// Background load of experiment design 5.5: constant-arrival-rate 20 rps, /api/orders 70% and /api/price/{item} 30%.
// Thresholds mirror the SLO (p95 < 500ms, failures < 1%); a breach makes k6 exit non-zero at the end of the run
// (the SLO verdict itself is the harness judge's Mimir query, design 4.2).
import http from 'k6/http';
import { check } from 'k6';

const base = __ENV.ALB_URL;
const items = ['apple', 'banana', 'cherry'];

export const options = {
  scenarios: {
    background: {
      executor: 'constant-arrival-rate',
      rate: 20,
      timeUnit: '1s',
      duration: __ENV.K6_DURATION || '12h',
      preAllocatedVUs: 20,
      maxVUs: 50,
    },
  },
  thresholds: {
    http_req_duration: ['p(95)<500'],
    http_req_failed: ['rate<0.01'],
  },
};

export default function () {
  const r = Math.random();
  let res;
  if (r < 0.7) {
    res = http.get(`${base}/api/orders`, { tags: { route: 'orders' } });
  } else {
    const item = items[Math.floor(Math.random() * items.length)];
    res = http.get(`${base}/api/price/${item}`, { tags: { route: 'price' } });
  }
  check(res, { 'status 200': (x) => x.status === 200 });
}