import java.io.*;
import java.util.Scanner;

public class hw7 {

	public static void main(String[] args)	throws IOException //added throw clause
	{
		//constant definition
		final int MAX_NUM = 10;

		//declare arrays
		int[] acctNumArray = new int[MAX_NUM];
		double[] balanceArray = new double[MAX_NUM];

		//declare variables
		char choice;
		int numAccts;

		//create scanner class
		Scanner inputFile = new Scanner(System.in);

		//create an PrintWriter reference variable to an output file PrintWriter object
		PrintWriter outputFile = new PrintWriter("myoutput.txt");

		//call method to read data
		numAccts = readAccts(acctNumArray, balanceArray, MAX_NUM);

		//call method to print initial database of accounts and balances
		printAccts(acctNumArray, balanceArray, numAccts, outputFile);

		//do while loop
		do {
			menu();
			choice = inputFile.next().charAt(0);
			switch (choice) {
			case 'Q':
			case 'q':
				printAccts(acctNumArray, balanceArray, numAccts, outputFile);
				break;
			case 'W':
				withdrawal(acctNumArray, balanceArray, numAccts, outputFile, inputFile);
				break;
			case 'D':
				deposit(acctNumArray, balanceArray, numAccts, outputFile, inputFile);
				break;
			case 'N':
				newAcct(acctNumArray, balanceArray, numAccts, outputFile, inputFile);
				break;
			case 'B':
				balance(acctNumArray, balanceArray, numAccts, outputFile, inputFile);
				break;
			default:
				System.out.print("An error has occured");
				menu();
				choice = inputFile.next().charAt(0);
				break;
			}
		}	while (choice != 'Q' && choice != 'q');

		//close the files
		inputFile.close();
		outputFile.close();

	}
	/*Input:
	*acctNum - reference to an array of account numbers
	*balance - reference to an array of account balances
	*maxAccts - the max amount of accounts that can be filled up
	* Process:
	*reads in data values of account numbers and balance
	* Output:
	*prints the actual number of accounts read in
	*/
	public static int readAccts(int[] acctNumArray, double[] balanceArray, int maxAccts)	throws IOException //add throw clause
	{
		//local variable declaration
		int count = 0;

		//Create a scanner object to read the input file
		Scanner inputFile = new Scanner(System.in);

		//read in account number and balance arrays and count number of accounts read in
		while (inputFile.hasNext() && count < maxAccts)
		{
			acctNumArray[count] = inputFile.nextInt();
			balanceArray[count] = inputFile.nextDouble();
			count++;
		}
		//close the input file
		inputFile.close();

		return count;
	}

	/*Input:
	 *acctNum - reference to an array of account numbers
	 *balance- reference to an array of account balances
	 *numAccts - number of account elements in the array
	 *myout - reference to the output file
	 * Process:
	 *makes a table to store all customers account numbers and balances
	 * Output:
	 *prints a two column table of customer account number and balance
	 */
	public static void printAccts(int[] acctNumArray, double[] balanceArray, int numAccts, PrintWriter outputFile)
	{
		outputFile.println("\t\tInitial database of accounts and balances");
		outputFile.println("\tAccount \tBalance");
		//use for loop to print account number and balances
		for (int count = 0; count < numAccts; count++)
		{
		outputFile.printf("%7d, $%7.2f", acctNumArray[count], balanceArray[count]);
		outputFile.println();
		}
	}
	/* Input:
	 * none
	 * Process:
	 * display different types of interactions that can be used
	 * Output:
	 * prints the command you want to use
	 */
	public static void menu() {
		System.out.println("\tSelect one of the following:\n\n"
			+ "W Representing Withdrawal\n"
			+ "D Representing Deposit\n"
			+ "N Representing New account\n"
			+ "B Representing Balance\n"
			+ "Q Indicating the user wants to quit the program\n");
	}
	/*Input:
	*acctNum - reference to an array of integer account numbers
	*numAccts - the number of account elements in the array
	*account - array of integer account numbers
	* Process:
	*finds the account number if the account exists, or if it doesn’t exist
	* Output:
	*prints the index of account in acctNum array if the account exists, and -1 if it doesn’t.
	*/
	public static int findAcct(int[] acctNumArray, int numAccts, int account)
	{
		for (int count = 0; count < numAccts; count++) {
			if (acctNumArray[count] == account) {
				return count;
			}
		}
		return -1;
	}

	/*Input:
	*acctNum - reference to an array of account numbers
	*balance - reference to an array of account balances
	*numAccts - number of account elements in the array
	* Process:
	*prompts the id the user entered, and prints an error if account is invalid. Then proceeds
to identify the balance
	* Output:
	*prints the current account balance
	*/
	public static void balance(int[] acctNumArray, double[] balanceArray, int numAccts, PrintWriter outputFile, Scanner inputFile)
	{
		int account;	//declare variable
		int count;

		System.out.println("Enter an account number: ");
		account = inputFile.nextInt();

		//check to see if account exists by calling method
		count = findAcct(acctNumArray, numAccts, account);

