import fs from 'node:fs/promises';
import path from 'node:path';
import { LOG_FILE } from './config.js';

// Simple JSON-lines log stored on the data volume. Newest entries are returned
// first for the management page.
export async function logEvent({ level = 'info', actor = 'system', action = 'event', message = '', meta } = {}) {
  const entry = { ts: Date.now(), level, actor, action, message, ...(meta ? { meta } : {}) };
  try {
    await fs.mkdir(path.dirname(LOG_FILE), { recursive: true });
    await fs.appendFile(LOG_FILE, JSON.stringify(entry) + '\n');
  } catch {
    // Logging must never take the app down.
  }
  const tag = level === 'error' ? 'ERROR' : level === 'warn' ? 'warn' : 'log';
  console.log(`[${tag}] ${action}: ${message}`);
  return entry;
}

export async function readLogs(limit = 300) {
  try {
    const raw = await fs.readFile(LOG_FILE, 'utf8');
    const lines = raw.split('\n').filter(Boolean);
    return lines.slice(-limit).reverse().map((l) => {
      try { return JSON.parse(l); } catch { return { ts: 0, level: 'info', message: l }; }
    });
  } catch {
    return [];
  }
}

export async function clearLogs() {
  try { await fs.writeFile(LOG_FILE, ''); } catch {}
}