import type { AutomationRule } from '../../generated/prisma';

/** Default natural mite fall (mites per day) that triggers the varroa rule. */
export const DEFAULT_VARROA_THRESHOLD_MITES_PER_DAY = 10;

/**
 * Effective varroa threshold of the VARROA_THRESHOLD rule.
 * - no rule row yet: the default rule applies (ensureDefaults creates it active)
 * - inactive rule: null (no threshold in force)
 * - active rule: the configured value, or the default if it is not a
 *   positive finite number (a hand-edited config must never disable the check).
 */
export function varroaThresholdOf(
  rule: Pick<AutomationRule, 'active' | 'config'> | null,
): number | null {
  if (rule === null) {
    return DEFAULT_VARROA_THRESHOLD_MITES_PER_DAY;
  }
  if (!rule.active) {
    return null;
  }
  const config = rule.config;
  if (typeof config !== 'object' || config === null || Array.isArray(config)) {
    return DEFAULT_VARROA_THRESHOLD_MITES_PER_DAY;
  }
  const value = (config as Record<string, unknown>).thresholdMitesPerDay;
  return typeof value === 'number' && Number.isFinite(value) && value > 0
    ? value
    : DEFAULT_VARROA_THRESHOLD_MITES_PER_DAY;
}