using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;

namespace SocketExample
{
    /// <summary>
    /// LoginWindow.xaml 的交互逻辑
    /// </summary>
    public partial class LoginWindow : Window
    {
        // 定义事件
        public event Action LoginSuccess;
        public event Action LoginFailed;

        // 最大尝试次数
        private const int MAX_ATTEMPTS = 2;

        // 当前尝试次数
        private int _attemptCount = 0;

        // 正确的用户名和密码（实际应用中应从数据库或配置中读取）
        private const string CORRECT_USERNAME = "haiweiadmin";
        private const string CORRECT_PASSWORD = "haiweinb123";

        public LoginWindow()
        {
            InitializeComponent();
            UpdateAttemptsDisplay();

            // 设置焦点到用户名输入框
            txtUsername.Focus();

            // 绑定回车键事件
            txtPassword.KeyDown += OnPasswordKeyDown;
        }

        private void OnPasswordKeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Enter)
            {
                AttemptLogin();
            }
        }

        private void btnLogin_Click(object sender, RoutedEventArgs e)
        {
            AttemptLogin();
        }

        private void btnCancel_Click(object sender, RoutedEventArgs e)
        {
            // 取消登录，关闭程序
            LoginFailed?.Invoke();
            this.Close();
        }

        private void AttemptLogin()
        {
            string username = txtUsername.Text.Trim();
            string password = txtPassword.Password;

            // 验证输入
            if (string.IsNullOrWhiteSpace(username) || string.IsNullOrWhiteSpace(password))
            {
                ShowError("用户名和密码不能为空！");
                return;
            }

            // 验证用户名和密码
            if (username == CORRECT_USERNAME && password == CORRECT_PASSWORD)
            {
                // 登录成功
                LoginSuccess?.Invoke();
                this.Close();
            }
            else
            {
                // 登录失败
                _attemptCount++;
                UpdateAttemptsDisplay();

                if (_attemptCount >= MAX_ATTEMPTS)
                {
                    // 超过最大尝试次数
                    MessageBox.Show($"登录失败超过{MAX_ATTEMPTS}次，程序即将关闭！",
                                  "登录失败",
                                  MessageBoxButton.OK,
                                  MessageBoxImage.Error);

                    LoginFailed?.Invoke();
                    this.Close();
                }
                else
                {
                    ShowError($"用户名或密码错误！剩余尝试次数：{MAX_ATTEMPTS - _attemptCount}");
                    txtPassword.Password = "";
                    txtPassword.Focus();
                }
            }
        }

        private void ShowError(string message)
        {
            lblError.Text = message;
            lblError.Visibility = Visibility.Visible;
        }

        private void UpdateAttemptsDisplay()
        {
            int remainingAttempts = MAX_ATTEMPTS - _attemptCount;
            lblAttempts.Text = remainingAttempts > 0
                ? $"剩余尝试次数：{remainingAttempts}"
                : "已超过最大尝试次数";
        }

        protected override void OnClosed(EventArgs e)
        {
            base.OnClosed(e);

            // 清理事件绑定
            txtPassword.KeyDown -= OnPasswordKeyDown;
        }
    }
}