import { AppState, type AppStateStatus } from 'react-native'
import { create } from 'zustand'

import { subscription } from '@/lib/auth'
import type { ApiError } from '@/lib/types'

interface UserBalanceState {
  balance: number
  loading: boolean
  error: ApiError | null
  lastLoadTime: number
  pollingEnabled: boolean
}

interface UserBalanceActions {
  load: (force?: boolean) => Promise<void>
  setBalance: (balance: number) => void
  deductBalance: (amount: number) => void
  startPolling: () => void
  stopPolling: () => void
  restartPolling: () => void
  reset: () => void
}

type UserBalanceStore = UserBalanceState & UserBalanceActions

const POLLING_INTERVAL = 60e3 // 60秒轮询一次
const DEBOUNCE_TIME = 5e3 // 5秒防抖

let pollingInterval: ReturnType<typeof setInterval> | null = null
let loadingPromise: Promise<void> | null = null
let appStateSubscription: { remove: () => void } | null = null

export const useUserBalanceStore = create<UserBalanceStore>((set, get) => ({
  // State
  balance: 0,
  loading: false,
  error: null,
  lastLoadTime: 0,
  pollingEnabled: false,

  // Actions
  load: async (force = false) => {
    const state = get()
    const now = Date.now()
    const timeSinceLastLoad = now - state.lastLoadTime

    // 如果不是强制刷新，且距离上次调用少于5秒，则跳过
    if (!force && timeSinceLastLoad < DEBOUNCE_TIME) {
      console.log('跳过余额加载，距离上次调用时间过短:', timeSinceLastLoad + 'ms')
      return
    }

    // 如果已经在加载中且不是强制刷新，直接返回
    if (state.loading && !force) {
      console.log('余额加载中，跳过重复请求')
      return loadingPromise || undefined
    }

    set({ lastLoadTime: now, loading: true })

    loadingPromise = (async () => {
      try {
        const { data, error } = await subscription.list()

        if (error) {
          set({ error, loading: false })
          return
        }

        const meteredSubscriptions = data?.filter((sub) => sub.type === 'metered') || []
        const creditBalance = meteredSubscriptions[0]?.creditBalance?.remainingTokenBalance || 0
        set({ balance: creditBalance, error: null, loading: false })
      } catch (e) {
        console.error('加载余额失败:', e)
        set({ loading: false })
      } finally {
        loadingPromise = null
      }
    })()

    return loadingPromise
  },

  setBalance: (balance: number) => {
    set({ balance })
  },

  deductBalance: (amount: number) => {
    set((state) => ({ balance: Math.max(0, state.balance - amount) }))
  },

  startPolling: () => {
    const { stopPolling, load } = get()

    // 先清理可能存在的旧轮询状态
    stopPolling()

    console.log('开始余额轮询，间隔:', POLLING_INTERVAL / 1000, '秒')
    set({ pollingEnabled: true })

    // 立即执行一次
    load(false)

    // 设置定时器
    pollingInterval = setInterval(() => {
      const state = get()
      if (state.pollingEnabled) {
        load(false)
      }
    }, POLLING_INTERVAL)

    // 设置应用状态监听
    if (!appStateSubscription) {
      appStateSubscription = AppState.addEventListener('change', (nextAppState: AppStateStatus) => {
        const state = get()
        if (nextAppState === 'active' && state.pollingEnabled) {
          console.log('应用回到前台，重启余额轮询')
          get().restartPolling()
        } else if (nextAppState === 'background' || nextAppState === 'inactive') {
          console.log('应用进入后台，暂停余额轮询')
          get().stopPolling()
        }
      })
    }
  },

  stopPolling: () => {
    console.log('停止余额轮询')
    set({ pollingEnabled: false })

    if (pollingInterval) {
      clearInterval(pollingInterval)
      pollingInterval = null
    }
  },

  restartPolling: () => {
    const { stopPolling, startPolling } = get()
    stopPolling()
    setTimeout(() => startPolling(), 1000) // 延迟1秒重启
  },

  reset: () => {
    const { stopPolling } = get()
    stopPolling()

    set({
      balance: 0,
      loading: false,
      error: null,
      lastLoadTime: 0,
      pollingEnabled: false,
    })

    // 清理应用状态监听器
    if (appStateSubscription) {
      appStateSubscription.remove()
      appStateSubscription = null
    }
  },
}))