/*
 * Copyright 2014 (C) Tom Parker <thpr@users.sourceforge.net>
 * 
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 * 
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package plugin.jepcommands;

import java.util.Stack;

import org.nfunk.jep.ParseException;

import pcgen.core.PlayerCharacter;
import pcgen.core.VariableProcessor;
import pcgen.util.PCGenCommand;

/**
 * JEP command for get vars
 * 
 * eg. mastervar("CL=Fighter")
 */
public class MasterVarCommand extends PCGenCommand
{

	/** Constructor */
	public MasterVarCommand()
	{
		//We say variable here and enforce below like our other JEP commands
		//Not sure why exactly, but not messing with the black box
		numberOfParameters = -1;
	}

	/**
	 * Gets the name of the function handled by this class.
	 * @return The name of the function.
	 */
    @Override
	public String getFunctionName()
	{
		return "MASTERVAR";
	}

	/**
	 * Runs mastervar on the inStack. The parameter is popped
	 * off the {@code inStack}, and the variable's value is
	 * pushed back to the top of {@code inStack}.
	 * @param inStack the jep stack
	 * @throws ParseException
	 */
	@SuppressWarnings("unchecked") //Uses JEP, which doesn't use generics
    @Override
	public void run(final Stack inStack) throws ParseException
	{
		// check the stack
		checkStack(inStack);

		// get the parameter from the stack
		final Object param1;

		if (curNumberOfParameters == 1)
		{
			param1 = inStack.pop();
		}
		else
		{
			throw new ParseException("Invalid parameter count");
		}

        if (param1 instanceof String)
		{
            Float result = null;
			PlayerCharacter pc = getPC();
            if (pc == null)
			{
				throw new ParseException("Invalid parent for function");
			}
			PlayerCharacter master = pc.getMasterPC();
            if (master == null)
			{
				throw new ParseException("Invalid: PC had no master");
			}
			result = master.getVariableValue((String) param1, variableSource);

			if (result == null)
			{
				throw new ParseException("Error retreiving variable:" + param1);
			}

			inStack.push(result.doubleValue());
		}
		else
		{
			throw new ParseException("Invalid parameter type");
		}
	}


	/**
	 * Get the PC that will be used to determine the master
	 *
	 * @return the pc
	 */
	private PlayerCharacter getPC()
	{
		PlayerCharacter pc = null;
		if (parent instanceof VariableProcessor)
		{
			pc = ((VariableProcessor) parent).getPc();
		}
		else if (parent instanceof PlayerCharacter)
		{
			pc = (PlayerCharacter) parent;
		}
		return pc;
	}
}