import { useEffect } from 'react'
import { useLocation } from 'react-router-dom'
import { useQueryClient } from '@tanstack/react-query'
import { useAuthStore } from '@/app/store/auth'
import { toast } from '@/app/store/toast'
import type { Customer, Message } from '@/types'
import { getWebSocketTicket } from '@/services/api/auth'

export function GlobalRealtime() {
  const token = useAuthStore((state) => state.token)
  const location = useLocation()
  const queryClient = useQueryClient()

  useEffect(() => {
    if (!token) return
    const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:'
    let socket: WebSocket | undefined
    let reconnectTimer: ReturnType<typeof setTimeout> | undefined
    let stopped = false
    let retryDelay = 500

    const connect = async () => {
      if (stopped) return
      try {
        const { ticket } = await getWebSocketTicket()
        if (stopped) return
        socket = new WebSocket(`${protocol}//${window.location.host}/api/ws?ticket=${encodeURIComponent(ticket)}`)
      } catch {
        reconnectTimer = setTimeout(() => { void connect() }, retryDelay)
        retryDelay = Math.min(retryDelay * 2, 10_000)
        return
      }
      socket.onopen = () => { retryDelay = 500 }
      socket.onmessage = (raw) => {
        let event: { type?: string; message?: Message; customer?: Customer; conversationId?: string }
        try { event = JSON.parse(String(raw.data)) } catch { return }
        if (event.type !== 'message.created' || event.message?.sender !== 'customer') return
        void queryClient.invalidateQueries({ queryKey: ['notifications'] })
        void queryClient.invalidateQueries({ queryKey: ['conversations'] })
        if (!location.pathname.startsWith('/inbox')) {
          const preview = event.message.translatedText || event.message.originalText || `[${event.message.type}]`
          toast.info(`${event.customer?.name || event.message.senderName || 'Telegram 客户'} 发来新消息`, preview.slice(0, 120))
        }
      }
      socket.onerror = () => socket?.close()
      socket.onclose = () => {
        if (stopped) return
        reconnectTimer = setTimeout(() => { void connect() }, retryDelay)
        retryDelay = Math.min(retryDelay * 2, 10_000)
      }
    }
    void connect()
    return () => {
      stopped = true
      if (reconnectTimer) clearTimeout(reconnectTimer)
      socket?.close()
    }
  }, [token, location.pathname, queryClient])

  return null
}