import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react';
import {
  Alert, Button, Card, Col, Dropdown, Image, Input, Row, Select,
  Space, Spin, Statistic, Switch, Table, Tabs, Tag, Tooltip, Typography, message,
} from 'antd';
import { DownloadOutlined, ReloadOutlined, SearchOutlined } from '@ant-design/icons';
import { SycmPage } from '../../components/Common';
import { getModularStockList, getModularStockFilters } from '../../api/modularStockMonitor';
import { exportTableFile } from '../../utils/tableExport';
import './style.css';

const { Title, Text } = Typography;

const WARNING_COLOR = { 缺货: 'red', 预警: 'orange', 正常: 'green' };

// 表头带口径说明，避免把「真实值 0」误读成「没数据」
const TipTitle = ({ title, tip }) => (
  <Tooltip title={tip}>
    <span className="msm-th-tip">{title}</span>
  </Tooltip>
);

const number = (value, digits = 2) => value === null || value === undefined || value === ''
  ? '--' : Number(value).toLocaleString('zh-CN', { minimumFractionDigits: digits, maximumFractionDigits: digits });
const int = (value) => number(value, 0);
const text = (value) => (value === null || value === undefined || value === '' ? '--' : value);

const toOptions = (list = []) => (Array.isArray(list) ? list : [])
  .filter(Boolean)
  .map((value) => ({ value, label: value }));

const EMPTY_FILTERS = { keyword: '', category: '', warningLevel: '', mkhStatus: '' };

const AccessoryStockPanel = () => {
  const [filters, setFilters] = useState(EMPTY_FILTERS);
  const [onlyWarning, setOnlyWarning] = useState(false);
  const [filterOptions, setFilterOptions] = useState({ categories: [], warningLevels: [] });
  const [data, setData] = useState({ rows: [], total: 0, page: 1, pageSize: 50, summary: {}, monitorDate: null });
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState('');
  const [page, setPage] = useState(1);
  const [pageSize, setPageSize] = useState(50);
  const [sorter, setSorter] = useState({ field: 'realtimeStock', order: 'DESC' });
  const tableWrapRef = useRef(null);
  const [bodyHeight, setBodyHeight] = useState(420);

  // 表体高度按「表格顶部 → 内容区底部」实测计算，替代纯 CSS calc：
  // 不同显示器缩放（125%/150%）下 100vh 偏小，写死的 calc 会把表格压到只剩一两行
  useEffect(() => {
    const el = tableWrapRef.current;
    if (!el) return undefined;

    // 分页器 + 卡片内边距 + 横向滚动条余量
    const RESERVE_BELOW = 104;

    const measure = () => {
      const scroller = el.closest('.planning-subsystem-content');
      const elRect = el.getBoundingClientRect();
      let available;
      if (scroller) {
        const scrollerRect = scroller.getBoundingClientRect();
        // 加回 scrollTop，抵消滚动对 getBoundingClientRect 的影响
        available = scrollerRect.bottom - elRect.top - RESERVE_BELOW + scroller.scrollTop;
      } else {
        available = window.innerHeight - elRect.top - RESERVE_BELOW;
      }
      const next = Math.max(240, Math.round(available));
      setBodyHeight((prev) => (Math.abs(prev - next) > 1 ? next : prev));
    };

    measure();
    const ro = new ResizeObserver(measure);
    ro.observe(el);
    if (el.parentElement) ro.observe(el.parentElement);
    window.addEventListener('resize', measure);
    return () => {
      ro.disconnect();
      window.removeEventListener('resize', measure);
    };
  }, []);

  useEffect(() => {
    let cancelled = false;
    getModularStockFilters()
      .then((result) => {
        const payload = result?.data || {};
        if (cancelled) return;
        setFilterOptions({
          categories: payload.categories || [],
          warningLevels: payload.warningLevels || ['缺货', '预警', '正常'],
          mkhStatuses: payload.mkhStatuses || ['已配置MKH', '未配置MKH'],
        });
      })
      .catch(() => {});
    return () => { cancelled = true; };
  }, []);

