package plugin.jepcommands;

import org.nfunk.jep.ParseException;
import pcgen.util.PCGenCommand;
import pcgen.util.PJEP;

import java.util.Stack;

/**
 * eg. roll("10+d10") 
 */
public class RollCommand extends PCGenCommand
{

	/** Constructor */
	public RollCommand()
	{
		numberOfParameters = 1;
	}

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

    @Override
	public boolean updateVariables(final PJEP jep)
	{
		return false;
	}

	/**
	 * Is this command cacheable?
	 * @return true if cacheable, false if not.
	 */
    @Override
	public boolean getCachable()
	{
		return false;
	}

	/**
	 * Runs getvar 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

        //
		// have to do this in reverse order...this is a stack afterall
		//
        final Object param1 = inStack.pop();

        if (param1 instanceof String)
		{
            final Object result = pcgen.core.RollingMethods.roll((String) param1);
            inStack.push(result);
		}
		else
		{
			throw new ParseException("Invalid parameter type");
		}
	}
}