package com.example.mathsystemtogether;

import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import java.util.*;
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Paths;

/**
 * 考试系统控制器
 */
public class ExamController {

    // 登录界面控件
    @FXML private TextField usernameField;
    @FXML private PasswordField passwordField;
    @FXML private Button loginButton;
    @FXML private Button registerButton;
    @FXML private Label loginStatusLabel;

    // 考试设置界面控件
    @FXML private VBox examSetupPanel;
    @FXML private Label welcomeLabel;
    @FXML private ComboBox<String> levelComboBox;
    @FXML private TextField questionCountField;
    @FXML private Button startExamButton;
    @FXML private Button logoutButton;
    @FXML private Label statusLabel;
    @FXML private Button changePasswordButton;

    // 数据成员
    private Account currentAccount;
    private List<Question> examQuestions;
    private ChoiceQuestionGenerator questionGenerator;
    private final Map<String, Account> userMap = new HashMap<>();
    private static final String USER_DATA_FILE = "user_data.txt";

    // 常量定义
    private static final int MIN_QUESTIONS = 5;
    private static final int MAX_QUESTIONS = 20;

    @FXML
    public void initialize() {
        initAccounts();
        loadUserDataFromFile();
        setupLevelComboBox();
        examSetupPanel.setVisible(false);
        questionCountField.setText("10");
    }

    private void initAccounts() {
        // 小学三个账号
        userMap.put("张三1", new Account("张三1", "123", Level.小学));
        userMap.put("张三2", new Account("张三2", "123", Level.小学));
        userMap.put("张三3", new Account("张三3", "123", Level.小学));
        // 初中三个账号
        userMap.put("李四1", new Account("李四1", "123", Level.初中));
        userMap.put("李四2", new Account("李四2", "123", Level.初中));
        userMap.put("李四3", new Account("李四3", "123", Level.初中));
        // 高中三个账号
        userMap.put("王五1", new Account("王五1", "123", Level.高中));
        userMap.put("王五2", new Account("王五2", "123", Level.高中));
        userMap.put("王五3", new Account("王五3", "123", Level.高中));
    }

    private void setupLevelComboBox() {
        ObservableList<String> levels = FXCollections.observableArrayList("小学", "初中", "高中");
        levelComboBox.setItems(levels);
        levelComboBox.setValue("小学");
    }

    private void loadUserDataFromFile() {
        try {
            if (!Files.exists(Paths.get(USER_DATA_FILE))) {
                return;
            }

            List<String> lines = Files.readAllLines(Paths.get(USER_DATA_FILE));
            for (String line : lines) {
                String[] parts = line.split("\\|");
                if (parts.length >= 4) {
                    String username = parts[0];
                    String password = parts[1];
                    String levelStr = parts[3];

                    Level level;
                    try {
                        level = Level.valueOf(levelStr);
                    } catch (IllegalArgumentException e) {
                        level = Level.小学; // 默认级别
                    }

                    userMap.put(username, new Account(username, password, level));
                }
            }
        } catch (IOException e) {
            // 加载用户数据失败，静默处理
        }
    }

    @FXML
    private void handleLogin() {
        String username = usernameField.getText().trim();
        String password = passwordField.getText();

        if (username.isEmpty() || password.isEmpty()) {
            loginStatusLabel.setText("请输入用户名和密码");
            loginStatusLabel.setStyle("-fx-text-fill: red;");
            return;
        }

        Account account = userMap.get(username);
        if (account != null && account.password.equals(password)) {
            currentAccount = account;
            welcomeLabel.setText("欢迎，" + username + "！当前级别：" + account.level);
            levelComboBox.setValue(account.level.toString());
            examSetupPanel.setVisible(true);
            loginStatusLabel.setText("登录成功！");
            loginStatusLabel.setStyle("-fx-text-fill: green;");
        } else {
            loginStatusLabel.setText("用户名或密码错误");
            loginStatusLabel.setStyle("-fx-text-fill: red;");
        }
    }

    @FXML
    private void handleRegister() {
        try {
            // 打开注册界面
            FXMLLoader loader = new FXMLLoader(getClass().getResource("register-view.fxml"));
            Scene scene = new Scene(loader.load(), 800, 800);
            Stage registerStage = new Stage();
            registerStage.setTitle("数学考试系统 - 用户注册");
            registerStage.setScene(scene);
            registerStage.setResizable(false);
            
            // 获取注册控制器并设置原始登录界面引用
            RegisterController registerController = loader.getController();
            Stage currentStage = (Stage) loginStatusLabel.getScene().getWindow();
            registerController.setOriginalLoginStage(currentStage);
            
            registerStage.show();

