/**
 * Operator-facing `/proc/bare_os/kernel_program.json` snapshot (env-driven, non-secret).
 * Legacy path `/proc/bare_os/giant_phase_program.json` resolves to the same payload.
 * Guest surfaces avoid Node `node:*` built-ins.
 * @param {Record<string, string | undefined>} env
 */
export const KERNEL_PROGRAM_PROC_SCHEMA = 2
export const KERNEL_PROGRAM_PROC_VERSION = 2

export function buildKernelProgramProcJson(env) {
  const now = Date.now()
  const esc = (k) => String(env[k] ?? '').trim()
  const on = (k) => {
    const v = esc(k)
    return v === '1' || v === 'true'
  }

  function parseOverride() {
    const rawNew = esc('BARE_OS_KERNEL_PROGRAM_PROC_JSON')
    const rawLegacy = esc('BARE_OS_GIANT_PHASE_PROGRAM_JSON')
    const raw = rawNew || rawLegacy
    if (!raw) return null
    const key = rawNew
      ? 'BARE_OS_KERNEL_PROGRAM_PROC_JSON'
      : 'BARE_OS_GIANT_PHASE_PROGRAM_JSON'
    try {
      const o = JSON.parse(raw)
      return o && typeof o === 'object' ? o : null
    } catch {
      return { error: 'invalid_json', key, atMs: now }
    }
  }

  function parseJsonEnv(key) {
    const raw = esc(key)
    if (!raw) return null
    try {
      const o = JSON.parse(raw)
      return o && typeof o === 'object' ? o : null
    } catch {
      return { error: 'invalid_json', key, atMs: now }
    }
  }

