'use client'
import { useState, useEffect } from 'react'
import { Card, Button, Table, Badge, Modal, Input, Select } from '@/components/ui'
import { Plus, Pencil, Trash2 } from 'lucide-react'

interface User {
  id: number
  username: string
  display_name: string
  email: string | null
  role: string
  is_active: number
  created_at: string
}

export default function UsersPage() {
  const [users, setUsers] = useState<User[]>([])
  const [loading, setLoading] = useState(true)
  const [modalOpen, setModalOpen] = useState(false)
  const [editUser, setEditUser] = useState<User | null>(null)
  const [form, setForm] = useState({ username: '', password: '', display_name: '', email: '', role: 'viewer' })
  const [error, setError] = useState('')

  const fetchUsers = () => {
    fetch('/api/users').then(r => r.json()).then(d => { if (d.users) setUsers(d.users) }).catch(() => {}).finally(() => setLoading(false))
  }

  useEffect(() => { fetchUsers() }, [])

  const openCreate = () => {
    setEditUser(null)
    setForm({ username: '', password: '', display_name: '', email: '', role: 'viewer' })
    setError('')
    setModalOpen(true)
  }

  const openEdit = (u: User) => {
    setEditUser(u)
    setForm({ username: u.username, password: '', display_name: u.display_name, email: u.email || '', role: u.role })
    setError('')
    setModalOpen(true)
  }

  const handleSave = async () => {
    setError('')
    try {
      if (editUser) {
        const body: Record<string, unknown> = { display_name: form.display_name, email: form.email, role: form.role }
        if (form.password) body.password = form.password
        const res = await fetch(`/api/users/${editUser.id}`, { method: 'PUT', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(body) })
        if (!res.ok) { const d = await res.json(); setError(d.error || '更新失败'); return }
      } else {
        if (!form.username || !form.password || !form.display_name) { setError('请填写必填项'); return }
        const res = await fetch('/api/users', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(form) })
        if (!res.ok) { const d = await res.json(); setError(d.error || '创建失败'); return }
      }
      setModalOpen(false)
      fetchUsers()
    } catch { setError('操作失败') }
  }

  const handleDelete = async (id: number) => {
    if (!confirm('确定删除此用户？')) return
    const res = await fetch(`/api/users/${id}`, { method: 'DELETE' })
    if (res.ok) fetchUsers()
  }

  const handleToggleActive = async (u: User) => {
    await fetch(`/api/users/${u.id}`, { method: 'PUT', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ is_active: u.is_active ? 0 : 1 }) })
    fetchUsers()
  }

  const roleLabel: Record<string, string> = { admin: '管理员', operator: '运维人员', viewer: '查看者' }

  return (
    <div className="space-y-4">
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-2xl font-bold text-slate-900 dark:text-slate-100">用户管理</h1>
          <p className="text-slate-500 dark:text-slate-400 mt-1">系统用户与账号管理</p>
        </div>
        <Button size="sm" onClick={openCreate}><Plus size={16} className="mr-1" />新建用户</Button>
      </div>

      {loading ? (
        <div className="text-center py-12 text-slate-500 dark:text-slate-400">加载中...</div>
      ) : (
        <Table headers={['用户名', '显示名称', '邮箱', '角色', '状态', '创建时间', '操作']}>
          {users.map(u => (
            <tr key={u.id} className="hover:bg-slate-50 dark:hover:bg-slate-800/50 transition-colors">
              <td className="px-4 py-3 font-medium text-slate-900 dark:text-slate-100">{u.username}</td>
              <td className="px-4 py-3 text-slate-700 dark:text-slate-300">{u.display_name}</td>
              <td className="px-4 py-3 text-slate-500 dark:text-slate-400">{u.email || '-'}</td>
              <td className="px-4 py-3"><Badge variant="info">{roleLabel[u.role] || u.role}</Badge></td>
              <td className="px-4 py-3">
                <button onClick={() => handleToggleActive(u)}>
                  <Badge variant={u.is_active ? 'success' : 'danger'}>{u.is_active ? '启用' : '禁用'}</Badge>
                </button>
              </td>
              <td className="px-4 py-3 text-sm text-slate-500 dark:text-slate-400">{u.created_at || '-'}</td>
              <td className="px-4 py-3">
                <div className="flex items-center gap-1">
                  <Button variant="ghost" size="sm" onClick={() => openEdit(u)}><Pencil size={14} /></Button>
                  <Button variant="ghost" size="sm" onClick={() => handleDelete(u.id)}><Trash2 size={14} className="text-red-500" /></Button>
                </div>
              </td>
            </tr>
          ))}
        </Table>
      )}

      <Modal open={modalOpen} onClose={() => setModalOpen(false)} title={editUser ? '编辑用户' : '新建用户'}>
        <div className="space-y-4">
          {!editUser && <Input label="用户名" value={form.username} onChange={e => setForm(p => ({ ...p, username: e.target.value }))} required />}
          <Input label="显示名称" value={form.display_name} onChange={e => setForm(p => ({ ...p, display_name: e.target.value }))} required />
          <Input label={editUser ? '新密码（留空不修改）' : '密码'} type="password" value={form.password} onChange={e => setForm(p => ({ ...p, password: e.target.value }))} />
          <Input label="邮箱" type="email" value={form.email} onChange={e => setForm(p => ({ ...p, email: e.target.value }))} />
          <Select label="角色" options={[{ value: 'viewer', label: '查看者' }, { value: 'operator', label: '运维人员' }, { value: 'admin', label: '管理员' }]} value={form.role} onChange={e => setForm(p => ({ ...p, role: e.target.value }))} />
          {error && <p className="text-sm text-red-500">{error}</p>}
          <div className="flex gap-3">
            <Button onClick={handleSave}>{editUser ? '保存' : '创建'}</Button>
            <Button variant="secondary" onClick={() => setModalOpen(false)}>取消</Button>
          </div>
        </div>
      </Modal>
    </div>
  )
}