package org.opensourcephysics.sip.ch6;
import java.awt.Color;
import org.opensourcephysics.controls.*;
import org.opensourcephysics.display.*;

public class PendulumApp implements Animation {

   Control myControl;
   // contains the graph
   PlottingPanel plottingPanel = new PlottingPanel("Time", "Theta", "angle vs time");
   DrawingFrame plottingFrame = new DrawingFrame(plottingPanel);
   // contains the animation
   DrawingPanel drawingPanel = new DrawingPanel();
   DrawingFrame drawingFrame = new DrawingFrame(drawingPanel);
   Thread animationThread;
   DatasetCollection dataset;
   Pendulum pendulum;
   double dt; 

   public PendulumApp() {
      pendulum = new Pendulum();
      drawingPanel.setPreferredMinMax(-1.2, 1.2, -1.2, 1.2);
      drawingPanel.addDrawable(pendulum);
      dataset = new DatasetCollection();
      dataset.setXYColumnNames(0, "time", "theta");
      plottingPanel.addDrawable(dataset);
   }

   public void setControl(Control control) {
      myControl = control;
      resetAnimation();
   }

   public void startAnimation() {
      animationThread = new Thread(this);
      animationThread.start(); // start the animation
   }

   public void initializeAnimation() {
      dt = myControl.getDouble("dt"); // time step
      double theta = myControl.getDouble("theta");
      double omega = myControl.getDouble("omega");
      double[] state = pendulum.getState();
      pendulum.setState(theta, omega, state[2]); 
      plottingPanel.repaint();
      drawingPanel.repaint();
   }

   public void stopAnimation() {
      Thread runningThread = animationThread;
      animationThread = null; // stop the animation
      try { // wait for the thread to die
         if (runningThread != null) {
            runningThread.join();
         }
      } catch(InterruptedException e) {}
      updateControlValues();
   }

   public void updateControlValues() {
      double[] state = pendulum.getState();
      myControl.setValue("theta", state[0]);
      myControl.setValue("omega", state[1]);
   }

   public void stepAnimation() {
      stepPendulum();
      plottingPanel.repaint();
      drawingPanel.repaint();
      updateControlValues();
   }

   public void stepPendulum() {
      double[] state = pendulum.getState(); // get the state
      dataset.append(0, state[2], state[0]); // add data to the curve
      pendulum.step(dt); // advance the SHO state by dt
   }

   public void resetAnimation() {
      dataset.clear();
      plottingPanel.repaint();
      drawingPanel.repaint();
      double[] state = pendulum.getState();
      double theta = 1;
      double omega = 1;
      double t = 0;
      pendulum.setState(theta, omega, t);
      updateControlValues();
      myControl.setValue("dt", 0.1);
   }

   public void run() {
      while(animationThread == Thread.currentThread()) {
         stepPendulum();
         plottingPanel.render();       // paint the plot
         drawingPanel.render();        // paint the animation
         try {
            animationThread.sleep(100);
         } catch(InterruptedException ie) {}
      }
   }

   public static void main(String[] args) {
      Animation app = new PendulumApp();
      AnimationControl control = new AnimationControl(app);
      app.setControl(control);
   }
}