import React, { useCallback, useEffect, useMemo, useState } from 'react';
import { Alert, Button, Modal, Space, Spin, Table, Tooltip, Typography } from 'antd';
import { InfoCircleOutlined, ReloadOutlined } from '@ant-design/icons';
import { SycmPage } from '../../components/Common';
import { getDailyInventory } from '../../api/dailyInventory';
import {
  DAILY_INVENTORY_COLUMNS,
  COLUMN_SOURCE,
  FORMULA_DESCRIPTION,
} from '../../constants/dailyInventory.js';
import './style.css';

const { Title, Text } = Typography;

const TipTitle = ({ tip, children }) => (
  <Tooltip title={tip}>
    <span className="daily-inventory-th-tip">{children}</span>
  </Tooltip>
);

const int = (value) => {
  if (value === null || value === undefined || value === '') return '—';
  return Number(value).toLocaleString('zh-CN', { maximumFractionDigits: 0 });
};

const decimal = (value, digits = 1) => {
  if (value === null || value === undefined || value === '') return '—';
  return Number(value).toLocaleString('zh-CN', {
    minimumFractionDigits: digits,
    maximumFractionDigits: digits,
  });
};

/** 负数标红、正数标黑：出入库列以负数表示流出，便于一眼分辨方向 */
const renderSigned = (value) => {
  if (value === null || value === undefined || value === '') return '—';
  const n = Number(value);
  if (!Number.isFinite(n) || n === 0) return <span className="daily-inventory-cell--zero">0</span>;
  return <span className={n < 0 ? 'daily-inventory-cell--out' : 'daily-inventory-cell--in'}>{int(n)}</span>;
};

const DailyInventory = () => {
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState('');
  const [data, setData] = useState(null);
  const [helpOpen, setHelpOpen] = useState(false);

  const load = useCallback(async () => {
    setLoading(true);
    setError('');
    try {
      const res = await getDailyInventory();
      setData(res?.data ?? null);
    } catch (err) {
      setError(err?.response?.data?.error || err?.message || '每日进销存数据加载失败');
      setData(null);
    } finally {
      setLoading(false);
    }
  }, []);

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

  const items = useMemo(() => data?.items ?? [], [data]);

  const columns = useMemo(() => DAILY_INVENTORY_COLUMNS.map((col) => {
    const isRuntime = col.source === COLUMN_SOURCE.runtime;
    return {
      title: <TipTitle tip={col.tip}>{col.label}</TipTitle>,
      dataIndex: col.key,
      key: col.key,
      align: col.key === 'warehouse' ? 'left' : 'right',
      width: col.key === 'warehouse' ? 240 : 130,
      fixed: col.key === 'warehouse' ? 'left' : undefined,
      className: isRuntime ? 'daily-inventory-col--runtime' : undefined,
      render: (value, record) => {
        if (record?.isTotal) {
          // 合计行：周转天数不累加，显示「—」
          if (col.key === 'turnoverDays') return '—';
          return int(value);
        }
        if (col.key === 'warehouse') return <span className="daily-inventory-warehouse">{value}</span>;
        if (col.key === 'closingQty') return int(value);
        if (col.key === 'turnoverDays') return decimal(value, 1);
        return renderSigned(value);
      },
    };
  }), []);

  const tableRows = useMemo(() => {
    if (!data?.totals) return items;
    return [...items, { ...data.totals, key: '__total__' }];
  }, [items, data]);

  const noGradeCount = useMemo(() => items.filter((it) => !it.hasGrade).length, [items]);

  return (
    <SycmPage className="daily-inventory-page">
      <div className="daily-inventory-header">
        <div className="daily-inventory-header__title">
          <Title level={4} style={{ margin: 0 }}>每日进销存</Title>
          <Button
            type="text"
            icon={<InfoCircleOutlined />}
            onClick={() => setHelpOpen(true)}
            className="daily-inventory-header__help"
          >
            口径说明
          </Button>
        </div>
        <div className="daily-inventory-header__meta">
          <span>基准日期：{data?.baselineDate || '—'}</span>
          <span>库存快照日：{data?.latestBizDate || '—'}</span>
          <span>分级基准时刻：{data?.asOf || '—'}</span>
          {data?.items?.[0]?.closingTakenAt ? (
            <span>
              库存取数时间：{new Date(data.items[0].closingTakenAt).toLocaleString('zh-CN', { hour12: false })}
            </span>
          ) : null}
        </div>
        <Space>
          <Button icon={<ReloadOutlined />} onClick={load} loading={loading}>刷新</Button>
        </Space>
      </div>

      <Alert
        type="info"
        showIcon
        message="数据来源混合，请注意口径"
        description={
          <span>
            期初数量与 12 个流水列取自 <b>{data?.baselineDate || '2026-09-22'}</b> 聚水潭进销存导出值（业务库缺少调拨／盘点／加工／其它出入库单据表，无法还原）；
            期末数量与右侧 5 列为运行时实时取数。悬浮表头可看每列口径。
            {noGradeCount > 0 ? ` 其中 ${noGradeCount} 个仓在库存快照中无数据，周转天数与四级库存量显示「—」。` : ''}
          </span>
        }
        style={{ marginBottom: 12 }}
      />

      {error ? <Alert type="error" showIcon message={error} style={{ marginBottom: 12 }} /> : null}

      <Spin spinning={loading}>
        <Table
          className="daily-inventory-table"
          columns={columns}
          dataSource={tableRows}
          rowKey={(record) => record.key || record.warehouse}
          size="small"
          bordered
          pagination={false}
          scroll={{ x: 'max-content', y: 'calc(100vh - 300px)' }}
          rowClassName={(record) => (record?.isTotal ? 'daily-inventory-row--total' : '')}
        />
      </Spin>

      <Text type="secondary" className="daily-inventory-footer">
        共 {items.length} 个仓库；蓝色底纹列为运行时取数，其余为基准值。
      </Text>

      <Modal
        title="计算口径说明"
        open={helpOpen}
        onCancel={() => setHelpOpen(false)}
        footer={null}
        width={720}
      >
        <div className="daily-inventory-help">
          {FORMULA_DESCRIPTION.map((line, i) => (
            <p key={i} className={line.startsWith('  ') ? 'is-indent' : ''}>{line}</p>
          ))}
        </div>
      </Modal>
    </SycmPage>
  );
};

export default DailyInventory;