  const base = {
    schema: KERNEL_PROGRAM_PROC_SCHEMA,
    program: 'bare-os-kernel-program',
    programVersion: KERNEL_PROGRAM_PROC_VERSION,
    atMs: now,
    hooks: {
      bootSafeMode: on('BARE_OS_BOOT_SAFE_MODE'),
      bootTransactionJournal: (() => {
        const v = esc('BARE_OS_BOOT_TRANSACTION_JOURNAL')
        return v === '1' || v === 'true' || v === 'ndjson' ? v : ''
      })(),
      bootCheckpoint: on('BARE_OS_BOOT_CHECKPOINT'),
      bootPolicy: on('BARE_OS_BOOT_POLICY'),
      bootPolicyStrict: on('BARE_OS_BOOT_POLICY_STRICT'),
      bootMinimal: on('BARE_OS_BOOT_MINIMAL'),
      bootDryRun: on('BARE_OS_BOOT_DRY_RUN'),
      bootRollbackApply: on('BARE_OS_BOOT_ROLLBACK_APPLY'),
      kernelDebug: on('BARE_OS_KERNEL_DEBUG'),
      lazyPersonalDrive: on('BARE_OS_LAZY_PERSONAL_DRIVE'),
      kernelHotReload: on('BARE_OS_KERNEL_HOT_RELOAD'),
      delegateTrace: on('BARE_OS_DELEGATE_TRACE'),
      loaderAudit: on('BARE_OS_LOADER_AUDIT')
    },
    bareStacks: {
      note:
        'Prefer bare-module, bare-crypto, bare-fs, bare-net, bare-dns, bare-process, bare-subprocess, bare-ipc, bare-worker, bare-tls, bare-fetch, bare-http1, bare-ws per holepunch bare-node map.',
      bareCryptoVersion: esc('BARE_OS_BARE_CRYPTO_VERSION').slice(0, 64),
      pearIpcVersion: esc('BARE_OS_PEAR_IPC_PACKAGE_VERSION').slice(0, 64),
      bareTlsVersion: esc('BARE_OS_BARE_TLS_VERSION').slice(0, 64)
    },
    workstreams: {
      bootRuntime: { status: 'active', items: '1-20' },
      moduleLoading: { status: 'active', items: '21-30' },
      processIpc: { status: 'framework', items: '31-40' },
      vfsStorage: { status: 'framework', items: '41-50' },
      networking: { status: 'framework', items: '51-60' },
      security: { status: 'framework', items: '61-70' },
      observability: { status: 'framework', items: '71-80' },
      distribution: { status: 'framework', items: '81-90' },
      quality: { status: 'active', items: '91-100' }
    },
    operatorSketches: {
      schema: 1,
      bootBundleDigestHex: esc('BARE_OS_BOOT_BUNDLE_DIGEST_HEX').slice(0, 128),
      requireCtxApiMin: esc('BARE_OS_REQUIRE_CTX_API_MIN').slice(0, 32),
      dnsProfile: esc('BARE_OS_DNS_PROFILE').slice(0, 64),
      netDelegateSketch: parseJsonEnv(
        'BARE_OS_NET_DELEGATE_SKETCH_JSON'
      ) || parseJsonEnv('BARE_OS_GP2_NET_DELEGATE_SKETCH_JSON'),
      egressPolicyV2: parseJsonEnv('BARE_OS_EGRESS_POLICY_V2_JSON'),
      listenerRegistry: parseJsonEnv('BARE_OS_LISTENER_REGISTRY_JSON'),
      tlsSessionCacheHint: parseJsonEnv('BARE_OS_BARE_TLS_SESSION_CACHE_HINT_JSON'),
      wsDevtoolsSketch: parseJsonEnv('BARE_OS_BARE_WS_DEVTOOLS_SKETCH_JSON'),
      subprocessResourceHints: parseJsonEnv('BARE_OS_SUBPROCESS_RESOURCE_HINTS_JSON'),
      vfsWatchDebounceMs: Math.min(
        60000,
        Math.max(
          0,
          Number.parseInt(esc('BARE_OS_VFS_WATCH_DEBOUNCE_MS'), 10) || 0
        )
      ),
      binCacheStats: parseJsonEnv('BARE_OS_VFS_BIN_CACHE_STATS_JSON'),
      zlibLogPolicy: parseJsonEnv('BARE_OS_ZLIB_LOG_POLICY_JSON'),
      keyringRotationPointer: parseJsonEnv('BARE_OS_KEYRING_ROTATION_POINTER_JSON'),
      configAttestation: parseJsonEnv('BARE_OS_CONFIG_ATTESTATION_JSON'),
      entropyHealth: parseJsonEnv('BARE_OS_ENTROPY_HEALTH_JSON'),
      otelResourceAttrs:
        parseJsonEnv('BARE_OS_OTEL_RESOURCE_ATTRS_KERNEL_JSON') ||
        parseJsonEnv('BARE_OS_OTEL_RESOURCE_ATTRS_GP2_JSON'),
      logRetentionHints: parseJsonEnv('BARE_OS_LOG_RETENTION_HINTS_JSON'),
      circuitBreakerDelegates: parseJsonEnv('BARE_OS_DELEGATE_CIRCUIT_BREAKER_JSON'),
      execLineAnomalyThreshold: Math.min(
        1e9,
        Math.max(0, Number.parseInt(esc('BARE_OS_EXEC_LINE_ANOMALY_THRESHOLD'), 10) || 0)
      ),
      signedComponentManifest: parseJsonEnv('BARE_OS_SIGNED_COMPONENT_MANIFEST_JSON'),
      abChannelHint: esc('BARE_OS_AB_CHANNEL_HINT').slice(0, 64),
      lockfileTransitiveAllow: parseJsonEnv('BARE_OS_LOCKFILE_TRANSITIVE_ALLOW_JSON'),
      sandboxProfileRegistry: parseJsonEnv('BARE_OS_SANDBOX_PROFILE_REGISTRY_JSON'),
      cpuSliceHints: parseJsonEnv('BARE_OS_CPU_SLICE_HINTS_JSON'),
      ipcReadWatchdogMs: Math.min(
        300000,
        Math.max(0, Number.parseInt(esc('BARE_OS_IPC_READ_WATCHDOG_MS'), 10) || 0)
      ),
      crossDriveTxPointer: parseJsonEnv('BARE_OS_CROSS_DRIVE_TX_POINTER_JSON'),
      mountNamespaceSketch: parseJsonEnv('BARE_OS_MOUNT_NAMESPACE_SKETCH_JSON'),
      note:
        'Optional operator JSON hints (non-secret). See developer-guide/kernel-program.md and kernel-superfeature-backlog.md.'
    },
    docAnchor: 'developer-guide/kernel-program.md'
  }

  const override = parseOverride()
  if (override && !override.error) {
    const sch =
      typeof override.schema === 'number' && override.schema >= 1 && override.schema <= 3
        ? override.schema
        : KERNEL_PROGRAM_PROC_SCHEMA
    return { ...base, ...override, schema: sch, atMs: now }
  }
  if (override && override.error) {
    return { ...base, overrideError: override }
  }
  return base
}