import { Redis } from '@upstash/redis';

// Upstash Redis client for serverless/Vercel compatibility.
// For self-hosted Docker, run redis-rest-proxy or use Upstash Cloud free tier.
// Env vars: UPSTASH_REDIS_REST_URL, UPSTASH_REDIS_REST_TOKEN

const url = process.env.UPSTASH_REDIS_REST_URL;
const token = process.env.UPSTASH_REDIS_REST_TOKEN;

export const redis = url && token
  ? new Redis({ url, token })
  : null;

export function ensureRedis() {
  if (!redis) {
    throw new Error('Redis is not configured. Set UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN.');
  }
  return redis;
}