/*****
 * TestRCXComm
 *
 *   Try to get two bricks talking to each other.
 *
 *     Push the PRGM button to send :
 *        sequence =  preparing
 *        buzz     =  IO exception
 *        2 beeps  =  sent
 *
 *     Push the VIEW button to recieve :
 *        sequence = preparing
 *        buzz     =  IO exception
 *        4 beeps  = success
 *        1 beep   = failure
 *
 *     Push the RUN button to see if its awake: 
 *        3 beeps  = yup
 *
 *  Suggested procedure :
 *     1) Download this program into 2 different bricks.
 *     2) Make sure both are "awake" with the RUN button.
 *     3) Push VIEW on one; it should "block" and just listen ...
 *     4) Push PRGRM on other; hopefull it sends one byte of data
 *     ... and the one listening should get the data and beep accordingly.
 *
 *  To test compilation on cs:
 *     $ . unix/environment
 *     $ lejosc TestRCXComm.java
 *  creates TestRCXComm.class
 *
 * Jim M
 * v 1.0 April 30   evening before class, compiled but not run on brick.
 * v 1.5 May 1      version on PC worked (!) though beeping was awkward.
 * v 2.0 May 1      after class, updated cs version
 *
 * $Id: TestRCXComm.java 13265 2007-05-02 13:26:13Z mahoney $
 ************/

import java.io.*;
import josx.rcxcomm.*;         // infrared communication stuff
import josx.platform.rcx.*;    // includes Sound object

public class TestRCXComm {
    public static RCXPort port;
    public static int message = 7;  // what we're going to send and receive.

    // Inititialize the communications port.
    public static void initPort(){
	try {
	    port = new RCXPort();
	}
	catch (IOException ioe){
	    Sound.buzz();
	}
    }

    // Pause for a given number of seconds.
    public static void wait(double seconds){
        try {
	    Thread.sleep((long)(seconds*1000.0));
        }
        catch (InterruptedException ie){
        }
    }
    
    // If the button isn't being pressed, return false immediately.
    // If it is being pressed, wait for release, and then return true.
    public static boolean press_and_release(Button b){
	boolean state = b.isPressed();
	if (state){
	    while (b.isPressed()){
	    }
	}
	return state;
    }

    // Beep n times with a short delay between beeps.
    public static void nBeeps(int n){
	double timeBetweenBeeps = 0.3;  // seconds
        for (int i=0; i<n; i++){
	    Sound.beep();
	    wait(timeBetweenBeeps);
        }
    }

    // Send a byte out the infrared port.
    // Beep twice after its sent.
    public static void send(int data){
	Sound.beepSequence();        // Signal "sending"
	try {
	    OutputStream os = port.getOutputStream();
	    os.write(data);
	    os.flush();
	}
	catch (IOException ioe){
	    Sound.buzz();            // Signal "IO exception"
	}
	nBeeps(2);                   // Signal "done"
    }

    // Listen until a byte is read from the infrared port.
    // Beep when one is read: four times if its what's expected, once if not.
    public static void receive(int expected){
	Sound.beepSequence();        // Signal "listening"
	int data = 0;
	try {
	    InputStream is = port.getInputStream();
	    data = is.read(); 
	    // The Java API says    
	    //   "This method blocks (i.e. waits) until data is available,
	    //    the end of stream is detected, or an exception is thrown."
	}
	catch (IOException ioe){
	    Sound.buzz();            // Signal "IO exception"
	}
	wait(1.0);                   // pause for sender to finish beeping
	if (data == expected){
	    nBeeps(4);               // Signal "expected data received"
	}
	else {
	    nBeeps(1);               // Signal "something else received"
	}
    }
 
    public static void main(String [] args) {
	initPort();
        while (true){
	    if (press_and_release(Button.VIEW)){
		receive(message);
	    }
	    else if (press_and_release(Button.PRGM)){
		send(message);
	    }
	    else if (press_and_release(Button.RUN)){
		nBeeps(3);
	    }
	    else {
	    }
	}
    }

}