// ATMInfra.java - ATM INFRASTRUCTURE EMULATOR
//
// MODULE INDEX
// NAME				CONTENTS
// ATMInfra.genRandPix		Generate random pixels
// ATMInfra.changePix		Change a small percentage of the pixels in an
//				array
// ATMInfra.emulateCardIn	Emulate insertion of a card into the reader
// ATMInfra.readScreenPixels	Read the current screen
// ATMInfra.readScreenDump	Read a saved screen dump
// ATMInfra.emulateTouch	Emulate touching the screen
// ATMInfra.getAmountPaid	Get the amount paid out by the bill dispenser
//
// MAINTENANCE HISTORY
// DATE		PROGRAMMER AND DETAILS
// 19-08-07	JS	Original
//
//-----------------------------------------------------------------------------

// IMPORTS

import java.util.*;

//-----------------------------------------------------------------------------

public class ATMInfra {

    //-------------------------------------------------------------------------

    // DEFINITIONS

    static private final int PIX_ARR_SIZE = 307200;
				// Pixel array size
    static private final int MAX_CHG_PIX = 200;
				// Maximum changed pixels
    static private final int ATM_PIN_SIZE = 6;
				// PIN size
    static private final int MAX_DLR_LEN = 4;
				// Maximum dollar value length
    static private final int CNT_LEN = 2;
				// Length of the cents field
    static private final int DISP_UNIT = 1000;
				// Dispensing unit (cents)
    static private final int MAX_AMT = 100000;
				// Maximum amount to dispense (cents)
    static private final int MIN_AMT = 1000;
				// Minimum amount to dispense (cents)

    //-------------------------------------------------------------------------

    // ATM STATE

    static private final int ATM_IDLE = 0;
				// The ATM is between transactions
    static private final int ATM_RECV_PIN = 1;
				// The ATM is receiving a PIN
    static private final int ATM_RECV_ACC = 2;
				// The ATM is receiving an account selection
    static private final int ATM_RECV_DOLLARS = 3;
				// The ATM is receiving the dollars component
				// of the amount to be withdrawn
    static private final int ATM_RECV_CENTS = 4;
				// The ATM is receiving the cents component
				// of the amount to be withdrawn
    static private final int ATM_DISPENSING = 5;
				// The ATM is dispensing cash

    //-------------------------------------------------------------------------

    // STATIC VARIABLES

    static private int	atmState = ATM_IDLE;	// ATM state
    static private String atmCardNumber;	// Current card number
    static private String atmPinVal;		// PIN value
    static private String atmAccVal;		// Account code
    static private int	atmAmtVal;		// Amount value
    static private int	atmDlrLen;		// Length of dollars field
    static private int	atmCntLen;		// Length of cents field
    static private int	atmDlrRem = 0;		// Dollars remaining to be
						// dispensed
    static private Random atmRandom = new Random(20360);
						// Random number generator
    static private long[] atmAcpCrdPix = genRandPix();
						// Card accepted pixels
    static private long[] atmAcpPinPix = genRandPix();
						// PIN accepted pixels
    static private long[] atmAcpAccPix = genRandPix();
						// Account accepted pixels
    static private long[] atmRejectPix = genRandPix();
						// Request rejected pixels

    //-------------------------------------------------------------------------

    // GENERATE RANDOM PIXELS

    static private long[]
    genRandPix ()
    {
	long[]		pixArray;	// Pixel array
	int		i;		// General purpose index

	pixArray = new long [ PIX_ARR_SIZE ];
	for (i = 0; i < PIX_ARR_SIZE; i++)
	    pixArray[i] = atmRandom.nextInt ();
	return pixArray;
    }

    //-------------------------------------------------------------------------

    // CHANGE A SMALL PERCENTAGE OF THE PIXELS IN AN ARRAY

    static private long[]
    changePix (
	long[]		orgPix)		// Original pixels
    {
	long[]		chgPix;		// Changed pixels
	int		i;		// General purpose index
	int		chgRem;		// Pixel changes remaining
	int		chgRand;	// Pixel change random number

	chgPix = new long [ PIX_ARR_SIZE ];
	chgRem = atmRandom.nextInt(MAX_CHG_PIX + 1);
	for (i = 0; i < PIX_ARR_SIZE; i++) {
		chgRand = atmRandom.nextInt(PIX_ARR_SIZE-i);
		if (chgRand < chgRem) {
			chgPix[i] = atmRandom.nextLong();
			chgRem -- ;
		} else {
			chgPix[i] = orgPix[i];
		}
	}
	return chgPix;
    }

    //-------------------------------------------------------------------------

    // EMULATE INSERTION OF A CARD INTO THE READER

    static public void
    emulateCardIn (
	String		cardNumber)	// Card number
    {
	if (atmState != ATM_IDLE)
	    throw new RuntimeException ("bad state " + atmState);
	atmCardNumber = cardNumber;
	System.out.println ("Card number " + atmCardNumber + " inserted");
	atmState = ATM_RECV_PIN;
	atmPinVal = "";
    }

