package arduino.serial;

import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.LinkedList;
import javax.comm.*;

/**
 * Knihovna pro práci s Arduino pomocí seriového portu
 * @author Jan Dvořák z Vozerovic
 */
public class ArduinoSerial implements SerialPortEventListener
{
    private CommPortIdentifier comPortID;
    private SerialPort comPort=null;

    private String comAppName="MOJECOM"; //kdo drzi port
    private int  comTimeOut=2000; //t-out je 2000ms

    private InputStream comInputStream;
    private OutputStream comOutputStream;

    private LinkedList<Byte> buffer=new LinkedList<Byte>();

    private Exception noPort=new Exception("No selected Com port");

    /**************************************************************************/
    /**
     * Constructors
     */
    public ArduinoSerial(){}
    public ArduinoSerial(String appName){this.comAppName=appName;}
    public ArduinoSerial(String appName, int connectionTimeOut){this.comAppName=appName;this.comTimeOut=connectionTimeOut;}

    /**************************************************************************/
    /**
     * List of all COM ports (serial)
     */
    public ArrayList<String> getAllComPorts()
    {
        ArrayList<String>out=new ArrayList<String>();

        Enumeration en=CommPortIdentifier.getPortIdentifiers();
        CommPortIdentifier cid;

        while(en.hasMoreElements() )
        {
            cid=(CommPortIdentifier)en.nextElement();

            if( cid.getPortType()==CommPortIdentifier.PORT_SERIAL )
            {
               out.add( cid.getName() );
            }
        }

        return out;
    }

    /**************************************************************************/
    /**
     * Select com port
     */
    public void selectComPort(String portID)throws Exception
    {
        //info
        comPortID=CommPortIdentifier.getPortIdentifier(portID);

        //serial port
        comPort=(SerialPort)comPortID.open( comAppName, comTimeOut );

        //stream
        comInputStream=comPort.getInputStream();

        //handler
        comPort.addEventListener(this);
        comPort.notifyOnDataAvailable(true);

        //params
        comPort.setSerialPortParams(9600,SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE); //baud; databit; stop bit; parity bit
        comPort.setDTR(false);
        comPort.setRTS(false);
    }

    /**************************************************************************/
    /**
     * Send one Byte
     */
    public void sendByte(int data)throws Exception
    {
        if( comPort==null )throw noPort;

        comOutputStream=comPort.getOutputStream();
        comOutputStream.write(data);
        comOutputStream.close();
    }

    /**************************************************************************/
    /**
     * Send more bytes
     */
    public void sendBytes(byte data[])throws Exception
    {
        if( comPort==null )throw noPort;
        
        comOutputStream=comPort.getOutputStream();
        comOutputStream.write(data);
        comOutputStream.close();
    }

    /**************************************************************************/
    /**
     * Send text as bytes
     */
    public void sendData(String data)throws Exception
    {
        if( comPort==null )throw noPort;

        comOutputStream=comPort.getOutputStream();
        byte dt[]=data.getBytes();
        comOutputStream.write(dt);
        comOutputStream.close();
    }

    /**************************************************************************/
    /**
     * Handler 
     */
    public void serialEvent(SerialPortEvent event)throws Exception
    {        
        switch( event.getEventType() )
        {
            case SerialPortEvent.DATA_AVAILABLE:
                byte b=0;

                for( int i=0; i<comInputStream.available(); i++ )
                {
                    b=(byte)comInputStream.read();
                    buffer.addLast(b);                    
                }

                break;
        }
    }

    /**************************************************************************/
    /**
     * Number of bytes in buffer
     */
    public int getAvailableBytesCount()
    {
        if( comPort==null )return -1;
        
        return buffer.size();
    }

    /**************************************************************************/
    /**
     * Get one byte
     */
    public byte getByte()
    {
        if( comPort==null )return '\0';

        return buffer.pollFirst();
    }

    /**************************************************************************/
    /**
     * Get specified amount of bytes
     */
    public byte[] getBytes(int count)
    {
        if( comPort==null )return null;
        
        byte[] out=new byte[count];

        for( int i=0; i<count; i++)
            out[i]=buffer.pollFirst();

        return out;
    }

    /**************************************************************************/
    /**
     * Get all bytes
     */
    public byte[] getAllBytes()
    {
        if( comPort==null )return null;
        
        return getBytes( getAvailableBytesCount() );
    }

    /**************************************************************************/
    /**
     * Free com port
     */
    public void freeComPort()
    {
        if( comPort==null )return;
        
        comPort.close();
        comPort=null;
        buffer.clear();
    }

}