#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_STUDENTS 100
#define MAX_LEN 20

struct Student {
    char id[MAX_LEN];
    char clas[MAX_LEN];
    char name[MAX_LEN];
    double score1;
    double score2;
    double score3;
    double score;
} students[MAX_STUDENTS];
int studentCount = 0;

void inputStudent() {
    if (studentCount >= MAX_STUDENTS) {
        printf("Database is full.\n");
        return;
    }
    struct Student s;
    printf("Id: ");
    scanf("%s", s.id);
    printf("class: ");
    scanf("%s", s.clas);
    printf("name: ");
    scanf("%s", s.name);
    printf("score1: ");
    scanf("%lf", &s.score1);
    printf("score2: ");
    scanf("%lf", &s.score2);
    printf("score3: ");
    scanf("%lf", &s.score3);
    s.score = s.score1 + s.score2 + s.score3;
    students[studentCount++] = s;
    printf("continue? (yes/no): ");
    char cont[3];
    scanf("%s", cont);
    if (strcmp(cont, "no") == 0 || strcmp(cont, "No") == 0 || strcmp(cont, "NO") == 0) {
        return;
    }
    else
    {
    	inputStudent() ;
	}
	return;
}

void deleteStudent() {
    char searchIdOrName[MAX_LEN];
    printf("Enter student id or name to delete: ");
    scanf("%s", searchIdOrName);
    int found = 0;
    for (int i = 0; i < studentCount; i++) {
        if (strcmp(students[i].id, searchIdOrName) == 0 || strcmp(students[i].name, searchIdOrName) == 0) {
            for (int j = i; j < studentCount - 1; j++) {
                students[j] = students[j + 1];
            }
            studentCount--;
            found = 1;
            i--;
        }
    }
    if (!found) {
        printf("There is no eligible student.\n");
    }
    printf("continue? (yes/no): ");
    char cont[3];
    scanf("%s", cont);
    if (strcmp(cont, "no") != 0) {
        deleteStudent();
    }
}

void selectStudent() {
    char searchIdOrClass[MAX_LEN];
    printf("Enter student id or class to select: ");
    scanf("%s", searchIdOrClass);
    int found = 0;
    for (int i = 0; i < studentCount; i++) {
        if (strcmp(students[i].id, searchIdOrClass) == 0 || strcmp(students[i].clas, searchIdOrClass) == 0) {
            printf("%s,%s,%s,%.1f,%.1f,%.1f,%.1f\n", students[i].id, students[i].clas, students[i].name, students[i].score1, students[i].score2, students[i].score3, students[i].score);
            found = 1;
        }
    }
    if (!found) {
        printf("There is no eligible student.\n");
    }
    printf("continue? (yes/no): ");
    char cont[3];
    scanf("%s", cont);
    if (strcmp(cont, "yes") == 0 || strcmp(cont, "Yes") == 0 || strcmp(cont, "YES") == 0) {
        selectStudent();
    }
}

void orderStudents() {
    // Simple bubble sort for demonstration purposes
    for (int i = 0; i < studentCount - 1; i++) {
        for (int j = 0; j < studentCount - i - 1; j++) {
            if (strcmp(students[j].clas, students[j + 1].clas) > 0 ||
                (strcmp(students[j].clas, students[j + 1].clas) == 0 && students[j].score < students[j + 1].score)) {
                struct Student temp = students[j];
                students[j] = students[j + 1];
                students[j + 1] = temp;
            }
        }
    }
}

void outputStudents() {
    for (int i = 0; i < studentCount; i++) {
        printf("%s,%s,%s,%.1f,%.1f,%.1f,%.1f\n", students[i].id, students[i].clas, students[i].name, students[i].score1, students[i].score2, students[i].score3, students[i].score);
    }
}

int main() {
    int option;
    do {
        printf("1.input\n2.delete\n3.select\n4.order\n5.output\n6.quit\nplease input your option: ");
        scanf("%d", &option);
        switch (option) {
            case 1:
                inputStudent();
                break;
            case 2:
                deleteStudent();
                break;
            case 3:
                selectStudent();
                break;
            case 4:
                orderStudents();
                break;
            case 5:
                outputStudents();
                break;
            case 6:
                printf("Exiting program.\n");
                break;
            default:
                printf("Invalid option.\n");
        }
    } while (option != 6);
    return 0;
}