Atm Machine Using File Handling

/*

Humza Khawar BS CS 10C
CMS 343114

FoCP Lab 14
ATM Machince with File Handling

Logic:
All the data regarding accounts  is stored on the accounts details file in the format " name pin cash ".
They are stored via the structure "account"

All the transaction summary is stored in summary file.
1.First the program reads data from the accounts file and stores it in an data base array which is of type "account".
2.Then it asks user for the type of operation.
3. Each operation has its own function
4. All comparisons and editing is done in the data base array
5. At the program exit, All the data in account details file is over written by the updated data from data base array.

*/


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

//Account structure
typedef struct account_details {
	char name[60];
	int pin;
	int cash;
}account;
//global variable so the present account can be used through out the program
account present_account; //account being used currently

int account_no;	//account no is the location in the data base array where the required account is located
FILE* accounts_ptr = NULL; //file pointor for the acount details file
FILE* summary_ptr = NULL; //file pointor for the summary file
account data_base[50]; //data base to store all accounts from accounts file (Max 50)

time_t t;
int account_counter = 0; //counter to keep check of accounts in the data base array and control the loop and avoid extra iterations

void file_open(int a);//1:append mode or file creation mode   //function to open the files
void file_close(); //closes all files and flushes the file pointors
void account_creation(); //function to deal with account creation stuff
void account_withdrawl(); //function for maintaining the balance regarding account cash withdraw
void account_deposit(); //function for maintaining the balance regarding account cash deposit
void account_balance(); //function for checking balance of account
void account_summary(); //function to show the summary / transaction details of the account since account creation
int account_validation( int); //function to check if the user entered account is a valid account and to get the data in case of a valid account
										//type 1 = new account username check
										//type 2 = old account find


//this function takes all the data from accounts file and stores in data base array
void get_data() 
{
	accounts_ptr = fopen("Account_Details.txt","r"); //opens file in read mode
	char filechar = fgetc(accounts_ptr); //character to check for eof

	while ((filechar != EOF))
	{
		if (filechar == '\n') { //takes data stored at each nenw line

			fscanf(accounts_ptr, "\n%s %d %d", &data_base[account_counter].name, &data_base[account_counter].pin, &data_base[account_counter].cash);

			account_counter++; //counter to keep check of accounts in database array

		}
		
		filechar = fgetc(accounts_ptr); //takes next character
	}
	fclose(accounts_ptr); //closing file after taking data
	fflush(accounts_ptr);
}

//this function over writes the data in the accounts file with the new updated data
void put_data() 
{
	accounts_ptr= fopen("Account_Details.txt", "w"); //opens file in write mode
	for (int i = 0; i < account_counter; i++)
	{
		fprintf(accounts_ptr,"\n%s %d %d", data_base[i].name, data_base[i].pin, data_base[i].cash);

	}
	fclose(accounts_ptr);//cosing the file
	fflush(accounts_ptr);
}

//main fuction
int main() {
	
	file_open(0); //opens and closes files so files can be created if they are not present
	
	get_data(); //gets data from file to data base array
	int choice = 6; //initializing choice variable to take user input
	time(&t);
	
	printf("\nWelcome to Nust Atm By Humza Khawar BSCS-10C\t\t\t\t %s\n", ctime(&t));

	printf("\nTo access the facilities. Kindly Navigate through the given options.\n");

	printf("\n1.Account Creation\n2.Balance Check\n3.Cash Withdrawl\n4.Cash Deposit\n5.Account Statement\n6.Exit\n"); //prints available options to the user

	printf("\n\7Enter Choice : ");
	scanf("%d", &choice); //user inputs choice (1-6)

	file_open(5); //opens the summary file in append mode so it can be appended during runtime

	while (choice != 6) //loop to keep execting the program until user decides to exit
	{
		switch (choice) //choice statement to run the functions according to user request
		{

		case (1)://Account creation
		{
			system("cls");
			printf("\nWelcome to Account Creation\t\t\t\t %s\n", ctime(&t));
			account_creation(); //sends control to accounts function
			printf("\nPress Any Key To Continue!!");
			getchar();
			getchar();
			break;
		}


