type RateLimitEntry = { count: number; resetAt: number };

const entries = new Map<string, RateLimitEntry>();
const windowMs = 10 * 60 * 1000;
const maxRequests = 5;

export function consumeRateLimit(key: string, limit: number, durationMs: number) {
  const now = Date.now();
  const current = entries.get(key);
  if (!current || current.resetAt <= now) {
    entries.set(key, { count: 1, resetAt: now + durationMs });
    return true;
  }
  if (current.count >= limit) return false;
  current.count += 1;
  return true;
}

export function consumeContactRateLimit(key: string) {
  return consumeRateLimit(key, maxRequests, windowMs);
}

export function getClientIp(requestHeaders: Headers) {
  const forwardedFor = requestHeaders.get("x-forwarded-for")?.split(",")[0]?.trim();
  return forwardedFor || requestHeaders.get("x-real-ip")?.trim() || "unknown";
}