// src/hooks/useWatchlist.js
// 自选股管理自定义 Hook（导航栏专用，与 Redux 状态同步）

import { useState, useCallback, useEffect, useRef } from 'react';
import { useSelector, useDispatch } from 'react-redux';
import { useToast } from '@chakra-ui/react';
import { logger } from '../utils/logger';
import { getApiBase } from '../utils/apiConfig';
import { toggleWatchlist as toggleWatchlistAction, loadWatchlist } from '../store/slices/stockSlice';

const WATCHLIST_PAGE_SIZE = 10;

/**
 * 自选股管理 Hook（导航栏专用）
 * 提供自选股加载、分页、移除等功能
 * 监听 Redux 中的 watchlist 变化，自动刷新行情数据
 *
 * @returns {{
 *   watchlistQuotes: Array,
 *   watchlistLoading: boolean,
 *   watchlistPage: number,
 *   setWatchlistPage: Function,
 *   WATCHLIST_PAGE_SIZE: number,
 *   loadWatchlistQuotes: Function,
 *   followingEvents: Array,
 *   handleAddToWatchlist: Function,
 *   handleRemoveFromWatchlist: Function,
 *   isInWatchlist: Function
 * }}
 */
export const useWatchlist = () => {
    const toast = useToast();
    const dispatch = useDispatch();
    const [watchlistQuotes, setWatchlistQuotes] = useState([]);
    const [watchlistLoading, setWatchlistLoading] = useState(false);
    const [watchlistPage, setWatchlistPage] = useState(1);
    const [followingEvents, setFollowingEvents] = useState([]);

    // 从 Redux 获取自选股列表长度（用于监听变化）
    // 使用 length 作为依赖，避免数组引用变化导致不必要的重新渲染
    const reduxWatchlistLength = useSelector(state => state.stock.watchlist?.length || 0);

    // 检查 Redux watchlist 是否已初始化（加载状态）
    const reduxWatchlistLoading = useSelector(state => state.stock.loading?.watchlist);

    // 用于跟踪上一次的 watchlist 长度
    const prevWatchlistLengthRef = useRef(-1); // 初始设为 -1，确保第一次变化也能检测到

    // 初始化时加载 Redux watchlist（确保 Redux 状态被初始化）
    const hasInitializedRef = useRef(false);
    useEffect(() => {
        if (!hasInitializedRef.current) {
            hasInitializedRef.current = true;
            logger.debug('useWatchlist', '初始化 Redux watchlist');
            dispatch(loadWatchlist());
        }
    }, [dispatch]);

    // 加载自选股实时行情
    const loadWatchlistQuotes = useCallback(async () => {
        try {
            setWatchlistLoading(true);
            const base = getApiBase();
            const resp = await fetch(base + '/api/account/watchlist/realtime', {
                credentials: 'include',
                cache: 'no-store',
                headers: { 'Cache-Control': 'no-cache' }
            });
            if (resp.ok) {
                const data = await resp.json();
                if (data && data.success && Array.isArray(data.data)) {
                    setWatchlistQuotes(data.data);
                    logger.debug('useWatchlist', '自选股行情加载成功', { count: data.data.length });
                } else {
                    setWatchlistQuotes([]);
                }
            } else {
                setWatchlistQuotes([]);
            }
        } catch (e) {
            logger.warn('useWatchlist', '加载自选股实时行情失败', {
                error: e.message
            });
            setWatchlistQuotes([]);
        } finally {
            setWatchlistLoading(false);
        }
    }, []);

    // 监听 Redux watchlist 长度变化，自动刷新行情数据
    useEffect(() => {
        const currentLength = reduxWatchlistLength;
        const prevLength = prevWatchlistLengthRef.current;

        // 只有当 watchlist 长度发生变化时才刷新
        // prevLength = -1 表示初始状态，此时不触发刷新（由菜单打开时触发）
        if (prevLength !== -1 && currentLength !== prevLength) {
            logger.debug('useWatchlist', 'Redux watchlist 长度变化，刷新行情', {
                prevLength,
                currentLength
            });

            // 延迟一小段时间再刷新，确保后端数据已更新
            const timer = setTimeout(() => {
                logger.debug('useWatchlist', '执行 loadWatchlistQuotes');
                loadWatchlistQuotes();
            }, 500);

            prevWatchlistLengthRef.current = currentLength;
            return () => clearTimeout(timer);
        }

        // 更新 ref
        prevWatchlistLengthRef.current = currentLength;
    }, [reduxWatchlistLength, loadWatchlistQuotes]);

    // 添加到自选股
    const handleAddToWatchlist = useCallback(async (stockCode, stockName) => {
        try {
            const base = getApiBase();
            const resp = await fetch(base + '/api/account/watchlist', {
                method: 'POST',
                credentials: 'include',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ stock_code: stockCode, stock_name: stockName })
            });
            const data = await resp.json().catch(() => ({}));
            if (resp.ok && data.success) {
                // 刷新自选股列表
                loadWatchlistQuotes();
                toast({ title: '已添加至自选股', status: 'success', duration: 1500 });
                return true;
            } else {
                toast({ title: '添加失败', status: 'error', duration: 2000 });
                return false;
            }
        } catch (e) {
            toast({ title: '网络错误，添加失败', status: 'error', duration: 2000 });
            return false;
        }
    }, [toast, loadWatchlistQuotes]);

    // 从自选股移除
    const handleRemoveFromWatchlist = useCallback(async (stockCode) => {
        try {
            // 找到股票名称
            const stockItem = watchlistQuotes.find(item => {
                const normalize6 = (code) => {
                    const m = String(code || '').match(/(\d{6})/);
                    return m ? m[1] : String(code || '');
                };
                return normalize6(item.stock_code) === normalize6(stockCode);
            });
            const stockName = stockItem?.stock_name || '';

            // 通过 Redux action 移除（会同步更新 Redux 状态）
            await dispatch(toggleWatchlistAction({
                stockCode,
                stockName,
                isInWatchlist: true  // 表示当前在自选股中，需要移除
            })).unwrap();

            // 更新本地状态（立即响应 UI）
            setWatchlistQuotes((prev) => {
                const normalize6 = (code) => {
                    const m = String(code || '').match(/(\d{6})/);
                    return m ? m[1] : String(code || '');
                };
                const target = normalize6(stockCode);
                const updated = (prev || []).filter((x) => normalize6(x.stock_code) !== target);
                const newMaxPage = Math.max(1, Math.ceil((updated.length || 0) / WATCHLIST_PAGE_SIZE));
                setWatchlistPage((p) => Math.min(p, newMaxPage));
                return updated;
            });

            toast({ title: '已从自选股移除', status: 'info', duration: 1500 });
        } catch (e) {
            logger.error('useWatchlist', '移除自选股失败', e);
            toast({ title: e.message || '移除失败', status: 'error', duration: 2000 });
        }
    }, [dispatch, watchlistQuotes, toast]);

    // 判断股票是否在自选股中
    const isInWatchlist = useCallback((stockCode) => {
        const normalize6 = (code) => {
            const m = String(code || '').match(/(\d{6})/);
            return m ? m[1] : String(code || '');
        };
        const target = normalize6(stockCode);
        return watchlistQuotes.some(item => normalize6(item.stock_code) === target);
    }, [watchlistQuotes]);

    return {
        watchlistQuotes,
        watchlistLoading,
        watchlistPage,
        setWatchlistPage,
        WATCHLIST_PAGE_SIZE,
        loadWatchlistQuotes,
        followingEvents,
        handleAddToWatchlist,
        handleRemoveFromWatchlist,
        isInWatchlist
    };
};