/**
 * BaileysManager - Manages multiple WhatsApp instances
 * Singleton pattern for managing all Baileys connections
 */
import makeWASocket, {
  DisconnectReason,
  fetchLatestBaileysVersion,
  makeCacheableSignalKeyStore,
  useMultiFileAuthState,
  type WASocket,
  type BaileysEventMap,
  Browsers
} from '@whiskeysockets/baileys'
import { Boom } from '@hapi/boom'
import { EventEmitter } from 'events'
import QRCode from 'qrcode'
import pino from 'pino'
import { usePostgresAuthState, clearAuthState } from './auth-state'
import { query } from '../../utils/database'

// Types
export interface ManagedInstance {
  id: string
  name: string
  socket: WASocket | null
  status: 'disconnected' | 'connecting' | 'connected' | 'qr_ready' | 'pairing'
  phoneNumber: string | null
  qrCode: string | null
  pairingCode: string | null
  reconnectAttempts: number
  lastError: string | null
}

export interface InstanceEvents {
  'instance.status': { instanceId: string; status: string; phoneNumber?: string }
  'instance.qr': { instanceId: string; qr: string; qrDataUrl: string }
  'instance.pairing': { instanceId: string; code: string }
  'message.received': { instanceId: string; message: any }
  'message.sent': { instanceId: string; message: any }
  'message.status': { instanceId: string; messageId: string; status: string }
}

const logger = pino({ level: 'warn' })

class BaileysManager extends EventEmitter {
  private instances: Map<string, ManagedInstance> = new Map()
  private static instance: BaileysManager | null = null
  private initialized = false

  private constructor() {
    super()
  }

  static getInstance(): BaileysManager {
    if (!BaileysManager.instance) {
      BaileysManager.instance = new BaileysManager()
    }
    return BaileysManager.instance
  }

  /**
   * Initialize manager and reconnect previously connected instances
   */
  async initialize(): Promise<void> {
    if (this.initialized) return

    console.log('[BaileysManager] Initializing...')

    try {
      // Load instances that were previously connected
      const result = await query<{ id: string; name: string; phone_number: string }>(
        `SELECT id, name, phone_number FROM instances WHERE status = 'connected'`
      )

      for (const row of result.rows) {
        console.log(`[BaileysManager] Reconnecting instance: ${row.name}`)
        await this.connect(row.id)
      }

      this.initialized = true
      console.log('[BaileysManager] Initialized successfully')
    } catch (error) {
      console.error('[BaileysManager] Initialization error:', error)
    }
  }

  /**
   * Connect an instance to WhatsApp
   */
  async connect(instanceId: string, usePairingCode = false, phoneNumber?: string): Promise<void> {
    // Check if already connected
    const existing = this.instances.get(instanceId)
    if (existing?.socket) {
      console.log(`[BaileysManager] Instance ${instanceId} already has active socket`)
      return
    }

    // Load instance from DB
    const instanceResult = await query<{ id: string; name: string; phone_number: string }>(
      'SELECT id, name, phone_number FROM instances WHERE id = $1',
      [instanceId]
    )

    if (instanceResult.rows.length === 0) {
      throw new Error(`Instance ${instanceId} not found`)
    }

    const instanceData = instanceResult.rows[0]

    // Update status
    await this.updateInstanceStatus(instanceId, 'connecting')

    // Create managed instance
    const managed: ManagedInstance = {
      id: instanceId,
      name: instanceData.name,
      socket: null,
      status: 'connecting',
      phoneNumber: instanceData.phone_number || null,
      qrCode: null,
      pairingCode: null,
      reconnectAttempts: 0,
      lastError: null
    }
    this.instances.set(instanceId, managed)

    try {
      // Load auth state from PostgreSQL
      const { state, saveCreds } = await usePostgresAuthState(instanceId)
      const { version } = await fetchLatestBaileysVersion()

      // Create socket
      const socket = makeWASocket({
        version,
        auth: {
          creds: state.creds,
          keys: makeCacheableSignalKeyStore(state.keys, logger)
        },
        printQRInTerminal: false,
        browser: Browsers.ubuntu('WhatsApp Nucleo'),
        logger,
        generateHighQualityLinkPreview: true,
        syncFullHistory: false,
        markOnlineOnConnect: false
      })

      managed.socket = socket

      // Setup event handlers
      this.setupEventHandlers(instanceId, socket, saveCreds, usePairingCode, phoneNumber)

    } catch (error) {
      console.error(`[BaileysManager] Error connecting instance ${instanceId}:`, error)
      managed.lastError = (error as Error).message
      await this.updateInstanceStatus(instanceId, 'disconnected')
      throw error
    }
  }

  /**
   * Setup event handlers for a socket
   */
  private setupEventHandlers(
    instanceId: string,
    socket: WASocket,
    saveCreds: () => Promise<void>,
    usePairingCode: boolean,
    phoneNumber?: string
  ): void {
    const managed = this.instances.get(instanceId)!

