import { useState, useEffect } from 'react';
import { fetchDictItemsByTypeCode } from '../api/dict';
import { SysDictItem } from '../types';

const dictCache: Record<string, SysDictItem[]> = {};
const pendingRequests: Record<string, Promise<SysDictItem[]>[]> = {};

export function useDict(typeCode: string) {
  const [items, setItems] = useState<SysDictItem[]>(dictCache[typeCode] || []);
  const [loading, setLoading] = useState(!dictCache[typeCode]);

  useEffect(() => {
    if (dictCache[typeCode]) {
      setItems(dictCache[typeCode]);
      setLoading(false);
      return;
    }

    let isMounted = true;

    const load = async () => {
      try {
        const data = await fetchDictItemsByTypeCode(typeCode);
        if (isMounted) {
          dictCache[typeCode] = data;
          setItems(data);
        }
      } catch (e) {
        console.error(`Failed to fetch dictionary ${typeCode}:`, e);
      } finally {
        if (isMounted) {
          setLoading(false);
        }
      }
    };

    load();

    return () => {
      isMounted = false;
    };
  }, [typeCode]);

  return { items, loading };
}