import {
  Button,
  Card,
  Drawer,
  Form,
  Input,
  message,
  Popconfirm,
  Space,
  Table,
  Tag,
  Typography,
  InputNumber,
  Row,
  Col,
  Select,
  Empty
} from "antd";
import { useEffect, useState, useMemo } from "react";
import { useTranslation } from "react-i18next";
import { createOrg, deleteOrg, listOrgs, updateOrg, listTenants } from "../api";
import { usePermission } from "../hooks/usePermission";
import {
  PlusOutlined,
  EditOutlined,
  DeleteOutlined,
  ApartmentOutlined,
  ReloadOutlined,
  ShopOutlined
} from "@ant-design/icons";
import type { SysOrg, SysTenant, OrgNode } from "../types";

const { Title, Text } = Typography;

function buildOrgTree(list: SysOrg[]): OrgNode[] {
  const map = new Map<number, OrgNode>();
  const roots: OrgNode[] = [];

  list.forEach((item) => {
    map.set(item.id, { ...item, children: [] });
  });

  map.forEach((node) => {
    if (node.parentId && map.has(node.parentId)) {
      map.get(node.parentId)!.children.push(node);
    } else {
      roots.push(node);
    }
  });

  const sortTree = (nodes: OrgNode[]) => {
    nodes.sort((a, b) => (a.sortOrder || 0) - (b.sortOrder || 0));
    nodes.forEach(n => n.children && sortTree(n.children));
  };
  sortTree(roots);
  return roots;
}

export default function Orgs() {
  const { t } = useTranslation();
  const { can } = usePermission();
  const [loading, setLoading] = useState(false);
  const [saving, setSaving] = useState(false);
  const [data, setData] = useState<SysOrg[]>([]);
  const [tenants, setTenants] = useState<SysTenant[]>([]);
  const [selectedTenantId, setSelectedTenantId] = useState<number | undefined>(undefined);
  
  // Platform admin check
  const isPlatformMode = useMemo(() => {
    const profileStr = sessionStorage.getItem("userProfile");
    if (profileStr) {
      const profile = JSON.parse(profileStr);
      return profile.isPlatformAdmin && localStorage.getItem("activeTenantId") === "0";
    }
    return false;
  }, []);

  const activeTenantId = useMemo(() => Number(localStorage.getItem("activeTenantId") || 0), []);

  const [drawerOpen, setDrawerOpen] = useState(false);
  const [editing, setEditing] = useState<SysOrg | null>(null);
  const [form] = Form.useForm();

  const loadTenants = async () => {
    try {
      const resp = await listTenants({ current: 1, size: 100 });
      const list = resp.records || [];
      setTenants(list);
      
      if (!isPlatformMode) {
        setSelectedTenantId(activeTenantId);
      } else if (list.length > 0 && selectedTenantId === undefined) {
        setSelectedTenantId(list[0].id);
      }
    } catch (e) {
      message.error(t('common.error'));
    }
  };

  const loadOrgs = async () => {
    if (selectedTenantId === undefined) return;
    setLoading(true);
    try {
      const list = await listOrgs(selectedTenantId);
      setData(list || []);
    } catch (e) {
      message.error(t('common.error'));
    } finally {
      setLoading(false);
    }
  };

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

  useEffect(() => {
    loadOrgs();
  }, [selectedTenantId]);

  const treeData = useMemo(() => buildOrgTree(data), [data]);

  const parentOptions = useMemo(() => {
    return data.map(o => ({ label: o.orgName, value: o.id }));
  }, [data]);

  const openCreate = (parentId?: number) => {
    setEditing(null);
    form.resetFields();
    form.setFieldsValue({ 
      tenantId: selectedTenantId, 
      parentId: parentId,
      status: 1, 
      sortOrder: 0 
    });
    setDrawerOpen(true);
  };

  const openEdit = (record: SysOrg) => {
    setEditing(record);
    form.setFieldsValue(record);
    setDrawerOpen(true);
  };

  const handleDelete = async (id: number) => {
    try {
      await deleteOrg(id);
      message.success(t('common.success'));
      loadOrgs();
    } catch (e: any) {
      message.error(e.message || t('common.error'));
    }
  };

  const submit = async () => {
    try {
      const values = await form.validateFields();
      setSaving(true);
      if (editing) {
        await updateOrg(editing.id, values);
        message.success(t('common.success'));
      } else {
        await createOrg(values);
        message.success(t('common.success'));
      }
      setDrawerOpen(false);
      loadOrgs();
    } catch (e) {
      if (e instanceof Error && e.message) message.error(e.message);
    } finally {
      setSaving(false);
    }
  };

