# Logger Module

A file-based logger that writes structured entries to a JSONL file in the WordPress uploads directory. Designed as a drop-in replacement for `error_log()` that produces entries you can read, table-display, and download from the admin UI.

**Namespace:** `Reservair\Logger`  
**Log file:** `wp-content/uploads/reservair/reservair.log`

## Usage

```php
use Reservair\Logger\Logger;

Logger::info('Timetable reservation created.');
Logger::warning('Maintainer email not set for timetable #' . $id);
Logger::error('Insert failed: ' . $message);

// Accepts Throwable directly — replaces error_log($e) call sites directly
Logger::error($exception);
```

## Admin UI integration

```php
use Reservair\Logger\Logger;

// Table — get_entries() returns newest-first; each entry has time/level/message keys
foreach (Logger::get_entries() as $entry) {
    // $entry['time']    e.g. "2026-05-30 14:22:01"
    // $entry['level']   "info" | "warning" | "error"
    // $entry['message'] the log text
}

// Download button — serve this path as a file download
$path = Logger::get_path();

// Clear the log
Logger::clear();
```

## Log file format

Each line is a JSON object (JSONL). Safe to tail, grep, or import into any log viewer.

```json
{"time":"2026-05-30 14:22:01","level":"info","message":"Reservation #12 created."}
{"time":"2026-05-30 14:22:03","level":"error","message":"Insert failed: Duplicate entry"}
```

## Notes

- Written to `wp-content/uploads/reservair/` rather than the plugin directory so the file survives plugin updates.
- The directory is created on first write with an `.htaccess` that blocks direct browser access (`Deny from all`).
- `LOCK_EX` is used on every write to prevent interleaved entries under concurrent requests.
- `wp_upload_dir()` result is cached statically to avoid repeated database lookups per request.