// License: GPL. See LICENSE file for details.

package org.openstreetmap.josm.gui;

import static org.openstreetmap.josm.tools.I18n.tr;

import java.awt.AWTEvent;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GridBagLayout;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.AWTEventListener;
import java.awt.event.InputEvent;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.lang.reflect.InvocationTargetException;
import java.text.DecimalFormat;
import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.Map.Entry;

import javax.swing.BorderFactory;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.Popup;
import javax.swing.PopupFactory;

import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.actions.HelpAction.Helpful;
import org.openstreetmap.josm.data.coor.LatLon;
import org.openstreetmap.josm.data.osm.OsmPrimitive;
import org.openstreetmap.josm.data.osm.visitor.NameVisitor;
import org.openstreetmap.josm.tools.GBC;
import org.openstreetmap.josm.tools.ImageProvider;

/**
 * A component that manages some status information display about the map.
 * It keeps a status line below the map up to date and displays some tooltip
 * information if the user hold the mouse long enough at some point.
 *
 * All this is done in background to not disturb other processes.
 *
 * The background thread does not alter any data of the map (read only thread).
 * Also it is rather fail safe. In case of some error in the data, it just does
 * nothing instead of whining and complaining.
 *
 * @author imi
 */
public class MapStatus extends JPanel implements Helpful {

	/**
	 * The MapView this status belongs to.
	 */
	final MapView mv;
	
	/** 
	 * A small user interface component that consists of an image label and
	 * a fixed text content to the right of the image.
	 */
	class ImageLabel extends JPanel {
		private JLabel tf; 
		private JLabel lbl;
		private int chars;
		public ImageLabel(String img, String tooltip, int chars) {
			super();
			setLayout(new GridBagLayout());
			setBackground(Color.decode("#b8cfe5"));
			add(lbl = new JLabel(ImageProvider.get("statusline/"+img+".png")), GBC.std().anchor(GBC.WEST).insets(0,1,1,0));
			add(tf = new JLabel(), GBC.std().fill(GBC.BOTH).anchor(GBC.WEST).insets(2,1,1,0));
			setToolTipText(tooltip);
			this.chars = chars;
		}
		public void setText(String t) {
			tf.setText(t);
		}
		@Override public Dimension getPreferredSize() {
			return new Dimension(25 + chars*tf.getFontMetrics(tf.getFont()).charWidth('0'), super.getPreferredSize().height);
		}
		@Override public Dimension getMinimumSize() {
			return new Dimension(25 + chars*tf.getFontMetrics(tf.getFont()).charWidth('0'), super.getMinimumSize().height);	
		}
	}

    DecimalFormat latlon = new DecimalFormat("###0.0000");
    ImageLabel lonText = new ImageLabel("lon", tr("The geographic longitude at the mouse pointer."), 8);
    ImageLabel nameText = new ImageLabel("name", tr("The name of the object at the mouse pointer."), 20);
    JTextField helpText = new JTextField();
    ImageLabel latText = new ImageLabel("lat", tr("The geographic latitude at the mouse pointer."), 7);
    ImageLabel angleText = new ImageLabel("angle", tr("The angle between the previous and the current way segment."), 6);
    ImageLabel headingText = new ImageLabel("heading", tr("The (compass) heading of the line segment being drawn."), 6);
    ImageLabel distText = new ImageLabel("dist", tr("The length of the new way segment being drawn."), 8);

