import { ref, computed } from 'vue'
import { useRouter } from 'vue-router'
import { rpcClient } from '@/api/rpc-client'

export interface ReceivedMessage {
  from_pubkey: string
  message: string
  timestamp: string
}

const MESSAGE_POLL_INTERVAL = 30000 // 30s

// Shared state (singleton) so toast works across route changes
const receivedMessages = ref<ReceivedMessage[]>([])
const lastMessageCount = ref(0)
const loadingMessages = ref(false)
const toastMessage = ref<{ show: boolean; text: string }>({ show: false, text: '' })
let pollTimer: ReturnType<typeof setInterval> | null = null

export function useMessageToast() {
  const router = useRouter()

  const unreadCount = computed(() =>
    Math.max(0, receivedMessages.value.length - lastMessageCount.value)
  )

  async function loadReceivedMessages() {
    loadingMessages.value = true
    try {
      const res = await rpcClient.getReceivedMessages()
      const msgs = (res.messages || []) as ReceivedMessage[]
      receivedMessages.value = msgs
      // New messages since last check? (don't show toast on initial load)
      if (msgs.length > lastMessageCount.value && lastMessageCount.value > 0) {
        const newCount = msgs.length - lastMessageCount.value
        const latest = msgs[msgs.length - 1]
        toastMessage.value = {
          show: true,
          text: (newCount === 1 ? latest?.message : null) ?? `${newCount} new messages`,
        }
        lastMessageCount.value = msgs.length
      } else {
        lastMessageCount.value = msgs.length
      }
    } catch (e) {
      // Stop polling on auth failure — session expired, no point retrying
      if (e instanceof Error && /401|Unauthorized/i.test(e.message)) {
        stopPolling()
        return
      }
      if (import.meta.env.DEV) console.error('Failed to load messages:', e)
    } finally {
      loadingMessages.value = false
    }
  }

  function startPolling() {
    if (pollTimer) return
    loadReceivedMessages()
    pollTimer = setInterval(loadReceivedMessages, MESSAGE_POLL_INTERVAL)
  }

  function stopPolling() {
    if (pollTimer) {
      clearInterval(pollTimer)
      pollTimer = null
    }
  }

  function markAsRead() {
    lastMessageCount.value = receivedMessages.value.length
  }

  function dismissToastAndOpenMessages() {
    toastMessage.value = { show: false, text: '' }
    markAsRead()
    router.push({ path: '/dashboard/web5', query: { tab: 'messages' } })
  }

  return {
    receivedMessages,
    lastMessageCount,
    loadingMessages,
    toastMessage,
    unreadCount,
    loadReceivedMessages,
    startPolling,
    stopPolling,
    markAsRead,
    dismissToastAndOpenMessages,
  }
}