package com.student.controller;

import com.student.model.Student;
import com.student.model.StudentRepository;
import com.student.view.StudentView;

import java.util.List;

/**
 * 学生控制器类，负责处理业务逻辑，连接模型和视图
 * 实现MVC架构中的控制器角色
 */
public class StudentController {
    private final StudentRepository repository;
    private final StudentView view;

    /**
     * 构造函数
     * @param repository 学生数据仓库
     * @param view 学生视图
     */
    public StudentController(StudentRepository repository, StudentView view) {
        this.repository = repository;
        this.view = view;
    }

    /**
     * 启动控制器，处理用户交互
     */
    public void start() {
        boolean running = true;
        while (running) {
            view.displayMenu();
            int choice = view.getMenuChoice();

            switch (choice) {
                case 1:
                    addStudent();
                    break;
                case 2:
                    displayAllStudents();
                    break;
                case 3:
                    findStudent();
                    break;
                case 4:
                    updateStudent();
                    break;
                case 5:
                    deleteStudent();
                    break;
                case 0:
                    running = false;
                    view.displayMessage("感谢使用学生管理系统，再见！");
                    break;
                default:
                    view.displayMessage("无效的选择，请重新输入");
            }
        }
    }

    /**
     * 添加学生
     */
    private void addStudent() {
        Student student = view.getStudentInput();
        // 检查学生ID是否已存在
        if (repository.getStudentById(student.getId()) != null) {
            view.displayMessage("该学生ID已存在，添加失败");
            return;
        }
        repository.addStudent(student);
        view.displayMessage("学生添加成功");
    }

    /**
     * 显示所有学生
     */
    private void displayAllStudents() {
        List<Student> students = repository.getAllStudents();
        view.displayAllStudents(students);
    }

    /**
     * 查找学生
     */
    private void findStudent() {
        String id = view.getStudentIdInput();
        Student student = repository.getStudentById(id);
        view.displayStudent(student);
    }

    /**
     * 更新学生信息
     */
    private void updateStudent() {
        String id = view.getStudentIdInput();
        Student existingStudent = repository.getStudentById(id);
        
        if (existingStudent == null) {
            view.displayMessage("未找到该学生，更新失败");
            return;
        }

        // 显示当前学生信息
        view.displayStudent(existingStudent);
        view.displayMessage("请输入更新后的学生信息：");
        
        // 获取更新后的信息
        Student updatedStudent = view.getStudentInput();
        // 确保ID保持一致
        updatedStudent.setId(id);
        
        if (repository.updateStudent(updatedStudent)) {
            view.displayMessage("学生信息更新成功");
        } else {
            view.displayMessage("学生信息更新失败");
        }
    }

    /**
     * 删除学生
     */
    private void deleteStudent() {
        String id = view.getStudentIdInput();
        
        if (repository.getStudentById(id) == null) {
            view.displayMessage("未找到该学生，删除失败");
            return;
        }
        
        if (repository.deleteStudent(id)) {
            view.displayMessage("学生删除成功");
        } else {
            view.displayMessage("学生删除失败");
        }
    }
}