package com.wsf.mathapp.view;

import com.wsf.mathapp.controller.SceneManager;
import com.ybw.mathapp.util.Login;
import com.ybw.mathapp.util.LoginFileUtils;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.PasswordField;
import javafx.scene.control.TextField;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;

/**
 * 登录视图类，提供用户登录功能界面.
 * 支持用户名或邮箱登录，包含输入验证和登录状态提示.
 */
public class LoginView {
  private Scene scene;
  private final SceneManager sceneManager;

  // 将UI组件声明为类的成员变量
  private TextField usernameOrEmailField;
  private PasswordField passwordField;
  private Label statusLabel;

  /**
   * 构造函数，初始化登录视图.
   *
   * @param sceneManager 场景管理器，用于界面导航.
   */
  public LoginView(SceneManager sceneManager) {
    this.sceneManager = sceneManager;
    createScene();
  }

  /**
   * 创建登录界面的主场景.
   */
  private void createScene() {
    VBox root = new VBox(20);
    root.setPadding(new Insets(40));
    root.setAlignment(Pos.CENTER);

    // 创建用户名/邮箱输入框
    usernameOrEmailField = createUsernameField();

    // 创建密码输入框
    passwordField = createPasswordField();

    // 创建登录按钮
    Button loginButton = createLoginButton();

    // 创建注册按钮
    Button registerButton = createRegisterButton();

    // 创建状态标签
    statusLabel = new Label();

    // 设置按钮事件
    setupLoginButtonAction(loginButton);
    setupRegisterButtonAction(registerButton);

    // 添加回车键登录支持
    setupEnterKeySupport(loginButton);
    // 创建界面标题
    Label titleLabel = createTitleLabel();

    // 创建副标题
    Label subtitleLabel = createSubtitleLabel();
    root.getChildren().addAll(
        titleLabel, subtitleLabel, usernameOrEmailField, passwordField,
        loginButton, registerButton, statusLabel
    );
    scene = new Scene(root, 400, 500);
  }

  /**
   * 创建主标题标签.
   *
   * @return Label 主标题标签对象.
   */
  private Label createTitleLabel() {
    Label titleLabel = new Label("数学学习软件");
    titleLabel.setFont(Font.font(24));
    return titleLabel;
  }

  /**
   * 创建副标题标签.
   *
   * @return Label 副标题标签对象.
   */
  private Label createSubtitleLabel() {
    Label subtitleLabel = new Label("用户登录");
    subtitleLabel.setFont(Font.font(18));
    return subtitleLabel;
  }

  /**
   * 创建用户名/邮箱输入框.
   *
   * @return TextField 用户名/邮箱输入框对象.
   */
  private TextField createUsernameField() {
    TextField field = new TextField();
    field.setPromptText("请输入用户名或邮箱");
    field.setMaxWidth(300);
    field.setPrefHeight(40);
    return field;
  }

  /**
   * 创建密码输入框.
   *
   * @return PasswordField 密码输入框对象.
   */
  private PasswordField createPasswordField() {
    PasswordField field = new PasswordField();
    field.setPromptText("请输入密码");
    field.setMaxWidth(300);
    field.setPrefHeight(40);
    return field;
  }

  /**
   * 创建登录按钮.
   *
   * @return Button 登录按钮对象.
   */
  private Button createLoginButton() {
    Button button = new Button("登录");
    button.setStyle("-fx-background-color: #4CAF50; -fx-text-fill: white; -fx-font-size: 14px;");
    button.setPrefSize(300, 40);
    return button;
  }

  /**
   * 创建注册按钮.
   *
   * @return Button 注册按钮对象.
   */
  private Button createRegisterButton() {
    Button button = new Button("注册账号");
    button.setStyle("-fx-background-color: #2196F3; -fx-text-fill: white; -fx-font-size: 14px;");
    button.setPrefSize(300, 40);
    return button;
  }

  /**
   * 设置登录按钮的点击事件.
   *
   * @param loginButton 登录按钮对象.
   */
  private void setupLoginButtonAction(Button loginButton) {
    loginButton.setOnAction(e -> handleLogin());
  }

  /**
   * 设置注册按钮的点击事件.
   *
   * @param registerButton 注册按钮对象.
   */
  private void setupRegisterButtonAction(Button registerButton) {
    registerButton.setOnAction(e -> sceneManager.showRegisterView());
  }

  /**
   * 设置回车键登录支持.
   *
   * @param loginButton 登录按钮对象.
   */
  private void setupEnterKeySupport(Button loginButton) {
    usernameOrEmailField.setOnAction(e -> loginButton.fire());
    passwordField.setOnAction(e -> loginButton.fire());
  }

  /**
   * 处理登录逻辑.
   */
  private void handleLogin() {
    String usernameOrEmail = usernameOrEmailField.getText().trim();
    String password = passwordField.getText();

    if (usernameOrEmail.isEmpty() || password.isEmpty()) {
      showError(statusLabel, "用户名/邮箱和密码不能为空！");
      return;
    }

    // 调用后端的登录方法，支持用户名或邮箱登录
    boolean success = Login.login(usernameOrEmail, password);
    System.out.println(usernameOrEmail);
    System.out.println(password);

    if (success) {
      handleLoginSuccess(usernameOrEmail);
    } else {
      showError(statusLabel, "用户名/邮箱或密码错误！");
    }
  }

  /**
   * 处理登录成功后的逻辑.
   *
   * @param usernameOrEmail 登录使用的用户名或邮箱.
   */
  private void handleLoginSuccess(String usernameOrEmail) {
    showSuccess(statusLabel);
    String username = getUsernameFromInput(usernameOrEmail);
    sceneManager.setCurrentUserName(username);
    sceneManager.showMainMenuView();
  }

  /**
   * 根据输入获取用户名.
   *
   * @param usernameOrEmail 用户输入的用户名或邮箱.
   * @return String 对应的用户名.
   */
  private String getUsernameFromInput(String usernameOrEmail) {
    String foundName = LoginFileUtils.emailFindName(usernameOrEmail);
    return foundName == null ? usernameOrEmail : foundName;
  }

  /**
   * 清空所有输入字段和状态信息.
   */
  public void clearFields() {
    usernameOrEmailField.clear();
    passwordField.clear();
    statusLabel.setText("");
  }

  /**
   * 显示错误信息.
   *
   * @param label 状态标签对象.
   * @param message 错误信息内容.
   */
  private void showError(Label label, String message) {
    label.setText(message);
    label.setStyle("-fx-text-fill: red;");
  }

  /**
   * 显示成功信息.
   *
   * @param label 状态标签对象.
   */
  private void showSuccess(Label label) {
    label.setText("登录成功！");
    label.setStyle("-fx-text-fill: green;");
  }

  /**
   * 获取当前场景.
   *
   * @return Scene 登录界面的场景对象.
   */
  public Scene getScene() {
    return scene;
  }
}