import { verifySignedReferenceRun } from './reference-evidence.mjs';

const median = (values) => {
  if (values.length === 0) throw new Error('At least one value is required.');
  const sorted = [...values].sort((left, right) => left - right);
  return sorted[Math.floor(sorted.length / 2)];
};

export const aggregateFiveDriveTraces = (runs, trustPolicy) => {
  if (!Array.isArray(runs) || runs.length !== 5) throw new Error('Exactly five drive-trace.v1 runs are required.');
  for (const run of runs) verifySignedReferenceRun(run, trustPolicy);
  const profile = runs[0]?.profile;
  if (typeof profile !== 'string' || runs.some((run) => run?.schema !== 'drive-trace.v1' || run.profile !== profile)) {
    throw new Error('All runs must use one drive-trace.v1 profile.');
  }
  const identities = runs.map((run) => run.referenceRun);
  const indexes = identities.map((identity) => identity?.runIndex).sort((left, right) => left - right);
  if (JSON.stringify(indexes) !== JSON.stringify([1, 2, 3, 4, 5])) {
    throw new Error('Reference evidence must contain unique run indexes 1 through 5.');
  }
  const runIds = new Set(identities.map((identity) => identity?.runId));
  const digests = new Set(identities.map((identity) => identity?.attestationDigest));
  if (runIds.size !== 5 || digests.size !== 5 || identities.some((identity) => !/^[a-f0-9]{64}$/u.test(identity?.attestationDigest ?? ''))) {
    throw new Error('Reference evidence must contain five unique authenticated identities.');
  }
  const lcp = runs.map((run) => run.metrics.lcp);
  const tbt = runs.map((run) => run.metrics.tbt);
  const everyPerRunBudgetPass = runs.every((run) => Object.values(run.budgetResults).every(Boolean));
  const referenceEvidence = runs.every((run) => run.gatingReferenceResult === true && run.validReferenceCadence === true);
  const summary = {
    lcpWorst: Math.max(...lcp),
    lcpMedian: median(lcp),
    tbtWorst: Math.max(...tbt),
    tbtMedian: median(tbt),
    everyPerRunBudgetPass,
    referenceEvidence,
  };
  return {
    schema: 'drive-trace-aggregation/v1',
    profile,
    runCount: 5,
    summary,
    passes: referenceEvidence
      && everyPerRunBudgetPass
      && summary.lcpWorst <= 3_000
      && summary.lcpMedian <= 2_500
      && summary.tbtWorst <= 300
      && summary.tbtMedian <= 200,
  };
};