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

public class pgm00_01BankAccounts {

	public static void main(String[] args) throws IOException
	{
		//constant definitions
		final int MAX_NUM = 50;
		
		//variable declarations
		int[] acctNumArray = new int[MAX_NUM];			//array of account numbers
	    double[] balanceArray = new double[MAX_NUM];	//array of balances
	    int numAccts;									//number of accounts
	    char choice;									//menu item selected
	    boolean not_done = true;						//loop control flag

	    // open input test cases file
	    //File testFile = new File("/bc/cisc3115/pgms/chapter_00/prj00_01BankAccounts/mytestcases.txt");
	    File testFile = new File("mytestcases.txt");
	    
	    //create Scanner object
	    Scanner kybd = new Scanner(testFile);
	    //Scanner kybd = new Scanner(System.in);

	    // open the output file
	    //PrintWriter outFile = new PrintWriter("/bc/cisc3115/pgms/chapter_00/prj00_01BankAccounts/myoutput.txt");
	    PrintWriter outFile = new PrintWriter("myoutput.txt");
	    //PrintWriter outFile = new PrintWriter(System.out);

	    /* first part */
	    /* fill and print initial database */
	    numAccts = readAccts(acctNumArray,balanceArray,MAX_NUM);
	    printAccts(acctNumArray,balanceArray,numAccts,outFile);
	    
	    /* second part */
	    /* prompts for a transaction and then */
	    /* call functions to process the requested transaction */
	    do {
	        menu();
	        choice = kybd.next().charAt(0);
	        switch(choice)
	        {
	            case 'q':
	            case 'Q':
	                not_done = false;
	                printAccts(acctNumArray,balanceArray,numAccts,outFile);
	                break;
	            case 'b':
	            case 'B':
	                balance(acctNumArray,balanceArray,numAccts,outFile,kybd);
	                break;
	            case 'd':
	            case 'D':
	                deposit(acctNumArray,balanceArray,numAccts,outFile,kybd);
	                break;
	            case 'w':
	            case 'W':
	                withdrawal(acctNumArray,balanceArray,numAccts,outFile,kybd);
	                break;
	            case 'n':
	            case 'N':
	                numAccts = newAcct(acctNumArray,balanceArray,numAccts,outFile,kybd);
	                break;
	            case 'x':
	            case 'X':
	                numAccts = deleteAcct(acctNumArray,balanceArray,numAccts,outFile,kybd);
	                break;
	            default:
	                outFile.println("Error: " + choice + " is an invalid selection -  try again");
	                outFile.println();
	                outFile.flush();
	                break;
	        }
	        // give user a chance to look at output before printing menu
	        //pause(kybd);
	    } while (not_done);
	    
	    //close the output file
	    outFile.close();
	    
	    //close the test cases input file
	    kybd.close();
	    
	    System.out.println();
	    System.out.println("The program is terminating");
	}
	
	/* Method readAccts()
	 * Input:
	 *  acctNumArray - reference to array of account numbers
	 *  balanceArray - reference to array of account balances
	 *  maxAccts - maximum number of active accounts allowed
	 * Process:
	 *  Reads the initial database of accounts and balances
	 * Output:
	 *  Fills in the initial account and balance arrays and returns the number of active accounts
	 */
	public static int readAccts(int[] acctNumArray, double[] balanceArray, int maxAccts) throws IOException
	{
	    // open database input file
		//create File object
	    //File dbFile = new File("/bc/cisc3115/pgms/chapter_00/prj00_01BankAccounts/myinput.txt");
	    File dbFile = new File("myinput.txt");

	    //create Scanner object
	    Scanner sc = new Scanner(dbFile);
	    		
	    int count = 0;                          //account number counter

	    while (sc.hasNext() && count < maxAccts)
	    {
	    	acctNumArray[count] = sc.nextInt();
	        balanceArray[count] = sc.nextDouble();
	        count++;
	    }

	    //close the input file
	    sc.close();
	    
	    //return the account number count
	    return count;
	}

	/* Method printAccts:
	 * Input:
	 *  acctNumArray - array of account numbers
	 *  balanceArray - array of account balances
	 *  numAccts - number of active accounts
	 *  outFile - reference to the output file
	 * Process:
	 *  Prints the database of accounts and balances
	 * Output:
	 *  Prints the database of accounts and balances
	*/
	public static void printAccts(int[] acctNumArray, double[] balanceArray, int numAccts,
									PrintWriter outFile)
	{
	    outFile.println();
	    outFile.println("\t\tDatabase of Bank Accounts");
	    outFile.println();
	    outFile.println("Account   Balance");
	    for (int index = 0; index < numAccts; index++)
	    {
		    outFile.printf("%7d  $%7.2f", acctNumArray[index], balanceArray[index]);
		    outFile.println();
	    }
	    outFile.println();

	    //flush the output file
	    outFile.flush();
	}
	
	/* Method menu()
	 * Input:
	 *  none
	 * Process:
	 *  Prints the menu of transaction choices
	 * Output:
	 *  Prints the menu of transaction choices
	 */
	public static void menu()
	{
	    System.out.println();
	    System.out.println("Select one of the following transactions:");
	    System.out.println("\t****************************");
	    System.out.println("\t    List of Choices         ");
	    System.out.println("\t****************************");
	    System.out.println("\t     W -- Withdrawal");
	    System.out.println("\t     D -- Deposit");
	    System.out.println("\t     N -- New Account");
	    System.out.println("\t     B -- Balance Inquiry");
	    System.out.println("\t     X -- Delete Account");
	    System.out.println("\t     Q -- Quit");
	    System.out.println();
	    System.out.print("\tEnter your selection: ");
	}
	
