import { useEffect, useRef, useState, useCallback } from "react";
import { getApi } from "./useApi";

interface ItemSseHandlers {
  onEvent: (data: any) => void;
  onOpen?: () => void;
  onError?: (evt: Event) => void;
}

interface ItemSseResult {
  connected: boolean;
  events: any[];
}

export function useItemSse(url: string | null, handlers: ItemSseHandlers): ItemSseResult {
  const [connected, setConnected] = useState(false);
  const [events, setEvents] = useState<any[]>([]);
  const handlersRef = useRef(handlers);
  handlersRef.current = handlers;

  useEffect(() => {
    if (!url) return;

    const api = getApi();
    const baseUrl = (api.defaults.baseURL ?? "").replace(/\/+$/, "");
    const fullUrl = baseUrl + url;
    const es = new EventSource(fullUrl);

    es.onopen = () => {
      setConnected(true);
      handlersRef.current.onOpen?.();
    };

    es.onmessage = (e) => {
      try {
        const data = JSON.parse(e.data);
        setEvents((prev) => [...prev, data]);
        handlersRef.current.onEvent(data);
      } catch {
        // ignore malformed JSON
      }
    };

    es.onerror = (e) => {
      setConnected(false);
      handlersRef.current.onError?.(e);
    };

    return () => {
      es.close();
      setConnected(false);
    };
  }, [url]);

  const clearEvents = useCallback(() => setEvents([]), []);

  return { connected, events };
}