// What the admin's Health page shows: a short in-memory log of things that went wrong (failed sign-ins, failed
// notifications, backups), plus disk use and the snapshot list. The log resets when the server restarts.
import { existsSync, statSync, statfsSync } from 'fs';
import { join } from 'path';
import { dataDir } from './db.js';
import { backupDir, listSnapshots } from './backups.js';

const MAX_EVENTS = 200;
const events = [];
const started = Date.now();

// kind: 'signin' | 'notify' | 'backup'. `ok` false marks a failure.
export function logEvent(kind, detail, { ok = false, userId = null } = {}) {
  events.unshift({ at: Date.now(), kind, ok, detail: String(detail).slice(0, 300), userId });
  if (events.length > MAX_EVENTS) events.length = MAX_EVENTS;
}

export const recentEvents = (kind, limit = 50) => events.filter((e) => !kind || e.kind === kind).slice(0, limit);
export function clearEvents() { events.length = 0; }

const size = (path) => { try { return statSync(path).size; } catch { return 0; } };

export function diskUse() {
  const dir = dataDir();
  const db = size(join(dir, 'projects.db')) + size(join(dir, 'projects.db-wal'));
  const backups = listSnapshots(backupDir()).reduce((n, s) => n + s.bytes, 0);
  let free = null; let total = null;
  try { const s = statfsSync(existsSync(dir) ? dir : '.'); free = s.bavail * s.bsize; total = s.blocks * s.bsize; } catch { /* not supported here */ }
  return { db, backups, free, total };
}

export function backupStatus() {
  const snapshots = listSnapshots(backupDir());
  return { enabled: process.env.BACKUP_DISABLED !== '1', keep: Number(process.env.BACKUP_KEEP) || 7, snapshots, latest: snapshots[0] ?? null };
}

export const uptimeSeconds = () => Math.round((Date.now() - started) / 1000);