package ac.essex.ooechs.ecj.ecj2java.example.functions;

import ec.gp.GPData;
import ec.gp.ADFStack;
import ec.gp.GPIndividual;
import ec.EvolutionState;
import ec.Problem;
import ac.essex.ooechs.ecj.ecj2java.nodes.ParseableGPNode;
import ac.essex.ooechs.ecj.ecj2java.example.data.DoubleData;

/**
 * Performs Protected Division on two numbers.<Br />
 * If the denominator is zero, then zero is returned.
 */
public class Divide extends ParseableGPNode {

    public Divide() {
        // I have 2 children - this must match the type in the params file. It is ECJ's checking mechanism.
        super("/", 2);
    }

    /**
     * Called as the function is evaluated.
     */
    public void eval(final EvolutionState state, final int thread, final GPData input, final ADFStack stack, final GPIndividual individual, final Problem problem) {

        DoubleData dd = ((DoubleData) (input));

        // evaluate the left child
        children[0].eval(state, thread, input, stack, individual, problem);

        // get the first number
        double number1 = dd.x;

        // then the right child
        children[1].eval(state, thread, input, stack, individual, problem);

        // get the second number
        double number2 = dd.x;

        // then add them together (but avoid divide by zero)
        dd.x = number2 == 0? 0 : number1 / number2;

    }

    public int getObjectType() {
        return ParseableGPNode.DOUBLE;
    }

    /**
     * Convert this code to pure Java
     */
    public String getJavaCode() {
        return getChild(1).getVariableName() + " == 0 ? 0 : " + getChild(0).getVariableName() + " / " + getChild(1).getVariableName();
    }

}