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

struct studentInfo {
    struct {
        char *name;
        char *surname;
        char *patronymic;
    };
    union {
        int height;
        int weight;
    };
};

char* stringInput(char *text) {
    int i = 0, key = 0;
    printf("%s", text);
    char *string = nullptr;
    if (!(string = (char*)malloc(sizeof(char)))) {
        return NULL;
    }
    while ((key = getchar()) != '\n') {
        string = (char*)realloc(string, sizeof(char) * (i + 1));
        string[i++] = key;
    }
    string[i] = '\0';
    return string;
}

int numberInput(int verification, char* string) {
    int number = 0;
    char buffer = 0;
    printf("%s", string);
    printf(" ");
    while ((!(scanf_s(" %d%c", &number, &buffer, 1))) || (buffer != '\n') || (number < verification) || (number <= 0)) {
        rewind(stdin);
        printf(" You've entered the wrong value. Please, enter again: ");
    }
    return number;
}

void studentsInfoOutput(struct studentInfo* studentInitial, int checkup, int studentsAmount) {
    for (int i = 0; i < studentsAmount; i++) {
        if (checkup == 1) {
            printf("___________________\n");
            printf(" Surname: %s\n", studentInitial[i].surname);
            printf(" Name: %s\n", studentInitial[i].name);
            printf(" Patronymic: %s\n", studentInitial[i].patronymic);
            printf(" Height is: %d\n", studentInitial[i].height);
            printf("___________________\n");
        }
        if (checkup == 2) {
            printf("___________________\n");
            printf(" Surname: %s\n", studentInitial[i].surname);
            printf(" Name: %s\n", studentInitial[i].name);
            printf(" Patronymic: %s\n", studentInitial[i].patronymic);
            printf(" Weight is: %d\n", studentInitial[i].weight);
            printf("___________________\n");
        }
    }
}

struct studentInfo studentInfoInput() {
    int key = 0;
    struct studentInfo studentInitial;
    studentInitial.name = stringInput(" Enter student name: ");
    studentInitial.surname = stringInput(" Enter student surname: ");
    studentInitial.patronymic = stringInput(" Enter student patronymic: ");
    printf(" What you would like to enter: weight(W) or height(H)?\n Please, press the appropriate button(W/H): ");
    while (((key = getchar()) != 'H' && key != 'W')) {
        printf(" You've entered the wrong value. Please, enter again: ");
        rewind(stdin);
    }
    if (key == 'H') {
        studentInitial.height = numberInput(0, " Enter student height: ");
    }
    else if (key == 'W') {
        studentInitial.weight = numberInput(0, " Enter student weight: ");
    }
    return studentInitial;
}

int parityCheck(int &checkup, char* argv[]) {
    if (!(strcmp(argv[1], "Height")) || !(strcmp(argv[1], "height"))) {
        return 1;
    }
    if (!(strcmp(argv[1], "Weight")) || !(strcmp(argv[1], "weight"))) {
        return 2;
    }
}

int studentSearch(int studentInitial, int checkup) {
    if (studentInitial == checkup)
        return 1;
    else return 0;
}

int main(int argc, char *argv[]) {
    int i = 0;
    int checkup = 0;
    int studentsAmount = 0;
    int switchOption = 0;
    int hey = 0;
    struct studentInfo *studentInitial;
    if (!(studentInitial = (struct studentInfo*)malloc(sizeof(struct studentInfo)))) {
        printf(" Memory error.\n");
        return 0;
    }
    printf(" Hello!\n");
    do {
        while ((switchOption = numberInput(1, " 1. Enter students information. \n 2. Required information output. \n 3. Exit. \n")) > 3) {
            system("CLS");
            printf(" You've entered the wrong value. Please, enter again: ");
            rewind(stdin);
        }
        switch (switchOption) {
        case 1: {
            system("CLS");
            studentsAmount++;
            if (!(studentInitial = (struct studentInfo*)realloc(studentInitial, sizeof(struct studentInfo) * studentsAmount))) {
                printf(" Memory error.\n");
                return 0;
            }
            studentInitial[studentsAmount - 1] = studentInfoInput();
            break;
        }
        case 2: {
            system("CLS");
            checkup = parityCheck(checkup, argv);
            studentsInfoOutput(studentInitial, checkup, studentsAmount);
            break;
        }
        case 3: {
            system("CLS");
            printf("Thank you for using this programm! Have a good day!\n\n");
            break;
        }
        }
    } while (switchOption != 3);
    return 0;
}