::debug(sprintf('Read file in "%s"', $file));
+            $limits = json_decode(file_get_contents($file), true);
+        }
+        // limit reached?
+        foreach ($types as $type => $info) {
+            Log::debug(sprintf('Now checking limit "%s"', $type), $info);
+            if (!isset($limits[$type])) {
+                Log::debug(sprintf('Limit "%s" reset to zero, did not exist yet.', $type));
+                $limits[$type] = [
+                    'time' => time(),
+                    'sent' => 0,
+                ];
+            }
+
+            if (time() - $limits[$type]['time'] > $info['reset']) {
+                Log::debug(sprintf('Time past for this limit is %d seconds, exceeding %d seconds. Reset to zero.', (time() - $limits[$type]['time']), $info['reset']));
+                $limits[$type] = [
+                    'time' => time(),
+                    'sent' => 0,
+                ];
+            }
+
+            if ($limits[$type]['sent'] > $info['limit']) {
+                Log::warning(sprintf('Sent %d emails in %s, return true.', $limits[$type]['sent'], $type));
+                return true;
+            }
+            $limits[$type]['sent']++;
+        }
+        file_put_contents($file, json_encode($limits, JSON_PRETTY_PRINT));
+        Log::debug('No limits reached, return FALSE.');
+        return false;
+
+    }
 }