  const query = useMemo(() => {
    const params = {
      page,
      pageSize,
      sortField: sorter.field,
      sortOrder: sorter.order,
    };
    Object.entries(filters).forEach(([key, value]) => {
      if (value) params[key] = value;
    });
    if (onlyWarning) params.onlyWarning = '1';
    return params;
  }, [page, pageSize, sorter, filters, onlyWarning]);

  const load = useCallback(async () => {
    setLoading(true);
    setError('');
    try {
      const result = await getModularStockList(query);
      setData(result?.data || { rows: [], total: 0, summary: {} });
    } catch (requestError) {
      setError(requestError?.response?.data?.error || requestError?.message || '加载配件库存监控数据失败');
    } finally {
      setLoading(false);
    }
  }, [query]);

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

  const changeFilter = (key) => (value) => {
    setFilters((old) => ({ ...old, [key]: value || '' }));
    setPage(1);
  };
  const resetFilters = () => {
    setFilters(EMPTY_FILTERS);
    setOnlyWarning(false);
    setPage(1);
  };

  const columns = useMemo(() => [
    {
      title: '图片',
      dataIndex: 'imageUrl',
      width: 56,
      fixed: 'left',
      exportable: false,
      render: (value) => (value
        ? <Image src={value} width={36} height={36} style={{ objectFit: 'cover', borderRadius: 4 }} placeholder />
        : <span className="msm-muted">--</span>),
    },
    {
      title: '预警',
      dataIndex: 'warningLevel',
      width: 76,
      sorter: true,
      render: (value) => (value
        ? <Tag color={WARNING_COLOR[value] || 'default'}>{value}</Tag>
        : <span className="msm-muted">--</span>),
    },
    {
      title: <TipTitle
        title="状态"
        tip="该 SKU 是否已在「产品资料系统数据库」中建立商品档案。已配置MKH = 产品资料库中能查到该 SKU 编码的商品资料；未配置MKH = 产品资料库中查不到该 SKU 档案"
      />,
      dataIndex: 'mkhStatus',
      width: 110,
      sorter: true,
      render: (value) => {
        const v = value || '未配置MKH';
        return v === '已配置MKH'
          ? <Tag color="green">{v}</Tag>
          : <Tag color="default">{v}</Tag>;
      },
    },
    {
      title: 'SKU编码',
      dataIndex: 'skuId',
      width: 176,
      fixed: 'left',
      sorter: true,
      render: (value) => <span className="msm-sku">{text(value)}</span>,
    },
    {
      // 必须显式给 width：antd 在 scroll.x 场景下会把无宽度列压成 0 宽（此前该列不可见的原因）
      title: '商品名称',
      dataIndex: 'productName',
      width: 220,
      ellipsis: true,
      sorter: true,
      render: (value) => <Tooltip title={value}>{text(value)}</Tooltip>,
    },
    {
      title: <TipTitle
        title="当日入库库存"
        tip="监控日（pm_stockMonitor 最新快照日）的采购到货入库数量，取自 jst_purchaseItem.inQty。业务库无出入库流水表，0 表示该 SKU 当日无到货"
      />,
      dataIndex: 'inQtyToday',
      width: 116,
      align: 'right',
      render: (value) => (value === null || value === undefined
        ? <span className="msm-muted">--</span>
        : int(value)),
    },
    {
      title: <TipTitle
        title="当日出库库存"
        tip="监控日的最近一日发货量，取自 pm_stockMonitor.nearSecondSale。业务库无出入库流水表，0 表示该 SKU 当日无发货"
      />,
      dataIndex: 'outQtyToday',
      width: 116,
      align: 'right',
      render: (value) => (value === null || value === undefined
        ? <span className="msm-muted">--</span>
        : int(value)),
    },
    {
      title: '实时库存',
      dataIndex: 'realtimeStock',
      width: 96,
      align: 'right',
      sorter: true,
      render: int,
    },
    {
      title: <TipTitle
        title="仓位"
        tip="业务库 jst_sku.bin / other_bin 全库 55.7 万行均为空，上游未回传库位数据，因此该列暂无值"
      />,
      dataIndex: 'location',
      width: 88,
      sorter: true,
      render: (value) => (value
        ? <span>{value}</span>
        : <Tooltip title="上游未提供库位数据">
          <span className="msm-muted">未维护</span>
        </Tooltip>),
    },
    {
      title: '近15天日均发货量',
      dataIndex: 'avgShip15d',
      width: 138,
      align: 'right',
      sorter: true,
      render: (value) => number(value),
    },
    {
      title: '库存可用天数',
      dataIndex: 'stockDays',
      width: 116,
      align: 'right',
      sorter: true,
      render: (value) => number(value, 1),
    },
    {
      title: '所在仓库',
      dataIndex: 'warehouse',
      width: 200,
      ellipsis: true,
      sorter: true,
      render: (value) => <Tooltip title={value}>{text(value)}</Tooltip>,
    },
  ], []);

