import { io, type Socket } from 'socket.io-client'
import type { IntegrationAdapter, Resource } from './types.js'

/**
 * Uptime Kuma has no plain REST API for monitor data — the web UI talks to it
 * over a Socket.IO session (login, then the server pushes `monitorList` and
 * per-monitor `importantHeartbeatList` events). This connects the same way,
 * waits briefly for those events, then disconnects.
 */
interface UptimeKumaMonitor {
  id: number
  name: string
  active: boolean
}

interface Heartbeat {
  status: number // 0 = down, 1 = up, 2 = pending, 3 = maintenance
  msg: string
  time: string
}

function connectAndLogin(
  baseUrl: string,
  username: string,
  password: string,
): Promise<Socket> {
  return new Promise((resolve, reject) => {
    const socket = io(baseUrl, { transports: ['websocket', 'polling'], reconnection: false, timeout: 10000 })

    const timer = setTimeout(() => {
      socket.disconnect()
      reject(new Error('Timed out connecting to Uptime Kuma'))
    }, 10000)

    socket.on('connect_error', (err) => {
      clearTimeout(timer)
      socket.disconnect()
      reject(new Error(err.message || 'Connection failed'))
    })

    socket.on('connect', () => {
      socket.emit('login', { username, password, token: '' }, (res: { ok: boolean; msg?: string }) => {
        clearTimeout(timer)
        if (!res.ok) {
          socket.disconnect()
          reject(new Error(res.msg || 'Login failed'))
          return
        }
        resolve(socket)
      })
    })
  })
}

export const uptimeKuma: IntegrationAdapter = {
  async testConnection(config, secrets) {
    const baseUrl = config.baseUrl?.replace(/\/$/, '')
    const username = secrets.username
    const password = secrets.password
    if (!baseUrl) return { ok: false, message: 'Missing baseUrl' }
    if (!username || !password) return { ok: false, message: 'Missing username/password' }
    try {
      const socket = await connectAndLogin(baseUrl, username, password)
      socket.disconnect()
      return { ok: true, message: 'Connected' }
    } catch (err) {
      return { ok: false, message: err instanceof Error ? err.message : 'Connection failed' }
    }
  },

  async listResources(config, secrets): Promise<Resource[]> {
    const baseUrl = config.baseUrl?.replace(/\/$/, '')
    const username = secrets.username
    const password = secrets.password
    if (!baseUrl || !username || !password) return []

    const socket = await connectAndLogin(baseUrl, username, password)
    try {
      const monitors = new Map<number, UptimeKumaMonitor>()
      const lastHeartbeat = new Map<number, Heartbeat>()

      socket.on('monitorList', (list: Record<string, UptimeKumaMonitor>) => {
        for (const m of Object.values(list)) monitors.set(m.id, m)
      })
      socket.on('importantHeartbeatList', (monitorId: number, beats: Heartbeat[]) => {
        const latest = beats[beats.length - 1]
        if (latest) lastHeartbeat.set(monitorId, latest)
      })
      socket.on('heartbeat', (beat: Heartbeat & { monitorID: number }) => {
        lastHeartbeat.set(beat.monitorID, beat)
      })

      // Server pushes these events asynchronously right after login — there's no
      // single "done" signal, so give it a short window to arrive.
      await new Promise((resolve) => setTimeout(resolve, 2500))

      const resources: Resource[] = []
      for (const monitor of monitors.values()) {
        if (!monitor.active) continue
        const beat = lastHeartbeat.get(monitor.id)
        const status: Resource['status'] =
          beat === undefined
            ? 'unknown'
            : beat.status === 1
              ? 'healthy'
              : beat.status === 0
                ? 'critical'
                : beat.status === 2
                  ? 'warning'
                  : 'unknown'
        resources.push({ name: monitor.name, status, detail: beat?.msg || undefined })
      }
      return resources
    } finally {
      socket.disconnect()
    }
  },
}