// 米家客户端单例 + 认证状态 + 扫码流程状态机
import { MijiaAPI } from '@zythum02/mijia-api'
import { DiskCache } from '@zythum02/mijia-api/cache/disk-cache'
import { prisma } from '../db.js'
import { cacheDir } from './cache.js'

// 未授权/已过期 (模块内部错误, 路由层做 4xx 映射)
export class MihomeAuthError extends Error {
  constructor(message = '米家未授权或已过期') {
    super(message)
    this.name = 'MihomeAuthError'
  }
}

let _api = null

// 惰性单例: 首次调用时才构造并加载磁盘凭证
export function getApi() {
  if (!_api) _api = new MijiaAPI(new DiskCache(cacheDir()))
  return _api
}

// 认证状态内存缓存 (5 分钟 TTL, /status 不每次打米家账号服务)
let authCache = { status: 'unknown', lastError: '', checkedAt: 0 }

function persistAccount(status, lastError) {
  return prisma.mihomeAccount
    .upsert({
      where: { key: 'default' },
      create: { key: 'default', status, lastError: lastError || '' },
      update: { status, lastError: lastError || '' },
    })
    .catch((e) => {
      console.warn('[mihome] 写入授权状态失败(忽略):', e.message)
    })
}

// 校验米家是否可用: 有凭证 + 能刷新 token (刷新会自动处理 30 天过期)
// force=true 忽略 TTL 强查
export async function checkAuth(force = false) {
  const now = Date.now()
  if (!force && now - authCache.checkedAt < 5 * 60 * 1000) return authCache
  const api = getApi()
  let status = 'expired'
  let lastError = ''
  try {
    if (!api.available) throw new Error('无授权凭证')
    await api.refreshToken()
    status = 'ok'
  } catch (e) {
    status = 'expired'
    lastError = e?.message || String(e)
  }
  authCache = { status, lastError, checkedAt: now }
  await persistAccount(status, lastError)
  return authCache
}

// ==================== 扫码重授权流程 (模块级单例) ====================
// 状态: idle | waiting(已出二维码等扫码) | failed
// 扫码成功后 QRlogin 内部已保存凭证, 这里只置状态并回写 DB
const qrState = { running: false, canceled: false, state: 'idle', qrImageUrl: '', lastError: '', startedAt: 0 }

export function getQrState() {
  return { ...qrState }
}

export function getQrImageUrl() {
  return qrState.qrImageUrl || ''
}

export async function startQrLogin() {
  if (qrState.running) return getQrState()
  const api = getApi()
  qrState.running = true
  qrState.canceled = false
  qrState.lastError = ''
  qrState.qrImageUrl = ''
  qrState.startedAt = Date.now()
  ;(async () => {
    try {
      await api.QRlogin(async (info) => {
        qrState.qrImageUrl = info.qrImageUrl || info.loginUrl || ''
        qrState.state = 'waiting'
      })
      if (qrState.canceled) return
      qrState.state = 'idle'
      authCache = { status: 'ok', lastError: '', checkedAt: Date.now() }
      await persistAccount('ok', '')
    } catch (e) {
      if (qrState.canceled) {
        qrState.state = 'idle'
      } else {
        qrState.state = 'failed'
        qrState.lastError = e?.message || String(e)
      }
    } finally {
      qrState.running = false
    }
  })()
  return getQrState()
}

export function cancelQrLogin() {
  qrState.canceled = true
  if (qrState.running) {
    // 后台 QRlogin 仍在长轮询, 即便取消也让它自然结束, 只标记不再使用结果
  } else if (qrState.state !== 'failed') {
    qrState.state = 'idle'
  }
  return getQrState()
}