package com.cognitive.admin;

import gnu.io.CommPortIdentifier;
import gnu.io.NoSuchPortException;
import gnu.io.PortInUseException;
import gnu.io.SerialPort;
import gnu.io.UnsupportedCommOperationException;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.GregorianCalendar;

public class QualityScanner
{
    final int WAIT_FOR_DATA_TIMEOUT = 30000;
    final int WAIT_FOR_DATA_INTERVAL = 100;

    private InputStream inputStream;
    private SerialPort serialPort;
    private int baudRate;
    private CommPortIdentifier portId;
    private BufferedReader reader = null;

    public QualityScanner(String port, int baud) throws NoSuchPortException
    {
        GUIHelper.logger.trace("");
        
        baudRate = baud;
        portId = CommPortIdentifier.getPortIdentifier(port);
    }
 
    public void openConnection() throws IOException, PortInUseException, UnsupportedCommOperationException
    {
        GUIHelper.logger.trace("");

        serialPort = (SerialPort) portId.open("Quality Scanner", 2000);

        inputStream = serialPort.getInputStream();

        reader = new BufferedReader(new InputStreamReader(inputStream));

        serialPort.setSerialPortParams(baudRate, SerialPort.DATABITS_8, 
                SerialPort.STOPBITS_1, 
                SerialPort.PARITY_NONE);

        serialPort.setDTR(true);
        serialPort.setRTS(true);
    }
    
    public void closeConnection() throws IOException
    {
        GUIHelper.logger.trace("");
        
        if(null != reader)
        {
            reader.close();
            reader = null;
        }
        
        if(null != inputStream)
        {
            inputStream.close();
            inputStream = null;
        }
        
        if(null != serialPort)
        {
            serialPort.close();
            serialPort = null;
        }        
    }
        
    public boolean ready() throws IOException
    {
        if(reader != null)
        {
            return reader.ready();
        }
        else
        {
            GUIHelper.logger.error("ready() called on null reader; returning false.");
            throw new IOException("ready() called on null reader");
        }
    }
    
    public String readLine() throws IOException
    {
        return reader.readLine() + "\n";
    }

    public String waitForBarcode()
    {
        String line = null;
        String barcode = null;
        
        long currentTime = (new GregorianCalendar()).getTimeInMillis();
        long maxTime = currentTime + WAIT_FOR_DATA_TIMEOUT;
        
        while(currentTime <= maxTime )
        {
            try
            {
                if(ready())
                {
                    line = readLine().trim();
                    if(line.length() > 0) //the trim above could have nullified the line
                    {
                        GUIHelper.logger.info(line);
                        if(line.charAt(0) == '*'  //barcode line starts with a star 
                            && line.charAt(line.length()-1) == '*' //and ends with a star
                                && line.indexOf("Quick-Check") == -1) //but is not "*** Quick-Scan XXX ***"
                        {
                            barcode = line.substring(1, line.length()-1);
                            return barcode;
                        }
                    }
                }
                else
                {
                    Thread.sleep(WAIT_FOR_DATA_INTERVAL);
                    GUIHelper.update();
                    currentTime = (new GregorianCalendar()).getTimeInMillis();
                }
            }
            catch(Exception e)
            {
                GUIHelper.logger.error(e, e);
            }            
        }
        
        return null;
    }
    
    public String waitForGrade()
    {
        String gradeLine = null;
        String grade = null;
        String line = null;
        
        long currentTime = (new GregorianCalendar()).getTimeInMillis();
        long maxTime = currentTime + WAIT_FOR_DATA_TIMEOUT;
        
        while(gradeLine == null && currentTime <= maxTime )
        {
            try
            {
                if(ready())
                {
                    line = readLine();
                    System.out.println(line);
                    if(line.indexOf("Decodability") != -1)
                    {
                        //this line contains the grade we're looking for
                        gradeLine = line;
                    }
                }
                else
                {
                    Thread.sleep(WAIT_FOR_DATA_INTERVAL);
                    GUIHelper.update();
                    currentTime = (new GregorianCalendar()).getTimeInMillis();
                }
            }
            catch(Exception e)
            {
                GUIHelper.logger.error(e, e);
            }            
        }
        
        //At this point, we either have a grade line or we've timed out waiting for it, in
        //which case we'll return a null
        if(gradeLine != null)
        {
            GUIHelper.logger.info("Grade: " + gradeLine);
            grade = String.valueOf((GUIHelper.getMatch(line, "<[a-zA-Z]>")).charAt(1));
        }
        
        return grade;
    }
}