import javax.swing.*;
import javax.swing.event.*;
//import com.sun.java.swing.*;
//import com.sun.java.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Vector;
import java.text.*;

public class GraphPanel extends JPanel implements ChangeListener
{
  Vector v[] = new Vector[2];
  AspireGraph aspiregraph;
  PlotSource plotSource;
  String names[] = new String[2];
  double data[][] = new double[2][];
  int count[]  = new int[1];
  JButton regress;
  
  JLabel equationLabel = new JLabel("y = mx + b");
  JLabel mValueLabel   = new JLabel("m =");
  JLabel bValueLabel   = new JLabel("b =");
  
  DecimalFormat format;
    
  GraphPanel(PlotSource plotSource) {
    super(false);
    
    this.plotSource = plotSource;
    
    setLayout(new BorderLayout(15,0));
    aspiregraph = new AspireGraph(names, data, count);
    add(aspiregraph,BorderLayout.CENTER);
    
    JPanel infoPanel = new JPanel(new GridLayout(4,1));
    add(infoPanel,BorderLayout.WEST);
    
    ImageIcon icon1 = new ImageIcon(getClass().getResource("images/mreg.gif"));
    JPanel buttonHolder = new JPanel();
    regress = new JButton("Linear Regession", icon1);
    buttonHolder.add(regress);
    infoPanel.add(buttonHolder);
    regress.addActionListener(new FindLineButtonListener());
    
    JPanel MandBPanel = new JPanel(new GridLayout(3,1,10,10));
    MandBPanel.setBorder(BorderFactory.createCompoundBorder(
                         BorderFactory.createEtchedBorder(),
                         BorderFactory.createEmptyBorder(5,5,5,5)));
    Font f  = bValueLabel.getFont();
    Font f2 = new Font(f.getName(),f.getStyle(),3*f.getSize()/2);
    equationLabel.setFont(f2);
    bValueLabel.setFont(f2);
    mValueLabel.setFont(f2);
    MandBPanel.add(equationLabel);
    MandBPanel.add(bValueLabel);
    MandBPanel.add(mValueLabel);
    infoPanel.add(MandBPanel);
    
    setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
    
    // set number formatting
    format = new DecimalFormat();
    format.setMaximumFractionDigits(3);
  }
  
  
  public void stateChanged(ChangeEvent e) {
    if(((JTabbedPane)e.getSource()).getSelectedIndex() == 1){
      count[0] = plotSource.getData(names,data);
      aspiregraph.initializeLabels();
      bValueLabel.setText("b = ");
      mValueLabel.setText("m = ");
      aspiregraph.drawLine = false;
      if (count[0] < 2) {
        regress.setEnabled(false);
        return;
      } 
      else regress.setEnabled(true);
    }
  }
  
  class FindLineButtonListener implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      double b,m;
      double xsum = 0.0f;
      double ysum = 0.0f;
      double xxsum = 0.0f;
      double xysum = 0.0f;
    
      for(int i=0;i<count[0];i++) {
        xsum += data[0][i];
        ysum += data[1][i];
        xxsum += data[0][i]*data[0][i];
        xysum += data[0][i]*data[1][i];
      }
      b = (ysum*xxsum-xsum*xysum)/(xxsum*count[0]-xsum*xsum);
      m = (count[0]*xysum-xsum*ysum)/(xxsum*count[0]-xsum*xsum);
      mValueLabel.setText("m = " + (!aspiregraph.drawLine ? ""+format(m) : ""));
      bValueLabel.setText("b = " + (!aspiregraph.drawLine ? ""+format(b) : ""));
      if(!(Double.isNaN(b) || Double.isNaN(m)))
        aspiregraph.setupLine(b,m);
    }
  }
 

  public double format(double number) {
    try {
      number = format.parse(format.format(number)).doubleValue();
    }
    catch(ParseException pe) {
      System.out.println("Error: " + pe.getMessage());
      pe.printStackTrace();
    }
    return number;
  }
}