'use strict';

// Sampling-cabinet boundary + target math + rain-scaled flow prediction.
// All operations are pure given a domain handle — the domain owns the
// mutable fields (maxVolume, targetPuls, …) so legacy tests that read
// `monster.maxVolume` keep working.

const RAIN_STALE_MS = 2 * 60 * 60 * 1000;

function applyBoundsAndTargets(m) {
  m.maxVolume = m.maxWeight - m.emptyWeightBucket;
  m.minPuls = Math.round(m.minVolume / m.volume_pulse);
  m.maxPuls = Math.round(m.maxVolume / m.volume_pulse);
  m.absMaxPuls = Math.round(m.cap_volume / m.volume_pulse);
  m.targetVolume = m.minVolume * Math.sqrt(m.maxVolume / m.minVolume);
  m.targetPuls = Math.round(m.targetVolume / m.volume_pulse);
}

function validateFlowBounds(m) {
  // nominalFlowMin / flowMax must be declared in monster.json's `constraints`
  // section. If they aren't, configUtils strips them as unknown keys and the
  // bounds collapse to undefined → NaN → invalid here, which silently blocks
  // every sampling run. (Fixed 2026-05-11.)
  const min = Number(m.nominalFlowMin);
  const max = Number(m.flowMax);
  const valid = Number.isFinite(min) && Number.isFinite(max) && min >= 0 && max > 0 && min < max;
  m.invalidFlowBounds = !valid;
  if (!valid) m.logger.warn(`Invalid flow bounds. nominalFlowMin=${m.nominalFlowMin}, flowMax=${m.flowMax}`);
  return valid;
}

function getRainIndex(m) {
  if (!m.lastRainUpdate) return 0;
  if (Date.now() - m.lastRainUpdate > RAIN_STALE_MS) return 0;
  return Number.isFinite(m.avgRain) ? m.avgRain : 0;
}

function getPredictedFlowRate(m) {
  const min = Number(m.nominalFlowMin);
  const max = Number(m.flowMax);
  if (!Number.isFinite(min) || !Number.isFinite(max) || min < 0 || max <= 0 || min >= max) return 0;
  const rainIndex = getRainIndex(m);
  const scale = Math.max(0, Math.min(1, m.rainMaxRef > 0 ? rainIndex / m.rainMaxRef : 0));
  return min + (max - min) * scale;
}

function getSampleCooldownMs(m) {
  if (!m.lastSampleTime) return 0;
  const remaining = (m.minSampleIntervalSec * 1000) - (Date.now() - m.lastSampleTime);
  return Math.max(0, remaining);
}

module.exports = {
  applyBoundsAndTargets,
  validateFlowBounds,
  getRainIndex,
  getPredictedFlowRate,
  getSampleCooldownMs,
  RAIN_STALE_MS,
};