    // Credentials update
    socket.ev.on('creds.update', saveCreds)

    // Connection update
    socket.ev.on('connection.update', async (update) => {
      const { connection, lastDisconnect, qr } = update

      // QR Code received
      if (qr && !usePairingCode) {
        const qrDataUrl = await QRCode.toDataURL(qr)
        managed.qrCode = qrDataUrl
        managed.status = 'qr_ready'

        await this.updateInstanceStatus(instanceId, 'qr_ready', { qr_code: qrDataUrl })
        this.emit('instance.qr', { instanceId, qr, qrDataUrl })
      }

      // Request pairing code if needed
      if (usePairingCode && phoneNumber && !managed.pairingCode && connection === 'connecting') {
        try {
          // Wait a bit for socket to be ready
          await new Promise(resolve => setTimeout(resolve, 3000))

          if (!socket.authState.creds.registered) {
            const code = await socket.requestPairingCode(phoneNumber)
            managed.pairingCode = code
            managed.status = 'pairing'

            await this.updateInstanceStatus(instanceId, 'pairing', { pairing_code: code })
            this.emit('instance.pairing', { instanceId, code })
          }
        } catch (error) {
          console.error(`[BaileysManager] Error requesting pairing code:`, error)
        }
      }

      // Connection closed
      if (connection === 'close') {
        const statusCode = (lastDisconnect?.error as Boom)?.output?.statusCode
        const shouldReconnect = statusCode !== DisconnectReason.loggedOut

        managed.socket = null
        managed.qrCode = null
        managed.pairingCode = null

        if (shouldReconnect && managed.reconnectAttempts < 5) {
          managed.reconnectAttempts++
          console.log(`[BaileysManager] Reconnecting instance ${instanceId} (attempt ${managed.reconnectAttempts})`)

          // Wait before reconnecting
          await new Promise(resolve => setTimeout(resolve, 3000 * managed.reconnectAttempts))
          await this.connect(instanceId)
        } else {
          managed.status = 'disconnected'
          await this.updateInstanceStatus(instanceId, 'disconnected')

          if (statusCode === DisconnectReason.loggedOut) {
            // Clear auth state if logged out
            await clearAuthState(instanceId)
          }
        }

        this.emit('instance.status', { instanceId, status: 'disconnected' })
      }

      // Connection open
      if (connection === 'open') {
        const phoneNum = socket.user?.id.split(':')[0] || null
        managed.status = 'connected'
        managed.phoneNumber = phoneNum
        managed.qrCode = null
        managed.pairingCode = null
        managed.reconnectAttempts = 0

        await this.updateInstanceStatus(instanceId, 'connected', {
          phone_number: phoneNum,
          qr_code: null,
          pairing_code: null,
          last_connected_at: new Date()
        })

        this.emit('instance.status', { instanceId, status: 'connected', phoneNumber: phoneNum || undefined })
        console.log(`[BaileysManager] Instance ${instanceId} connected as ${phoneNum}`)
      }
    })

    // Messages received
    socket.ev.on('messages.upsert', async ({ messages, type }) => {
      for (const msg of messages) {
        // Emit event for webhooks
        this.emit('message.received', { instanceId, message: msg })

        // Save message to database
        await this.saveMessage(instanceId, msg, type === 'notify')
      }
    })

    // Message status update
    socket.ev.on('messages.update', async (updates) => {
      for (const update of updates) {
        if (update.update.status) {
          this.emit('message.status', {
            instanceId,
            messageId: update.key.id!,
            status: this.mapMessageStatus(update.update.status)
          })
        }
      }
    })
  }

  /**
   * Disconnect an instance
   */
  async disconnect(instanceId: string): Promise<void> {
    const managed = this.instances.get(instanceId)
    if (!managed?.socket) return

    managed.socket.end(new Error('Disconnected by user'))
    managed.socket = null
    managed.status = 'disconnected'
    managed.qrCode = null
    managed.pairingCode = null

    await this.updateInstanceStatus(instanceId, 'disconnected')
    this.emit('instance.status', { instanceId, status: 'disconnected' })
  }

