package com.rle.monitor;

/*
 * RLE Surface Crack Detector Graphing Software
 *
 * Copyright (C) 2002 RLE Technologies
 * For more information visit http://www.rletech.com/
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
 * USA.
 */

/**
 * @author Andy Goth
 * @author Eric Peterson
 * @author Matt Lane
 * @version 0.1
 */

import java.io.*;
import java.lang.*;
import java.util.*;

/** Scanner device emulated in software. */
public class Emulator extends ScannerAdapter implements Runnable {
	private Random rand = new Random();
	private boolean dataTransfer;
	private boolean opened;
	private int gain = 32;
	private int offset = 128;
	private int threshhold = 64;
	private Thread thread;
	private int nextEcho = GAIN;
	private int prevSample = 128;

	/** Returns the next filtered sample. */
	private int filter(int value)
	{
		return prevSample = (int)(value * 0.1 + prevSample * 0.9);
	}

	public void open(String portName) throws IOException
	{
		if (opened) throw new IOException("Device already opened");
		opened = true;
		thread = new Thread(this, "Emulation");
		thread.start();
		beginDataTransfer();
	}

	public void close() throws IOException
	{
		if (!opened) throw new IOException("Device not opened");
		opened = false;
		thread.interrupt();
		while (true) {
			try {
				thread.join();
				return;
			} catch (InterruptedException e) {}
		}
	}

	public void beginDataTransfer() throws IOException
	{
		dataTransfer = true;
	}

	public void reset() throws IOException
	{
		dataTransfer = false;
	}

	public void setOffset(int o) throws IOException
	{offset = o; nextEcho = OFFSET;}
	public void setGain(int g) throws IOException
	{gain= g; nextEcho = GAIN;}
	public void setAutoOffset() throws IOException {}
	public void setAlarm(boolean f) throws IOException {}
	public void setRedLED() throws IOException {}
	public void setGreenLED() throws IOException {}
	public void setLED(boolean f) throws IOException {}
	public void setThreshhold(int t) throws IOException
	{threshhold = t; nextEcho = THRESHHOLD;}
	public void queryOffset() throws IOException
	{nextEcho = OFFSET;}
	public void queryGain() throws IOException
	{nextEcho = GAIN;}
	public void queryThreshhold() throws IOException
	{nextEcho = THRESHHOLD;}

	/** Emulation thread. */
	public void run()
	{
		try {
			while (true) {
				if (!dataTransfer) {
					Thread.sleep(100);
					continue;
				}
				for (int i = 0; i < 19; i++) {
					Thread.sleep(0, 500000);
					int val;
					if (gain > 0) {
						val = rand.nextInt(gain * 2) +
								offset - gain;
						if (val < 0) val = 0;
						else if (val > 255) val = 255;
					} else val = offset;
					sendSample(filter(val));
				}
				Thread.sleep(0, 500000);
				switch (nextEcho) {
				case GAIN:
					sendEcho(Scanner.GAIN, gain);
					nextEcho = OFFSET;
					break;
				case OFFSET:
					sendEcho(Scanner.OFFSET, offset);
					nextEcho = GAIN;
					break;
				case THRESHHOLD:
					sendEcho(Scanner.THRESHHOLD,threshhold);
					nextEcho = GAIN;
				}
			}
		} catch (InterruptedException e) {}
	}
}