  const exportColumns = useMemo(
    () => columns.filter((column) => column.exportable !== false),
    [columns]
  );

  const handleExport = async (format) => {
    if (!data.rows.length) {
      message.warning('暂无数据可导出');
      return;
    }
    try {
      await exportTableFile(
        format,
        `配件库存监控_${data.monitorDate || '最新'}`,
        exportColumns,
        data.rows,
        '配件库存监控'
      );
      message.success(`已导出 ${data.rows.length} 条数据（${format.toUpperCase()}）`);
    } catch (exportError) {
      message.error(exportError?.message || '导出失败');
    }
  };

  const summary = data.summary || {};

  return (
    <>
      <Card className="msm-filter-card" bordered={false}>
        <Space wrap size={[12, 12]}>
          <Input
            allowClear
            prefix={<SearchOutlined />}
            placeholder="SKU 编码 / 名称"
            value={filters.keyword}
            onChange={(e) => changeFilter('keyword')(e.target.value)}
            style={{ width: 220 }}
          />
          <Select
            allowClear
            showSearch
            placeholder="品类"
            options={toOptions(filterOptions.categories)}
            value={filters.category || undefined}
            onChange={changeFilter('category')}
            style={{ width: 200 }}
          />
          <Select
            allowClear
            placeholder="预警等级"
            options={toOptions(filterOptions.warningLevels)}
            value={filters.warningLevel || undefined}
            onChange={changeFilter('warningLevel')}
            style={{ width: 140 }}
          />
          <Select
            allowClear
            placeholder="MKH 配置状态"
            options={toOptions(filterOptions.mkhStatuses)}
            value={filters.mkhStatus || undefined}
            onChange={changeFilter('mkhStatus')}
            style={{ width: 160 }}
          />
          <Space size={6}>
            <Switch checked={onlyWarning} onChange={(checked) => { setOnlyWarning(checked); setPage(1); }} size="small" />
            <Text type="secondary">仅看缺货 / 预警</Text>
          </Space>
          <Button onClick={resetFilters}>重置</Button>
          <Button icon={<ReloadOutlined />} onClick={load} loading={loading}>刷新数据</Button>
        </Space>
      </Card>

      {error ? <Alert type="error" showIcon message={error} action={<Button size="small" onClick={load}>重试</Button>} /> : null}

