/**
 * Host snapshot cache for dynamic UI auto-population.
 */
import { manager, Methods } from './manager.js'

const TTL_MS = 8000
/** @type {{ data: object, at: number, peerId: string }|null} */
let cache = null
/** @type {Promise<object>|null} */
let inflight = null

export function clearSnapshotCache() {
  cache = null
  inflight = null
}

/**
 * @param {{ force?: boolean }} [opts]
 */
export async function getSnapshot(opts = {}) {
  const peerId = manager.active?.id || ''
  const now = Date.now()
  if (
    !opts.force &&
    cache &&
    cache.peerId === peerId &&
    now - cache.at < TTL_MS
  ) {
    return cache.data
  }
  if (inflight && !opts.force) return inflight

  inflight = (async () => {
    if (!manager.active?.connected) {
      throw new Error('Not connected')
    }
    const data = await manager.request(Methods.getHostSnapshot, {})
    cache = { data, at: Date.now(), peerId }
    inflight = null
    return data
  })().catch((err) => {
    inflight = null
    throw err
  })

  return inflight
}

export async function suggestNetwork(opts = {}) {
  if (!manager.active?.connected) throw new Error('Not connected')
  return manager.request(Methods.suggestNetworkIPAM, opts)
}

export async function suggestName(kind, base) {
  if (!manager.active?.connected) throw new Error('Not connected')
  return manager.request(Methods.suggestResourceName, { kind, base })
}

export async function suggestFromImage(image) {
  if (!manager.active?.connected) throw new Error('Not connected')
  return manager.request(Methods.suggestFromImage, { image })
}

export async function suggestDefaults(kind, args = {}) {
  if (!manager.active?.connected) throw new Error('Not connected')
  return manager.request(Methods.suggestDefaults, { kind, ...args })
}

export async function listUsedHostPorts() {
  if (!manager.active?.connected) throw new Error('Not connected')
  return manager.request(Methods.listUsedHostPorts, {})
}

/** Warm cache after connect (best-effort). Notifies UI of engine/swarm state. */
export function warmSnapshot() {
  return getSnapshot({ force: true })
    .then((data) => {
      try {
        if (typeof window !== 'undefined' && typeof window.peardockOps?.onHostSnapshot === 'function') {
          window.peardockOps.onHostSnapshot(data)
        }
      } catch {
        // ignore UI hooks
      }
      return data
    })
    .catch(() => {})
}

export default {
  getSnapshot,
  clearSnapshotCache,
  warmSnapshot,
  suggestNetwork,
  suggestName,
  suggestFromImage,
  suggestDefaults,
  listUsedHostPorts,
}