	/* Method findAcct:
	 * Input:
	 *  acctNumArray - array of account numbers
	 *  numAccts - number of active accounts
	 *  requestedAccount - requested account requested_number
	 * Process:
	 *  Performs a linear search on the acctNunArray for the requested account
	 * Output:
	 *  If found, the index of the requested account is returned
	 *  Otherwise, returns -1
	 */
	public static int findAcct(int[] acctNumArray, int numAccts, int requestedAccount)
	{
	    for (int index = 0; index < numAccts; index++)
	        if (acctNumArray[index] == requestedAccount)
	            return index;
	    return -1;
	}
	
	/* Method balance:
	 * Input:
	 *  acctNumArray - array of account numbers
	 *  balanceArray - array of account balances
	 *  numAccts - number of active accounts
	 *  outFile - reference to output file
	 *  kybd - reference to the "test cases" input file
	 * Process:
	 *  Prompts for the requested account
	 *  Calls findAcct() to see if the account exists
	 *  If the account exists, the balance is printed
	 *  Otherwise, an error message is printed
	 * Output:
	 *  If the account exists, the balance is printed
	 *  Otherwise, an error message is printed
	 */
	public static void balance(int[] acctNumArray, double[] balanceArray, int numAccts, 
			PrintWriter outFile, Scanner kybd)
	{
	    int requestedAccount;
	    int index;

	    System.out.println();
	    System.out.print("Enter the account number: ");			//prompt for account number
	    requestedAccount = kybd.nextInt();						//read-in the account number
	    
	    //call findAcct to search if requestedAccount exists
	    index = findAcct(acctNumArray, numAccts, requestedAccount);
	    
	    if (index == -1)                                        //invalid account
	    {
	        outFile.println("Transaction Requested: Balance Inquiry");
	        outFile.println("Error: Account number " + requestedAccount + " does not exist");
	    }
	    else                                                    //valid zccount
	    {
	        outFile.println("Transaction Requested: Balance Inquiry");
	        outFile.println("Account Number: " + requestedAccount);
	        outFile.printf("Current Balance: $%.2f", balanceArray[index]);
		    outFile.println();
	    }
	    outFile.println();

	    outFile.flush();				//flush the output buffer
	}

	/* Method deposit:
	 * Input:
	 *  acctNumArray - array of account numbers
	 *  balanceArray - array of account balances
	 *  numAccts - number of active accounts
	 *  outFile - reference to the output file
	 *  kybd - reference to the "test cases" input file
	* Process:
	 *  Prompts for the requested account
	 *  Calls findacct() to see if the account exists
	 *  If the account exists, prompts for the amount to deposit
	 *  If the amount is valid, it makes the deposit and prints the new balance
	 *  Otherwise, an error message is printed
	 * Output:
	 *  For a valid deposit, the deposit transaction is printed
	 *  Otherwise, an error message is printed
	 */
	public static void deposit(int[] acctNumArray, double[] balanceArray, int numAccts, 
			PrintWriter outFile, Scanner kybd)
	{
	    int requestedAccount;
	    int index;
	    double amountToDeposit;

	    System.out.println();
	    System.out.print("Enter the account number: ");			//prompt for account number
	    requestedAccount = kybd.nextInt();						//read-in the account number

	    //call findAcct to search if requestedAccount exists
	    index = findAcct(acctNumArray, numAccts, requestedAccount);
	    
	    if (index == -1)                                        //invalid account
	    {
	        outFile.println("Transaction Requested: Deposit");
	        outFile.println("Error: Account number " + requestedAccount + " does not exist");
	    }
	    else                                                    //valid zccount
	    {
	        System.out.print("Enter amount to deposit: ");		//prompt for amount to deposit
	        amountToDeposit = kybd.nextDouble();						//read-in the amount to deposit

	        if (amountToDeposit <= 0.00)                		
	        {
	        	//invalid amount to deposit
		        outFile.println("Transaction Requested: Deposit");
		        outFile.println("Account Number: " + requestedAccount);
		        outFile.printf("Error: $%.2f is an invalid amount", amountToDeposit);
			    outFile.println();
	        }
	        else
	        {
		        outFile.println("Transaction Requested: Deposit");
		        outFile.println("Account Number: " + requestedAccount);
	            outFile.printf("Old Balance: $%.2f", balanceArray[index]);
			    outFile.println();
	            outFile.println("Amount to Deposit: $" + amountToDeposit);
	            balanceArray[index] += amountToDeposit;			//make the deposit
	            outFile.printf("New Balance: $%.2f", balanceArray[index]);
			    outFile.println();
	        }
	    }
	    outFile.println();

	    outFile.flush();				//flush the output buffer
	}
	
	public static void withdrawal(int[] acctNumArray, double[] balanceArray, int numAccts,
			PrintWriter outFile, Scanner kybd)
	{
	
	}

	public static int newAcct(int[] acctNumArray, double[] balanceArray, int numAccts,
			PrintWriter outFile, Scanner kybd)
	{
		return numAccts;
	}

	public static int deleteAcct(int[] acctNumArray, double[] balanceArray, int numAccts,
			PrintWriter outFile, Scanner kybd)
	{
		return numAccts;
	}

	/* Method pause() */
	public static void pause(Scanner keyboard)
	{
		String tempstr;
		System.out.println();
		System.out.print("press ENTER to continue");
		tempstr = keyboard.nextLine();		//flush previous ENTER
		tempstr = keyboard.nextLine();		//wait for ENTER
	}

}