import { ref, watch } from 'vue'
import { useWebSocket } from './useWebSocket'
import { getToken } from '~/utils/auth'

const count = ref(0)
const channelUnreadCount = ref(0)
let isInitialized = false
let wsSubscription = null

export function useUnreadCount() {
  const config = useRuntimeConfig()
  const API_BASE_URL = config.public.apiBaseUrl
  const { subscribe, isConnected, connect } = useWebSocket()

  const fetchTotalUnreadCount = async () => {
    const token = getToken()
    if (!token) {
      count.value = 0
      return
    }
    try {
      const response = await fetch(`${API_BASE_URL}/api/messages/unread-count`, {
        headers: { Authorization: `Bearer ${token}` },
      })
      if (response.ok) {
        const data = await response.json()
        count.value = data
      }
    } catch (error) {
      console.error('Failed to fetch unread count:', error)
    }
  }

  const fetchChannelUnreadCount = async () => {
    const token = getToken()
    if (!token) {
      channelUnreadCount.value = 0
      return
    }
    try {
      const response = await fetch(`${API_BASE_URL}/api/channels`, {
        headers: { Authorization: `Bearer ${token}` },
      })
      if (response.ok) {
        const channels = await response.json()
        channelUnreadCount.value = channels.reduce((sum, ch) => sum + (ch.unreadCount || 0), 0)
      }
    } catch (error) {
      console.error('Failed to fetch channel unread count:', error)
    }
  }

  const fetchUnreadCount = async () => {
    await Promise.all([fetchTotalUnreadCount(), fetchChannelUnreadCount()])
  }

  const initialize = async () => {
    const token = getToken()
    if (!token) {
      count.value = 0
      channelUnreadCount.value = 0
      return
    }

    // 总是获取最新的未读数量
    fetchUnreadCount()

    // 确保WebSocket连接
    if (!isConnected.value) {
      connect(token)
    }

    // 设置WebSocket监听
    await setupWebSocketListener()
  }

  const setupWebSocketListener = async () => {
    // 只有在还没有订阅的情况下才设置监听
    if (!wsSubscription) {
      watch(
        isConnected,
        (newValue) => {
          if (newValue && !wsSubscription) {
            const destination = `/user/queue/unread-count`
            wsSubscription = subscribe(destination, (message) => {
              const unreadCount = parseInt(message.body, 10)
              if (!isNaN(unreadCount)) {
                count.value = unreadCount
                fetchChannelUnreadCount()
              }
            })
          }
        },
        { immediate: true },
      )
    }
  }

  // 自动初始化逻辑 - 确保每次调用都能获取到未读数量并设置监听
  const token = getToken()
  if (token) {
    if (!isInitialized) {
      isInitialized = true
      initialize() // 完整初始化，包括WebSocket监听
    } else {
      // 即使已经初始化，也要确保获取最新的未读数量并确保WebSocket监听存在
      fetchUnreadCount()

      // 确保WebSocket连接和监听都存在
      if (!isConnected.value) {
        connect(token)
      }
      setupWebSocketListener()
    }
  }

  return {
    count,
    channelUnreadCount,
    fetchUnreadCount,
    initialize,
  }
}