//Kenneth J. Goldman
//March 2000, Modified October 2003
//All rights reserved.

package canvas;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.Timer;
import javax.swing.border.*;
import java.lang.reflect.*;

public class DataView extends JPanel  {
	static HashMap views = new HashMap();
	static DataView lastAdded;

	static final int SPACING = 35;
	static final Color DEFAULT_COLOR = new Color(255, 255, 255, 80);

	Object model;
	JFrame frame;
	Field[] fields;
	JLabel[] fieldNames;
	JLabel[] fieldValues;
	Object[] fieldObjects;
	PointerLine[] pointerLines;

	public DataView(Object model, JFrame frame) {
		this.model = model;
		this.frame = frame;
		try {
			synchronized (views) {
				fields = model.getClass().getDeclaredFields();    // ****** Get the fields
				setLayout(new GridBagLayout());
				setBorder(new BevelBorder(BevelBorder.RAISED));
				setBackground(DEFAULT_COLOR);
				views.put(model, this);
				createFieldNamesAndViews();          // ****** Fill in the labels by reflection
				computeLocation();
				lastAdded = this;
				frame.add(this);
				frame.add(this);
				createPointers();
				frame.repaint();
				startUpdateTimer();
				addMouseMotionListener(new MouseMotionAdapter() {
					public void mouseDragged(MouseEvent e) {
						Rectangle r = getBounds();
						int deltax = e.getX() - r.width / 2;
						int deltay = e.getY() - r.height / 2;
						setLocation(r.x + deltax, r.y + deltay);
					}
				});
			}
		} catch (Exception e) {
			System.out.println(
					"CS101Canvas showData could not show data of type "
					+ model.getClass().getName()
					+ " due to "
					+ e);
			e.printStackTrace();
		}
	}

	public static void reset() {
		lastAdded = null;
	}
	
	boolean showAsText(Class c) {
		return c.isPrimitive() 
			|| c == String.class
			|| Number.class.isAssignableFrom(c)
			|| Boolean.class.isAssignableFrom(c);
	}

	void createFieldNamesAndViews() {
		//initialization:
		fieldNames = new JLabel[fields.length];
		fieldValues = new JLabel[fields.length];
		fieldObjects = new Object[fields.length];
		pointerLines = new PointerLine[fields.length];
		//layout setup and class name label:
		GridBagConstraints gbc = new GridBagConstraints();
		gbc.gridx = 0;
		gbc.gridy = 0;
		gbc.gridwidth = 2;
		gbc.anchor = GridBagConstraints.CENTER;
		JLabel className = new JLabel(model.getClass().getName());
		className.setForeground(Color.black);
		add(className, gbc);
		
		if (showAsText(model.getClass())) { 
			gbc.gridx = 0;
			gbc.gridy = 1;
			gbc.gridwidth = 2;
			gbc.anchor = GridBagConstraints.WEST;
			add(new JLabel(" value: " + model), gbc);
		} else
			// **** Consider each field in the model object
			for (int i = 0; i < fields.length; i++) {
				fieldNames[i] =
					new JLabel("  " + fields[i].getName() + ": ");
				gbc.gridx = 0;
				gbc.gridy = i + 1;
				gbc.gridwidth = 1;
				gbc.anchor = GridBagConstraints.WEST;
				add(fieldNames[i], gbc);
				fields[i].setAccessible(true);  // **** Ensure that we can read the field
				if (showAsText(fields[i].getType())) {
					try {
						fieldObjects[i] = fields[i].get(model);
						fieldValues[i] = new JLabel("" + fieldObjects[i]);
					} catch (IllegalAccessException iae) {
						fieldValues[i] = new JLabel("(unavailable)");
					}
				} else {  // Show as a pointer (* and arrow)
						fieldValues[i] = new JLabel("*");
				}
				gbc.gridx = 1;
				add(fieldValues[i], gbc);  // add the label to the right of the name
			}
	}
	
	void createPointers() {
		if (!showAsText(model.getClass()))
			for (int i = 0; i < fields.length; i++) 
					if (!showAsText(fields[i].getType()))
						pointerLines[i] = new PointerLine(i);
	}

	void updateSize() {
		setSize(getPreferredSize());
		validate();
		repaint();
	}
	
	public void paint(Graphics g) {
		g.setColor(Color.WHITE);
		g.fillRect(0, 0, getWidth(), getHeight());
		super.paint(g);
	}

	void startUpdateTimer() {
		Timer timer = new Timer(200, new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				for (int i = 0; i < fields.length; i++) {
					if (showAsText(fields[i].getType())) {
						try {
							Object x = fields[i].get(model);
							Object old = fieldObjects[i];
							if ((x == null && old != null) || (x != null  && !x.equals(fieldObjects[i]))) {
								fieldObjects[i] = x;
								fieldValues[i].setText("" + x);
								updateSize();
							}
						} catch (IllegalAccessException e) {
							// ignore exception... already shown
						}
					} else	if (pointerLines[i] != null) {
						pointerLines[i].updatePosition();
					}
				}
			}	
		});
		timer.start();
	}

	void computeLocation() {  // arrange the views in rows left to right
		if (lastAdded == null) {
			setLocation(SPACING, SPACING);
		} else {
			Rectangle r = lastAdded.getBounds();
			Dimension d = getPreferredSize();
			Dimension boundary = frame.getSize();
			if (r.x + r.width + SPACING + d.width < boundary.width)
				setLocation(r.x + r.width + SPACING, r.y);
			else
				setLocation(SPACING, r.y + r.height + SPACING);
		}
	}

