import { useCallback, useEffect, useMemo, useState } from 'react';
import { ProFormCascader, ProFormSelect } from '@ant-design/pro-components';
import {
  App as AntdApp,
  Button,
  Drawer,
  Form,
  Input,
  InputNumber,
  Space,
  Spin,
} from 'antd';
import { createEmployee, getEmployeeDetail, updateEmployee } from '../server';
import type {
  EmployeeFormValues,
  EmployeeVO,
  OrgTreeNode,
  SelectOption,
} from '../types';

interface OrgCascaderOption {
  value: number;
  label: string;
  children?: OrgCascaderOption[];
}

/** 去掉最外层公司节点，只保留公司下的组织用于选择。 */
const getSelectableOrgNodes = (nodes: OrgTreeNode[]): OrgTreeNode[] =>
  nodes.flatMap((node) => (node.children?.length ? node.children : [node]));

/** 组织树转为级联选择选项，按层级展示。 */
const toCascaderOptions = (nodes: OrgTreeNode[]): OrgCascaderOption[] =>
  nodes.map((node) => ({
    value: node.id,
    label: node.orgName,
    children: node.children?.length ? toCascaderOptions(node.children) : undefined,
  }));

/** 在组织树中查找某个组织 ID 的完整路径，用于编辑 / 详情时回填级联值。 */
const findOrgPath = (nodes: OrgTreeNode[], targetId: number): number[] | null => {
  for (const node of nodes) {
    if (node.id === targetId) return [node.id];

    const childPath = node.children ? findOrgPath(node.children, targetId) : null;
    if (childPath) return [node.id, ...childPath];
  }

  return null;
};

export type UserFormMode = 'create' | 'edit' | 'detail';

interface UserFormDrawerProps {
  open: boolean;
  mode: UserFormMode;
  /** 编辑 / 详情对象；新增时为空。 */
  record: EmployeeVO | null;
  /** 组织树，用于所属组织的二级联动选择。 */
  orgTree: OrgTreeNode[];
  roleOptions: SelectOption[];
  onClose: () => void;
  onSuccess: () => void;
}

const toFormValues = (
  employee: EmployeeVO,
  orgTree: OrgTreeNode[],
): EmployeeFormValues => ({
  name: employee.name,
  phone: employee.phone,
  orgPath: findOrgPath(getSelectableOrgNodes(orgTree), employee.orgId) ?? [],
  roleId: employee.roleId,
  position: employee.position,
  email: employee.email,
  holdLimit: employee.holdLimit,
  region: employee.region,
});

const UserFormDrawer = ({
  open,
  mode,
  record,
  orgTree,
  roleOptions,
  onClose,
  onSuccess,
}: UserFormDrawerProps) => {
  const [form] = Form.useForm<EmployeeFormValues>();
  const [submitting, setSubmitting] = useState(false);
  const [loading, setLoading] = useState(false);
  const { message } = AntdApp.useApp();
  const isDetail = mode === 'detail';
  const orgCascaderOptions = useMemo(
    () => toCascaderOptions(getSelectableOrgNodes(orgTree)),
    [orgTree],
  );

  useEffect(() => {
    if (!open) return;

    let active = true;

    const initForm = async () => {
      form.resetFields();

      if (mode === 'detail') {
        if (!record) return;

        setLoading(true);
        try {
          const data = await getEmployeeDetail({ id: record.id });
          if (active) form.setFieldsValue(toFormValues(data, orgTree));
        } catch {
          // 错误已由 request 统一提示
          if (active) onClose();
        } finally {
          if (active) setLoading(false);
        }
        return;
      }

      if (mode === 'edit' && record) {
        form.setFieldsValue(toFormValues(record, orgTree));
      }
    };

    void initForm();

    return () => {
      active = false;
    };
  }, [form, mode, onClose, open, orgTree, record]);

  const handleSubmit = useCallback(async () => {
    if (isDetail) return;

    let values: EmployeeFormValues;
    try {
      values = await form.validateFields();
    } catch {
      return;
    }

    setSubmitting(true);

    const { orgPath, ...rest } = values;
    const orgId = orgPath[orgPath.length - 1];

    try {
      if (mode === 'edit' && record) {
        await updateEmployee({ id: record.id, ...rest, orgId });
        message.success('员工信息已更新');
      } else {
        await createEmployee({ ...rest, orgId });
        message.success('员工创建成功');
      }

      onSuccess();
    } catch {
      // 错误已由 request 统一提示
    } finally {
      setSubmitting(false);
    }
  }, [form, isDetail, message, mode, onSuccess, record]);

  const title = mode === 'create' ? '新增员工' : mode === 'edit' ? '编辑员工' : '员工详情';

  return (
    <Drawer
      title={title}
      width={420}
      open={open}
      forceRender
      onClose={onClose}
      footer={
        <Space style={{ display: 'flex', justifyContent: 'flex-end' }}>
          <Button onClick={onClose}>{isDetail ? '关闭' : '取消'}</Button>
          {!isDetail && (
            <Button type="primary" loading={submitting} onClick={handleSubmit}>
              {mode === 'edit' ? '保存' : '创建'}
            </Button>
          )}
        </Space>
      }
    >
      <Spin spinning={loading}>
        <Form form={form} layout="vertical" preserve={false}>
          <Form.Item
            name="name"
            label="姓名"
            rules={[{ required: true, message: '请输入姓名' }]}
          >
            <Input placeholder="请输入员工姓名" disabled={isDetail} />
          </Form.Item>
          <Form.Item
            name="phone"
            label="手机号"
            rules={[
              { required: true, message: '请输入手机号' },
              { pattern: /^1[3-9]\d{9}$/, message: '请输入正确的手机号' },
            ]}
          >
            <Input placeholder="请输入手机号" maxLength={11} disabled={isDetail} />
          </Form.Item>
          <ProFormCascader
            name="orgPath"
            label="所属组织"
            rules={[{ required: true, message: '请选择所属组织' }]}
            placeholder="请选择所属组织"
            disabled={isDetail}
            fieldProps={{
              options: orgCascaderOptions,
              changeOnSelect: true,
              showSearch: true,
              style: { width: '100%' },
            }}
          />
          <ProFormSelect
            name="roleId"
            label="角色"
            rules={[{ required: true, message: '请选择角色' }]}
            placeholder="请选择角色"
            disabled={isDetail}
            showSearch
            options={roleOptions}
            fieldProps={{ optionFilterProp: 'label', style: { width: '100%' } }}
          />
          <Form.Item
            name="holdLimit"
            label="客户持有上限"
            rules={[{ required: true, message: '请输入客户持有上限' }]}
          >
            <InputNumber
              min={0}
              precision={0}
              placeholder="请输入客户持有上限"
              style={{ width: '100%' }}
              disabled={isDetail}
            />
          </Form.Item>
          <Form.Item name="position" label="职位">
            <Input placeholder="请输入职位" disabled={isDetail} />
          </Form.Item>
          <Form.Item name="region" label="负责区域">
            <Input placeholder="请输入负责区域" disabled={isDetail} />
          </Form.Item>
          <Form.Item
            name="email"
            label="邮箱"
            rules={[{ type: 'email', message: '请输入正确的邮箱' }]}
          >
            <Input placeholder="请输入邮箱" disabled={isDetail} />
          </Form.Item>
        </Form>
      </Spin>
    </Drawer>
  );
};

export default UserFormDrawer;