    //-------------------------------------------------------------------------

    // READ THE CURRENT SCREEN

    static public long []
    readScreenPixels ()
    {
	long[]		pixArray;	// Pixel array

	switch (atmState) {
	case ATM_IDLE:
	    pixArray = genRandPix();
	    break;
	case ATM_RECV_PIN:
	    pixArray = changePix(atmAcpCrdPix);
	    break;
	case ATM_RECV_ACC:
	    pixArray = changePix(atmAcpPinPix);
	    break;
	case ATM_RECV_DOLLARS:
	case ATM_RECV_CENTS:
	    pixArray = changePix(atmAcpAccPix);
	    break;
	case ATM_DISPENSING:
	    pixArray = genRandPix();
	    break;
	default:
	    throw new RuntimeException ("bad state " + atmState);
	}
	return pixArray;
    }

    //-------------------------------------------------------------------------

    // READ A SAVED SCREEN DUMP

    static public long []
    readScreenDump (
	String		fileName)	// File name
    {
	long[]		pixArray;	// Pixel array

	if (fileName.equals ("AcceptedCard.rgb"))
	    pixArray = atmAcpCrdPix;
	else if (fileName.equals ("AcceptedPIN.rgb"))
	    pixArray = atmAcpPinPix;
	else if (fileName.equals ("AcceptedAccount.rgb"))
	    pixArray = atmAcpAccPix;
	else
	    throw new RuntimeException (fileName + " does not exist");
	return pixArray;
    }

    //-------------------------------------------------------------------------

    // EMULATE TOUCHING THE SCREEN

    static public void
    emulateTouch (
	int		x,		// Horizontal position
	int		y)		// Vertical position
    {
	char		ch;		// Received character

	// Decode the character

	if (x == 246 && y == 406)
		ch = '0';
	else if (x == 394 && y == 406)
		ch = '.';
	else if (x == 246 && y == 332)
		ch = '1';
	else if (x == 320 && y == 332)
		ch = '2';
	else if (x == 394 && y == 332)
		ch = '3';
	else if (x == 246 && y == 258)
		ch = '4';
	else if (x == 320 && y == 258)
		ch = '5';
	else if (x == 394 && y == 258)
		ch = '6';
	else if (x == 246 && y == 184)
		ch = '7';
	else if (x == 320 && y == 184)
		ch = '8';
	else if (x == 394 && y == 184)
		ch = '9';
	else if (x == 560 && y == 184)
		ch = '\n';
	else if (x == 560 && y == 258)
		ch = '\b';
	else {
		throw new RuntimeException ("bad touch point x=" + x
		    + " y=" + y);
	}

	// Process the character depending on the current state

	switch (atmState) {
	case ATM_RECV_PIN:
	    if ( ! Character.isDigit (ch))
		throw new RuntimeException (
		    "received non-digit while reading PIN");
	    atmPinVal += ch;
	    if (atmPinVal.length() >= ATM_PIN_SIZE) {
		System.out.println ("PIN " + atmPinVal + " entered");
		atmState = ATM_RECV_ACC;
	    }
	    break;
	case ATM_RECV_ACC:
	    switch (ch) {
	    case '8':
		atmAccVal = "Cheque";
		break;
	    case '5':
		atmAccVal = "Savings";
		break;
	    case '2':
		atmAccVal = "Credit";
		break;
	    default:
		throw new RuntimeException ("invalid account selection");
	    }
	    System.out.println (atmAccVal + " selected");
	    atmState = ATM_RECV_DOLLARS;
	    atmAmtVal = 0;
	    atmDlrLen = 0;
	    atmCntLen = 0;
	    break;
	case ATM_RECV_DOLLARS:
	    if (Character.isDigit (ch)) {
		if (atmDlrLen >= MAX_DLR_LEN)
		    throw new RuntimeException ("dollar value length too big");
		atmAmtVal = atmAmtVal * 10 + Character.digit (ch, 10);
		atmDlrLen ++ ;
	    } else if (ch == '.') {
		atmState = ATM_RECV_CENTS;
	    } else {
		throw new RuntimeException (
		    "invalid character in dollars field");
	    }
	    break;
	case ATM_RECV_CENTS:
	    if (Character.isDigit (ch)) {
		if (atmCntLen >= CNT_LEN)
		    throw new RuntimeException ("cents length too big");
		atmAmtVal = atmAmtVal * 10 + Character.digit (ch, 10);
		atmCntLen ++ ;
	    } else if (ch == '\n') {
		if (atmCntLen != CNT_LEN)
		    throw new RuntimeException ("wrong number of cents digits");
		if (atmAmtVal % DISP_UNIT != 0)
		    throw new RuntimeException (
			"amount not multiple of dispensing unit");
		if (atmAmtVal > MAX_AMT)
		    throw new RuntimeException ("too much");
		if (atmAmtVal < MIN_AMT)
		    throw new RuntimeException ("too little");
	        System.out.println ("Dispensing $" + atmAmtVal/100);
		atmState = ATM_DISPENSING;
		atmDlrRem += atmAmtVal;
	    } else {
		throw new RuntimeException ("invalid character in cents field");
	    }
	    break;
	default:
	    throw new RuntimeException ("bad state " + atmState);
	}
    }

    //-------------------------------------------------------------------------

    // GET THE AMOUNT PAID OUT BY THE BILL DISPENSER

    static public int
    getAmountPaid ()
    {
	int		amtDisp;	// Amount dispensed

	if (atmDlrRem > 25000)
		amtDisp = 25000;
	else
		amtDisp = atmDlrRem;
	atmDlrRem -= amtDisp;
	if (amtDisp != 0 && atmDlrRem == 0) {
	    System.out.println ("Dispensing finished");
	    atmState = ATM_IDLE;
	}
	return amtDisp / 100;
    }
}