import React, { useState, useEffect } from 'react';
import { X, User, Trash2, Shield, ShieldAlert, Lock, Unlock, Loader2, UserPlus } from 'lucide-react';

interface UserManagementModalProps {
  isOpen: boolean;
  onClose: () => void;
}

export const UserManagementModal: React.FC<UserManagementModalProps> = ({ isOpen, onClose }) => {
  const [users, setUsers] = useState<any[]>([]);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState('');

  const fetchUsers = async () => {
    setLoading(true);
    try {
      const API_BASE = `http://${window.location.hostname}:3001`;
      const response = await fetch(`${API_BASE}/api/v1/users`, {
        headers: { 'Authorization': `Bearer ${localStorage.getItem('token')}` }
      });
      if (!response.ok) throw new Error('Không thể tải danh sách người dùng');
      const data = await response.json();
      setUsers(data);
    } catch (err: any) {
      setError(err.message);
    } finally {
      setLoading(false);
    }
  };

  useEffect(() => {
    if (isOpen) fetchUsers();
  }, [isOpen]);

  const handleToggleBlock = async (id: string) => {
    try {
      const API_BASE = `http://${window.location.hostname}:3001`;
      await fetch(`${API_BASE}/api/v1/users/block/${id}`, {
        method: 'POST',
        headers: { 'Authorization': `Bearer ${localStorage.getItem('token')}` }
      });
      fetchUsers();
    } catch (err) {
      alert('Lỗi khi thay đổi trạng thái block');
    }
  };

  const handleDelete = async (id: string) => {
    if (!confirm('Bạn có chắc chắn muốn xóa người dùng này?')) return;
    try {
      const API_BASE = `http://${window.location.hostname}:3001`;
      const res = await fetch(`${API_BASE}/api/v1/users/${id}`, {
        method: 'DELETE',
        headers: { 'Authorization': `Bearer ${localStorage.getItem('token')}` }
      });
      if (!res.ok) {
        const data = await res.json();
        throw new Error(data.message);
      }
      fetchUsers();
    } catch (err: any) {
      alert(err.message);
    }
  };

  if (!isOpen) return null;

  return (
    <div className="fixed inset-0 z-[2000] flex items-center justify-center p-4">
      <div className="absolute inset-0 bg-gray-900/60 backdrop-blur-sm" onClick={onClose} />
      <div className="relative w-full max-w-4xl bg-white rounded-3xl shadow-2xl overflow-hidden flex flex-col max-h-[90vh]">
        <div className="p-6 border-b border-gray-100 flex justify-between items-center bg-gray-50/50">
          <div>
            <h2 className="text-2xl font-bold text-gray-900 flex items-center gap-2">
              <Shield className="w-6 h-6 text-blue-600" /> Quản lý người dùng
            </h2>
            <p className="text-sm text-gray-500">Quản trị viên có quyền thêm, sửa, xóa hoặc khóa tài khoản.</p>
          </div>
          <button onClick={onClose} className="p-2 hover:bg-gray-200 rounded-full transition-colors">
            <X className="w-6 h-6 text-gray-400" />
          </button>
        </div>

        <div className="flex-1 overflow-y-auto p-6">
          {loading ? (
            <div className="flex justify-center py-20"><Loader2 className="w-10 h-10 animate-spin text-blue-600" /></div>
          ) : error ? (
            <div className="p-4 bg-red-50 text-red-600 rounded-xl font-bold">{error}</div>
          ) : (
            <table className="w-full text-left border-collapse">
              <thead>
                <tr className="text-gray-400 text-xs uppercase tracking-wider border-b border-gray-100">
                  <th className="pb-4 font-bold px-2">Người dùng</th>
                  <th className="pb-4 font-bold">Vai trò</th>
                  <th className="pb-4 font-bold">Trạng thái</th>
                  <th className="pb-4 font-bold text-right">Thao tác</th>
                </tr>
              </thead>
              <tbody className="divide-y divide-gray-50">
                {users.map(u => (
                  <tr key={u.id} className="group hover:bg-gray-50/50 transition-colors">
                    <td className="py-4 px-2">
                      <div className="flex items-center gap-3">
                        <div className="w-10 h-10 rounded-full bg-blue-100 flex items-center justify-center text-blue-600 font-bold">
                          {u.name?.charAt(0) || <User className="w-5 h-5" />}
                        </div>
                        <div>
                          <div className="font-bold text-gray-900">{u.name || 'N/A'}</div>
                          <div className="text-xs text-gray-400">{u.email}</div>
                        </div>
                      </div>
                    </td>
                    <td className="py-4">
                      {u.isAdmin ? (
                        <span className="px-2 py-1 bg-purple-50 text-purple-600 text-[10px] font-black rounded-md border border-purple-100">ADMIN</span>
                      ) : (
                        <span className="px-2 py-1 bg-gray-50 text-gray-500 text-[10px] font-black rounded-md border border-gray-100">USER</span>
                      )}
                    </td>
                    <td className="py-4">
                      {u.isBlocked ? (
                        <span className="flex items-center gap-1 text-red-500 text-xs font-bold"><ShieldAlert className="w-3 h-3" /> Đã khóa</span>
                      ) : (
                        <span className="text-green-500 text-xs font-bold">Đang hoạt động</span>
                      )}
                    </td>
                    <td className="py-4 text-right">
                      <div className="flex justify-end gap-2">
                        <button 
                          onClick={() => handleToggleBlock(u.id)}
                          className={`p-2 rounded-xl transition-all ${u.isBlocked ? 'bg-green-50 text-green-600 hover:bg-green-100' : 'bg-amber-50 text-amber-600 hover:bg-amber-100'}`}
                          title={u.isBlocked ? 'Mở khóa' : 'Khóa tài khoản'}
                        >
                          {u.isBlocked ? <Unlock className="w-4 h-4" /> : <Lock className="w-4 h-4" />}
                        </button>
                        <button 
                          onClick={() => handleDelete(u.id)}
                          className="p-2 bg-red-50 text-red-600 rounded-xl hover:bg-red-100 transition-all"
                          title="Xóa người dùng"
                        >
                          <Trash2 className="w-4 h-4" />
                        </button>
                      </div>
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          )}
        </div>
      </div>
    </div>
  );
};