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

char name [20]; // onoma
char lastname [20]; //epwnumo
int age; //hlikia
int grade1; //c
int grade2; // c++
int grade3; // java
float average; // mesos oros kai twn 3 mathimatwn

int regi(void); // sunarthsh gia register
int login(void); // sunarthsh gia login
int modify(void); // sunarthsh gia modify
int view(void); // sunarthsh gia view
int search(void); // sunarthsh gia search
int sort (void); // sunarthsh gia to sort

static char users [100][7][32]; // 100 grammes diaforetikous xrhstes 7 sthles xarakthristika 32 to periexomeno keliou (xarakthres)
static int count= 0; // metraei posous xrhstes uparxoun sto susthma ekeinh thn stigmh!
static int id;

int main (void)
{
	char user_input[32];
	printf("\t \t \t \t \t WELCOME TO MF Scholarships!\n \n");
	while (1)
	{

	printf ("\t \t * Please insert: \n \t \t - REGISTER \n \t \t - LOG IN \n \n "); // epilogh gia eisodo ki eggrafh
	scanf("\t %s", user_input);

	if (strcmp(user_input,"REGISTER")==0)
	{
		regi();


	}
	else if (strcmp(user_input,"LOGIN")==0)
	{
		id = login();

		if (id == -1)
		{
			break;
		}
     while (1)
{
	char user_input2[32];
	printf("\t \t Please insert: \n \t\t - Modify \n \t \t - View \n \t \t -Search \n \t \t -Sort \n \t \t -Exit\n");
	scanf("%s", user_input2);


	if (strcmp(user_input2,"Modify")==0)
	{
		int n = modify();
	}

	if (strcmp(user_input2,"View")==0)
	{
		int p = view();
	}

	if (strcmp(user_input2,"Search")==0)
	{
		int k = search();
	}

	if (strcmp(user_input2,"Sort")==0)
	{
		int l = sort();
	}

	if (strcmp(user_input2, "Exit")==0)
	{
		break;
	}

}


}

}
	return 0;

}

int regi(void)
{   int i;

	//metablhtes eggrafhs

	printf("\t \t *Type a user record (name lastname age grade in c grade in java grade in c++)\n");
    scanf("%s %s %d %d %d %d", name, lastname, &age,&grade1, &grade2, &grade3);
	printf("\t  -You typed : %s %s %d %d %d %d\n", name, lastname, age, grade1, grade2, grade3);
	average = (grade1 + grade2 + grade3) / 3;
	printf ("\t  *Your average is : %1.f\n\n", average);

	for (i=0; i<100; i++)
	{
		if (strcmp(lastname,users[i][1])==0)
		{
			printf("\t The last-name already exists!\n");
			return 1;
		}


	}

 // antigrafei to string pou einai to last name sto users count

	strcpy(users [count] [0],name); // antigrafei to string pou brisketai sto name sto users
	strcpy(users [count] [1],lastname);
    sprintf(users[count] [2], "%d", age); // metatrepei ena int se string
	sprintf(users[count] [3], "%d", grade1);
	sprintf(users[count] [4], "%d", grade2);
	sprintf(users[count] [5], "%d", grade3);
	sprintf(users[count] [6], "%f", average);

	count++;

	return 1;


}

int login(void)
	{
		char username[32];
		char password [32];
		char *lastname2; // metablhtes gia  log in

		printf("\t \t*Give me you username:\n");
		scanf("%s",username);
		printf("\t \t*Give me your password:\n");
		scanf("%s",password);
		int j;
		int exists = -1;

		for (j=0; j<100; j++)
	{
		if (strcmp(username,users[j][1])==0) // ELEGXOS AN UPARXEI XRHSTHS STO SUSTHMA!
		{

			exists = j;
		}


	}
		int i=0;
		if (exists == -1)
		{
			return -1;
		}


    	lastname2 = strdup (username); //strdup mas kanei ena neo antigrafo

		while(lastname2 [i])
		{
			if (i%2 == 0)
			{
				lastname2 [i] = toupper (lastname2 [i]);
			}
			else
			{

				lastname2 [i] = tolower (lastname2 [i]);
			}
			i++;
		}

		if (strcmp(lastname2 , password) == 0)
		{
			printf("\t \t -Success login!\n\n");
			return exists;

