/** @type {Map<string, number>} */
const delegateBuckets = new Map()

/**
 * @param {string} kind
 * @param {Record<string, string | undefined> | null | undefined} env
 */
function delegateMaxPerMinute(kind, env) {
  if (!env) return 0
  const spec = env[`BARE_OS_DELEGATE_${String(kind).toUpperCase()}_MAX_PER_MIN`]
  if (spec != null && String(spec).trim() !== '') {
    const n = Number.parseInt(String(spec), 10)
    if (Number.isFinite(n) && n > 0) return n
  }
  const g = env.BARE_OS_DELEGATE_MAX_PER_MIN
  if (g != null && String(g).trim() !== '') {
    const n = Number.parseInt(String(g), 10)
    if (Number.isFinite(n) && n > 0) return n
  }
  return 0
}

/**
 * @param {string} kind
 * @param {Record<string, string | undefined> | null | undefined} env
 * @returns {boolean}
 */
export function bareOsDelegateRateAllow(kind, env) {
  const max = delegateMaxPerMinute(kind, env)
  if (!max) return true
  const minute = Math.floor(Date.now() / 60000)
  const key = `${kind}:${minute}`
  const cur = delegateBuckets.get(key) || 0
  if (cur >= max) return false
  delegateBuckets.set(key, cur + 1)
  if (delegateBuckets.size > 128) {
    const drop = [...delegateBuckets.keys()].slice(0, 64)
    for (const k of drop) delegateBuckets.delete(k)
  }
  return true
}

/** Sample of per-minute counters (keys `kind:minuteEpoch`). */
export function bareOsDelegateRateBucketsSnapshot() {
  return Object.fromEntries(delegateBuckets)
}