const CDN = "https://esm.sh/";

const hexchain = async (toml) => {
  const [
    { parse },
    { default: seedrandom },
    ss,
    { default: Ajv },
    { default: table },
    { default: DOMPurify }
  ] = await Promise.all([
    import(`${CDN}smol-toml`),
    import(`${CDN}seedrandom`),
    import(`${CDN}simple-statistics`),
    import(`${CDN}ajv`),
    import(`${CDN}text-table`),
    import(`${CDN}dompurify`)
  ]);

  const config = parse(toml);

  const schema = {
    type: "object",
    required: ["seed", "count", "label"],
    properties: {
      seed: { type: "string" },
      count: { type: "integer", minimum: 1, maximum: 10000 },
      label: { type: "string", minLength: 1 }
    }
  };

  const ajv = new Ajv();
  if (!ajv.validate(schema, config))
    return { valid: false, errors: ajv.errorsText() };

  const rng = new seedrandom(config.seed);
  const nums = Array.from({ length: config.count }, () => rng());

  const r = (n) => Math.round(n * 1e6) / 1e6;
  const mean = r(ss.mean(nums));
  const stddev = r(ss.standardDeviation(nums));
  const median = r(ss.median(nums));

  const tableString = table([
    ["Stat", "Value"],
    ["mean", String(mean)],
    ["stddev", String(stddev)],
    ["median", String(median)]
  ]);

  const sanitized = DOMPurify.sanitize(
    `<pre class="stats">${tableString}</pre>`
  );

  return {
    valid: true,
    label: config.label,
    stats: { mean, stddev, median },
    table: sanitized,
    count: config.count
  };
};

export { hexchain };
export default hexchain;
// Generation time: 8.247s
// Result: PASS