/**
 * Validate `BARE_OS_SEED_DHT_BOOTSTRAP_JSON`.
 * Accepts either string entries "host:port" or objects { host, port, addressClass? }.
 * Returns normalized `host:port` strings for safe proc exposure.
 * @param {string} raw
 * @returns {string[]}
 */
export function parseSeedDhtBootstrapJson(raw) {
  const s = String(raw || '').trim()
  if (!s) return []
  let parsed
  try {
    parsed = JSON.parse(s)
  } catch {
    throw new Error('BARE_OS_SEED_DHT_BOOTSTRAP_JSON must be valid JSON')
  }
  if (!Array.isArray(parsed)) {
    throw new Error('BARE_OS_SEED_DHT_BOOTSTRAP_JSON must be a JSON array')
  }
  /** @type {string[]} */
  const out = []
  for (const row of parsed.slice(0, 64)) {
    if (typeof row === 'string') {
      const n = normalizeHostPort(row)
      if (!n) {
        throw new Error('Invalid DHT bootstrap entry (expected host:port string)')
      }
      out.push(n)
      continue
    }
    if (!row || typeof row !== 'object' || Array.isArray(row)) {
      throw new Error('Invalid DHT bootstrap entry (expected string or object)')
    }
    const host = String(row.host || '').trim()
    const port = Number.parseInt(String(row.port || ''), 10)
    if (!host || !Number.isFinite(port) || port < 1 || port > 65535) {
      throw new Error('Invalid DHT bootstrap object (host/port)')
    }
    const cls = String(row.addressClass || '').trim().toLowerCase()
    if (cls && !['ipv4', 'ipv6', 'relay', 'local', 'wan'].includes(cls)) {
      throw new Error('Invalid DHT bootstrap object (addressClass)')
    }
    out.push(`${host}:${port}`)
  }
  return out
}

/**
 * @param {string} s
 * @returns {string | null}
 */
function normalizeHostPort(s) {
  const m = String(s || '').trim().match(/^(.+):([0-9]{1,5})$/)
  if (!m) return null
  const host = String(m[1] || '').trim()
  const port = Number.parseInt(String(m[2] || ''), 10)
  if (!host || !Number.isFinite(port) || port < 1 || port > 65535) return null
  return `${host}:${port}`
}