import {
  productcontrollerCreateproduct,
  productcontrollerGetcategoriesall,
  productcontrollerGetcategoryattributes,
  productcontrollerGetproductlist,
} from '@/servers/api/product';
import { request } from '@umijs/max';
import {
  ActionType,
  PageContainer,
  ProCard,
  ProColumns,
  ProForm,
  ProFormSelect,
  ProTable,
} from '@ant-design/pro-components';
import { Button, Table, Tag, message } from 'antd';
import React, { useEffect, useState, useRef } from 'react';
import CreateModal from './components/CreateModal';
import EditForm from '../List/EditForm';

const PermutationPage: React.FC = () => {
  const [categoryId, setCategoryId] = useState<number>();
  const [attributes, setAttributes] = useState<any[]>([]);
  const [loading, setLoading] = useState(false);
  const [attributeValues, setAttributeValues] = useState<Record<string, any[]>>({});
  const [permutations, setPermutations] = useState<any[]>([]);
  const [existingProducts, setExistingProducts] = useState<Map<string, API.Product>>(new Map());
  const [productsLoading, setProductsLoading] = useState(false);
  
  const [createModalVisible, setCreateModalVisible] = useState(false);
  const [selectedPermutation, setSelectedPermutation] = useState<any>(null);
  const [categories, setCategories] = useState<any[]>([]);
  const [form] = ProForm.useForm();

  // Create a ref to mock ActionType for EditForm
  const actionRef = useRef<ActionType>();

  useEffect(() => {
    productcontrollerGetcategoriesall().then((res) => {
      const list = Array.isArray(res) ? res : (res?.data || []);
      setCategories(list);
      if (list.length > 0) {
        setCategoryId(list[0].id);
        form.setFieldValue('categoryId', list[0].id);
      }
    });
  }, []);

  const fetchProducts = async (catId: number) => {
    setProductsLoading(true);
    try {
      const productRes = await productcontrollerGetproductlist({ 
        categoryId: catId, 
        pageSize: 2000, 
        current: 1 
      });
      const products = productRes.data?.items || [];
      
      const productMap = new Map<string, API.Product>();
      products.forEach((p: any) => {
        if (p.attributes && Array.isArray(p.attributes)) {
           const key = generateAttributeKey(p.attributes);
           if (key) productMap.set(key, p);
        }
      });
      setExistingProducts(productMap);
    } catch (error) {
      console.error(error);
      message.error('获取现有产品失败');
    } finally {
      setProductsLoading(false);
    }
  };

  // Assign reload method to actionRef
  useEffect(() => {
    actionRef.current = {
      reload: async () => {
        if (categoryId) await fetchProducts(categoryId);
      },
      reloadAndRest: async () => {
        if (categoryId) await fetchProducts(categoryId);
      },
      reset: () => {},
      clearSelected: () => {},
    } as any;
  }, [categoryId]);

  // Fetch attributes and products when category changes
  useEffect(() => {
    if (!categoryId) {
      setAttributes([]);
      setAttributeValues({});
      setPermutations([]);
      setExistingProducts(new Map());
      return;
    }

    const fetchData = async () => {
      setLoading(true);
      try {
        // 1. Fetch Attributes
        const attrRes = await productcontrollerGetcategoryattributes({ id: categoryId });
        const attrs = Array.isArray(attrRes) ? attrRes : (attrRes?.data || []);
        setAttributes(attrs);

        // 2. Fetch Attribute Values (Dict Items)
        const valuesMap: Record<string, any[]> = {};
        for (const attr of attrs) {
          const dictId = attr.dict?.id || attr.dictId;
          if (dictId) {
             const itemsRes = await request('/dict/items', { params: { dictId } });
             valuesMap[attr.name] = itemsRes || []; 
          }
        }
        setAttributeValues(valuesMap);

        // 3. Fetch Existing Products
        await fetchProducts(categoryId);

      } catch (error) {
        console.error(error);
        message.error('获取数据失败');
      } finally {
        setLoading(false);
      }
    };

    fetchData();
  }, [categoryId]);

  // Generate Permutations when attributes or values change
  useEffect(() => {
    if (attributes.length === 0 || Object.keys(attributeValues).length === 0) {
      setPermutations([]);
      return;
    }

    const validAttributes = attributes.filter(attr => attributeValues[attr.name]?.length > 0);
    
    if (validAttributes.length === 0) {
        setPermutations([]);
        return;
    }

    const generateCombinations = (index: number, current: any): any[] => {
      if (index === validAttributes.length) {
        return [current];
      }

      const attr = validAttributes[index];
      const values = attributeValues[attr.name];
      let res: any[] = [];

      for (const val of values) {
        res = res.concat(generateCombinations(index + 1, { ...current, [attr.name]: val }));
      }
      return res;
    };

    const combos = generateCombinations(0, {});
    setPermutations(combos);