	/**
	 * The collector class that waits for notification and then update
	 * the display objects.
	 *
	 * @author imi
	 */
	private final class Collector implements Runnable {
		/**
		 * The last object displayed in status line.
		 */
		Collection<OsmPrimitive> osmStatus;
		/**
		 * The old modifiers that was pressed the last time this collector ran.
		 */
		private int oldModifiers;
		/**
		 * The popup displayed to show additional information
		 */
		private Popup popup;

		private MapFrame parent;

		public Collector(MapFrame parent) {
			this.parent = parent;
		}

		/**
		 * Execution function for the Collector.
		 */
		public void run() {
			for (;;) {
				MouseState ms = new MouseState();
				synchronized (this) {
					try {wait();} catch (InterruptedException e) {}
					ms.modifiers = mouseState.modifiers;
					ms.mousePos = mouseState.mousePos;
				}
				if (parent != Main.map)
					return; // exit, if new parent.
				if ((ms.modifiers & MouseEvent.CTRL_DOWN_MASK) != 0 || ms.mousePos == null)
					continue; // freeze display when holding down ctrl

				if (mv.center == null)
					continue;

				// This try/catch is a hack to stop the flooding bug reports about this.
				// The exception needed to handle with in the first place, means that this
				// access to the data need to be restarted, if the main thread modifies
				// the data.
				try {
					OsmPrimitive osmNearest = null;
					// Set the text label in the bottom status bar
					osmNearest = mv.getNearest(ms.mousePos);
					if (osmNearest != null) {
						NameVisitor visitor = new NameVisitor();
						osmNearest.visit(visitor);
						nameText.setText(visitor.name);
					} else
						nameText.setText(tr("(no object)"));

					// Popup Information
					if ((ms.modifiers & MouseEvent.BUTTON2_DOWN_MASK) != 0 ) {
						Collection<OsmPrimitive> osms = mv.getAllNearest(ms.mousePos);

						if (osms == null)
							continue;
						if (osms != null && osms.equals(osmStatus) && ms.modifiers == oldModifiers)
							continue;

						if (popup != null) {
							try {
	                            EventQueue.invokeAndWait(new Runnable() {
	                                public void run() {
	                                	popup.hide();
	                                }
	                            });
                            } catch (InterruptedException e) {
                            } catch (InvocationTargetException e) {
                            	throw new RuntimeException(e);
                            }
						}

						JPanel c = new JPanel(new GridBagLayout());
						for (final OsmPrimitive osm : osms) {
							NameVisitor visitor = new NameVisitor();
							osm.visit(visitor);
							final StringBuilder text = new StringBuilder();
							if (osm.id == 0 || osm.modified)
								visitor.name = "<i><b>"+visitor.name+"*</b></i>";
							text.append(visitor.name);
							if (osm.id != 0)
								text.append("<br>id="+osm.id);
							for (Entry<String, String> e : osm.entrySet())
								text.append("<br>"+e.getKey()+"="+e.getValue());
							final JLabel l = new JLabel("<html>"+text.toString()+"</html>", visitor.icon, JLabel.HORIZONTAL);
							l.setFont(l.getFont().deriveFont(Font.PLAIN));
							l.setVerticalTextPosition(JLabel.TOP);
							l.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
							l.addMouseListener(new MouseAdapter(){
								@Override public void mouseEntered(MouseEvent e) {
									l.setText("<html><u color='blue'>"+text.toString()+"</u></html>");
								}
								@Override public void mouseExited(MouseEvent e) {
									l.setText("<html>"+text.toString()+"</html>");
								}
								@Override public void mouseClicked(MouseEvent e) {
									Main.ds.setSelected(osm);
									mv.repaint();
								}
							});
							c.add(l, GBC.eol());
						}

						Point p = mv.getLocationOnScreen();
						popup = PopupFactory.getSharedInstance().getPopup(mv, c, p.x+ms.mousePos.x+16, p.y+ms.mousePos.y+16);
						final Popup staticPopup = popup;
						EventQueue.invokeLater(new Runnable(){
							public void run() {
								staticPopup.show();
                            }
						});
					} else if (popup != null) {
						final Popup staticPopup = popup;
						popup = null;
						EventQueue.invokeLater(new Runnable(){
							public void run() {
								staticPopup.hide();
                            }
						});
					}
				} catch (ConcurrentModificationException x) {
				} catch (NullPointerException x) {
				}
			}
		}
	}

