import { Request } from 'express';
import { db } from '../db/database';

export function getClientIp(req: Request): string | null {
  const xff = req.headers['x-forwarded-for'];
  if (typeof xff === 'string') {
    const first = xff.split(',')[0]?.trim();
    return first || null;
  }
  if (Array.isArray(xff) && xff[0]) return String(xff[0]).trim() || null;
  return req.socket?.remoteAddress || null;
}

/** Best-effort; never throws — failures are logged only. */
export function writeAudit(entry: {
  userId: number | null;
  action: string;
  resource?: string | null;
  details?: Record<string, unknown>;
  ip?: string | null;
}): void {
  try {
    const detailsJson = entry.details && Object.keys(entry.details).length > 0 ? JSON.stringify(entry.details) : null;
    db.prepare(
      `INSERT INTO audit_log (user_id, action, resource, details, ip) VALUES (?, ?, ?, ?, ?)`
    ).run(entry.userId, entry.action, entry.resource ?? null, detailsJson, entry.ip ?? null);
  } catch (e) {
    console.error('[audit] write failed:', e instanceof Error ? e.message : e);
  }
}