/**
 *  file :  BankApp.java
 *  desc :  A bank application.  Allows a user to
 *          create and manipulate banking accounts.
 */


import java.io.*;

public class BankApp {


  static private VirtualTeller ATM = new VirtualTeller();

  public static void main( String[] args ) {

    greeting();
    usage();


    String command = readLine( "--> ");
    while( !command.equals( "quit" ) ) {
      try {
	if( command.equals( "open" ) ) {
	  open();
	}
	else if( command.equals( "deposit" ) ) {
	  doDeposit();
	}
	else if( command.equals( "withdraw" ) ) {
	  doWithdraw();
	}
	else if( command.equals( "inquire" ) ) {
	  doInquire();
	}
	else {
	  System.err.println( "Invalid command: " + command );
	  usage();
	}
      } catch( Exception e ) {
	System.err.println( e );
      }
      command = readLine( "\n--> " );
    }
  }

  /**
   *  post :  prompts the user to create an account and creates
   *          one in the ATM
   */
  private static void open() throws IOException {

    // Get name
    String name = readLine( "Enter name: " );

    int newNum = ATM.openAccount( name );

    System.out.println( name + ", your new account number is: " + newNum );
    System.out.println( "Thanks for opening an account with us!" );
  }

  /**
   *  post :  prompts the user for an account number and tries
   *          to perform a deposit transaction on that account
   */
  private static void doDeposit() throws IOException {
    // Get account number
    int acctNumber = readInt( "Enter account number: " );
    int amount = readInt( "Enter amount to deposit: " );

    ATM.deposit( acctNumber, amount );
    System.out.println( "New balance for #" + acctNumber + " is " +
			ATM.balanceInquiry( acctNumber ) );
  }


  /**
   *  post :  prompts the user for an account number and tries
   *          to perform a withdrawl transaction from that account
   */
  private static void doWithdraw() throws IOException {
    // Get account number
    int acctNumber = readInt( "Enter account number: " );
    int amount = readInt( "Enter amount to withdraw: " );

    ATM.withdraw( acctNumber, amount );
    System.out.println( "New balance for #" + acctNumber + " is " +
			ATM.balanceInquiry( acctNumber ) );
  }


  /**
   *  post :  prompts the user for an account number and tries
   *          to get that account's balance
   */
  private static void doInquire() throws IOException {
    // Get account number
    int acctNumber = readInt( "Enter account number: " );

    System.out.println( "Balance for #" + acctNumber + " is " +
			ATM.balanceInquiry( acctNumber ) );
  }

  /**
   *  post :  displays a greeting message
   */
  private static void greeting() {
    System.out.println( "-------------------" );
    System.out.println( "Welcome to the bank" );
    System.out.println( "-------------------" );
    System.out.println( "" );
  }


  /**
   *  post :  displays instructions on using the command
   *          line arguments
   */
  private static void usage() {
    System.out.println( "Valid commands are: " +
			"open, deposit, withdraw, inquire, quit" );
  }


  // some clumsy I/O stuff
  private static DataInputStream dis = new DataInputStream( System.in );

  /**
   *  post :  return a string from the input stream
   */
  private static String readLine( String prompt ) throws IOException {
    System.out.print( prompt );
    return dis.readLine();
  }

  /**
   *  post :  return an integer from the input stream
   */
  private static int readInt( String prompt ) throws IOException {
    String text = readLine( prompt );
    return Integer.valueOf(text).intValue();
  }
}


// eof