WIP: Poll for logged events

Signed-off-by: Pablo Zmdl <pablo@nextcloud.com>

php/src/Data/ContainerEventsLog.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace AIO\Data;
+
+class ContainerEventsLog {
+    readonly public string $filename;
+
+    public function __construct()
+    {
+        $this->filename = DataConst::GetDataDirectory() . "/container_events.log";
+        if (file_exists($this->filename)) {
+            $this->pruneFileIfTooLarge();
+        } else {
+            touch($this->filename);
+        }
+    }
+
+    public function lastModified() : int|false {
+        return filemtime($this->filename);
+    }
+
+    public function add(string $id, string $message) : void
+    {
+        $json = json_encode(['time' => time(), 'id' => $id, 'message' => $message]);
+
+        // Append new event (atomic via LOCK_EX)
+        file_put_contents($this->filename, $json . PHP_EOL, FILE_APPEND | LOCK_EX);
+    }
+
+    // Truncate the file to keep only the last bytes, aligned to a newline boundary.
+    protected function pruneFileIfTooLarge() : void {
+        $maxBytes = 512 * 1024; // 512 KB
+        $maxLines = 1000; // keep last 1000 events
+
+        if (filesize($this->filename) <= $maxBytes) {
+            return;
+        }
+
+        $lines = file($this->filename, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
+        if ($lines !== false) {
+            $total = count($lines);
+            $start = max(0, $total - $maxLines);
+            $keep = array_slice($lines, $start);
+            // rewrite file with kept lines
+            file_put_contents($this->filename, implode(PHP_EOL, $keep) . PHP_EOL, LOCK_EX);
+        }
+    }
+}