import java.awt.event.*;
import java.awt.*;
import java.awt.geom.*;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartFrame;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.plot.*;
import org.jfree.chart.axis.*;
import org.jfree.chart.event.*;
import org.jfree.chart.*;

import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.data.xy.*;

import javax.swing.*;
import javax.swing.JApplet;
import javax.swing.JPanel;
import javax.swing.JFrame;

import java.awt.*;
import java.awt.Color;

import java.lang.Math;
import java.lang.Double;

public class SC extends JApplet implements ActionListener {
	// Classes for (x,y) data
	XYSeries data = new XYSeries("Potential");
	XYSeriesCollection data2 = new XYSeriesCollection();
	
	// For plotting
	JFreeChart chart;
	ChartPanel chartPanel;
	
	// Panels
	JPanel InputPanel, GraphPanel, OutputPanel;
	
	// Variables
	double VDT = 2000., VCATH = 500.;
	double rDT = 0.010, rEB = 0.00004;
	double iEB = 0.01, vEB = 0.01, qEB = 1.;
	
	double e0 = 8.85e-12;
	double twopi = 2.*3.1415926;
	double qe = 1.602e-19;
	double me = 9.11e-31;
	
	// TextFields/JLabels
	TextField txtEbeamRad;
	JLabel EBTag;
	TextField txtDTRad;
	JLabel DTRadTag;
	TextField txtVDT;
	JLabel VDTTag;
	TextField txtVCATH;
	JLabel VCATHTag;
	TextField txtCurrent;
	JLabel CurrentTag;
	
	JLabel V_0, V_rEB, V_rDT;
	
	// Button
	Button calcButton = new Button("Calc!");
	//calcButton.setBackground(Color.lightGray);
	
	ChartChangeEvent ChartEvent = new ChartChangeEvent(calcButton,chart);
	
	public SC() {
	   	LayoutManager Layout;
		
		Container cp;
		cp = getContentPane();
		
		Layout = new FlowLayout();
		InputPanel = new JPanel();
		OutputPanel = new JPanel();
		
		txtEbeamRad = new TextField();
		EBTag = new JLabel();
		txtDTRad = new TextField();
		DTRadTag = new JLabel();
		txtVDT = new TextField();
		VDTTag = new JLabel();
		txtVCATH = new TextField();
		VCATHTag = new JLabel();
		txtCurrent = new TextField();
		CurrentTag = new JLabel();
		
		V_0 = new JLabel();
		V_rEB = new JLabel();
		V_rDT = new JLabel();
		
		InputPanel.setLayout(Layout);
		OutputPanel.setLayout(Layout);
		
		txtEbeamRad.setColumns(8);
		txtEbeamRad.setText(Double.toString(rEB));
		EBTag.setText(" E-Beam Rad (m): ");
		txtDTRad.setColumns(8);
		txtDTRad.setText(Double.toString(rDT));
		DTRadTag.setText("DT Rad (m): ");
		txtVDT.setColumns(8);
		txtVDT.setText(Double.toString(VDT));
		VDTTag.setText("V_DT (V): ");
		txtVCATH.setColumns(8);
		txtVCATH.setText(Double.toString(VCATH));
		VCATHTag.setText("V_CATH (V): ");
		txtCurrent.setColumns(8);
		txtCurrent.setText(Double.toString(iEB));
		CurrentTag.setText("Current (A): ");
		
		V_0.setText("V(r=0) = " + Double.toString(f(0.)) + ", ");
		V_rEB.setText("V(r_eb) = " + Double.toString(f(rEB)) + ", ");
		V_rDT.setText("V(r_DT) = " + Double.toString(f(rDT)));
		
		InputPanel.add(calcButton);
		InputPanel.add(EBTag);
		InputPanel.add(txtEbeamRad);
		InputPanel.add(DTRadTag);
		InputPanel.add(txtDTRad);
		InputPanel.add(VDTTag);
		InputPanel.add(txtVDT);
		InputPanel.add(VCATHTag);
		InputPanel.add(txtVCATH);
		InputPanel.add(CurrentTag);
		InputPanel.add(txtCurrent);
		
		OutputPanel.add(V_0);
		OutputPanel.add(V_rEB);
		OutputPanel.add(V_rDT);
		
		calcButton.addActionListener(this);
		
		cp.add(InputPanel, BorderLayout.NORTH);
		cp.add(OutputPanel, BorderLayout.SOUTH);
		//cp.add(GraphPanel, BorderLayout.SOUTH);
	}
	
	public void init() {
		chart = ChartFactory.createXYLineChart(
			"Space Charge Potential with e-beam",
			"Radial Distance (cm)",
			"Voltage (V)",
			data2,
			PlotOrientation.VERTICAL,
			true,
			true,
			false
		);
		chartPanel = new ChartPanel(chart);
		chartPanel.setPopupMenu(null);
		
		Container cp = getContentPane();
		cp.add(chartPanel);
		//chartPanel.setVisible(true);
	}
	
	public void paint(Graphics g) {	
		CreateGraph(chart);

		chart.fireChartChanged();
		
		// Set the y range
		XYPlot plot = chart.getXYPlot();
		final ValueAxis rangeAxis = (ValueAxis) plot.getRangeAxis();
		rangeAxis.setRangeWithMargins(data.getMinY(),data.getMaxY());
		
		chartPanel.setChart(chart);
		
		chartPanel.repaint();
		InputPanel.repaint();
		OutputPanel.repaint();;
		
		V_0.setText("V(r=0) = " + Double.toString(f(0.)) + ", ");
		V_rEB.setText("V(r_eb) = " + Double.toString(f(rEB)) + ", ");
		V_rDT.setText("V(r_DT) = " + Double.toString(f(rDT)));
	}
	
	public void actionPerformed (ActionEvent evt) {
		if(evt.getSource() == calcButton) {
			updateParams();
			repaint();
		}
	}
	
	public static void main(String[] args) {
		run(new SC());
	}
	
	public static void run(JApplet applet) {
		JFrame frame = new JFrame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.getContentPane().add(applet);
		frame.setSize(1000,700);
		applet.init();
		applet.start();
		frame.setVisible(true);
	}
	
	public void CreateGraph(JFreeChart jChart) {
		double start = 0., end = rDT;
		double step = (end - start)/100;
		
		data.clear();
		
		for(double i = start; i < end; i+=step) {
			// Convert x points to cm, assign y values
			data.add(i*100,f(i));
		}
		
		data2.removeSeries(data);
		data2.addSeries(data);
		
		chart = ChartFactory.createXYLineChart(
			"Space Charge Potential with e-beam",
			"Radial Distance (cm)",
			"Voltage (V)",
			data2,
			PlotOrientation.VERTICAL,
			true,
			true,
			false
		);
	}
	
	public double f(double x) {
		calcParams();
		
		if(x > rEB) {
			return (VDT + (qEB/(twopi*e0))*Math.log(rDT/x));
		}
		else {
			return (VDT + (qEB/(twopi*e0))*( (rEB+x)*(rEB-x)/(2.*rEB*rEB) + Math.log(rDT/rEB)));
		}
	}
	
	public void calcParams() {
			vEB = Math.sqrt( 2*qe*(VDT - VCATH)/me );
			qEB = -Math.abs(iEB/vEB);
	}
	
	public void updateParams() {
		rEB = Double.valueOf(txtEbeamRad.getText());
		rDT = Double.valueOf(txtDTRad.getText());
		VDT = Double.valueOf(txtVDT.getText());
		VCATH = Double.valueOf(txtVCATH.getText());
		iEB = Double.valueOf(txtCurrent.getText());
	}
}