pairedProject/src/main/java/com/wsf/mathapp/view/QuestionCountView.java

package com.wsf.mathapp.view;

import com.wsf.mathapp.controller.SceneManager;
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.TextField;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;

/**
 * 题目数量选择视图类，提供用户选择答题数量的界面.
 * 允许用户输入10-30之间的题目数量，并开始答题.
 */
public class QuestionCountView {
  private Scene scene;
  private final SceneManager sceneManager;
  private String level;

  /**
   * 构造函数，初始化题目数量选择视图.
   *
   * @param sceneManager 场景管理器，用于界面导航.
   */
  public QuestionCountView(SceneManager sceneManager) {
    this.sceneManager = sceneManager;
    createScene();
  }

  /**
   * 创建主场景，包含题目数量选择界面.
   */
  private void createScene() {
    VBox root = new VBox(20);
    root.setPadding(new Insets(40));
    root.setAlignment(Pos.CENTER);

    // 创建标题标签
    Label titleLabel = createTitleLabel();

    // 创建级别显示标签
    Label levelLabel = createLevelLabel();

    // 创建数量输入框
    TextField countField = createCountField();

    // 创建开始答题按钮
    Button startButton = createStartButton();

    // 创建返回按钮
    Button backButton = createBackButton();

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

    // 设置按钮事件
    setupStartButtonAction(startButton, countField, statusLabel);
    setupBackButtonAction(backButton);

    root.getChildren().addAll(
        titleLabel, levelLabel, countField, startButton, backButton, statusLabel
    );

    scene = new Scene(root, 400, 400);
  }

  /**
   * 创建标题标签.
   *
   * @return Label 标题标签对象.
   */
  private Label createTitleLabel() {
    Label titleLabel = new Label("选择题目数量");
    titleLabel.setFont(Font.font(20));
    return titleLabel;
  }

  /**
   * 创建级别显示标签.
   *
   * @return Label 级别显示标签对象.
   */
  private Label createLevelLabel() {
    Label levelLabel = new Label();
    levelLabel.setFont(Font.font(16));
    return levelLabel;
  }

  /**
   * 创建数量输入框.
   *
   * @return TextField 数量输入框对象.
   */
  private TextField createCountField() {
    TextField countField = new TextField();
    countField.setPromptText("请输入题目数量 (10-30)");
    countField.setMaxWidth(250);
    countField.setPrefHeight(40);
    return countField;
  }

  /**
   * 创建开始答题按钮.
   *
   * @return Button 开始答题按钮对象.
   */
  private Button createStartButton() {
    Button startButton = new Button("开始答题");
    startButton.setStyle("-fx-background-color: #4CAF50; -fx-text-fill: white; "
        + "-fx-font-size: 14px;");
    startButton.setPrefSize(250, 45);
    return startButton;
  }

  /**
   * 创建返回按钮.
   *
   * @return Button 返回按钮对象.
   */
  private Button createBackButton() {
    Button backButton = new Button("返回");
    backButton.setStyle("-fx-background-color: #757575; -fx-text-fill: white;");
    backButton.setPrefSize(250, 40);
    return backButton;
  }

  /**
   * 设置开始答题按钮的点击事件.
   *
   * @param startButton 开始答题按钮.
   * @param countField 数量输入框.
   * @param statusLabel 状态标签.
   */
  private void setupStartButtonAction(Button startButton, TextField countField,
      Label statusLabel) {
    startButton.setOnAction(e -> handleStartQuiz(countField, statusLabel));
  }

  /**
   * 设置返回按钮的点击事件.
   *
   * @param backButton 返回按钮.
   */
  private void setupBackButtonAction(Button backButton) {
    backButton.setOnAction(e -> sceneManager.showLevelSelectionView());
  }

  /**
   * 处理开始答题逻辑.
   *
   * @param countField 数量输入框.
   * @param statusLabel 状态标签.
   */
  private void handleStartQuiz(TextField countField, Label statusLabel) {
    try {
      String countText = countField.getText().trim();
      if (countText.isEmpty()) {
        showError(statusLabel, "请输入题目数量！");
        return;
      }

      int count = Integer.parseInt(countText);
      if (count < 10 || count > 30) {
        showError(statusLabel, "题目数量必须在10-30之间！");
        return;
      }

      // 直接调用 showQuizView 并传递参数
      sceneManager.showQuizView(level, count);

    } catch (NumberFormatException ex) {
      showError(statusLabel, "请输入有效的数字！");
    }
  }

  /**
   * 设置当前选择的题目级别.
   *
   * @param level 题目难度级别.
   */
  public void setLevel(String level) {
    this.level = level;
    updateLevelDisplay();
  }

  /**
   * 更新界面显示当前选择的级别.
   */
  private void updateLevelDisplay() {
    if (scene != null) {
      VBox root = (VBox) scene.getRoot();
      Label levelLabel = (Label) root.getChildren().get(1);
      levelLabel.setText("当前级别: " + level);
      levelLabel.setStyle("-fx-text-fill: #2196F3;");
    }
  }

  /**
   * 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;");
  }

  /**
   * 获取当前场景.
   *
   * @return Scene 题目数量选择界面的场景对象.
   */
  public Scene getScene() {
    return scene;
  }
}