package edu.course_text;

import java.util.Scanner;

public class System_stu {
    private static final int MaxNum=100;
    private static Score[] scoreStudent=new Score[MaxNum];
    private static int numStudent=0;

    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        System.out.println("*************************");
        System.out.println("***欢迎使用学生成绩管理系统***");
        System.out.println("*************************");
        ABC: while(true){
            System.out.println("以下是菜单栏");
            System.out.println("1-查看、2-添加");
            System.out.println("3-修改、4-删除");
            System.out.println("5-统计、6-查找");
            System.out.println("7-排序、0-退出");
            System.out.println("请输入你的选项:");
            String choose=sc.next();
            switch (choose){
                case "1" : displayScore();break;
                case "2" : AddScore(sc);break;
                case "3" : updateScore(sc);break;
                case "4" : deleteScore(sc);break;
                case "5" : sumScore(sc);break;
                case "6" : searchScore(sc);break;
                case "7" : sortScore(sc);break;
                case "0" : System.out.println("退出成功！");break ABC;
                default  :System.out.println("没有此选项");
            }
        }
    }
    private static void displayScore(){//查询
        if(numStudent==0){
            System.out.println("尚未添加学生，请返回菜单首页添加");
            return;
        }
        System.out.println("下面为您展示学生成绩单");
        System.out.println("序号\t\t学生姓名\t学生学号\t课程名称\t课程成绩");
        for(int i=0;i<numStudent;i++){
            Score s=scoreStudent[i];
            System.out.print(s.id);
            System.out.print(s.stuName);
            System.out.print(s.stu_id);
            System.out.print(s.scoreName);
            System.out.print(s.score);
            System.out.println();
        }
    }
    private static void AddScore(Scanner scanner){//增加
        System.out.println("请输入添加的人数");
        int temp=scanner.nextInt();
        int j=numStudent;
        for(int i=j;i<j+temp;i++){
            //先创建具体数组的对象
            scoreStudent[i]=new Score();
            while(true){
                System.out.println("输入学号");
                String stu_id=scanner.next();
                boolean flag=contains(stu_id);
                if(flag){
                    System.out.println("学号重复，请重新输入");
                    //bug多组输入出问题,bug解决原因是循环内num没有改变
                }
                else{
                    scoreStudent[i].stu_id=stu_id;
                    break;
                }
            }
            System.out.println("请输入该学生的序号");
            int id=scanner.nextInt();
            scoreStudent[i].id=id;
            System.out.println("输入学生姓名");
            String name= scanner.next();
            scoreStudent[i].stuName=name;
            System.out.println("课程名称");
            String scoreName=scanner.next();
            scoreStudent[i].scoreName=scoreName;
            System.out.println("成绩");
            int score=scanner.nextInt();
            scoreStudent[i].score=score;
            numStudent++;
        }

        System.out.println("现在有"+numStudent+"人");
    }
    private static void searchScore(Scanner scanner){//查询信息
        System.out.println("请输入查询该学生的学号");
        String stu_id=scanner.next();
        boolean flag=true;
        for(int i=0;i<numStudent;i++){
            Score s=scoreStudent[i];
            if(s.stu_id.equals(stu_id)){
                System.out.println("该学生的名字为："+s.stuName);
                System.out.println("该学生的学号为："+s.stu_id);
                System.out.println("该学生的序号为："+s.id);
                System.out.println("该学生的所选课程为："+s.scoreName);
                System.out.println("该学生的课程成绩为："+s.score);
                flag=false;
            }
        }
        if(flag){
            System.out.println("没有该学生的信息，请重新输入");
        }
    }
    private static boolean contains(String stu_id){//判断是否重复
        for(int i=0;i<numStudent;i++){
            Score s=scoreStudent[i];
            if(s.stu_id.equals(stu_id)){
                return true;
            }
        }
        return false;
    }
    private static void updateScore(Scanner sc){//修改
        System.out.println("请输入该同学的学号");
        String stu_id=sc.next();
        if(!contains(stu_id)){
            System.out.println("该同学学号不存在！");
            return;
        }
        for(int i=0;i<numStudent;i++){
            Score s=scoreStudent[i];
            if(s.stu_id.equals(stu_id)){
                System.out.println("您要修改的同学的姓名为"+s.stuName);
                System.out.println("请输入该同学的新成绩");
                scoreStudent[i].score=sc.nextInt();
            }
        }
    }
    private static void deleteScore(Scanner sc){
        int k=0;
        System.out.println("请输入您有删除的学生学号");
        String stu_id=sc.next();
        if(!contains(stu_id)){
            System.out.println("您输入的学号不存在");
            return;
        }
        for(int i=0;i<numStudent;i++){
            Score s=scoreStudent[i];
            if(s.stu_id.equals(stu_id)){
                k=i;
                System.out.println("您要删除的是"+s.stuName+"同学");
                System.out.println("是否删除，输入Y或N,Y代表删除，N代表不删除");
                String temp=sc.next();
                if(temp.equals("N")||temp.equals("n")){
                    System.out.println("信息没有删除");
                    return;
                }
            }
        }
        for(int i=k;i<numStudent;i++){//循环判断条件-1或不减1无太大差别
            scoreStudent[i]=scoreStudent[i+1];
        }
        numStudent--;
        System.out.println("信息删除成功！");
    }
    private static void sumScore(Scanner sc){
        System.out.println("一共有"+numStudent+"人");
        int max=scoreStudent[0].score;
        int min=scoreStudent[0].score;
        double sum=0;
        for (int i = 0; i < numStudent; i++) {
            if(scoreStudent[i].score>max){
                max=scoreStudent[i].score;
            }
            if(scoreStudent[i].score<min){
                min=scoreStudent[i].score;
            }
            sum+=scoreStudent[i].score;
        }
        System.out.println("最高分为"+max);
        System.out.println("最低分为"+min);
        System.out.printf("平均分%.2f",sum/numStudent);
    }
    private static void sortScore(Scanner sc){
        for (int i = numStudent; i >0 ; i--) {
            for(int j=0;j<i-1;j++){
                Score s=new Score();
                if(scoreStudent[j].score>scoreStudent[j+1].score){
                    s=scoreStudent[j];
                    scoreStudent[j]=scoreStudent[j+1];
                    scoreStudent[j+1]=s;
                }
            }
        }
        System.out.println("展示排序后结果");
        displayScore();
    }
}
class Score{
    int id;//序号
    String stuName;//学生姓名
    String stu_id;//学生学号
    String scoreName;//课程名称
    int score;//分数
    public String toString(){
        return "序号："+id+"，学号"+stu_id
                +",姓名:"+stuName+",课程名称:"+scoreName+",分数:"+score;
    }
}