"use client"

import { useEffect, useRef } from "react"
import { useQueryClient } from "@tanstack/react-query"
import { createSupabaseBrowserClient } from "@/lib/supabase/client"
import { queryKeys } from "@/lib/queries/query-keys"
import { toast } from "sonner"
import { useNotificationStore } from "@/lib/stores/notification-store"

const DEBOUNCE_MILLISECONDS = 3000

export function useRealtimeEntries() {
  const queryClient = useQueryClient()
  const supabaseClientReference = useRef(createSupabaseBrowserClient())
  const pendingCountReference = useRef(0)
  const debounceTimerReference = useRef<ReturnType<typeof setTimeout> | null>(null)

  useEffect(() => {
    function flushPendingNotifications() {
      const count = pendingCountReference.current
      if (count === 0) return

      pendingCountReference.current = 0
      debounceTimerReference.current = null

      const message =
        count === 1 ? "1 new entry" : `${count} new entries`

      useNotificationStore.getState().addNotification(message)
      toast(message, {
        action: {
          label: "refresh",
          onClick: () => {
            queryClient.invalidateQueries({
              queryKey: queryKeys.timeline.all,
            })
          },
        },
      })
    }

    const channel = supabaseClientReference.current
      .channel("entries-realtime")
      .on(
        "postgres_changes",
        {
          event: "INSERT",
          schema: "public",
          table: "entries",
        },
        () => {
          pendingCountReference.current++

          if (debounceTimerReference.current) {
            clearTimeout(debounceTimerReference.current)
          }

          debounceTimerReference.current = setTimeout(
            flushPendingNotifications,
            DEBOUNCE_MILLISECONDS
          )
        }
      )
      .subscribe()

    return () => {
      if (debounceTimerReference.current) {
        clearTimeout(debounceTimerReference.current)
      }

      supabaseClientReference.current.removeChannel(channel)
    }
  }, [queryClient])
}