import React, {useEffect, useMemo, useState} from 'react';
import {Button, Form, Tag, TreeSelect, Typography} from 'antd';
import type {FormInstance} from 'antd';
import {NodeExpandOutlined} from '@ant-design/icons';
import XinTable from '@/components/XinTable';
import type { XinTableColumn, XinTableProps } from '@/components/XinTable/typings.ts';
import type IProductCategory from '@/domain/iProductCategory.ts';
import type { IProductCategoryTree } from '@/domain/iProductCategory.ts';
import { CATEGORY_STATUS_MAP } from '@/domain/iProductCategory.ts';
import {getCategoryTable, getCategoryTree} from '@/api/product/category.ts';

const { Title, Text } = Typography;

/**
 * 上级分类选择（分类最多二级）：
 * - 二级分类禁选（不能作为上级，否则出现三级）
 * - 编辑时禁选自身
 * - 编辑的分类含子分类时禁选所有一级分类（只能保持顶级，否则其子分类会变成三级）
 */
const ParentCategorySelect: React.FC<{
  form: FormInstance;
  tree: IProductCategoryTree[];
  value?: number;
  onChange?: (value: number) => void;
}> = ({ form, tree, value, onChange }) => {
  // id/children 由 XinTable 编辑时 setFieldsValue(record) 写入（非表单项，需传 form 监听）
  const editingId = Form.useWatch('id', form);
  const children = Form.useWatch('children', form);
  const hasChildren = Array.isArray(children) && children.length > 0;

  const treeData = useMemo(() => {
    const walk = (nodes: IProductCategoryTree[], depth: number): IProductCategoryTree[] =>
      nodes.map((node) => ({
        ...node,
        disabled: depth >= 2 || node.id === editingId || (hasChildren && depth >= 1),
        children: node.children?.length ? walk(node.children, depth + 1) : node.children,
      }));
    return [{ id: 0, name: '顶级分类', children: walk(tree, 1) }];
  }, [tree, editingId, hasChildren]);

  return (
    <TreeSelect
      value={value}
      onChange={onChange}
      treeData={treeData}
      fieldNames={{ label: 'name', value: 'id', children: 'children' }}
      placeholder="默认顶级分类"
      treeDefaultExpandAll
    />
  );
};

/**
 * 递归收集全部节点 id（用于展开整棵树）
 */
function collectAllIds(nodes: IProductCategory[]): number[] {
  const ids: number[] = [];
  const walk = (list: IProductCategory[]) => {
    list.forEach((node) => {
      if (node.id !== undefined) {
        ids.push(node.id);
      }
      if (node.children?.length) {
        walk(node.children);
      }
    });
  };
  walk(nodes);
  return ids;
}

/**
 * 商品分类管理（多级分类树表）
 */
const ProductCategoryPage: React.FC = () => {
  const [expandedKeys, setExpandedKeys] = useState<number[]>([]);
  const [allIds, setAllIds] = useState<number[]>([]);
  const [categoryTree, setCategoryTree] = useState<IProductCategoryTree[]>([]);

  useEffect(() => {
    getCategoryTree().then((res) => setCategoryTree(res.data.data ?? []));
  }, []);

  const columns: XinTableColumn<IProductCategory>[] = [
    {
      title: '分类名称',
      dataIndex: 'name',
      valueType: 'text',
      required: true,
      rules: [{ required: true, message: '请输入分类名称' }],
    },
    {
      title: '上级分类',
      dataIndex: 'parent_id',
      hideInTable: true,
      hideInSearch: true,
      initialValue: 0,
      fieldRender: (form) => <ParentCategorySelect form={form} tree={categoryTree} />,
    },
    {
      title: '排序',
      dataIndex: 'sort',
      valueType: 'digit',
      hideInSearch: true,
      initialValue: 0,
      fieldProps: { min: 0 },
      align: 'center',
    },
    {
      title: '状态',
      dataIndex: 'status',
      valueType: 'radioButton',
      initialValue: 1,
      hideInSearch: true,
      fieldProps: {
        options: [
          { value: 1, label: '正常' },
          { value: 0, label: '停用' },
        ],
      },
      render: (_, record) => {
        const item = CATEGORY_STATUS_MAP[record.status ?? 1];
        return <Tag color={item?.color}>{item?.text}</Tag>;
      },
      align: 'center',
    },
    {
      title: '创建时间',
      dataIndex: 'updated_at',
      hideInForm: true,
      hideInSearch: true,
      align: 'center',
    },
    {
      title: '创建时间',
      dataIndex: 'created_at',
      hideInForm: true,
      hideInSearch: true,
      align: 'center',
    },
  ];

  const tableProps: XinTableProps<IProductCategory> = {
    api: '/product/category',
    columns,
    rowKey: 'id',
    accessName: 'product.category',
    // 后端直接返回分类树，不走分页接口
    handleRequest: async () => {
      const res = await getCategoryTable();
      const tree = res.data.data ?? [];
      setAllIds(collectAllIds(tree));
      return { data: tree, total: tree.length };
    },
    pagination: { pageSize: 200 },
    expandable: {
      expandedRowKeys: expandedKeys,
      onExpandedRowsChange: (keys) => setExpandedKeys([...keys] as number[]),
    },
    actionBarRender: (dom) => [
      dom.add,
      <Button
        icon={<NodeExpandOutlined />}
        onClick={() =>
          setExpandedKeys(expandedKeys.length ? [] : allIds)
        }
      >
        {expandedKeys.length ? '全部收起' : '全部展开'}
      </Button>,
      dom.keywordSearch,
    ],
    formProps: {
      grid: true,
      colProps: { span: 12 },
      rowProps: { gutter: 20 },
      layout: 'vertical',
    },
    modalProps: { width: 640 },
  };

  return (
    <>
      <div className={"mb-5"}>
        <Title level={3}>商品分类</Title>
        <Text type="secondary">
          多级分类（如蔬菜/水果/其他），采购单导出与对账筛选按分类归组；有子分类或挂载商品时不可删除。
        </Text>
      </div>
      <XinTable<IProductCategory> {...tableProps} />
    </>
  );
};

export default ProductCategoryPage;