import { onUnmounted, ref } from 'vue'
import type { BotStatus } from '@/types/status'
import { getGuildId, setGuildId } from '@/api/client'

const RECONNECT_DELAY_MS = 3000

const status = ref<BotStatus | null>(null)
const connected = ref(false)
/** Wstrzymuje przyjmowanie aktualizacji, gdy użytkownik przeciąga utwory. */
const paused = ref(false)
const pendingTracks = ref<{ id: string; guildId: string; title: string }[]>([])

let socket: WebSocket | null = null
let reconnectTimer: number | null = null
let subscribers = 0

/** Jedno połączenie WebSocket na aplikację, niezależnie od liczby komponentów. */
export function useBotStatus() {
  function open() {
    const scheme = window.location.protocol === 'https:' ? 'wss:' : 'ws:'
    const guild = getGuildId()
    const currentSocket = new WebSocket(
      `${scheme}//${window.location.host}/ws${guild ? `?guild_id=${guild}` : ''}`,
    )
    socket = currentSocket

    currentSocket.onopen = () => {
      connected.value = true
    }

    currentSocket.onmessage = (event) => {
      if (socket !== currentSocket) return
      if (paused.value) return
      try {
        status.value = JSON.parse(event.data) as BotStatus
      } catch (error) {
        console.error('Błąd parsowania danych z WS:', error)
      }
    }

    currentSocket.onclose = () => {
      if (socket !== currentSocket) return
      connected.value = false
      socket = null
      if (subscribers > 0) {
        reconnectTimer = window.setTimeout(open, RECONNECT_DELAY_MS)
      }
    }

    currentSocket.onerror = () => currentSocket.close()
  }

  function connect() {
    subscribers += 1
    if (!socket) open()
  }

  function disconnect() {
    subscribers = Math.max(0, subscribers - 1)
    if (subscribers > 0) return
    if (reconnectTimer !== null) {
      window.clearTimeout(reconnectTimer)
      reconnectTimer = null
    }
    socket?.close()
    socket = null
  }

  function selectGuild(guildId: string) {
    setGuildId(guildId)
    if (reconnectTimer !== null) {
      window.clearTimeout(reconnectTimer)
      reconnectTimer = null
    }
    if (socket) {
      const previousSocket = socket
      socket = null
      previousSocket.close()
      open()
    }
  }

  function addPendingTrack(guildId: string, title: string) {
    const id = `pending-${Date.now()}-${Math.random().toString(36).slice(2)}`
    pendingTracks.value.push({ id, guildId, title })
    return id
  }

  function removePendingTrack(id: string) {
    pendingTracks.value = pendingTracks.value.filter((track) => track.id !== id)
  }

  onUnmounted(disconnect)

  return {
    status,
    connected,
    paused,
    pendingTracks,
    connect,
    disconnect,
    selectGuild,
    addPendingTrack,
    removePendingTrack,
  }
}