        } catch (Exception e) {
            loginStatusLabel.setText("打开注册界面失败：" + e.getMessage());
            loginStatusLabel.setStyle("-fx-text-fill: red;");
        }
    }

    @FXML
    private void handleLogout() {
        currentAccount = null;
        examQuestions = null;
        examSetupPanel.setVisible(false);
        usernameField.clear();
        passwordField.clear();
        loginStatusLabel.setText("");
        statusLabel.setText("");
    }

    @FXML
    private void handleStartExam() {
        if (currentAccount == null) {
            statusLabel.setText("请先登录");
            statusLabel.setStyle("-fx-text-fill: red;");
            return;
        }

        try {
            int count = Integer.parseInt(questionCountField.getText());
            if (count < MIN_QUESTIONS || count > MAX_QUESTIONS) {
                statusLabel.setText("题目数量应在" + MIN_QUESTIONS + "-" + MAX_QUESTIONS + "之间");
                statusLabel.setStyle("-fx-text-fill: red;");
                return;
            }

            // 获取选择的级别
            String selectedLevel = levelComboBox.getValue();
            ChoiceQuestionGenerator.Level level = ChoiceQuestionGenerator.Level.valueOf(selectedLevel);

            // 生成考试题目
            questionGenerator = new ChoiceQuestionGenerator();
            examQuestions = questionGenerator.generateQuestions(level, count);

            if (examQuestions.isEmpty()) {
                statusLabel.setText("无法生成题目，请重试");
                statusLabel.setStyle("-fx-text-fill: red;");
                return;
            }

            // 开始考试
            startExam();

        } catch (NumberFormatException e) {
            statusLabel.setText("请输入有效的数字");
            statusLabel.setStyle("-fx-text-fill: red;");
        }
    }

@FXML
private void handleChangePassword() {
    if (currentAccount == null) {
        statusLabel.setText("请先登录");
        statusLabel.setStyle("-fx-text-fill: red;");
        return;
    }

    try {
        FXMLLoader loader = new FXMLLoader(getClass().getResource("change-password-view.fxml"));
        Scene scene = new Scene(loader.load(), 600, 500);
        Stage changePasswordStage = new Stage();
        changePasswordStage.setTitle("修改密码");
        changePasswordStage.setScene(scene);
        changePasswordStage.setResizable(false);

        // 传递当前用户信息给密码修改控制器
        ChangePasswordController controller = loader.getController();
        controller.setCurrentUser(currentAccount.username);
        controller.setExamController(this);

        changePasswordStage.show();
    } catch (Exception e) {
        statusLabel.setText("打开修改密码界面失败：" + e.getMessage());
        statusLabel.setStyle("-fx-text-fill: red;");
    }
}

// 供 ChangePasswordController 调用的方法
public boolean checkUserPassword(String username, String password) {
    Account account = userMap.get(username);
    return account != null && account.password.equals(password);
}

    // 更新用户密码
    public void updateUserPassword(String username, String newPassword) {
        Account account = userMap.get(username);
        if (account != null) {
            account.password = newPassword;
        }
    }

    // 为继续做题设置用户信息
    public void setUserForContinueExam(String username, String level) {
        // 设置当前用户
        Account account = userMap.get(username);
        if (account != null) {
            currentAccount = account;
            welcomeLabel.setText("欢迎，" + username + "！当前级别：" + account.level);
            levelComboBox.setValue(account.level.toString());
            examSetupPanel.setVisible(true);
            loginStatusLabel.setText("继续做题模式");
            loginStatusLabel.setStyle("-fx-text-fill: green;");
        }
    }

    private void startExam() {
        try {
            // 打开专门的考试界面
            FXMLLoader loader = new FXMLLoader(getClass().getResource("exam-taking-view.fxml"));
            Scene scene = new Scene(loader.load(), 1000, 950);
            Stage examStage = new Stage();
            examStage.setTitle("数学考试 - " + currentAccount.username);
            examStage.setScene(scene);
            examStage.setResizable(false);

            // 设置考试数据
            ExamTakingController examController = loader.getController();
            examController.setExamData(examQuestions, currentAccount.username, levelComboBox.getValue());

            // 显示考试窗口
            examStage.show();

            // 隐藏主窗口
            Stage mainStage = (Stage) startExamButton.getScene().getWindow();
            mainStage.hide();

        } catch (Exception e) {
            statusLabel.setText("启动考试失败：" + e.getMessage());
            statusLabel.setStyle("-fx-text-fill: red;");
        }
    }

    // 内部类
    static class Account {
        final String username;
        String password;
        final Level level;

        Account(String username, String password, Level level) {
            this.username = username;
            this.password = password;
            this.level = level;
        }
    }

    enum Level {
        小学, 初中, 高中
    }
}