/**
 * Artillery processor functions.
 *
 * Artillery loads this file and calls exported functions
 * as hooks during virtual user lifecycle.
 *
 * Note: this must be plain JS/MJS (not TypeScript) — Artillery loads it directly.
 */

import { readFileSync } from "fs";
import { join, dirname } from "path";
import { fileURLToPath } from "url";

const __dirname = dirname(fileURLToPath(import.meta.url));

// ── Load customer -> stripeId mapping (generated by setup.ts) ───

let customerMap = {};
try {
  customerMap = JSON.parse(
    readFileSync(join(__dirname, ".customers.json"), "utf-8")
  );
} catch {
  console.warn(
    "[processor] No .customers.json found — attach scenarios will fail.\n" +
      "  Run: cd server && bun loadtest:setup"
  );
}

const CUSTOMER_IDS = Object.keys(customerMap);
const CUSTOMER_COUNT = CUSTOMER_IDS.length || 500;
const CUSTOMER_PREFIX = "load-cus-";

/** Products in the load-test group (for upgrade/downgrade cycling). */
const PLAN_PRODUCTS = ["load-pro", "load-premium", "load-free"];

/** The main metered feature all products include. */
const FEATURE_ID = "messages";

function padNumber(n) {
  return String(n).padStart(3, "0");
}

function pickRandom(arr) {
  return arr[Math.floor(Math.random() * arr.length)];
}

function getRandomCustomerId() {
  if (CUSTOMER_IDS.length > 0) {
    return pickRandom(CUSTOMER_IDS);
  }
  // Fallback if .customers.json not loaded
  const num = Math.floor(Math.random() * 500) + 1;
  return `${CUSTOMER_PREFIX}${padNumber(num)}`;
}

/**
 * Called before each "Core API loop" virtual user.
 * Sets customer + feature for check/track/get requests.
 */
export function setCustomerContext(ctx, _events, done) {
  ctx.vars.customerId = getRandomCustomerId();
  ctx.vars.featureId = FEATURE_ID;
  done();
}

/**
 * Called before each "Attach flow" virtual user.
 * Sets customer + a random product for upgrade/downgrade.
 */
export function setAttachContext(ctx, _events, done) {
  const customerId = getRandomCustomerId();
  ctx.vars.customerId = customerId;
  ctx.vars.stripeId = customerMap[customerId] || "";
  ctx.vars.productId = pickRandom(PLAN_PRODUCTS);
  ctx.vars.featureId = FEATURE_ID;
  done();
}