import { store } from '@/store/store'
import * as signalR from '@microsoft/signalr'
import { MessengerAttachmentDto, MessengerMessageDeletedDto, MessengerMessageDto } from './messenger.service'

export interface MessengerSendMessageDto {
  conversationId?: string
  recipientIds: string[]
  text?: string
  attachments: MessengerAttachmentDto[]
}

type MessageHandler = (message: MessengerMessageDto) => void
type MessageDeletedHandler = (message: MessengerMessageDeletedDto) => void
type StateHandler = (connected: boolean) => void

class MessengerSignalRService {
  private connection?: signalR.HubConnection
  private messageHandlers = new Set<MessageHandler>()
  private messageDeletedHandlers = new Set<MessageDeletedHandler>()
  private stateHandlers = new Set<StateHandler>()

  private createConnection() {
    const { auth } = store.getState()

    this.connection = new signalR.HubConnectionBuilder()
      .withUrl(`${import.meta.env.VITE_API_URL}/messengerhub`, {
        accessTokenFactory: () => store.getState().auth.session.token || auth.session.token || '',
      })
      .withAutomaticReconnect()
      .configureLogging(signalR.LogLevel.Warning)
      .build()

    this.connection.on('MessengerMessageReceived', (message: MessengerMessageDto) => {
      this.messageHandlers.forEach((handler) => handler(message))
    })

    this.connection.on('MessengerMessageDeleted', (message: MessengerMessageDeletedDto) => {
      this.messageDeletedHandlers.forEach((handler) => handler(message))
    })

    this.connection.onreconnected(() => this.emitState(true))
    this.connection.onreconnecting(() => this.emitState(false))
    this.connection.onclose(() => this.emitState(false))
  }

  async start() {
    if (!store.getState().auth.session.signedIn) return

    if (!this.connection) {
      this.createConnection()
    }

    if (this.connection?.state === signalR.HubConnectionState.Connected) {
      this.emitState(true)
      return
    }

    if (this.connection?.state === signalR.HubConnectionState.Connecting) return

    try {
      await this.connection?.start()
      this.emitState(true)
    } catch {
      this.emitState(false)
    }
  }

  async stop() {
    if (!this.connection) return

    await this.connection.stop()
    this.connection = undefined
    this.emitState(false)
  }

  async sendMessage(input: MessengerSendMessageDto) {
    await this.start()
    if (this.connection?.state !== signalR.HubConnectionState.Connected) {
      throw new Error('Messenger bağlantısı yok')
    }

    await this.connection.invoke('SendMessage', input)
  }

  async deleteMessage(messageId: string) {
    await this.start()
    if (this.connection?.state !== signalR.HubConnectionState.Connected) {
      throw new Error('Messenger bağlantısı yok')
    }

    await this.connection.invoke('DeleteMessage', messageId)
  }

  onMessage(handler: MessageHandler) {
    this.messageHandlers.add(handler)
    return () => this.messageHandlers.delete(handler)
  }

  onMessageDeleted(handler: MessageDeletedHandler) {
    this.messageDeletedHandlers.add(handler)
    return () => this.messageDeletedHandlers.delete(handler)
  }

  onStateChange(handler: StateHandler) {
    this.stateHandlers.add(handler)
    handler(this.getConnectionState())
    return () => this.stateHandlers.delete(handler)
  }

  getConnectionState() {
    return this.connection?.state === signalR.HubConnectionState.Connected
  }

  private emitState(connected: boolean) {
    this.stateHandlers.forEach((handler) => handler(connected))
  }
}

export const messengerSignalR = new MessengerSignalRService()