/**
 * 微信小程序正式版更新 + 版本/状态可见性。
 * 新包就绪后强制重启；「我的」页可展示「已是最新 / 有新版本…」。
 *
 * @see docs/superpowers/specs/2026-09-26-mp-weixin-force-update-design.md
 * @see docs/superpowers/specs/2026-09-26-mp-version-status-design.md
 */

const SHOW_DEBOUNCE_MS = 30 * 1000
const USER_CHECK_FALLBACK_MS = 2800

const ENV_LABEL = {
  release: '正式版',
  trial: '体验版',
  develop: '开发版'
}

let listenersBound = false
let readyModalShown = false
let failedModalShown = false
let lastCheckAt = 0
let cachedUpdateManager = null
let userToastUnsub = null
let userFallbackTimer = null

let snapshot = {
  status: 'idle',
  version: '',
  envVersion: '',
  envLabel: '',
  isRelease: false,
  hasUpdate: false
}

const listeners = new Set()

function notify() {
  const copy = { ...snapshot }
  listeners.forEach((fn) => {
    try {
      fn(copy)
    } catch (e) {
      console.warn('[mpUpdate] listener error', e)
    }
  })
}

function patchSnapshot(partial) {
  snapshot = { ...snapshot, ...partial }
  notify()
}

/**
 * @returns {{ version: string, envVersion: string, envLabel: string, isRelease: boolean }}
 */
export function getMpAccountInfo() {
  // #ifdef MP-WEIXIN
  try {
    if (typeof uni.getAccountInfoSync === 'function') {
      const mini = (uni.getAccountInfoSync() || {}).miniProgram || {}
      const envVersion = mini.envVersion || ''
      return {
        version: mini.version || '',
        envVersion,
        envLabel: ENV_LABEL[envVersion] || envVersion || '未知',
        isRelease: envVersion === 'release'
      }
    }
  } catch (e) {
    console.warn('[mpUpdate] getAccountInfoSync failed', e)
  }
  // #endif
  return {
    version: '',
    envVersion: '',
    envLabel: '',
    isRelease: false
  }
}

export function getMpUpdateSnapshot() {
  return { ...snapshot }
}

/**
 * @param {(s: typeof snapshot) => void} listener
 * @returns {() => void}
 */
export function subscribeMpUpdate(listener) {
  listeners.add(listener)
  listener({ ...snapshot })
  return () => listeners.delete(listener)
}

function refreshAccountIntoSnapshot(statusOverride) {
  const account = getMpAccountInfo()
  const next = {
    version: account.version,
    envVersion: account.envVersion,
    envLabel: account.envLabel,
    isRelease: account.isRelease,
    hasUpdate: snapshot.hasUpdate,
    status: snapshot.status
  }

  if (!account.isRelease) {
    next.status = account.envVersion ? 'unsupported' : snapshot.status
    next.hasUpdate = false
  } else if (statusOverride) {
    next.status = statusOverride
  } else if (snapshot.status === 'unsupported') {
    next.status = 'idle'
  }

  patchSnapshot(next)
}

function showReadyModal(updateManager) {
  if (readyModalShown) return
  readyModalShown = true
  uni.showModal({
    title: '更新提示',
    content: '新版本已准备好，需要重启以使用最新功能',
    showCancel: false,
    confirmText: '立即重启',
    success: (res) => {
      if (res.confirm) {
        updateManager.applyUpdate()
      }
    }
  })
}

function clearUserFeedbackHooks() {
  if (userToastUnsub) {
    userToastUnsub()
    userToastUnsub = null
  }
  if (userFallbackTimer) {
    clearTimeout(userFallbackTimer)
    userFallbackTimer = null
  }
}

function toastForStatus(status) {
  if (status === 'latest') {
    uni.showToast({ title: '已是最新', icon: 'none' })
  } else if (status === 'downloading') {
    uni.showToast({ title: '发现新版本，正在下载', icon: 'none' })
  } else if (status === 'failed') {
    uni.showToast({ title: '更新失败，请稍后重试', icon: 'none' })
  }
}

function feedbackFromKnownStatus() {
  const { status } = snapshot
  if (status === 'ready' && cachedUpdateManager) {
    readyModalShown = false
    showReadyModal(cachedUpdateManager)
    return true
  }
  if (status === 'latest' || status === 'downloading' || status === 'failed') {
    toastForStatus(status)
    return true
  }
  return false
}

