//----------------------- Factory class ----------------------------
//
// Employee is abstract class for all employees
//
// kah 09/05

package mazeApplications.mazeCreation;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.*;
//import mazeCreation.magical.*;

public class Factory implements FactoryInterface
{
	private static ArrayList<Factory> factories;	
	private String name;
	
	private Factory( String type ) {
		name = type;
	}
	
	public String toString() { return name; }

	public static Factory getInstance( String type ) {
		Factory temp = null;
		
		//	Search the arraylist to see if c_type is in there already
		for(Factory f: factories) {
			if(f.toString().equals(type)) {
				return f;
			}
		}
		
		//	Instantiate a new Factory for the proposed MazeObject type.
		temp = new Factory(type);
		factories.add(temp);
		return temp;
	}

	//	The problem with this is the fact that the "Basic" type can't instantiate itself immediately.
	//	So what needs to happen is  
	
	public Door createDoor() throws FactoryException {
		String classname;
		Door d = null;
		
		if(this.toString().equals("Basic")) {
			classname = "mazeApplications.MazeCreation.Door";
		} else classname = "mazeApplications.MazeCreation." + this.toString().toLowerCase() + this.toString() + "Door";
		
		//	Let's instantiate it!
		d = (Door) this.instantiate(classname);
		if(d == null) {
			throw new FactoryException("Unable to instantiate class " + classname + ".");
		}
		
		return d;
	}

	public Room createRoom() throws FactoryException {
		String classname;
		Room r = null;
		if(this.toString().equals("Basic")) {
			classname = "mazeApplications.MazeCreation.Room";
		} else classname = "mazeApplications.MazeCreation." + this.toString().toLowerCase() + this.toString() + "Room";
		
		r = (Room) this.instantiate(classname);
		if(r == null) {
			throw new FactoryException("Unable to instantiate class " + classname + ".");
		}
		
		return r;
	}

	public Wall createWall() throws FactoryException {
		String classname;
		Wall w = null;
		
		if(this.toString().equals("Basic")) {
			classname = "mazeApplications.MazeCreation.Wall";
		} else classname = "mazeApplications.MazeCreation." + this.toString().toLowerCase() + this.toString() + "Wall";
		
		w = (Wall) this.instantiate(classname);
		if (w == null) {
			throw new FactoryException("Unable to instantiate class " + classname + ".");
		}
		
		return w;
	}

	private Object instantiate(String what) throws FactoryException {
		Class c = null;
		Constructor cons = null;
		try {
			c = Class.forName(what);
		} catch (ClassNotFoundException e) {
			throw new FactoryException("ClassNotFoundException while trying to find the class " + what);	
		}
		
		if(!Door.class.isAssignableFrom(c)) {
			throw new FactoryException("Class " + c.toString() + " is not assignable to Door");
		}
		
		try {
			cons = c.getConstructor();
			cons.setAccessible(true);
		} catch (SecurityException e) {
			throw new FactoryException(e.getMessage());
		} catch (NoSuchMethodException e) {
			throw new FactoryException(e.getMessage());
		}
		
		try {
			return (Object) cons.newInstance();
		} catch (IllegalArgumentException e) {
			throw new FactoryException(e.getMessage());
		} catch (InstantiationException e) {
			throw new FactoryException(e.getMessage());
		} catch (IllegalAccessException e) {
			throw new FactoryException(e.getMessage());
		} catch (InvocationTargetException e) {
			throw new FactoryException(e.getMessage());
		}
	}
}