import gnu.io.CommPortIdentifier;
import gnu.io.CommPortOwnershipListener;
import gnu.io.PortInUseException;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import gnu.io.SerialPortEventListener;
import gnu.io.UnsupportedCommOperationException;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.TooManyListenersException;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
import javax.swing.JTextArea;

/**
 *
 * @author andrelp
 */
public class GSMGateway implements SerialPortEventListener, CommPortOwnershipListener {

    private String comPort; // This COM Port must be connect with GSM Modem or your mobile phone
    private String messageString = "";
    private CommPortIdentifier portId = null;
    private Enumeration portList;
    private InputStream inputStream = null;
    private OutputStream outputStream = null;
    private SerialPort serialPort;
    String readBufferTrial = "";


    /**
     *
     * @param comm
     */
    public GSMConnect(String comm) {
        this.comPort = comm;

    }

    public boolean getPort() {
        portList = CommPortIdentifier.getPortIdentifiers();
        while (portList.hasMoreElements()) {
            portId = (CommPortIdentifier) portList.nextElement();
            if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                if (portId.getName().equals(comPort)) {
                    System.out.println("Got PortName");
                    return true;
                }
            }
        }
        return false;
    }

    public void connect() throws NullPointerException, TooManyListenersException {
        if (portId != null) {

            try {
                portId.addPortOwnershipListener(this);

                serialPort = (SerialPort) portId.open("GatewayGSM", 2000);
                serialPort.setSerialPortParams(115200, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
            } catch (PortInUseException | UnsupportedCommOperationException ex) {
                Logger.getLogger(GSMConnect.class.getName()).log(Level.SEVERE, null, ex);

            }
            try {
                inputStream = serialPort.getInputStream();
                outputStream = serialPort.getOutputStream();
            } catch (IOException ex) {
                 Logger.getLogger(GSMConnect.class.getName()).log(Level.SEVERE, null, ex);
            }
            /*
                    *  Set the hardware flow control
             */
            try {
//                serialPort.setFlowControlMode(SerialPort.FLOWCONTROL_NONE);
                serialPort.setFlowControlMode(SerialPort.FLOWCONTROL_RTSCTS_IN | SerialPort.FLOWCONTROL_RTSCTS_OUT);
                serialPort.setDTR(true);
            } catch (UnsupportedCommOperationException ex) {
                Logger.getLogger(GSMConnect.class.getName()).log(Level.SEVERE, null, ex);
            }
            /**
             * These are the events we want to know about /** These are the
             * events we want to know about
             */
            serialPort.addEventListener(this);
            serialPort.notifyOnCTS(true);
            serialPort.notifyOnDSR(true);
            serialPort.notifyOnOutputEmpty(true);

        } else {
            System.out.println("COM Port not found!!");
            throw new NullPointerException("COM Port not found!!");
        }
    }

    public void send(String cmd, int timeout) {
        serialPort.setRTS(true);
        try {
            outputStream.write(cmd.getBytes());
            outputStream.flush();
            System.out.println("Sended" + cmd);
            Thread.sleep(timeout);
        } catch (InterruptedException ex) {
            Logger.getLogger(GSMConnect.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(GSMConnect.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public void closePort() {
        serialPort.close();
    }

    @Override
    public void serialEvent(SerialPortEvent serialPortEvent) {
        switch (serialPortEvent.getEventType()) {
            case SerialPortEvent.BI:
                break;
            case SerialPortEvent.OE:
                break;
            case SerialPortEvent.FE:
                break;
            case SerialPortEvent.PE:
                break;
            case SerialPortEvent.CD:
                break;
            case SerialPortEvent.CTS: //recieve a ask to send data, this side must prepare to read.
                count++;
                if (serialPort.isCTS()) {
                    System.out.println("CTS");
                    try {
                        if (inputStream.available() > 0) {
                            System.out.println("buffer-CTS");
                            while (inputStream.available() > 0) {
                                String aux;
                                byte[] readBuffer = new byte[2048];
                                int numBytes = inputStream.read(readBuffer);
                                aux = new String(readBuffer);
                                readBuffer = new byte[2048];
                                System.out.println(LocalDateTime.now().toString() + ": " + aux);
                                send("OK", 5000);
                            }
                        }
                    } catch (IOException ex) {
                        Logger.getLogger(GSMConnect.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
                break;
            case SerialPortEvent.DSR:
                break;
            case SerialPortEvent.RI:
                break;
            case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
                System.out.println("OUTPUT_BUFFER_EMPTY");
                serialPort.setRTS(false);
                break;
            case SerialPortEvent.DATA_AVAILABLE:
                break;
        }
    }

    @Override
    public void ownershipChange(int type
    ) {
        switch (type) {
            case CommPortOwnershipListener.PORT_UNOWNED:
                System.out.println(portId.getName() + ": PORT_UNOWNED");
                break;
            case CommPortOwnershipListener.PORT_OWNED:
                System.out.println(portId.getName() + ": PORT_OWNED");
                break;
            case CommPortOwnershipListener.PORT_OWNERSHIP_REQUESTED:
                System.out.println(portId.getName() + ": PORT_INUSED");
                break;
        }
    }

}