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

typedef struct
{
	int cid;
	char name[40];
	char address[80];
	double deposit;

}client;

typedef struct
{
	char line[300];

}data;

typedef struct
{
	int cid;

}finds;

typedef struct
{
	double money;

}deposit;

void menu();
int calculateMax(void);
void addClient();
void find();
void display();
void total();

void main()
{
	menu();
}

void menu()
{
	int selection;

	printf("%s", "Program menu :\n");
	printf("%s", "1. Add a new client\n");
	printf("%s", "2. Find/retrieve information for a particular client\n");
	printf("%s", "3. Display client list\n");
	printf("%s", "4. Display the total amount of clients' deposit\n");
	printf("%s", "5. Find a client that has the lowest and the highest deposit\n");
	printf("%s", "6. Quit\n");
	printf("%s", "Selection : ");
	scanf("%d", &selection);

	if(selection == 1)
	{
		addClient();
	}

	else if(selection == 2)
	{
		find();
	}

	else if(selection == 3)
	{
		display();

	}

	else if(selection == 4)
	{
		total();

	}

	else if(selection == 5)
	{

	}

	else if(selection == 6)
	{

	}

	else {
		printf("%s", "\n\aError, please key in correct input!\n\n");
		menu();
	}
}

void addClient()
{
	int max, i;

	FILE *f, *id, *name, *address, *deposit;
	
	printf("%s", "\n\nADD CLIENT\n");
	printf("%s", "How many client you would like to add : ");
	scanf("%d", &max);

	client *client_info;

	client_info = (client *) malloc(max * sizeof(client)); /*Allocate Memory For Client's Info*/

	if(client_info == NULL)
	{
		printf("Unable to allocate space for client\n\n");
		exit (EXIT_FAILURE);
	}

	if ((id = fopen("id.txt", "a+")) == NULL) /*Open file id.txt*/
	{
		printf("Error, the file cannot be opened\n");
	}

	if ((name = fopen("name.txt", "a+")) == NULL) /*Open file name.txt*/
	{
		printf("Error, the file cannot be opened\n");
	}

	if ((address = fopen("address.txt", "a+")) == NULL) /*Open file address.txt*/
	{
		printf("Error, the file cannot be opened\n");
	}

	if ((deposit = fopen("deposit.txt", "a+")) == NULL) /*Open file deposit.txt*/
	{
		printf("Error, the file cannot be opened\n");
	}

	if ((f = fopen("clients.txt", "a+")) == NULL) /*Open file clients.txt*/
	{
		printf("Error, the file cannot be opened\n");
	}

	else {

		for (i = 0; i < max ; i++) { /*Get the input data*/
			printf("\nClient %d\n", i + 1);
			printf("%s", "Client's Id : ");
			scanf("%d", &client_info[i].cid);
			printf("%s", "Client's Name : ");
			fflush(stdin);
			gets(client_info[i].name);
			printf("%s", "Client's Address : ");
			fflush(stdin);
			gets(client_info[i].address);
			printf("%s", "Client's Deposit : ");
			scanf("%lf", &client_info[i].deposit);
			printf("\n");
			}
	}

	for(i = 0; i < max; i++) { /*Store input data into files*/
		
		fprintf(id, "%d\n", client_info[i].cid);
		fputs(client_info[i].name, name);
		fprintf(name, "\n");
		fputs(client_info[i].address, address);
		fprintf(address, "\n");
		fprintf(deposit, "%lf\n", client_info[i].deposit);

	}

	for(i = 0; i < max; i++) {
		
		fprintf(f, "%d", client_info[i].cid, "");
		fprintf(f, "%3s", "");
		fputs(client_info[i].name, f);
		fprintf(f, "%5s", "");
		fputs(client_info[i].address, f);
		fprintf(f, "%7s", "");
		fprintf(f, "%lf\n", client_info[i].deposit);

