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


/**	This class contains the button-, command- and macrocommand-objects.
	It draws the objects to the applet-surface and lets the user move around
	and connect the objects.
*/
public class ConstructionPanel extends Panel implements MouseListener, MouseMotionListener {

	/** defines the number of possible buttons */
	private static int MAX_BUTTONS = 5;
	/** defines the number of possible commands */
	private static int MAX_COMMANDS = 5;
	/** defines the number of possible macro-commands */
	private static int MAX_MACROS = 5;
	/** defines the number of possible connections */
	private static int MAX_CONNECTIONS = 10;

	/** represents one of the two connection-points of a connection */
	public class ConnectionNode {
		/* the object the connection is connected to */
		private CP_Item item;
		/* the port to which the connection is bound */
		private int port;

		public ConnectionNode(CP_Item _item, int _port) {
			item = _item;
			port = _port;
		}
	}

	/** a list of button-objects */
	private CP_Button  buttons[]	= new CP_Button[MAX_BUTTONS];
	/** a list of command-objects */
	private CP_Command commands[]	= new CP_Command[MAX_COMMANDS];
	/** a list of macrocommand-objects */
	private CP_MacroCommand macros[]= new CP_MacroCommand[MAX_MACROS];
	/** a list of connection-objects */
	private CP_Connection connections[] = new CP_Connection[MAX_CONNECTIONS];
	/** the current number of buttons */
	private int n_buttons=0;
	/** the current number of commands */
	private int n_commands=0;
	/** the current number of macros */
	private int n_macros=0;
	/** the currently edited node */
	private ConnectionNode node=null;
	/** help variables */
	private int mx, my;

	/** The constructor. */
	public ConstructionPanel() {
		addMouseListener(this);
		addMouseMotionListener(this);
		// mark all connection-objects as not available
		for (int i=0;i<MAX_CONNECTIONS;i++) connections[i]=null;
	}

	/** Returns the connection node (that means the object and the port) on
	    position (mx,my) on the screen if there is one else it returns null.
	    If an object has been found but no port the port will be set to -1.
	    It will be called when the user clicks somewhere on the applet. */
	public ConnectionNode getConnectionNode(int mx, int my) {
		/* create a new connection-node */
		ConnectionNode node = new ConnectionNode(null, -1);

		/* check all buttons */
		for (int i=0;i<n_buttons;i++) {
			int x = buttons[i].getX(); int y = buttons[i].getY();
			int w = buttons[i].getW(); int h = buttons[i].getH();
			if ((mx>x-w/2) && (mx<x+w/2) && (my>y-h/2) && (my<y+h/2)) {
				node.item = buttons[i];
			}
			if ((mx>x+w/2) && (mx<x+w/2+6) && (my>y-3) && (my<y+3)) {
				node.item = buttons[i];
				node.port = 0;
			}
		}
		/* check all commands */
		for (int i=0;i<n_commands;i++) {
			int x = commands[i].getX(); int y = commands[i].getY();
			int w = commands[i].getW(); int h = commands[i].getH();
			if ((mx>x-w/2) && (mx<x+w/2) && (my>y-h/2) && (my<y+h/2)) {
				node.item = commands[i];
			}
			if ((mx>x-w/2-6)&& (mx<x-w/2) && (my>y-3) && (my<y+3)) {
				node.item = commands[i];
				node.port = 0;
			}
		}
		/* check all macro-commands */
		for (int i=0;i<n_macros;i++) {
			int x = macros[i].getX(); int y = macros[i].getY();
			int w = macros[i].getW(); int h = macros[i].getH();
			if ((mx>x-w/2) && (mx<x+w/2) && (my>y-h/2) && (my<y+h/2)) {
				node.item = macros[i];
			}
			if ((mx>x-w/2-6) && (mx<x-w/2) && (my>y-3) && (my<y+3)) {
				node.item = macros[i];
				node.port = 0;
			}
			if ((mx>x+w/2) && (mx<x+w/2+6) && (my>y-18) && (my<y-12)) {
				node.item = macros[i];
				node.port = 1;
			}
			if ((mx>x+w/2) && (mx<x+w/2+6) && (my>y-3) && (my<y+3)) {
				node.item = macros[i];
				node.port = 2;
			}
			if ((mx>x+w/2) && (mx<x+w/2+6) && (my>y+12) && (my<y+18)) {
				node.item = macros[i];
				node.port = 3;
			}
		}

		/* if no object was found return null */
		if (node.item == null)
			return null;
		else
			return node;
	}

	/** If an object is selected (indicated by node.port<0) the object
	    will be moved with the mouse.<br>
	    If node.port is >0 a port has been selected and we have to draw
	    a connection (that means a line from the selected port to the
	    mouse-pointer. Therefor mx and my will be updated and the panel
	    will be redrawn. */
	public void mouseDragged(MouseEvent e) {
		if (node != null) {
			if (node.port<0) {
				node.item.setPosition(e.getX(), e.getY());
			}
			mx = e.getX(); my = e.getY();
			repaint();
		}
	}

	public void mouseMoved(MouseEvent e) {
	}

	/** Finds out whether an object was hit or not. */
	public void mousePressed(MouseEvent e) {
		mx = e.getX();
		my = e.getY();
		node = getConnectionNode(mx, my);
		if (node != null)
			if (node.port>=0) {
				CP_Connection c = null;
				c = node.item.getConnection(node.port);
				if (c != null) {
					c.getSrc().setConnection(node.port,null);
					c.getDest().setConnection(node.port,null);
					int i=0;
					while ((i<MAX_CONNECTIONS) && (connections[i]!=c)) i++;
					if (i<MAX_CONNECTIONS) connections[i]=null;
					if (c.getSrc().getType()==1) {
						((CP_Button)c.getSrc()).getButton().setCommand(null);
					}
					if (c.getSrc().getType()==3) {
						((CP_MacroCommand)c.getSrc()).getMacroCommand().setCommand(c.getSrcPort(),null);
					}
					if (c.getDest().getType()==1) {
						((CP_Button)c.getDest()).getButton().setCommand(null);
					}
					if (c.getDest().getType()==3) {
						((CP_MacroCommand)c.getDest()).getMacroCommand().setCommand(c.getDestPort(),null);
					}
					repaint();
				}
			}
	}

