// src/queue.js — Rate limiting, retry, per-domain throttle
const pRetry = require("p-retry");

// ── Per-domain rate limiter ───────────────────────────────────────────────
const domainLastRequest = new Map();
const DOMAIN_DELAY_MS = 1000; // একই domain-এ ১ সেকেন্ড gap

async function domainThrottle(url) {
  try {
    const domain = new URL(url).hostname;
    const last = domainLastRequest.get(domain) || 0;
    const wait = DOMAIN_DELAY_MS - (Date.now() - last);
    if (wait > 0) await new Promise((r) => setTimeout(r, wait));
    domainLastRequest.set(domain, Date.now());
  } catch (_) {}
}

// ── Retry wrapper ─────────────────────────────────────────────────────────
async function withRetry(fn, options = {}) {
  const { retries = 3, minTimeout = 1000, onRetry } = options;
  return pRetry(fn, {
    retries,
    minTimeout,
    maxTimeout: 10000,
    randomize: true,
    onFailedAttempt: (err) => {
      console.warn(`⚠️ Retry ${err.attemptNumber}/${retries + 1}: ${err.message}`);
      if (onRetry) onRetry(err);
    },
  });
}

// ── Webhook sender ────────────────────────────────────────────────────────
async function sendWebhook(url, data) {
  if (!url) return;
  const fetch = require("node-fetch");
  try {
    await fetch(url, {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ ...data, timestamp: new Date().toISOString() }),
      timeout: 10000,
    });
    console.log(`📡 Webhook sent → ${url}`);
  } catch (err) {
    console.warn(`⚠️ Webhook failed: ${err.message}`);
  }
}

module.exports = { domainThrottle, withRetry, sendWebhook };