/**
 * Idempotent managed Holesail entry for the stock bare-openssh listen address (see `bare-openssh.js`).
 * Same persistence rules as **`bare-os-www-holesail.js`** (`~/.holesail/state.json`).
 */
import { bareHolesailEnvTruthy } from './bare-holesail-env.js'
import {
  bareHolesailManagedEnsureServerSeedPersisted,
  bareHolesailManagedGenerateSeedHex,
  bareHolesailManagedReadState,
  bareHolesailManagedRuntimeRunning,
  bareHolesailManagedServiceIsRunning,
  bareHolesailManagedStartOne,
  bareHolesailManagedStopOne,
  bareHolesailManagedWriteState
} from './bare-holesail-managed.js'

export const BARE_OS_SSH_HOLESAIL_CONNECTION_ID_PREFIX = 'bare-ssh-'

/**
 * @param {number} port
 */
export function bareOsSshHolesailConnectionId(port) {
  return `${BARE_OS_SSH_HOLESAIL_CONNECTION_ID_PREFIX}${port}`
}

/**
 * Resolve canonical SSH connection id (always `bare-ssh-<live_port>`), while selecting
 * one existing row to carry forward for key/seed reuse and listing stale ids to prune.
 * @param {{ connections: Record<string, unknown> }} state
 * @param {number} port
 */
function bareOsSshResolveManagedIdentity(state, port) {
  const exactId = bareOsSshHolesailConnectionId(port)
  const allIds = Object.keys(state.connections).filter((id) =>
    id.startsWith(BARE_OS_SSH_HOLESAIL_CONNECTION_ID_PREFIX)
  )
  if (allIds.includes(exactId)) {
    return { id: exactId, sourceId: exactId, staleIds: allIds.filter((id) => id !== exactId) }
  }
  if (allIds.length === 0) return { id: exactId, sourceId: exactId, staleIds: [] }
  const idsSorted = allIds.sort()
  const sourceId = idsSorted[0]
  return { id: exactId, sourceId, staleIds: idsSorted }
}

/**
 * Default on (set **`BARE_OS_SSH_HOLESAIL=0`** or **`false`** to disable).
 * @param {Record<string, string | undefined>} env
 */
export function bareOsSshHolesailAutoEnabled(env) {
  const v = env.BARE_OS_SSH_HOLESAIL
  if (v === '0' || v === 'false') return false
  return true
}

/**
 * Normalize bind host for stable comparison (matches openssh listen string).
 * @param {string} host
 */
function normalizeWantHost(host) {
  const h = String(host ?? '').trim()
  return h || '127.0.0.1'
}

/**
 * Persist a managed server tunnel for SSH `port` / `host` and start it if bare-holesail is already active.
 * Call after **`sshServer.listen`** succeeds with the **actual** bound port and host.
 * @param {Record<string, unknown>} ctx
 * @param {Record<string, string | undefined>} env
 * @param {number} port
 * @param {string} [host]
 */
export async function ensureBareOsSshHolesailTunnel(ctx, env, port, host) {
  if (!bareOsSshHolesailAutoEnabled(env)) return
  const p =
    Number.isFinite(port) && port > 0 && port < 65536
      ? Math.floor(port)
      : 2222
  const wantHost = normalizeWantHost(host)
  const vfs = ctx.vfs
  if (!vfs || typeof vfs.readFile !== 'function' || typeof vfs.writeFile !== 'function') {
    return
  }
  if (!ctx.b4a || typeof ctx.b4a.from !== 'function') return

  const { path, state } = await bareHolesailManagedReadState(
    ctx,
    /** @type {Record<string, string | undefined>} */ (env)
  )
  const { id, sourceId, staleIds } = bareOsSshResolveManagedIdentity(state, p)
  /** @type {Record<string, unknown>} */
  const want = { server: true, port: p, host: wantHost, enabled: true }
  const existing = state.connections[sourceId]
  let shouldRestartRuntime = false
  if (existing && typeof existing === 'object') {
    const ex = /** @type {Record<string, unknown>} */ (existing)
    const curPort = Number.parseInt(String(ex.port ?? ''), 10)
    const server = bareHolesailEnvTruthy(ex.server)
    const enabled =
      ex.enabled === undefined || ex.enabled === null || String(ex.enabled) === ''
        ? true
        : bareHolesailEnvTruthy(ex.enabled)
    const rawHost = String(ex.host ?? '').trim()
    const hostOk = rawHost === wantHost
    shouldRestartRuntime = !(curPort === p && hostOk && server && enabled)
    if (server && curPort === p && enabled && hostOk) {
      await bareHolesailManagedEnsureServerSeedPersisted(
        ctx,
        /** @type {Record<string, string | undefined>} */ (env),
        id
      )
      if (
        bareHolesailManagedServiceIsRunning() &&
        !bareHolesailManagedRuntimeRunning(id)
      ) {
        try {
          await bareHolesailManagedStartOne(
            ctx,
            /** @type {Record<string, string | undefined>} */ (env),
            id
          )
        } catch {
          /* may already run */
        }
      }
      return
    }
  }

  /** @type {Record<string, unknown>} */
  const next = { ...want }
  if (existing && typeof existing === 'object') {
    const ex = /** @type {Record<string, unknown>} */ (existing)
    const k = String(ex.key ?? '').trim()
    if (k) next.key = k
    const s = String(ex.seed ?? '').trim()
    if (s) next.seed = s
  }
  const legacyHsOnly =
    /^hs:\/\//i.test(String(next.key ?? '').trim()) && !String(next.seed ?? '').trim()
  if (!legacyHsOnly && !String(next.seed ?? '').trim()) {
    next.seed = bareHolesailManagedGenerateSeedHex()
  }
  state.connections[id] = next
  for (const staleId of staleIds) delete state.connections[staleId]
  await bareHolesailManagedWriteState(
    ctx,
    /** @type {Record<string, string | undefined>} */ (env),
    state
  )
  await bareHolesailManagedEnsureServerSeedPersisted(
    ctx,
    /** @type {Record<string, string | undefined>} */ (env),
    id
  )
  void path
  if (shouldRestartRuntime && bareHolesailManagedRuntimeRunning(id)) {
    try {
      await bareHolesailManagedStopOne(ctx, id)
    } catch {
      /* ignore */
    }
  }
  for (const staleId of staleIds) {
    if (bareHolesailManagedRuntimeRunning(staleId)) {
      try {
        await bareHolesailManagedStopOne(ctx, staleId)
      } catch {
        /* ignore */
      }
    }
  }
  if (
    bareHolesailManagedServiceIsRunning() &&
    !bareHolesailManagedRuntimeRunning(id)
  ) {
    try {
      await bareHolesailManagedStartOne(
        ctx,
        /** @type {Record<string, string | undefined>} */ (env),
        id
      )
    } catch (e) {
      try {
        ctx.console?.error?.(
          `[bare-os-ssh] holesail start ${id}: ${(e && /** @type {{ message?: string }} */ (e).message) || String(e)}`
        )
      } catch {
        /* ignore */
      }
    }
  }
}