function armUserCheckFeedback() {
  clearUserFeedbackHooks()
  const startedStatus = snapshot.status
  userToastUnsub = subscribeMpUpdate((s) => {
    if (s.status === startedStatus && s.status === 'checking') return
    if (s.status === 'latest' || s.status === 'downloading' || s.status === 'failed') {
      toastForStatus(s.status)
      clearUserFeedbackHooks()
    } else if (s.status === 'ready') {
      clearUserFeedbackHooks()
    }
  })
  userFallbackTimer = setTimeout(() => {
    userFallbackTimer = null
    if (snapshot.status === 'checking') {
      // 微信未必再次回调：无 hasUpdate 信号时按「已是最新」收口
      patchSnapshot({ status: 'latest', hasUpdate: false })
      uni.showToast({ title: '已是最新', icon: 'none' })
    }
    clearUserFeedbackHooks()
  }, USER_CHECK_FALLBACK_MS)
}

function bindUpdateListeners(updateManager) {
  if (listenersBound) return
  listenersBound = true

  updateManager.onCheckForUpdate((res) => {
    const hasUpdate = !!(res && res.hasUpdate)
    console.log('[mpUpdate] onCheckForUpdate hasUpdate=', hasUpdate)
    if (!snapshot.isRelease) {
      patchSnapshot({ status: 'unsupported', hasUpdate: false })
      return
    }
    if (hasUpdate) {
      if (snapshot.status !== 'ready') {
        patchSnapshot({ status: 'downloading', hasUpdate: true })
      } else {
        patchSnapshot({ hasUpdate: true })
      }
    } else {
      patchSnapshot({ status: 'latest', hasUpdate: false })
    }
  })

  updateManager.onUpdateReady(() => {
    console.log('[mpUpdate] onUpdateReady')
    patchSnapshot({ status: 'ready', hasUpdate: true })
    showReadyModal(updateManager)
  })

  updateManager.onUpdateFailed(() => {
    console.log('[mpUpdate] onUpdateFailed')
    patchSnapshot({ status: 'failed', hasUpdate: snapshot.hasUpdate })
    if (failedModalShown) return
    failedModalShown = true
    uni.showModal({
      title: '更新失败',
      content: '新版本下载失败，请删除小程序后重新搜索打开，或检查网络后重试',
      showCancel: false
    })
  })
}

/**
 * @param {{ force?: boolean, fromUser?: boolean }} [options]
 */
export function checkMpUpdate(options = {}) {
  // #ifdef MP-WEIXIN
  const force = !!options.force
  const fromUser = !!options.fromUser

  refreshAccountIntoSnapshot()

  if (!snapshot.isRelease) {
    if (fromUser) {
      uni.showToast({
        title: '开发/体验版无正式更新流',
        icon: 'none'
      })
    }
    return
  }

  if (fromUser && feedbackFromKnownStatus()) {
    return
  }

  const now = Date.now()
  if (!force && lastCheckAt && now - lastCheckAt < SHOW_DEBOUNCE_MS) {
    return
  }
  lastCheckAt = now

  if (typeof uni.canIUse !== 'function' || !uni.canIUse('getUpdateManager')) {
    if (fromUser) {
      uni.showToast({ title: '当前基础库不支持检查更新', icon: 'none' })
    }
    return
  }

  if (fromUser || snapshot.status === 'idle') {
    patchSnapshot({ status: 'checking' })
  }

  const updateManager = uni.getUpdateManager()
  cachedUpdateManager = updateManager
  bindUpdateListeners(updateManager)

  if (fromUser) {
    armUserCheckFeedback()
  }
  // #endif
}

/**
 * @param {ReturnType<typeof getMpUpdateSnapshot>} [s]
 */
export function formatMpUpdateLine(s) {
  const state = s || getMpUpdateSnapshot()
  if (state.status === 'unsupported' || (!state.isRelease && state.envVersion)) {
    const env = state.envLabel || '非正式版'
    return `${env} · 无正式更新流`
  }
  const ver = state.version ? `版本 ${state.version}` : '版本 —'
  const env = state.envLabel || '正式版'
  let tip = '点此检查更新'
  switch (state.status) {
    case 'checking':
      tip = '检查中…'
      break
    case 'latest':
      tip = '已是最新'
      break
    case 'downloading':
      tip = '有新版本（下载中）'
      break
    case 'ready':
      tip = '有新版本，点此更新'
      break
    case 'failed':
      tip = '更新失败'
      break
    default:
      tip = '点此检查更新'
  }
  return `${ver} · ${env} · ${tip}`
}

/** 是否需要用户关注更新（下载中 / 待重启 / 失败） */
export function isMpUpdateUrgent(s) {
  const status = (s || getMpUpdateSnapshot()).status
  return status === 'downloading' || status === 'ready' || status === 'failed'
}

refreshAccountIntoSnapshot()