  }, [attributes, attributeValues]);

  const generateAttributeKey = (attrs: any[]) => {
    const parts = attrs.map(a => {
        const key = a.dict?.name || a.dictName; 
        const val = a.name || a.value;
        return `${key}:${val}`;
    });
    return parts.sort().join('|');
  };
  
  const generateKeyFromPermutation = (perm: any) => {
      const parts = Object.keys(perm).map(attrName => {
          const valItem = perm[attrName];
          const val = valItem.name; 
          return `${attrName}:${val}`;
      });
      return parts.sort().join('|');
  };

  const handleAdd = (record: any) => {
      setSelectedPermutation(record);
      setCreateModalVisible(true);
  };

  const columns: any[] = [
    ...attributes.map(attr => ({
      title: attr.title || attr.name,
      dataIndex: attr.name,
      width: 100, // Make columns narrower
      render: (item: any) => item?.name || '-',
      sorter: (a: any, b: any) => {
        const valA = a[attr.name]?.name || '';
        const valB = b[attr.name]?.name || '';
        return valA.localeCompare(valB);
      },
      filters: attributeValues[attr.name]?.map((v: any) => ({ text: v.name, value: v.name })),
      onFilter: (value: any, record: any) => record[attr.name]?.name === value,
    })),
    {
      title: '现有 SKU',
      key: 'sku',
      width: 150,
      sorter: (a: any, b: any) => {
        const keyA = generateKeyFromPermutation(a);
        const productA = existingProducts.get(keyA);
        const skuA = productA?.sku || '';

        const keyB = generateKeyFromPermutation(b);
        const productB = existingProducts.get(keyB);
        const skuB = productB?.sku || '';

        return skuA.localeCompare(skuB);
      },
      filters: [
        { text: '已存在', value: 'exists' },
        { text: '未创建', value: 'missing' },
      ],
      onFilter: (value: any, record: any) => {
        const key = generateKeyFromPermutation(record);
        const exists = existingProducts.has(key);
        if (value === 'exists') return exists;
        if (value === 'missing') return !exists;
        return true;
      },
      render: (_: any, record: any) => {
        const key = generateKeyFromPermutation(record);
        const product = existingProducts.get(key);
        return product ? <Tag color="green">{product.sku}</Tag> : '-';
      },
    },
    {
      title: '操作',
      key: 'action',
      width: 100,
      render: (_: any, record: any) => {
        const key = generateKeyFromPermutation(record);
        const product = existingProducts.get(key);
        if (product) {
            return (
                <EditForm 
                    record={product} 
                    tableRef={actionRef}
                    trigger={<Button type="link" size="small">编辑</Button>}
                />
            );
        }
        
        return (
          <Button type="primary" size="small" onClick={() => handleAdd(record)}>
            添加
          </Button>
        );
      },
    },
  ];

  return (
    <PageContainer>
      <ProCard>
        <ProForm
          form={form}
          layout="inline"
          submitter={false}
          style={{ marginBottom: 24 }}
        >
          <ProFormSelect
            name="categoryId"
            label="选择分类"
            width="md"
            options={categories.map((item: any) => ({
                label: item.name,
                value: item.id,
            }))}
            fieldProps={{
              onChange: (val) => setCategoryId(val as number),
            }}
          />
        </ProForm>

        {categoryId && (
           <ProTable
             size="small"
             dataSource={permutations}
             columns={columns}
             loading={loading || productsLoading}
             rowKey={(record) => generateKeyFromPermutation(record)}
             pagination={{ 
                defaultPageSize: 50,
                showSizeChanger: true,
                pageSizeOptions: ['50', '100', '200', '500', '1000', '2000'] 
             }}
             scroll={{ x: 'max-content' }}
             search={false}
             toolBarRender={false}
           />
        )}
      </ProCard>

      {selectedPermutation && (
        <CreateModal
            visible={createModalVisible}
            onClose={() => setCreateModalVisible(false)}
            onSuccess={() => {
                setCreateModalVisible(false);
                if (categoryId) fetchProducts(categoryId);
            }}
            category={categories.find(c => c.id === categoryId) || null}
            permutation={selectedPermutation}
            attributes={attributes}
        />
      )}
    </PageContainer>
  );
};

export default PermutationPage;