/**
 * @param {{
 *   initialJsGzipBytes: number,
 *   lazyChunks: Array<{ path: string, gzipBytes: number }>
 * }} measurements
 * @param {{ initialJsGzipBytes: number, lazyChunkGzipBytes: number }} thresholds
 */
export function evaluateBundleBudget(measurements, thresholds) {
  const initialPassed =
    measurements.initialJsGzipBytes <= thresholds.initialJsGzipBytes;
  const lazyResults = measurements.lazyChunks.map((chunk) => ({
    ...chunk,
    threshold: thresholds.lazyChunkGzipBytes,
    passed: chunk.gzipBytes <= thresholds.lazyChunkGzipBytes,
  }));
  return Object.freeze({
    initialPassed,
    lazyResults: Object.freeze(lazyResults),
    passed: initialPassed && lazyResults.every((chunk) => chunk.passed),
  });
}

/**
 * @param {{
 *   context?: Record<string, unknown>,
 *   metrics: { lcpMs: number, cls: number, namedInteractionMs: number }
 * }} report
 * @param {{ lcpMs: number, cls: number, namedInteractionMs: number }} thresholds
 */
export function evaluateLabBudget(report, thresholds) {
  const requiredContext = [
    "runner",
    "browser",
    "viewport",
    "network",
    "cpu",
    "cache",
    "build",
  ];
  const missingContext = requiredContext.filter(
    (field) => report.context?.[field] === undefined,
  );
  const results = {
    lcp: report.metrics.lcpMs <= thresholds.lcpMs,
    cls: report.metrics.cls <= thresholds.cls,
    namedInteraction:
      report.metrics.namedInteractionMs <= thresholds.namedInteractionMs,
  };
  return Object.freeze({
    missingContext: Object.freeze(missingContext),
    results: Object.freeze(results),
    passed: missingContext.length === 0 && Object.values(results).every(Boolean),
  });
}

/** @param {number[]} values */
export function percentile75(values) {
  if (values.length === 0) return null;
  const sorted = [...values].sort((left, right) => left - right);
  return sorted[Math.ceil(sorted.length * 0.75) - 1];
}

/**
 * @param {{
 *   metrics: { p75LcpMs: number | null, p75Cls: number | null, p75InpMs: number | null },
 *   eligibleSamples: number
 * }} report
 * @param {{
 *   p75LcpMs: number,
 *   p75Cls: number,
 *   p75InpMs: number,
 *   minimumEligibleSamples: number | null
 * }} thresholds
 */
export function evaluateFieldBudget(report, thresholds) {
  if (
    thresholds.minimumEligibleSamples === null ||
    report.eligibleSamples < thresholds.minimumEligibleSamples ||
    Object.values(report.metrics).some((value) => value === null)
  ) {
    return Object.freeze({
      status: /** @type {const} */ ("FAIL_UNVERIFIED"),
      passed: false,
    });
  }
  const passed =
    /** @type {number} */ (report.metrics.p75LcpMs) <= thresholds.p75LcpMs &&
    /** @type {number} */ (report.metrics.p75Cls) <= thresholds.p75Cls &&
    /** @type {number} */ (report.metrics.p75InpMs) <= thresholds.p75InpMs;
  return Object.freeze({
    status: passed
      ? /** @type {const} */ ("PASS")
      : /** @type {const} */ ("FAIL_THRESHOLD"),
    passed,
  });
}