		case (2)://Balance Check
		{
			system("cls");
			printf("\nWelcome to Balance Check\t\t\t\t %s\n", ctime(&t));
			account_balance(); //sends control to balance check function
			printf("\nPress Any Key To Continue!!");
			getchar();
			getchar();
			break;
		}
		case(3)://Cash Withdrawl
		{
			system("cls");
			printf("\nWelcome to Cash Withdrawl\t\t\t\t %s\n", ctime(&t));
			account_withdrawl(); //sends control to cash withdrawl function
			printf("\nPress Any Key To Continue!!");
			getchar();
			getchar();
			break;
		}
		case(4)://Cash deposit
		{
			system("cls");
			printf("\nWelcome to Cash Deposit\t\t\t\t %s\n", ctime(&t));
			account_deposit(); //sends control to cash deposit function
			printf("\nPress Any Key To Continue!!");
			getchar();
			getchar();
			break;
		}

		case(5)://Account Statement
		{
			system("cls");
			printf("\nWelcome to Account Statement\t\t\t\t %s\n", ctime(&t));
			account_summary(); //sends control to account summary function
			printf("\nPress Any Key To Continue!!");
			getchar();
			getchar();
			break;
		}

			default: //To cater the wrong input
			{

				printf("\n Wrong Input. Try again.");
				printf("\n\7Press any key to retry ");


				break;
			}
		}
	
		

		system("cls"); //clear screen 

		time(&t); //updates the time and date
		printf("\nWelcome to Nust Atm\t\t %s\n", ctime(&t));

		printf("\nTo access the facilities. Kindly Navigate through the given options.\n");

		printf("\n1.Account Creation\n2.Balance Check\n3.Cash Withdrawl\n4.Cash Deposit\n5.Account Statement\n6.Exit\n");

		printf("\n\7Enter Choice : "); //retakes input for next action
		scanf("%d", &choice);

		//exits if user inputs "6"
	}
	put_data(); //writes the updated data into the accounts file
	file_close(); //closes any files that might not be closed during above functions

	return 0;
}
//file open funtion
void file_open(int a) {
	//0:file check / creation		(any other number):opeining summary
	
	if (a == 0) {
		accounts_ptr = fopen("Account_Details.txt", "a+"); //opens/creates accounts file
		if (accounts_ptr == NULL)
		{
			printf("Error Opening Accounts File"); //accounts pointer error handling
		}
		summary_ptr = fopen("Summary.txt", "a+");  //opens/creates summary file
		if (summary_ptr == NULL)
		{
			printf("Error Opening Summary File"); //Summary pointer error handling
		}
		file_close();	//closing files after they are created
		

	}
	else  //opening the summary file for appending new transaction details
	{
		summary_ptr = fopen("Summary.txt", "a+");

		summary_ptr = fopen("Summary.txt", "a+");
		if (summary_ptr == NULL)
		{
			printf("Error Opening Summary File"); //Summary pointer error handling
		}
	}
	
	
}

//file close functions
void file_close() {
	
	//closing all files and flushing the pointors (just to be sure)
	fclose(accounts_ptr);
	fflush(accounts_ptr);
	fclose(summary_ptr);
	fflush(summary_ptr);
	
}

//account validation fuction
int account_validation( int type) {

	//compares user input account to the database to check for any duplicates

	//type 1 = new account username check
	//type 2 = old account find
	
	//flag to return the results of check
	int flag = 0;
	//counter to calculate the required account number in database
	int i = 0;
	//loop to compare usernames in the database with the user input username
	for ( i = 0; i <= account_counter; i++)
	{
		if (strcmp(present_account.name, data_base[i].name) == 0) {
			flag++; //flag is raised and loop breaks if the username is founf in database
			break;
		}

	}
	if ((flag>0) && (type==2)){
		present_account = data_base[i]; //the data from that position is stored in present account variable so it can be used for the required function
		account_no = i;	//account number is stored so it can be used for updating the data in the database in the end

	}
	

	return flag; //returns the flang. It is non zero if the account is found
}

//account creation function
void account_creation()
{
	//shows the guidelines of the username to create an account 

	printf("\n User name should be :\n\n 1.Case Sensitive\t\t 2.Should not contain spaces.\n\n");

	printf("\nEnter Username : "); //takes user name as input and stores it in the global variable (present account [name])
	scanf("%s", &present_account.name);


	while (account_validation( 1) != 0) //in case the username exists in the database, non zero flag is returned 
	{
		printf("\nTry Again \n"); //retakes the username from user and validates it
		printf("\nEnter UserName: ");
		scanf("%s", &present_account.name);
	}

	printf("\nUsername can be used.");
	file_close(); //closes the files
	file_open(1);//opens the summary file in append mode