	}

	fclose(f);
	fclose(id);
	fclose(name);
	fclose(address);
	fclose(deposit);
	free(client_info);
	client_info = NULL;

	printf("\n");

	menu();
}

void find()
{
	int find_id = 0, i = 0, client_cid, n = 0, max, selection;
	FILE *id, *f;

	max = calculateMax();

	finds *result;

	result = (finds *) malloc(max * sizeof(finds));

	if(result == NULL)
	{
		printf("Unable to allocate space for client\n\n");
		exit (EXIT_FAILURE);
	}

	if ((id = fopen("id.txt", "r")) == NULL)
	{
		printf("Error, the file cannot be opened\n");
	}

	else {

		while (!feof(id)) { /*Get all clients' id number and store to array*/

			fscanf(id, "%d", &result[i].cid);
			i++;
		}
	}

	fclose(id);

	printf("%s", "\n\nFIND CLIENT\n");
	printf("%s", "Key in client's id : "); /*Get the client's id that user want to query*/
	scanf("%d", &client_cid);

	data *clients_info;

	clients_info = (data *) malloc(max * sizeof(data));

	if(clients_info == NULL)
	{
		printf("Unable to allocate space for client\n\n");
		exit (EXIT_FAILURE);
	}

	if ((f = fopen("clients.txt", "r")) == NULL)
	{
		printf("Error, the file cannot be opened\n");
	}

	i = 0;

	while (!feof(f)) {  /*Get all the clients' data from clients.txt and stored to array*/

		fflush(stdin);
		fgets(clients_info[i].line, 300, f);
		i++;
     }

	fclose (f);

	for(i = 0; i < max + 1; i++)
	{
		if(client_cid == result[i].cid)
		{
			printf("\n\n%s%6s%20s%17s\n", "ID", "NAME", "ADDRESS", "DEPOSIT");
			puts(clients_info[i].line);

			free(clients_info);
			clients_info = NULL;
			
			free(result);
			result = NULL;

			printf("Would you like to find another client?\nKey in 1 for yes or 2 to go to menu : ");
			scanf("%d",&selection);

			if(selection == 1) {
				find();
			}

			else if(selection == 2) {
				menu();
			}

			break;
		}

		else if(i == max)
		{
			printf("\nSory, there's no client with that id in our database.\n");
			free(clients_info);
			clients_info = NULL;
			
			free(result);
			result = NULL;
			printf("Would you like to find another client?\nKey in 1 for yes or 2 to go to menu : ");
			scanf("%d",&selection);

			if(selection == 1) {
				find();
			}

			else if(selection == 2) {
				printf("\n\n");
				menu();
			}

		}
	}



}


void display()
{
    int max = 0, i;
	
	FILE *f;

	printf("\n\nDISPLAY CLIENTS");

	max = calculateMax();

	data *clients_info;

	clients_info = (data *) malloc(max * sizeof(data));

	if(clients_info == NULL)
	{
		printf("Unable to allocate space for client\n\n");
		exit (EXIT_FAILURE);
	}

	if ((f = fopen("clients.txt", "r")) == NULL)
	{
		printf("Error, the file cannot be opened\n");
	}

	i = 0;

	while (!feof(f)) {

		fflush(stdin);
		fgets(clients_info[i].line, 200, f);
		i++;
     }

	fclose (f);

	printf("\n\n%s%6s%20s%17s\n", "ID", "NAME", "ADDRESS", "DEPOSIT");

	for(i = 0; i < max; i++)
	{
		puts(clients_info[i].line);
	}

	free(clients_info);
	clients_info = NULL;

}

void total()
{
	int find_id = 0, max = 0, i = 0;
	double total = 0;
	FILE *deposits;

	max = calculateMax();

	deposit *result;

	result = (deposit *) malloc(max * sizeof(deposit));

	if(result == NULL)
	{
		printf("Unable to allocate space for client\n\n");
		exit (EXIT_FAILURE);
	}

	if ((deposits = fopen("deposit.txt", "r")) == NULL)
	{
		printf("Error, the file cannot be opened\n");
	}

	else {

		while (!feof(deposits)) { /*Get all clients' id number and store to array*/

			fscanf(deposits, "%lf", &result[i].money);
			i++;
		}
	}

	fclose(deposits);

	for(i = 0; i < max; i++)
	{
		total += result[i].money;
	}

	printf("\n\nTOTAL OF CLIENTS' DEPOSIT\n\n");

	printf("Total Deposit is RM%.2lf\n\n\n", total);
	menu();
}

int calculateMax(void)
{
	char str[150];
	int maximum = 0;
	FILE *f;
	
	if ((f = fopen("clients.txt", "r")) == NULL)
	{
		printf("Error, the file cannot be opened\n");
	}

    else {

         while (!feof(f)) {
			maximum++;
			fgets (str , 200 , f);
         }
    }

	fclose (f);

	maximum = maximum - 1;

	return maximum;
}