		}
		else
		{
			printf("\t \t -Please try again!\n\n");
			return -1;
		}

	}

	int modify (void)
	{
		int change; //allagh stoixeiou
		char last2[32];
		char nam[32];
		int ag;
		int c;
		int java;
		int cpp;
		float av;//metablhtes allaghs

		char input [10];
		printf ("\t \t*You have entered the following personal data:\n 1.Last-name:%s\n 2.Name: %s \n 3.Age:%s \n 4Grade in C:%s \n 5.Grade in Java: %s \n 6.Grade in C++: %s\n 7. Average: %s\n\n",
     users[id][1], users[id][0], users[id][2], users[id][3], users[id][4], users[id][5], users[id][6]);
		printf("\t  *Do you want to change anything? \n \t Type Yes or NO \n");
		scanf("%s",input);

		if (strcmp(input , "Yes") == 0)
		{
			printf("\t \t *Please insert the number that you want to change:\n");
			scanf("%d",&change);
			if (change == 1)
			{
				printf("\t \t *You want to change your LAST-NAME. Please type:\n\n");
				scanf("%s",last2);
        strcpy(users [id] [1],last2);
			}

			else if(change == 2)
			{
				printf("\t \t *You want to change your NAME. Please type:\n\n");
				scanf("%s",nam);
        strcpy(users [id] [0],nam);
			}

			else	if(change == 3)
			{
				printf("\t \t*You want to change your AGE. Please type:\n\n");
				scanf("%d",&ag);
        sprintf(users[id] [2], "%d", ag);
			}
			else	if(change == 4)
			{
				printf("\t \t*You want to change your grade in C. Please type:\n\n");
				scanf("%d",&c);
        sprintf(users[id] [3], "%d", c);
			}
			else	if(change == 5)
			{
				printf("\t \t*You want to change your grade in JAVA. Please type:\n\n");
				scanf("%d",&java);
        sprintf(users[id] [4], "%d", java);
			}
			else	if(change == 6)
			{
				printf("\t \t*You want to change your grade in C++. Please type:\n\n");
				scanf("%d",&cpp);
        sprintf(users[id] [5], "%d", cpp);
			}

      if(change == 4 || change == 5 || change == 6)
			{
        av = (atoi(users[id][3]) + atoi(users[id][4]) + atoi(users[id][5]))/3;
				printf("\t  -Your new average is:%1.f\n\n ",av);
        sprintf(users[id] [6], "%f", av);
			}

      printf ("\t \t*Your new entered the following personal data:\n 1.Last-name:%s\n 2.Name: %s \n 3.Age:%s \n 4Grade in C:%s \n 5.Grade in Java: %s \n 6.Grade in C++: %s\n 7. Average: %s\n\n",
       users[id][1], users[id][0], users[id][2], users[id][3], users[id][4], users[id][5], users[id][6]);
		}

		if (strcmp (input,"No")==0)
		{
			printf("\t -Thank you!\n");
		}
		return 1;
	}

	int view(void)
	{
		int i;
		for (i=0; i<count; i++)
		{
		printf(" -Students are: \n 1.Last-name:%s\n 2.Name: %s \n 3.Age:%s 4. Average: %s\n\n",
         users[i][1], users[i][0], users[i][2],users[i][6]);
		}
		printf(" -Number of students: %d\n\n",count);
		return 1;
	}

	int search(void)
	{	int i;
	    char search[32];
	    int element;
		printf("\t \t*Enter the element to search:\n ");
    	scanf("%s", search);

    	element = 0;
    	for(i=0; i<count; i++)
    {

    	 if(users[i][1][0] == search[0])
        {
            element = 1;
            printf("\t \t-Students are: \n 1.Last-name:%s\n 2.Name: %s \n 3.Age:%s \n 4. Average: %s\n\n",
            users[id][1], users[id][0], users[id][2],users[id][6]);
            break;
        }
   }
        if(element==0)
    {
        printf("\t -No results.\n");
    }

	}

	int sort(void)
	{
		int i , j ;
		static char temp [7][32];
    int memsize = sizeof(temp); //metraei tn mhnmh pou katanalwnei to temp
		for (i=0; i<count; i++)
		{
			for (j=0; j<count-i; j++)
			{

				if (atof(users[j][6]) < atof(users[j+1][6]))// metatroph string se float
				{

					memcpy(temp,users [j+1], memsize); // memcpy antigrafei oti brisketai stn mhn j+1 sto temp parametro gia na kserw thn mnhmh
					memcpy(users[j+1], users[j], memsize);
					memcpy(users[j],temp, memsize);

				}
			}
		}
    }