#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct Student {
    char *id;
    char *clas;
    char *name;
    double score1;
    double score2;
    double score3;
    double score;
};
void inputStudent(struct Student students[], int *count);
void deleteStudent(struct Student students[], int *count);
void selectStudent(struct Student students[], int count);
void orderStudent(struct Student students[], int count);
void outputStudent(struct Student students[], int count);
void freeStudentMemory(struct Student student);
int isValidId(const char *id);
int isValidScore(double score);

int main() {
    struct Student students[100];
    int count = 0;
    int option;

    do {
        printf("1.input\n2.delete\n3.select \n4.order \n5.output \n6.quit\n");
        printf("please input your option\n");
        scanf("%d", &option);

        switch (option) {
        case 1:
            inputStudent(students, &count);
            break;
        case 2:
            deleteStudent(students, &count);
            break;
        case 3:
            selectStudent(students, count);
            break;
        case 4:
            orderStudent(students, count);
            break;
        case 5:
            outputStudent(students, count);
            break;
        case 6:
            printf("Exiting program...\n");
            break;
        default:
            printf("Invalid option. Please try again.\n");
        }
    } while (option!= 6);
int i; 
    for (i = 0; i < count; i++) {
        freeStudentMemory(students[i]);
    }

    return 0;
}

void inputStudent(struct Student students[], int *count) {
    char continueInput;
    do {
        students[*count].id = (char *)malloc(sizeof(char) * 10);
        students[*count].clas = (char *)malloc(sizeof(char) * 10);
        students[*count].name = (char *)malloc(sizeof(char) * 20);

        printf("Id ");
        scanf("%s", students[*count].id);
        if (!isValidId(students[*count].id)) {
            printf("\n");
            free(students[*count].id);
            continue;
        }

        printf("class ");
        scanf("%s", students[*count].clas);

        printf("name ");
        scanf("%s", students[*count].name);

        printf("score1 ");
        scanf("%lf", &students[*count].score1);
        if (!isValidScore(students[*count].score1)) {
            printf("\n");
            continue;
        }

        printf("score2 ");
        scanf("%lf", &students[*count].score2);
        if (!isValidScore(students[*count].score2)) {
            printf("\n");
            continue;
        }

        printf("score3 ");
        scanf("%lf", &students[*count].score3);
        if (!isValidScore(students[*count].score3)) {
            printf("\n");
            continue;
        }

        students[*count].score = students[*count].score1 + students[*count].score2 + students[*count].score3;

        (*count)++;

        printf("continue? \n");
        scanf(" %c", &continueInput);
    } while (continueInput == 'y');
}

void deleteStudent(struct Student students[], int *count) {
    char input[20];
    int i, j;
    do {
        printf("Enter the student ID or name to delete: ");
        scanf("%s", input);

        for (i = 0; i < *count; i++) {
            if (strcmp(students[i].id, input) == 0 || strcmp(students[i].name, input) == 0) {
                freeStudentMemory(students[i]);
                for (j = i; j < *count - 1; j++) {
                    students[j] = students[j + 1];
                }
                (*count)--;
                break;
            }
        }

        if (i == *count) {
            printf("Student not found.\n");
        } else {
            printf("Student deleted successfully.\n");
        }

        outputStudent(students, *count);

        printf("continue? \n");
        scanf("%s", input);
    } while (strcmp(input,"yes") == 0);
}

void selectStudent(struct Student students[], int count) {
    char input[20];
    int i;
    do {
		rewind(stdin);
        printf("Enter the student ID or class to select: ");
        scanf("%s", input);

        for (i = 0; i < count; i++) {
            if (strcmp(students[i].id, input) == 0 || strcmp(students[i].clas, input) == 0) {
                printf("%s %s %s %.1lf %.1lf %.1lf %.1lf\n", students[i].id, students[i].clas, students[i].name, students[i].score1, students[i].score2, students[i].score3, students[i].score);
            }
        }

        if (i == count) {
            printf("there is no eligible student\n");
        }

        printf("continue? \n");
        scanf("%s", input);
    } while (strcmp(input,"yes") == 0);
}

void orderStudent(struct Student students[], int count) {
    int i, j;
    struct Student temp;

    for (i = 0; i < count - 1; i++) {
        for (j = 0; j < count - 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)) {
                temp = students[j];
                students[j] = students[j + 1];
                students[j + 1] = temp;
            }
        }
    }

    outputStudent(students, count);
}

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

void freeStudentMemory(struct Student student) {
    free(student.id);
    free(student.clas);
    free(student.name);
}

int isValidId(const char *id) {
    if (strlen(id)!= 5) {
        return 0;
    }
    int i;
    for ( i = 0; i < 5; i++) {
        if (id[i] < '0' || id[i] > '9') {
            return 0;
        }
    }
    return id[0]!= '0';
}

int isValidScore(double score) {
    int integerPart = (int)score;
    double decimalPart = score - integerPart;
    if (integerPart < 0 || integerPart > 99) {
        return 0;
    }
    if (decimalPart < 0 || decimalPart >= 1) {
        return 0;
    }
    return 1;
}