import { db } from "../db";
import { users } from "@shared/schema";
import { eq } from "drizzle-orm";

// In-memory throttle to avoid writing last_activity_at on every authenticated request.
// Maps userId -> timestamp (ms) of the last DB update.
const lastActivityUpdate = new Map<number, number>();

const THROTTLE_MS = 60_000; // 1 minute

/**
 * Updates users.last_activity_at for the given user, throttled to once per minute.
 * Fire-and-forget: does not block the caller.
 */
export function trackUserActivity(userId: number): void {
  const now = Date.now();
  const lastUpdate = lastActivityUpdate.get(userId);
  if (lastUpdate && now - lastUpdate < THROTTLE_MS) return;

  lastActivityUpdate.set(userId, now);

  // Run async without awaiting so the request is not delayed.
  // Синхронные ошибки (например, недоступный пул соединений) тоже не должны
  // срывать аутентификацию — трекинг активности некритичен.
  try {
    db.update(users)
      .set({ lastActivityAt: new Date() })
      .where(eq(users.id, userId))
      .then(() => {
        // No-op on success
      })
      .catch((err) => {
        // Reset the throttle timestamp on error so the next request retries.
        lastActivityUpdate.delete(userId);
        console.error("[trackUserActivity] failed to update user activity:", err);
      });
  } catch (err) {
    lastActivityUpdate.delete(userId);
    console.error("[trackUserActivity] failed to update user activity:", err);
  }
}