import React, { useState, useEffect } from 'react';
import { List, Typography, Menu, Layout, Button, Empty, Spin, Space, Grid, Select } from 'antd';
import {
  BellOutlined,
  DollarOutlined,
  HomeOutlined,
  TeamOutlined,
  SettingOutlined,
} from '@ant-design/icons';
import { useNavigate } from 'react-router-dom';
import api from '../../api';
import { message } from '../../ui/app-message';
import { formatNotificationText } from '../../utils/notification-display';

const { Sider, Content } = Layout;
const { useBreakpoint } = Grid;

interface NotificationItem {
  id: number;
  type: string;
  title: string;
  content: string;
  link: string | null;
  isRead: boolean;
  createdAt: string;
}

const typeMap: Record<string, { label: string; icon: React.ReactNode }> = {
  bill_generated: { label: '账单', icon: <DollarOutlined /> },
  bill_paid: { label: '账单', icon: <DollarOutlined /> },
  check_in: { label: '入住', icon: <HomeOutlined /> },
  check_out: { label: '退宿', icon: <HomeOutlined /> },
  deposit_due: { label: '押金', icon: <DollarOutlined /> },
  deposit_refunded: { label: '押金', icon: <DollarOutlined /> },
  class_change: { label: '班级', icon: <TeamOutlined /> },
  schedule_conflict: { label: '排课', icon: <BellOutlined /> },
  announcement: { label: '公告', icon: <SettingOutlined /> },
};

function timeAgo(dateStr: string): string {
  const diff = Date.now() - new Date(dateStr).getTime();
  const mins = Math.floor(diff / 60000);
  if (mins < 1) return '刚刚';
  if (mins < 60) return `${mins}分钟前`;
  const hours = Math.floor(mins / 60);
  if (hours < 24) return `${hours}小时前`;
  const days = Math.floor(hours / 24);
  if (days < 7) return `${days}天前`;
  return new Date(dateStr).toLocaleDateString('zh-CN');
}

const FILTER_ITEMS: Array<{ key: string; icon: React.ReactNode; label: string }> = [
  { key: 'all', icon: <BellOutlined />, label: '全部' },
  { key: 'bill_generated', icon: <DollarOutlined />, label: '账单' },
  { key: 'check_in', icon: <HomeOutlined />, label: '入住' },
  { key: 'class_change', icon: <TeamOutlined />, label: '班级' },
  { key: 'announcement', icon: <SettingOutlined />, label: '公告' },
];

const NotificationsPage: React.FC = () => {
  const screens = useBreakpoint();
  const isMobile = !screens.sm;
  const [notifications, setNotifications] = useState<NotificationItem[]>([]);
  const [filter, setFilter] = useState('all');
  const [loading, setLoading] = useState(false);
  const navigate = useNavigate();

  const fetchData = async () => {
    setLoading(true);
    try {
      const data = (await api.get('/notifications?limit=50')) as unknown as NotificationItem[];
      setNotifications(data);
    } catch (e: any) {
      console.error('加载通知失败', e);
      message.error(e?.message || '加载通知失败');
    }
    setLoading(false);
  };

  useEffect(() => {
    fetchData();
  }, []);

  const handleClick = async (item: NotificationItem) => {
    if (!item.isRead) {
      try {
        await api.put(`/notifications/${item.id}/read`);
        setNotifications((prev) =>
          prev.map((n) => (n.id === item.id ? { ...n, isRead: true } : n)),
        );
      } catch (e: any) {
        console.error('标记已读失败', e);
        message.error(e?.message || '标记已读失败');
      }
    }
    if (item.link) navigate(item.link);
  };

  const handleMarkAll = async () => {
    try {
      await api.put('/notifications/read-all');
      setNotifications((prev) => prev.map((n) => ({ ...n, isRead: true })));
    } catch (e: any) {
      console.error('全部已读失败', e);
      message.error(e?.message || '操作失败');
    }
  };

  const filtered =
    filter === 'all' ? notifications : notifications.filter((n) => n.type === filter);

  return (
    <Layout className="notifications-layout" style={{ minHeight: '100%', background: '#fff' }}>
      {!isMobile && (
        <Sider width={180} style={{ background: '#fff', borderRight: '1px solid #f0f0f0' }}>
          <Menu
            mode="inline"
            selectedKeys={[filter]}
            onClick={({ key }) => setFilter(key)}
            items={FILTER_ITEMS}
          />
        </Sider>
      )}
      <Content className="notifications-content" style={{ padding: isMobile ? 0 : 24 }}>
        <div className="notifications-header">
          <Typography.Title level={4} style={{ margin: 0 }}>
            通知中心
          </Typography.Title>
          <Button onClick={handleMarkAll}>全部已读</Button>
        </div>
        {isMobile && (
          <Select
            value={filter}
            onChange={setFilter}
            options={FILTER_ITEMS.map((item) => ({ value: item.key, label: item.label }))}
            className="notifications-filter"
          />
        )}
        <Spin spinning={loading}>
          {filtered.length === 0 ? (
            <Empty description="暂无通知" />
          ) : (
            <List
              dataSource={filtered}
              renderItem={(item) => {
                const meta = typeMap[item.type] || { label: item.type, icon: <BellOutlined /> };
                return (
                  <List.Item
                    role="button"
                    tabIndex={0}
                    aria-label={`通知: ${item.title}`}
                    onClick={() => handleClick(item)}
                    onKeyDown={(e) => {
                      if (e.key === 'Enter' || e.key === ' ') {
                        e.preventDefault();
                        handleClick(item);
                      }
                    }}
                    style={{
                      cursor: 'pointer',
                      padding: '16px 0',
                      backgroundColor: item.isRead ? 'transparent' : '#f0f7ff',
                    }}
                  >
                    <List.Item.Meta
                      avatar={
                        <div
                          style={{
                            width: 40,
                            height: 40,
                            borderRadius: '50%',
                            background: '#f0f0f0',
                            display: 'flex',
                            alignItems: 'center',
                            justifyContent: 'center',
                          }}
                        >
                          {meta.icon}
                        </div>
                      }
                      title={
                        <Space wrap size={[8, 2]}>
                          <Typography.Text strong={!item.isRead} style={{ fontSize: 15 }}>
                            {formatNotificationText(item.title)}
                          </Typography.Text>
                          <Typography.Text type="secondary" style={{ fontSize: 12 }}>
                            {timeAgo(item.createdAt)}
                          </Typography.Text>
                        </Space>
                      }
                      description={
                        item.content && (
                          <Typography.Paragraph
                            type="secondary"
                            ellipsis={{ rows: 1 }}
                            style={{ marginBottom: 0 }}
                          >
                            {formatNotificationText(item.content)}
                          </Typography.Paragraph>
                        )
                      }
                    />
                  </List.Item>
                );
              }}
            />
          )}
        </Spin>
      </Content>
    </Layout>
  );
};

export default NotificationsPage;