import { useState, useEffect } from 'react'
import { Table, Button, Modal, Form, Input, InputNumber, Select, Tag, Space, message, Popconfirm, TreeSelect } from 'antd'
import { PlusOutlined, EditOutlined, DeleteOutlined, ReloadOutlined } from '@ant-design/icons'
import type { ColumnsType } from 'antd/es/table'
import { roleApi } from '@/api/role.api'
import type { Role, CreateRoleRequest, UpdateRoleRequest, RolePageRequest, Permission } from '@/api/role.api'
import type { PageResponse } from '@/api/user.api'
import { RoleStatus, roleStatusMap } from '@/constants/status'
import { VALIDATION } from '@/constants/validation-rules'
import PermissionGuard from '@/components/PermissionGuard'

export default function RoleManagement() {
  const [roles, setRoles] = useState<Role[]>([])
  const [loading, setLoading] = useState(false)
  const [modalOpen, setModalOpen] = useState(false)
  const [editingRole, setEditingRole] = useState<Role | null>(null)
  const [permissions, setPermissions] = useState<Permission[]>([])
  const [pagination, setPagination] = useState({ current: 1, pageSize: 10, total: 0 })
  const [form] = Form.useForm()

  useEffect(() => {
    loadRoles()
    loadPermissions()
  }, [])

  async function loadRoles() {
    setLoading(true)
    try {
      const params: RolePageRequest = { page: pagination.current - 1, size: pagination.pageSize }
      const res = await roleApi.getPage(params)
      const data = res as unknown as PageResponse<Role>
      setRoles(data.content)
      setPagination((prev) => ({ ...prev, total: data.totalElements }))
    } catch {
      message.error('加载角色列表失败')
    } finally {
      setLoading(false)
    }
  }

  async function loadPermissions() {
    try {
      const res = await roleApi.getAllPermissions()
      setPermissions(Array.isArray(res) ? res : [])
    } catch { /* ignored */ }
  }

  function handleAdd() {
    setEditingRole(null)
    form.resetFields()
    setModalOpen(true)
  }

  function handleEdit(record: Role) {
    setEditingRole(record)
    form.setFieldsValue({
      roleName: record.roleName,
      roleKey: record.roleKey,
      roleSort: record.roleSort,
      status: record.status,
      permissions: record.permissions?.map((p) => p.id),
    })
    setModalOpen(true)
  }

  async function handleDelete(id: number) {
    try {
      await roleApi.delete(id)
      message.success('删除成功')
      loadRoles()
    } catch {
      message.error('删除失败')
    }
  }

  async function handleSubmit() {
    try {
      const values = await form.validateFields()
      if (editingRole) {
        const data: UpdateRoleRequest = { ...values }
        await roleApi.update(editingRole.id, data)
        message.success('更新成功')
      } else {
        const data: CreateRoleRequest = { ...values }
        await roleApi.create(data)
        message.success('创建成功')
      }
      setModalOpen(false)
      loadRoles()
    } catch { /* ignored */ }
  }

  const permissionTreeData = buildPermissionTree(permissions)

  const columns: ColumnsType<Role> = [
    { title: '角色名称', dataIndex: 'roleName', key: 'roleName' },
    { title: '角色标识', dataIndex: 'roleKey', key: 'roleKey' },
    { title: '排序', dataIndex: 'roleSort', key: 'roleSort', width: 80 },
    {
      title: '状态',
      dataIndex: 'status',
      key: 'status',
      render: (status: RoleStatus) => {
        const info = roleStatusMap[status]
        return <Tag color={info?.color || 'default'}>{info?.label || status}</Tag>
      },
    },
    {
      title: '操作',
      key: 'action',
      render: (_, record) => (
        <Space>
          <PermissionGuard permission="system:role:edit">
            <Button type="link" icon={<EditOutlined />} onClick={() => handleEdit(record)} />
          </PermissionGuard>
          <PermissionGuard permission="system:role:delete">
            <Popconfirm title="确认删除？" onConfirm={() => handleDelete(record.id)}>
              <Button type="link" danger icon={<DeleteOutlined />} />
            </Popconfirm>
          </PermissionGuard>
        </Space>
      ),
    },
  ]

  return (
    <div style={{ padding: 24 }}>
      <div style={{ marginBottom: 16 }}>
        <Space>
          <PermissionGuard permission="system:role:add">
            <Button type="primary" icon={<PlusOutlined />} onClick={handleAdd}>新增角色</Button>
          </PermissionGuard>
          <Button icon={<ReloadOutlined />} onClick={loadRoles}>刷新</Button>
        </Space>
      </div>

      <Table<Role>
        rowKey="id"
        columns={columns}
        dataSource={roles}
        loading={loading}
        pagination={{
          ...pagination,
          showSizeChanger: true,
          showTotal: (total) => `共 ${total} 条`,
          onChange: (page, pageSize) => {
            setPagination((prev) => ({ ...prev, current: page, pageSize }))
            setTimeout(loadRoles, 0)
          },
        }}
      />

      <Modal
        title={editingRole ? '编辑角色' : '新增角色'}
        open={modalOpen}
        onOk={handleSubmit}
        onCancel={() => setModalOpen(false)}
        destroyOnHidden
        width={600}
      >
        <Form form={form} layout="vertical">
          <Form.Item name="roleName" label="角色名称" rules={VALIDATION.roleName.rules}>
            <Input />
          </Form.Item>
          <Form.Item name="roleKey" label="角色标识" rules={VALIDATION.roleKey.rules}>
            <Input />
          </Form.Item>
          <Form.Item name="roleSort" label="排序" initialValue={VALIDATION.roleSort.initialValue} rules={VALIDATION.roleSort.rules}>
            <InputNumber min={1} style={{ width: '100%' }} />
          </Form.Item>
          <Form.Item name="status" label="状态" initialValue={RoleStatus.ACTIVE}>
            <Select options={Object.entries(roleStatusMap).map(([value, info]) => ({ label: info.label, value }))} />
          </Form.Item>
          <Form.Item name="permissions" label="权限">
            <TreeSelect
              treeData={permissionTreeData}
              multiple
              treeCheckable
              showCheckedStrategy={TreeSelect.SHOW_CHILD}
              placeholder="请选择权限"
              style={{ width: '100%' }}
            />
          </Form.Item>
        </Form>
      </Modal>
    </div>
  )
}

function buildPermissionTree(permissions: Permission[]) {
  const grouped: Record<string, Permission[]> = {}
  for (const p of permissions) {
    const key = p.resource
    if (!grouped[key]) grouped[key] = []
    grouped[key].push(p)
  }

  return Object.entries(grouped).map(([resource, items]) => ({
    title: resource,
    value: `resource-${resource}`,
    key: `resource-${resource}`,
    children: items.map((item) => ({
      title: `${item.name} (${item.action})`,
      value: item.id,
      key: item.id,
    })),
  }))
}