      <Row gutter={[12, 12]} className="msm-summary-row">
        <Col xs={12} md={4}><Card bordered={false} className="msm-summary-card"><Statistic title="SKU 总数" value={summary.skuCount || 0} /></Card></Col>
        <Col xs={12} md={4}><Card bordered={false} className="msm-summary-card is-red"><Statistic title="缺货 SKU" value={summary.outOfStockCount || 0} /></Card></Col>
        <Col xs={12} md={4}><Card bordered={false} className="msm-summary-card is-orange"><Statistic title="可用天数不足" value={summary.lowStockDaysCount || 0} suffix="个 SKU" /></Card></Col>
        <Col xs={12} md={4}><Card bordered={false} className="msm-summary-card is-green"><Statistic title="实时库存合计" value={summary.totalStock || 0} /></Card></Col>
        <Col xs={12} md={4}><Card bordered={false} className="msm-summary-card"><Statistic title="已配置MKH" value={summary.configuredCount || 0} /></Card></Col>
        <Col xs={12} md={4}><Card bordered={false} className="msm-summary-card"><Statistic title="未配置MKH" value={summary.unconfiguredCount || 0} /></Card></Col>
      </Row>

      <Card
        bordered={false}
        className="msm-panel"
        title={(
          <Space size={12} wrap>
            <span>配件库存明细（{data.total || 0} 条）</span>
            {data.monitorDate ? <Text type="secondary" className="msm-panel__date">监控日 {data.monitorDate}</Text> : null}
          </Space>
        )}
        extra={(
          <Dropdown menu={{
            items: [
              { key: 'xlsx', label: '导出 XLSX' },
              { key: 'csv', label: '导出 CSV' },
            ],
            onClick: ({ key }) => handleExport(key),
          }}>
            <Button icon={<DownloadOutlined />}>导出</Button>
          </Dropdown>
        )}
      >
        <Spin spinning={loading} tip="正在加载配件库存监控数据…">
          <div ref={tableWrapRef}>
            <Table
              rowKey="skuId"
              size="small"
              columns={columns}
              dataSource={data.rows || []}
              onChange={(pagination, _filter, nextSorter) => {
                setPage(pagination.current || 1);
                setPageSize(pagination.pageSize || 50);
                if (nextSorter?.field) {
                  setSorter({
                    field: nextSorter.field,
                    order: nextSorter.order === 'ascend' ? 'ASC' : 'DESC',
                  });
                }
              }}
              pagination={{
                current: data.page || page,
                pageSize: data.pageSize || pageSize,
                total: data.total || 0,
                showSizeChanger: true,
                pageSizeOptions: [50, 100, 200],
                showTotal: (total) => `共 ${total} 条`,
              }}
              scroll={{ x: 1508, y: bodyHeight }}
            />
          </div>
        </Spin>
      </Card>
    </>
  );
};

const ModularStockMonitor = () => (
  <SycmPage className="msm-page">
    <header className="msm-header">
      <div className="msm-header__heading">
        <Title level={3}>模块化库存监控</Title>
        <Text type="secondary">
          配件库存监控：仅统计「简尚-崔桥工厂半成品包装项目仓」下的 SKU 实时库存、近 15 天日均发货量与可用天数
        </Text>
        <Text type="secondary" className="msm-note">
          数据口径：实时库存取 jst_inventoryInfo（wms_co_id 15718196）；近 15 天日均发货量、
          库存可用天数、安全天数取 pm_stockMonitor 最新快照（按完整 SKU 编码关联，794 个 SKU 全覆盖）；
          当日入库取采购到货、当日出库取近一日发货量，均以监控日为基准；仓位上游未回传，暂显示「未维护」；
          图片取自「产品资料系统数据库」商品档案（业务库图片字段均为空）。
          注：日均发货量 2026-09-17 起由近 7 天改为近 15 天（业务原要求 30 天，但业务库无 30 天日销，最长只到 15 天）；
          库存可用天数仍沿用监控表 jsUseDays（源系统口径），故两者并非同一时间窗。
          状态列：基于「产品资料系统数据库」判断该 SKU 是否已建立商品档案——已配置MKH = 资料库中可查到该 SKU；未配置MKH = 查不到。
        </Text>
      </div>
    </header>
    <Tabs
      className="msm-tabs"
      activeKey="accessory"
      items={[{
        key: 'accessory',
        label: '配件库存监控',
        children: <AccessoryStockPanel />,
      }]}
    />
  </SycmPage>
);

export default ModularStockMonitor;