47391 implement failsafe import mechanism

SQLiteManager.php

@@ -103,7 +103,9 @@ public static function createDb(string $path = ''): PDO
                 v TEXT NOT NULL
             );
         SQL);
-        $pdo->exec("INSERT OR IGNORE INTO kv(k, v) VALUES ('last_synchronization', '0');");
+        $pdo->exec("INSERT OR IGNORE INTO kv(k, v) VALUES ('last_export', '0');");
+        $pdo->exec("INSERT OR IGNORE INTO kv(k, v) VALUES ('last_import', '0');");
+        $pdo->exec("INSERT OR IGNORE INTO kv(k, v) VALUES ('last_import_fail_date', '0');");
         $pdo->exec("INSERT OR IGNORE INTO kv(k, v) VALUES ('last_key_check', '0');");
         $pdo->exec("INSERT OR IGNORE INTO kv(k, v) VALUES ('sync_in_process', '0');");
 

SyncManager.php

@@ -42,7 +42,7 @@ public function timeSinceLastSyncRequest(): int
     {
         $lastSyncUnixTime = (int)(
             $this->pdo
-                ->query("SELECT v FROM kv WHERE k = 'last_synchronization'")
+                ->query("SELECT v FROM kv WHERE k = 'last_export'")
                 ->fetchColumn() ?? 0
         );
         return (time() - $lastSyncUnixTime);
@@ -69,10 +69,23 @@ public function syncData(string $apiKey): void
         try {
             $this->declareAppVersion();
             $this->cleanOldVisitorsData();
-            $this->updateListsAndAgents($apiKey);
+            if ($this->importRecentlyFailed() === false) {
+                try {
+                    $this->updateListsAndAgents($apiKey);
+                    $this->setLastImportDate();
+                } catch (Exception $e) {
+                    $this->setLastImportFailDate();
+                    $lastImportTs = (int)(
+                        $this->pdo
+                            ->query("SELECT v FROM kv WHERE k = 'last_import'")
+                            ->fetchColumn() ?? 0
+                    );
+                    error_log('AntiCrawler failed to update filtering lists. Last import date: ' . date("Y-m-d H:i:s", $lastImportTs));
+                }
+            }
             $this->uploadRequestsToDB($apiKey);
 
-            $this->setLastSyncDate();
+            $this->setLastExportDate();
         } finally {
             $this->removeSyncLock();
         }
@@ -202,9 +215,30 @@ private function uploadRequestsToDB(string $apiKey): void
         $this->pdo->exec("UPDATE requests SET sync_state = 'sent' WHERE sync_state = 'sending'");
     }
 
-    private function setLastSyncDate()
+    private function setLastExportDate()
+    {
+        $this->pdo->exec("UPDATE kv SET v = " . time() . " WHERE k = 'last_export'");
+    }
+
+    private function setLastImportDate()
+    {
+        $this->pdo->exec("UPDATE kv SET v = " . time() . " WHERE k = 'last_import'");
+    }
+
+    private function setLastImportFailDate()
     {
-        $this->pdo->exec("UPDATE kv SET v = " . time() . " WHERE k = 'last_synchronization'");
+        $this->pdo->exec("UPDATE kv SET v = " . time() . " WHERE k = 'last_import_fail_date'");
+    }
+
+    private function importRecentlyFailed(): bool
+    {
+        $lastImportFailTs = (int)(
+            $this->pdo
+                ->query("SELECT v FROM kv WHERE k = 'last_import_fail_date'")
+                ->fetchColumn() ?? 0
+        );
+
+        return (time() - $lastImportFailTs) < 30;
     }
 
     public function updateListsAndAgents(string $apiKey)