// src/hooks/useFollowingEvents.js
// 关注事件管理自定义 Hook

import { useState, useCallback } from 'react';
import { useToast } from '@chakra-ui/react';
import { logger } from '../utils/logger';
import { getApiBase } from '../utils/apiConfig';

const EVENTS_PAGE_SIZE = 8;

/**
 * 关注事件管理 Hook
 * 提供事件加载、分页、取消关注等功能
 *
 * @returns {{
 *   followingEvents: Array,
 *   eventsLoading: boolean,
 *   eventsPage: number,
 *   setEventsPage: Function,
 *   EVENTS_PAGE_SIZE: number,
 *   loadFollowingEvents: Function,
 *   handleUnfollowEvent: Function
 * }}
 */
export const useFollowingEvents = () => {
    const toast = useToast();
    const [followingEvents, setFollowingEvents] = useState([]);
    const [eventsLoading, setEventsLoading] = useState(false);
    const [eventsPage, setEventsPage] = useState(1);

    // 加载关注的事件
    const loadFollowingEvents = useCallback(async () => {
        try {
            setEventsLoading(true);
            const base = getApiBase();
            const resp = await fetch(base + '/api/account/events/following', {
                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)) {
                    // 合并重复的事件（用最新的数据）
                    const eventMap = new Map();
                    for (const evt of data.data) {
                        if (evt && evt.id) {
                            eventMap.set(evt.id, evt);
                        }
                    }
                    const merged = Array.from(eventMap.values());
                    // 按创建时间降序排列（假设事件有 created_at 或 id）
                    if (merged.length > 0 && merged[0].created_at) {
                        merged.sort((a, b) => new Date(b.created_at || 0) - new Date(a.created_at || 0));
                    } else {
                        merged.sort((a, b) => (b.id || 0) - (a.id || 0));
                    }
                    setFollowingEvents(merged);
                } else {
                    setFollowingEvents([]);
                }
            } else {
                setFollowingEvents([]);
            }
        } catch (e) {
            logger.warn('useFollowingEvents', '加载关注事件失败', {
                error: e.message
            });
            setFollowingEvents([]);
        } finally {
            setEventsLoading(false);
        }
    }, []);

    // 取消关注事件
    const handleUnfollowEvent = useCallback(async (eventId) => {
        try {
            const base = getApiBase();
            const resp = await fetch(base + `/api/events/${eventId}/follow`, {
                method: 'POST',
                credentials: 'include'
            });
            const data = await resp.json().catch(() => ({}));
            if (resp.ok && data && data.success !== false) {
                setFollowingEvents((prev) => {
                    const updated = (prev || []).filter((x) => x.id !== eventId);
                    const newMaxPage = Math.max(1, Math.ceil((updated.length || 0) / EVENTS_PAGE_SIZE));
                    setEventsPage((p) => Math.min(p, newMaxPage));
                    return updated;
                });
                toast({ title: '已取消关注该事件', status: 'info', duration: 1500 });
            } else {
                toast({ title: '操作失败', status: 'error', duration: 2000 });
            }
        } catch (e) {
            toast({ title: '网络错误，操作失败', status: 'error', duration: 2000 });
        }
    }, [toast]);

    return {
        followingEvents,
        eventsLoading,
        eventsPage,
        setEventsPage,
        EVENTS_PAGE_SIZE,
        loadFollowingEvents,
        handleUnfollowEvent
    };
};