import { useCallback, useEffect } from 'react';
import { useAppDispatch, useAppSelector } from './hooks';
import { setError, setLoading, setValue } from './serverSettingSlice';
import { fetchSettingByCode } from '@/api/serversetting';

/**
 * 使用服务端配置（按 code）
 * - 自动拉取并存入 store
 * - 返回 loading/error/value 状态
 */
export function useServerSetting<T = unknown>(code: string, defaultValue?: T) {
    const dispatch = useAppDispatch();
    const entry = useAppSelector((s) => s.serverSetting.byCode[code]);

    const load = useCallback(async () => {
        if (!code) return;
        dispatch(setLoading({ code, loading: true }));
        try {
            const value = await fetchSettingByCode<T>(code, defaultValue as T | undefined);
            dispatch(setValue<T>({ code, value: value as T }));
        } catch (e: any) {
            dispatch(setError({ code, error: e?.message || 'Load failed' }));
        }
    }, [code, defaultValue, dispatch]);

    useEffect(() => {
        // 仅当未加载过或无值时加载
        if (!entry || (entry && entry.value === undefined && !entry.loading)) {
            load();
        }
    }, [entry, load]);

    return {
        loading: entry?.loading ?? false,
        error: entry?.error,
        value: (entry?.value as T | undefined) ?? defaultValue,
        reload: load,
    } as const;
}