		//if-else statement
		if (count == -1) {
			outputFile.println("Transaction Type: Balance");
			outputFile.println("Error the account number" + account + " does not exist\n\n");
		} else {
			outputFile.println("Transaction Type: Balance");
			outputFile.println("Account number" + account);
			outputFile.printf("Current Balance: $%.2f, balanceArray[index]\n\n");
		}

	}
	/*Input:
	*acctNum - reference to an array of integer account numbers
	*balance - reference to an array of account balances
	*num_accts - the number of account elements in the array
	* Process:
	*finds the account if it exists, and the amount of money being deposited
	* Output:
	*prints the amount of money being deposited, or an error message due to invalid acct
	*/
	public static void deposit(int[] acctNumArray, double[] balanceArray, int numAccts, PrintWriter outputFile, Scanner inputFile)
	{
		int account;	//declare variables
		int count;
		double amounttodeposit;

		outputFile.print("Enter an account number: ");
		account = inputFile.nextInt();

		//check to see if the account exists
		count = findAcct(acctNumArray, numAccts , account);

		//if-else statement
		if (count == -1) {
			outputFile.println("Transaction Type: Deposit");
			outputFile.println("Error, the account you entered" + account + "does not exist\n\n");
		} else {
			outputFile.println("Enter the amount to deposit: ");
			amounttodeposit = inputFile.nextDouble();
			if (amounttodeposit < 0.00) {
				outputFile.println("Transaction Type: Deposit");
				outputFile.println("Account number " + account);
				outputFile.println("Amount to Deposit" + amounttodeposit);
				outputFile.println("Error, can not deposit this amount of money");
			} else {
			outputFile.println("Transaction Type: Deposit");
			outputFile.println("Account number" + account);
			outputFile.println("Current Balance: $%.2f, balanceArray[count]\n\n");
			outputFile.println("Amount to Deposit" + amounttodeposit);

			outputFile.printf("New Balance: $%.2f, balanceArray[count]\n\n");
		}
	}
}
	/*Input:
	*acctNum - reference to an array of integer account numbers
	*balance - reference to an array of account balances
	*numAccts - the number of account elements in the array
	* Process:
	*finds account number if it exists, the amount of money being withdrawn, and if there is
sufficient funds
	* Output:
	*prints the amount of money withdrawn, or an error message saying non sufficient funds
	*/
	public static void withdrawal(int[] acctNumArray, double[] balanceArray, int numAccts,PrintWriter outputFile,Scanner inputFile)
	{
		//declare variables
		int account;
		int count;
		double amounttowithdraw = 0;

		outputFile.println("Enter an account number: ");
		account = inputFile.nextInt();

		//check to see if the account exists
		count = findAcct(acctNumArray, numAccts , account);

		//if-else statement
		if (count == -1) {
			outputFile.println("Transaction Type: Withdrawal");
			outputFile.println("Error, the account you entered does not exist");
		} else {
			outputFile.println("Transaction Type: Withdrawal");
			outputFile.println("Enter the amount to withdraw: ");
			amounttowithdraw = inputFile.nextDouble();
		}
		if (amounttowithdraw > balanceArray[count] && amounttowithdraw < 0) {
			outputFile.println("Transaction Type: Withdraw");
			outputFile.println("Account number " + account);
			outputFile.println("Amount to Withdraw" + amounttowithdraw);
			outputFile.println("Error, can not withdraw this amount of money\n\n");
		}
		else {
			balanceArray[count] -= amounttowithdraw;
			outputFile.println("Transaction Type: Withdraw");
			outputFile.println("Account number " + account);
			outputFile.println("Current Balance: $%.2f, balanceArray[count]\n\n");
			outputFile.println("Amount to withdraw" + amounttowithdraw);
			outputFile.printf("New Balance: $%.2f, balanceArray[count]\n\n");
		}
	}
	/*Input:
	*acctNum - reference to an array of integer account numbers
	*balance - reference to an array of account balances
	*numAccts - the number of account elements in the array
	* Process:
	*prompts id the user entered and checks to see if account is already taken. If it is, prints
an error message, and if not, adds the account to acctNum array
	* Output:
	*prints a new account with an initial balance of 0
	*/
	public static int newAcct(int[] acctNum, double[] balance, int numAccts, PrintWriter outputFile, Scanner inputFile)
	{
		int newaccount;
		int count = 0;

		outputFile.println("Enter a new account number: ");
		newaccount = inputFile.nextInt();

		if (count == newaccount) {
			outputFile.println("Transaction Type: New Account");
			outputFile.println("Error, the account you entered already exist");

			return numAccts;

		}
		if (newaccount < 0 || newaccount > 99999) {
			outputFile.println("Transaction Type: New Account");
			outputFile.println("Error, the account number you entered does not exist");

			return numAccts;

		}

			int[] acctNumArray = null;
			acctNumArray[numAccts] = newaccount;
			double balanceArray = 0.00;

			outputFile.println("Transaction Type: New Account");
			outputFile.println("account" + newaccount);

			return ++numAccts;
	}

}