'use client'

import { useEffect, useRef } from 'react'

import { getAuthToken } from '@/lib/apollo-client'

export type RealtimeEvent = {
  type: string
  payload?: any
  createdAt?: string
}

type Options = {
  onEvent?: (evt: RealtimeEvent) => void
  orgId?: string
}

export function useRealtime({ onEvent, orgId }: Options = {}) {
  const handlerRef = useRef(onEvent)
  handlerRef.current = onEvent

  useEffect(() => {
    if (typeof window === 'undefined') return
    const token = getAuthToken() || localStorage.getItem('adminAuthToken')
    // Try to infer orgId from cached userData if not provided
    let resolvedOrgId = orgId
    if (!resolvedOrgId) {
      try {
        const userDataRaw = localStorage.getItem('userData')
        if (userDataRaw) {
          const user = JSON.parse(userDataRaw)
          resolvedOrgId = user?.organization?.id
        }
      } catch {}
    }

    if (!token || !resolvedOrgId) return

    const url = `/api/events?token=${encodeURIComponent(token)}&orgId=${encodeURIComponent(resolvedOrgId)}`
    const es = new EventSource(url)

    es.onmessage = (event) => {
      try {
        const data = JSON.parse(event.data)
        handlerRef.current?.(data)
      } catch (e) {
        // ignore malformed events
      }
    }

    es.onerror = () => {
      // Let the browser auto-reconnect
    }

    return () => {
      es.close()
    }
  }, [orgId])
}