//	void computeLocation() { // arrange the views in rows right to left
//		Dimension boundary = screen.getSize();
//		Dimension d = getPreferredSize();
//		int x = boundary.width - d.width - SPACING;
//		int y = SPACING;
//		if (lastAdded != null) {
//			Rectangle r = lastAdded.getBounds();
//			x = r.x - d.width - SPACING;
//			y = r.y;
//			if (x < 0) { // go to the next line
//				x = boundary.width - d.width - SPACING;
//				y = r.y + r.height + SPACING;
//			}
//		}
//		setLocation(x, y);
//	}

	class ArrowComponent extends ShapeComponent {
		static final int HEAD_LENGTH = 15;
		static final int HEAD_HALF_WIDTH = 5;
		int oldX1, oldY1, oldX2, oldY2;
		Line2D.Double theLine;
		Polygon head;
		ArrowComponent(Line2D.Double line) {
			super(line);
			theLine = line;
		}
		public synchronized boolean setLine(int x1, int y1, int x2, int y2) {
			if (x1 != oldX1 || x2 != oldX2 || y1 != oldY1 || y2 != oldY2) {
				oldX1 = x1;
				oldX2 = x2;
				oldY1 = y1;
				oldY2 = y2;
				theLine.setLine(x1, y1, x2, y2);
				head = null;
				if (x1 != x2 || y1 != y2) {
					head = new Polygon();
					double rise = y2 - y1;
					double run = x2 - x1;
					double length = Math.sqrt(rise * rise + run * run);
					double slope = rise / run;
					double normalSlope = -1 / slope;
					double alpha = Math.atan(normalSlope);
					double xint = x2 - run * (HEAD_LENGTH / length);
					double yint = y2 - rise * (HEAD_LENGTH / length);
					double deltaX = HEAD_HALF_WIDTH * Math.cos(alpha);
					double deltaY = HEAD_HALF_WIDTH * Math.sin(alpha);
					int px = (int) Math.rint(xint + deltaX);
					int py = (int) Math.rint(yint + deltaY);
					int qx = (int) Math.rint(xint - deltaX);
					int qy = (int) Math.rint(yint - deltaY);
					head.addPoint(x2, y2);
					head.addPoint(px, py);
					head.addPoint(qx, qy);
				}
				updateBounds();
				return true;
			}
			return false;
		}

		synchronized void updateBounds() {
			if (head != null) {
				Rectangle union = theLine.getBounds().union(head.getBounds());
				this.setBounds(union);
			} else
				super.updateBounds();
		}

		public void paint(Graphics g) {
			Graphics2D g2 = (Graphics2D) g;
			// For smoother lines:
			g2.setRenderingHint(
					RenderingHints.KEY_ANTIALIASING,
					RenderingHints.VALUE_ANTIALIAS_ON);
			g2.setColor(this.getForeground());
			g2.translate(-this.getBounds().x, -this.getBounds().y);
			g2.draw(getShape());
			if (head != null)
				g2.fill(head);
		}
	}

	class PointerLine extends ArrowComponent {
		int index;

		PointerLine(int index) {
			super(new Line2D.Double(0, 0, 0, 0));
			this.index = index;
			updatePosition();
			frame.add(this);
		}
		void updatePosition() {
			Point start, end;
			start = fieldValues[index].getLocation();
			start =
				new Point(
						start.x + DataView.this.getLocation().x,
						start.y
						+ DataView.this.getLocation().y
						+ fieldValues[index].getSize().height / 2);
			try {
				synchronized (views) {
					Object dest = fields[index].get(model);
					if (dest == null) {
						end = start;
						if (!fieldValues[index].getText().equals("null")) {
							fieldValues[index].setText("null");
							updateSize();
						}
					} else {
						if (!fieldValues[index].getText().equals("*")) {
							fieldValues[index].setText("*");
							updateSize();
						}
						if (!views.containsKey(dest))
							new DataView(dest, frame);
						JComponent destView = (JComponent) views.get(dest);
						end =
							closestPointOnBoundary(destView.getBounds(), start);
					}
					//  System.out.println("start=" + start + "  end=" + end);
					if (setLine(start.x, start.y, end.x, end.y))
						frame.add(this);
				}
			} catch (IllegalAccessException iae) {
				fieldValues[index].setText("(not public)");
			} catch (Exception e) {
				System.out.println("Updating position... " + e);
			}
		}

		Point closestPointOnBoundary(Rectangle r, Point p) {
			Point center = new Point(r.x + r.width / 2, r.y + r.height / 2);
			int outcode = r.outcode(p.x, p.y);
			if ((outcode & Rectangle2D.OUT_LEFT) != 0)
				center.x = r.x;
			else if ((outcode & Rectangle2D.OUT_RIGHT) != 0)
				center.x = r.x + r.width;
			if ((outcode & Rectangle2D.OUT_TOP) != 0)
				center.y = r.y;
			else if ((outcode & Rectangle2D.OUT_BOTTOM) != 0)
				center.y = r.y + r.height;
			return center;
		}
	}
}