	//inputs pin and cash from user

	printf("\n Enter Pin: ");
	scanf("%d", &present_account.pin);
	printf("\n Input Cash: ");
	scanf("%d", &present_account.cash);
	while (present_account.cash % 500 != 0) //checks if cash is multiply of 500
	{
		printf("\nPlease Enter a multiple of 500\n");
		printf("\n Input Cash: ");
		scanf("%d", &present_account.cash);
	}


	//adds the account to the data base in the last position

	data_base[account_counter]= present_account;

	account_counter++; //increases the account counter

	printf("\nAccount Created Sucessfully\n");

	//stores the new transaction history in the summary file

	fprintf(summary_ptr, "\n %s Type : Account Creation  Amount: %d  Time: %s  \n", present_account.name, present_account.cash, ctime(&t));

	// closes and saves the summary file so the latest transaction data can be used again without exiting the program
	file_close();

}

//function to withdraw cash
void account_withdrawl()
{
	//initialization of variables
	int pin_counter = 1;
	int temp_pin = NULL;
	int withdraw_amount = 0;

	//takes username from the user

	printf("\nEnter Username :");
	scanf("%s", present_account.name);

	//checks if username is in the database. If it exists, the data of the user is retrieved and stored in "present account" variable so it can be used
	while (account_validation( 2) == 0)
	{
		printf("\nUser Not found\n");
		printf("\nEnter UserName: ");
		scanf("%s", &present_account.name);
	}

	//gives user 3 tries to input pin. It exits if the pin is entered wrong 3 times
	while ((present_account.pin != temp_pin) && (pin_counter <= 3))
	{
		printf("\n 3 tries allowed for Pin,\nThis is try %d.\n", pin_counter);
		printf("\nEnter Pin : ");
		scanf("%d", &temp_pin);
		pin_counter++;
	}

	//continues the operation if correct pin is entered
	if ((present_account.pin == temp_pin) && (pin_counter <= 3))
	{
		//displays the balance
		printf("\nBalance: %d ", present_account.cash);
		
		//asks for the withdraw account

		printf("\nEnter withdraw amount: ");
		scanf("%d", &withdraw_amount);

		//checks if withdraw account is less than or equal to balance. Also if it is a multiple of 500

		while ((withdraw_amount > present_account.cash) || (present_account.cash % 500 != 0))
		{
			while (present_account.cash % 500 != 0) //incase it is not the multiple of 500
			{
				printf("\nPlease Enter a multiple of 500\n");
				printf("\nEnter withdraw amount: ");
				scanf("%d", &withdraw_amount);

			}
			if (withdraw_amount > present_account.cash) //incase it is more than the available balance
			{
				printf("\nNot Enough balance");
				printf("\nTry Again or Enter 0");
				printf("\nEnter withdraw amount: ");
				scanf("%d", &withdraw_amount);

			}

		}
		
		//the present account cash is updated by subtracting the withdraw amount from it
		present_account.cash = (present_account.cash - withdraw_amount);
		//updates the present account in the database
		data_base[account_no] = present_account;

		//prints the remaining balance in the program
		printf("\nRemaining Balance : %d\n", present_account.cash);
		printf("\a\nCollect Your Cash\n");
		printf("\a\nThanks For Your vist.\n");

		//updating transaction data in the summary file
		file_open(1);
		fprintf(summary_ptr, "\n %s Type : Withdrawl  Amount: %d Balance: %d Time: %s  \n", present_account.name, withdraw_amount, present_account.cash, ctime(&t));
		file_close();
	}
}

//function to deposit cash
void account_deposit() {

	//initialization of variables
	int pin_counter = 1;
	int temp_pin = NULL;
	int deposit_amount = 0;

	//taking username input and validating it
	//checks if username is in the database. If it exists, the data of the user is retrieved and stored in "present account" variable so it can be used
	printf("\nEnter Username :");
	scanf("%s", present_account.name);
	while (account_validation( 2) == 0)
	{
		printf("\nUser Not found\n");
		printf("\nEnter UserName: ");
		scanf("%s", &present_account.name);
	}

	//gives user 3 tries to input pin. It exits if the pin is entered wrong 3 times
	while ((present_account.pin != temp_pin) && (pin_counter <= 3))
	{
		printf("\n3 tries allowed for Pin.\nThis is try %d.\n", pin_counter);
		printf("\nEnter Pin : ");
		scanf("%d", &temp_pin);
		pin_counter++;
	}


	//continues the operation if correct pin is entered
	if ((present_account.pin == temp_pin) && (pin_counter <= 3))
	{
		//displays the balance
		printf("\nBalance: %d ", present_account.cash);