  const columns = [
    {
      title: t('orgs.orgName'),
      dataIndex: "orgName",
      key: "orgName",
      render: (text: string) => <Text strong>{text}</Text>
    },
    {
      title: t('orgs.orgCode'),
      dataIndex: "orgCode",
      key: "orgCode",
      width: 150,
      render: (text: string) => <Tag className="tabular-nums">{text || "-"}</Tag>
    },
    {
      title: t('orgs.sort'),
      dataIndex: "sortOrder",
      width: 100,
      className: "tabular-nums"
    },
    {
      title: t('common.status'),
      dataIndex: "status",
      width: 100,
      render: (s: number) => <Tag color={s === 1 ? "green" : "red"}>{s === 1 ? "启用" : "禁用"}</Tag>
    },
    {
      title: t('common.action'),
      key: "action",
      width: 180,
      render: (_: any, record: SysOrg) => (
        <Space>
          {can("sys:org:create") && (
            <Button type="link" size="small" onClick={() => openCreate(record.id)}>{t('orgs.addSub')}</Button>
          )}
          {can("sys:org:update") && (
            <Button type="text" size="small" icon={<EditOutlined aria-hidden="true" />} onClick={() => openEdit(record)} aria-label={t('common.edit')} />
          )}
          {can("sys:org:delete") && (
            <Popconfirm title={`确定删除 "${record.orgName}" 吗？`} onConfirm={() => handleDelete(record.id)}>
              <Button type="text" size="small" danger icon={<DeleteOutlined aria-hidden="true" />} aria-label={t('common.delete')} />
            </Popconfirm>
          )}
        </Space>
      )
    }
  ];

  return (
    <div className="p-6">
      <div className="mb-6 flex justify-between items-end">
        <div>
          <Title level={4} className="mb-1">{t('orgs.title')}</Title>
          <Text type="secondary">{t('orgs.subtitle')}</Text>
        </div>
        {can("sys:org:create") && (
          <Button type="primary" icon={<PlusOutlined aria-hidden="true" />} onClick={() => openCreate()}>
            {t('orgs.createRoot')}
          </Button>
        )}
      </div>

      {isPlatformMode && (
        <Card className="shadow-sm mb-4">
          <Space>
            <Text strong>{t('users.tenant')}：</Text>
            <Select
              style={{ width: 220 }}
              placeholder={t('orgs.selectTenant')}
              value={selectedTenantId}
              onChange={setSelectedTenantId}
              options={tenants.map(t => ({ label: t.tenantName, value: t.id }))}
              suffixIcon={<ShopOutlined aria-hidden="true" />}
            />
            <Button icon={<ReloadOutlined aria-hidden="true" />} onClick={loadOrgs}>{t('common.refresh')}</Button>
          </Space>
        </Card>
      )}

      <Card className="shadow-sm" styles={{ body: { padding: 0 } }}>
        {selectedTenantId !== undefined ? (
          <Table
            rowKey="id"
            columns={columns}
            dataSource={treeData}
            loading={loading}
            pagination={false}
            size="middle"
            expandable={{ defaultExpandAllRows: true }}
          />
        ) : (
          <div className="py-20 flex justify-center">
            <Empty description={t('orgs.selectTenant')} />
          </div>
        )}
      </Card>

      <Drawer
        title={
          <Space>
            <ApartmentOutlined aria-hidden="true" />
            <span>{editing ? t('orgs.drawerTitleEdit') : t('orgs.drawerTitleCreate')}</span>
          </Space>
        }
        open={drawerOpen}
        onClose={() => setDrawerOpen(false)}
        width={420}
        destroyOnClose
        footer={
          <div className="flex justify-end gap-2 p-2">
            <Button onClick={() => setDrawerOpen(false)}>{t('common.cancel')}</Button>
            <Button type="primary" loading={saving} onClick={submit}>{t('common.confirm')}</Button>
          </div>
        }
      >
        <Form form={form} layout="vertical">
          <Form.Item 
            label={t('users.tenant')} 
            name="tenantId" 
            rules={[{ required: true }]}
            hidden={!isPlatformMode}
          >
            <Select disabled options={tenants.map(t => ({ label: t.tenantName, value: t.id }))} />
          </Form.Item>
          {!isPlatformMode && (
            <Form.Item label={t('users.tenant')}>
              <Input value={tenants.find(t => t.id === activeTenantId)?.tenantName || "当前租户"} disabled />
            </Form.Item>
          )}
          
          <Form.Item label={t('orgs.parentOrg')} name="parentId">
            <Select 
              placeholder={t('orgs.rootOrg')} 
              allowClear 
              showSearch
              optionFilterProp="label"
              options={parentOptions} 
            />
          </Form.Item>

          <Form.Item label={t('orgs.orgName')} name="orgName" rules={[{ required: true, message: t('orgs.orgName') }]}>
            <Input placeholder="例如：技术部、财务处…" />
          </Form.Item>

          <Form.Item label={t('orgs.orgCode')} name="orgCode">
            <Input placeholder="例如：DEPT_TECH" className="tabular-nums" />
          </Form.Item>

          <Row gutter={16}>
            <Col span={12}>
              <Form.Item label={t('dicts.sort')} name="sortOrder" initialValue={0}>
                <InputNumber style={{ width: "100%" }} min={0} className="tabular-nums" />
              </Form.Item>
            </Col>
            <Col span={12}>
              <Form.Item label={t('common.status')} name="status" initialValue={1}>
                <Select options={[{ label: "启用", value: 1 }, { label: "禁用", value: 0 }]} />
              </Form.Item>
            </Col>
          </Row>
        </Form>
      </Drawer>
    </div>
  );
}