	/**
	 * Everything, the collector is interested of. Access must be synchronized.
	 * @author imi
	 */
	class MouseState {
		Point mousePos;
		int modifiers;
	}
	/**
	 * The last sent mouse movement event.
	 */
	MouseState mouseState = new MouseState();

	/**
	 * Construct a new MapStatus and attach it to the map view.
	 * @param mapFrame The MapFrame the status line is part of.
	 */
	public MapStatus(final MapFrame mapFrame) {
		this.mv = mapFrame.mapView;

		// Listen for mouse movements and set the position text field
		mv.addMouseMotionListener(new MouseMotionListener(){
			public void mouseDragged(MouseEvent e) {
				mouseMoved(e);
			}
			public void mouseMoved(MouseEvent e) {
				if (mv.center == null)
					return;
				// Do not update the view, if ctrl is pressed.
				if ((e.getModifiersEx() & MouseEvent.CTRL_DOWN_MASK) == 0) {
					LatLon p = mv.getLatLon(e.getX(),e.getY());
					latText.setText(latlon.format(p.lat()));
					lonText.setText(latlon.format(p.lon()));
				}
			}
		});

		setLayout(new GridBagLayout());
		setBorder(BorderFactory.createEmptyBorder(5,5,5,5));

        add(latText, GBC.std());
        add(lonText, GBC.std().insets(3,0,0,0));
        add(headingText, GBC.std().insets(3,0,0,0));
        add(angleText, GBC.std().insets(3,0,0,0));
        add(distText, GBC.std().insets(3,0,0,0));

		helpText.setEditable(false);
		add(nameText, GBC.std().insets(3,0,0,0));
		add(helpText, GBC.eol().insets(3,0,0,0).fill(GBC.HORIZONTAL));
		
		// The background thread
		final Collector collector = new Collector(mapFrame);
		new Thread(collector).start();

		// Listen to keyboard/mouse events for pressing/releasing alt key and
		// inform the collector.
		try {
			Toolkit.getDefaultToolkit().addAWTEventListener(new AWTEventListener(){
				public void eventDispatched(AWTEvent event) {
					synchronized (collector) {
						mouseState.modifiers = ((InputEvent)event).getModifiersEx();
						if (event instanceof MouseEvent)
							mouseState.mousePos = ((MouseEvent)event).getPoint();
						collector.notify();
					}
				}
			}, AWTEvent.KEY_EVENT_MASK | AWTEvent.MOUSE_EVENT_MASK | AWTEvent.MOUSE_MOTION_EVENT_MASK);
		} catch (SecurityException ex) {
			mapFrame.mapView.addMouseMotionListener(new MouseMotionListener() {
				public void mouseMoved(MouseEvent e) {
					synchronized (collector) {
						mouseState.modifiers = e.getModifiersEx();
						mouseState.mousePos = e.getPoint();
						collector.notify();
					}
				}

				public void mouseDragged(MouseEvent e) {
					mouseMoved(e);
				}
			});

			mapFrame.mapView.addKeyListener(new KeyAdapter() {
				@Override public void keyPressed(KeyEvent e) {
					synchronized (collector) {
						mouseState.modifiers = e.getModifiersEx();
						collector.notify();
					}
				}

				@Override public void keyReleased(KeyEvent e) {
					keyPressed(e);
				}
			});
		}
	}

	public String helpTopic() {
		return "Statusline";
	}
	
	public void setHelpText(String t) {
		helpText.setText(t);
		helpText.setToolTipText(t);
	}
	public void setAngle(double a) {
		angleText.setText(a < 0 ? "--" : Math.round(a*10)/10.0 + "°");
	}
	public void setHeading(double h) {
		headingText.setText(h < 0 ? "--" : Math.round(h*10)/10.0 + "°");
	}
	public void setDist(double dist) {
		String text = dist > 1000 ? (Math.round(dist/100)/10.0)+"km" : Math.round(dist*10)/10.0 +"m";
		distText.setText(dist < 0 ? "--" : text);
	}
	
}