		//inputs deposit amount
		printf("\nEnter deposit amount: ");
		scanf("%d", &deposit_amount);

		//checks if it is multiple of 500
		while (present_account.cash % 500 != 0)
		{
			printf("\nPlease Enter a multiple of 500\n");
			printf("\nEnter withdraw amount: ");
			scanf("%d", &deposit_amount);
		}
		
		//updates the cash in present account by addition
		present_account.cash = (present_account.cash + deposit_amount);
		//updates present account data in the database
		data_base[account_no] = present_account;
		//displays the new balance
		printf("\nNew Balance : %d\n", present_account.cash);
		printf("\a\nThanks For Your vist.\n");

		//updates transaction details in the summary file
		file_open(3);
		fprintf(summary_ptr, "\n %s Type : Deposit  Amount: %d Balance: %d Time: %s  \n", present_account.name, deposit_amount, present_account.cash, ctime(&t));
		file_close();
	}
}
void account_balance()
{
	int pin_counter = 1;
	int temp_pin = NULL;

	//taking username input and validating it
	//checks if username is in the database. If it exists, the data of the user is retrieved and stored in "present account" variable so it can be used

	printf("\nEnter Username :");
	scanf("%s", present_account.name);
	while (account_validation( 2) == 0)
	{
		printf("\nUser Not found\n");
		printf("\nEnter UserName: ");
		scanf("%s", &present_account.name);
	}

	//gives user 3 tries to input pin. It exits if the pin is entered wrong 3 times

	while ((present_account.pin != temp_pin) && (pin_counter <= 3))
	{
		printf("\nThis is try %d. 3 tries allowed for Pin\n", pin_counter);
		printf("\nEnter Pin : ");
		scanf("%d", &temp_pin);
		pin_counter++;
	}

	//if the pin is correct then the balance is displayed
	if ((present_account.pin == temp_pin) && (pin_counter <= 3))
	{
		printf("\nBalance: %d ", present_account.cash);
	}
	printf("\a\nThanks For Your vist.\n");

}
void account_summary() {
	int pin_counter = 1;
	int temp_pin = NULL;
	account temp;

	//taking username input and validating it
	//checks if username is in the database. If it exists, the data of the user is retrieved and stored in "present account" variable so it can be used

	printf("\nEnter Username :");
	scanf("%s", present_account.name);
	while (account_validation( 2) == 0)
	{
		printf("\nUser Not found\n");
		printf("\nEnter UserName: ");
		scanf("%s", &present_account.name);
	}

	//gives user 3 tries to input pin. It exits if the pin is entered wrong 3 times

	while ((present_account.pin != temp_pin) && (pin_counter <= 3))
	{
		printf("\nThis is try %d. 3 tries allowed for Pin\n", pin_counter);
		printf("\nEnter Pin : ");
		scanf("%d", &temp_pin);
		pin_counter++;
	}

	//continuues operation if the pin is correct

	if ((present_account.pin == temp_pin) && (pin_counter <= 3))
	{
		//closes the open files so any data can be saved
		file_close();
		//opens the summary file with the latest data
		file_open(2);
		
		printf("\n Account Summary.\n\n");

		//variable to check for EOF
		char filechar = fgetc(summary_ptr);

		/*
		*  logic:	The transaction data of each account is stored in the same file. Each line begins with the name of the account.
		*			The algo first reads the name of the account and stores it in a temporary variable. If the temporary variable is 
		*			equal to the required account name. The it prints all the data written in that line. It reads till the end of file
		*			as data is stored according to transaction time. In this way it keeps on displaying the data for the required person
		* 
		*/

		while ((filechar != EOF))
		{

			if (filechar == '\n') // reads data only if the file pointor is at a new line to avoid any anamolies
			{
				char data[500] = {0}; //initializes the data to an empty array during each iteration of the loop
				strcpy(temp.name,"                      "); //clears the name at each iteration to avoid any anamolies
				fscanf(summary_ptr, "%s", &temp.name); //reads the name of the username written at the start of the line
		
				if (strcmp(temp.name, present_account.name) == 0) //if the name is the required name. It reads the data written after it
				{
					fgets(data, 499, summary_ptr);
					printf("\n%s", data); //printing the data
				}
			}
			filechar = fgetc(summary_ptr); //get char to check EOF
		}

	}
	file_close(); //closing all files
	printf("\a\nThanks For Your vist.\n");

}

//THE END