  /**
   * Send a message
   */
  async sendMessage(instanceId: string, jid: string, content: any): Promise<any> {
    const managed = this.instances.get(instanceId)
    if (!managed?.socket) {
      throw new Error('Instance not connected')
    }

    const result = await managed.socket.sendMessage(jid, content)
    this.emit('message.sent', { instanceId, message: result })
    return result
  }

  /**
   * Get QR code for an instance
   */
  getQRCode(instanceId: string): string | null {
    return this.instances.get(instanceId)?.qrCode || null
  }

  /**
   * Get pairing code for an instance
   */
  getPairingCode(instanceId: string): string | null {
    return this.instances.get(instanceId)?.pairingCode || null
  }

  /**
   * Get instance status
   */
  getStatus(instanceId: string): ManagedInstance | null {
    return this.instances.get(instanceId) || null
  }

  /**
   * Get all instances
   */
  getAllInstances(): ManagedInstance[] {
    return Array.from(this.instances.values())
  }

  /**
   * Update instance status in database
   */
  private async updateInstanceStatus(
    instanceId: string,
    status: string,
    extra: Record<string, any> = {}
  ): Promise<void> {
    const fields = ['status = $2']
    const values: any[] = [instanceId, status]
    let paramIndex = 3

    for (const [key, value] of Object.entries(extra)) {
      fields.push(`${key} = $${paramIndex}`)
      values.push(value)
      paramIndex++
    }

    await query(
      `UPDATE instances SET ${fields.join(', ')}, updated_at = NOW() WHERE id = $1`,
      values
    )
  }

  /**
   * Save message to database
   */
  private async saveMessage(instanceId: string, msg: any, isNew: boolean): Promise<void> {
    try {
      const jid = msg.key.remoteJid
      if (!jid) return

      // Ensure chat exists
      const chatResult = await query<{ id: string }>(
        `INSERT INTO chats (instance_id, jid, name, is_group)
         VALUES ($1, $2, $3, $4)
         ON CONFLICT (instance_id, jid) DO UPDATE SET updated_at = NOW()
         RETURNING id`,
        [instanceId, jid, msg.pushName || jid.split('@')[0], jid.includes('@g.us')]
      )
      const chatId = chatResult.rows[0].id

      // Get message content
      const content = msg.message?.conversation ||
        msg.message?.extendedTextMessage?.text ||
        msg.message?.imageMessage?.caption ||
        ''

      const messageType = this.getMessageType(msg.message)

      // Insert message
      await query(
        `INSERT INTO messages (
          instance_id, chat_id, message_id, from_jid, from_me,
          message_type, content, timestamp, raw_message
        ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
         ON CONFLICT (instance_id, message_id) DO NOTHING`,
        [
          instanceId,
          chatId,
          msg.key.id,
          msg.key.fromMe ? 'me' : jid,
          msg.key.fromMe || false,
          messageType,
          content,
          new Date(msg.messageTimestamp! * 1000),
          JSON.stringify(msg)
        ]
      )

      // Update chat last message
      if (isNew) {
        await query(
          `UPDATE chats SET last_message_at = $1, unread_count = unread_count + 1 WHERE id = $2`,
          [new Date(msg.messageTimestamp! * 1000), chatId]
        )
      }
    } catch (error) {
      console.error('[BaileysManager] Error saving message:', error)
    }
  }

  /**
   * Get message type from Baileys message object
   */
  private getMessageType(message: any): string {
    if (!message) return 'unknown'
    if (message.conversation || message.extendedTextMessage) return 'text'
    if (message.imageMessage) return 'image'
    if (message.videoMessage) return 'video'
    if (message.audioMessage) return 'audio'
    if (message.documentMessage) return 'document'
    if (message.stickerMessage) return 'sticker'
    if (message.contactMessage) return 'contact'
    if (message.locationMessage) return 'location'
    return 'unknown'
  }

  /**
   * Map Baileys message status to our status
   */
  private mapMessageStatus(status: number): string {
    switch (status) {
      case 0: return 'pending'
      case 1: return 'sent'
      case 2: return 'delivered'
      case 3: return 'read'
      case 4: return 'read'
      default: return 'sent'
    }
  }
}

// Export singleton
export const baileysManager = BaileysManager.getInstance()