	/** If a valid connection has been created it will be saved properly
	    as a connection object now. */
	public void mouseReleased(MouseEvent e) {
		if (node != null)
			if  (node.port>=0) {
				ConnectionNode node2 = getConnectionNode(e.getX(),e.getY());
				if (node2 != null)
				{
					CP_Connection c = null;
					c = node2.item.getConnection(node2.port);
					if (c != null) {
						c.getSrc().setConnection(c.getSrcPort(),null);
						c.getDest().setConnection(c.getDestPort(),null);
						if (c.getSrc().getType()==1) {
							((CP_Button)c.getSrc()).getButton().setCommand(null);
						}
						if (c.getSrc().getType()==3) {
							((CP_MacroCommand)c.getSrc()).getMacroCommand().setCommand(c.getSrcPort(),null);
						}
						if (c.getDest().getType()==1) {
							((CP_Button)c.getDest()).getButton().setCommand(null);
						}
						if (c.getDest().getType()==3) {
							((CP_MacroCommand)c.getDest()).getMacroCommand().setCommand(c.getDestPort(),null);
						}
						int i=0;
						while ((i<MAX_CONNECTIONS) && (connections[i]!=c)) i++;
						if (i<MAX_CONNECTIONS) connections[i]=null;
					}
					if (node.item.getType() != node2.item.getType()) {
						c = new CP_Connection(node.item, node.port, node2.item, node2.port);
						int i=0;
						while ((i<MAX_CONNECTIONS) && (connections[i]!=null)) i++;
						if (i<MAX_CONNECTIONS) {
						    connections[i]=c;
						    node.item.setConnection(node.port,c);
	    	    				    node2.item.setConnection(node2.port,c);
						    if ((node.item.getType()==1) && (node2.item.getType()==2)) {
							((CP_Button)node.item).getButton().setCommand(((CP_Command)node2.item).getCommand());
						    }
						    if ((node.item.getType()==1) && (node2.item.getType()==3) && (node2.port==0)) {
							((CP_Button)node.item).getButton().setCommand(((CP_MacroCommand)node2.item).getMacroCommand());
						    }
						    if ((node.item.getType()==3) && (node2.item.getType()==2)) {
							((CP_MacroCommand)node.item).getMacroCommand().setCommand(node.port,((CP_Command)node2.item).getCommand());
						    }
						    if ((node2.item.getType()==1) && (node.item.getType()==2)) {
							((CP_Button)node2.item).getButton().setCommand(((CP_Command)node.item).getCommand());
						    }
						    if ((node2.item.getType()==1) && (node.item.getType()==3) && (node2.port==0)) {
							((CP_Button)node2.item).getButton().setCommand(((CP_MacroCommand)node.item).getMacroCommand());
						    }
						    if ((node2.item.getType()==3) && (node.item.getType()==2)) {
							((CP_MacroCommand)node2.item).getMacroCommand().setCommand(node2.port,((CP_Command)node.item).getCommand());
						    }
						}
					}

				}
			}
		node = null;
		repaint();
	}

	public void mouseEntered(MouseEvent e) {
	}

	public void mouseExited(MouseEvent e) {
	}

	public void mouseClicked(MouseEvent e) {
	}

	/** Repaints the whole applet. */
	public void paint(Graphics g) {
		for (int i=0;i<n_buttons;i++) buttons[i].draw(g);
		for (int i=0;i<n_commands;i++) commands[i].draw(g);
		for (int i=0;i<n_macros;i++) macros[i].draw(g);
		for (int i=0;i<MAX_CONNECTIONS;i++)
		    if (connections[i]!=null) connections[i].draw(g);

		if (node != null) {
			if  (node.port>=0) g.drawLine(node.item.getPortX(node.port),
								node.item.getPortY(node.port),
								mx, my);
		}
	}

	/** Adds a button-object to the panel. With the constructed
	    CP_Button object a reference to the linked button will
	    be saved. */
	public void addButton(MyButton _b, int x, int y) {
		if (n_buttons < MAX_BUTTONS) {
			buttons[n_buttons] = new CP_Button(_b);
			buttons[n_buttons].setName(_b.getLabel());
			buttons[n_buttons].setPosition(x,y);
			n_buttons++;
		}
	}

	/** Adds a command-object to the panel. With the constructed
	    CP_Command object a reference to the linked command will
	    be saved. */
	public void addCommand(Command _command, String desc, int x, int y) {
		if (n_commands < MAX_COMMANDS) {
			commands[n_commands] = new CP_Command(_command);
			commands[n_commands].setName(desc);
			commands[n_commands].setPosition(x,y);
			n_commands++;
		}
	}

	/** Adds a macro-object to the panel. With the constructed
	    CP_MacroCommand object a reference to the linked macro will
	    be saved. */
	public void addMacroCommand(MacroCommand _macro, String desc, int x, int y) {
		if (n_macros < MAX_MACROS) {
			macros[n_macros] = new CP_MacroCommand(_macro);
			macros[n_macros].setName(desc);
			macros[n_macros].setPosition(x,y);
			n_macros++;
		}
	}
}