package com.studentmanagement.model;

import java.util.HashMap;
import java.util.Map;

/**
 * 学生实体类
 * 表示系统中的学生对象，包含基本信息和课程成绩
 */
public class Student {
    private String id;          // 学生ID
    private String name;        // 学生姓名
    private int age;            // 学生年龄
    private String gender;      // 学生性别
    private Map<String, Double> courseGrades; // 课程成绩映射

    /**
     * 构造函数
     * @param id 学生ID
     * @param name 学生姓名
     * @param age 学生年龄
     * @param gender 学生性别
     */
    public Student(String id, String name, int age, String gender) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.courseGrades = new HashMap<>();
    }

    // Getters and Setters
    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public Map<String, Double> getCourseGrades() {
        return courseGrades;
    }

    public void setCourseGrades(Map<String, Double> courseGrades) {
        this.courseGrades = courseGrades;
    }

    /**
     * 添加课程成绩
     * @param course 课程名称
     * @param grade 成绩
     */
    public void addCourseGrade(String course, double grade) {
        courseGrades.put(course, grade);
    }

    /**
     * 获取特定课程的成绩
     * @param course 课程名称
     * @return 成绩，如果课程不存在返回null
     */
    public Double getCourseGrade(String course) {
        return courseGrades.get(course);
    }

    /**
     * 计算平均成绩
     * @return 平均成绩，如果没有课程成绩返回0
     */
    public double calculateAverageGrade() {
        if (courseGrades.isEmpty()) {
            return 0.0;
        }
        double sum = 0.0;
        for (double grade : courseGrades.values()) {
            sum += grade;
        }
        return sum / courseGrades.size();
    }

    @Override
    public String toString() {
        return "Student{" +
                "id='" + id + "'" +
                ", name='" + name + "'" +
                ", age=" + age +
                ", gender='" + gender + "'" +
                ", averageGrade=" + String.format("%.2f", calculateAverageGrade()) +
                "}";
    }
}