import { acquireToken, getPoolInfo, getTotalCapacity } from './auth.js';

const MAX_QUEUE_SIZE = 100;
const queue = [];

const OVERLOAD_LOG_COOLDOWN = 60_000; // 1 min between overload logs to avoid spam
let lastOverloadLog = 0;

export function enqueueRequest(preferVision, timeoutMs = 30000) {
  return new Promise((resolve, reject) => {
    const timer = setTimeout(() => {
      const idx = queue.findIndex(e => e.resolve === resolve);
      if (idx !== -1) queue.splice(idx, 1);
      console.error(`⚠️ OVERLOAD: request timed out after ${timeoutMs}ms waiting for token (queue=${queue.length})`);
      reject(new Error('Request timed out waiting for available token'));
    }, timeoutMs);

    // Try immediate acquire first
    const slot = acquireToken(preferVision);
    if (slot) {
      clearTimeout(timer);
      resolve(slot);
      return;
    }

    // ⚠️ OVERLOAD: no token available, request must queue
    const now = Date.now();
    if (now - lastOverloadLog > OVERLOAD_LOG_COOLDOWN) {
      lastOverloadLog = now;
      const pool = getPoolInfo();
      const active = pool.reduce((s, t) => s + t.activeRequests, 0);
      const cap = getTotalCapacity();
      console.error(`⚠️ OVERLOAD: queue=${queue.length + 1}/${MAX_QUEUE_SIZE} active=${active}/${cap} — all tokens at capacity, consider adding more tokens (DS_TOKENS) or increasing MAX_CONCURRENT_PER_TOKEN`);
    }

    if (queue.length >= MAX_QUEUE_SIZE) {
      clearTimeout(timer);
      console.error(`🚨 OVERLOAD CRITICAL: queue FULL (${MAX_QUEUE_SIZE}), request rejected — immediate expansion needed`);
      reject(new Error('Too many queued requests, try again later'));
      return;
    }

    queue.push({ preferVision, resolve: (slot) => { clearTimeout(timer); resolve(slot); }, reject: (err) => { clearTimeout(timer); reject(err); } });
  });
}

// Call when a token is released — try to dispatch queued request
export function dispatchQueued() {
  while (queue.length > 0) {
    const next = queue[0];
    const slot = acquireToken(next.preferVision);
    if (!slot) break; // No token available yet
    queue.shift();
    next.resolve(slot);
  }
}

export function getQueueInfo() {
  return { queued: queue.length, maxQueueSize: MAX_QUEUE_SIZE };
}